A pcb engraver under 150 dollars. - Page 1
Forum section: electronics / projects

author: IonizedGears
author_rank: Regular Contributor
timestamp: July 20, 2013, 12:01:34 am
content: The driver board(Comes with the parallel cable and mach3 software): $40{http://www.ebay.com/itm/321149918892}5 stepper motors(only need 3 so 2 bonus steppers!): $50{http://www.ebay.com/itm/321123679262}The frame and power supply(): hopefully < $60I just wanted to share this with all of you guys that you can now cheaply build your own pcb engraver, 3d printer, etc !

author: Marco
author_rank: Super Contributor
timestamp: July 20, 2013, 12:20:00 am
content: A stiff frame requires a machine shop ... which I don't have and won't be able to build for 150$

author: smashedProton
author_rank: Frequent Contributor
timestamp: July 20, 2013, 02:27:24 am
content: You could make a frame from steel pipe.

author: David_AVD
author_rank: Super Contributor
timestamp: July 20, 2013, 03:24:42 am
content: People always underestimate how much work is involved in the frame, gantry and other metalwork.

author: Paul Price
author_rank: Super Contributor
timestamp: July 20, 2013, 01:14:18 pm
content: If you take apart a inkjet printer, you have a ready-made precision horizontal axis platform with precision optical encoding for positioning the printhead, plus you get a powerful built-in stepper motor and the correct power power supply to power it. Plus, inside you will find other stepper motors that can be used for lifting.Use two printers for parts and you can mount one on a platform upon the other so that you get x-y axis capability.

author: ddavidebor
author_rank: Super Contributor
timestamp: July 20, 2013, 02:14:07 pm
content: Quote from: Paul Price on July 20, 2013, 01:14:18 pmAaaah, no really no. That is not going to leave you with a cnc in your hand. Just a crappy plot.

author: PA0PBZ
author_rank: Super Contributor
timestamp: July 20, 2013, 02:15:33 pm
content: Quote from: Paul Price on July 20, 2013, 01:14:18 pmUnfortunately these things are just capable of moving the printhead, anything with more mass will be a gamble.

author: IonizedGears
author_rank: Regular Contributor
timestamp: July 20, 2013, 02:20:27 pm
content: Well, he has a point on the rails. I might be able to use the rails and gears to my advantage.

author: sleemanj
author_rank: Super Contributor
timestamp: July 20, 2013, 02:44:32 pm
content: Quote from: Paul Price on July 20, 2013, 01:14:18 pmOn all the inkjets I've taken apart, the carriage "axis" is just the bare minimum to slide the printhead (a very light weight) along smoothly, on a flat axis. There are no bearings or shafts that the head runs on, it just sits locked on top of the carriage frame.So in other words, they are not particulary suited.Steppers are not used in a modern inkjet (that I've taken apart) except for the scanner head which is very small slimline low torque stepper run through a gear reduction. All the other motors (feed, carriage, and pump if separate) are just standard small 2.3 or 2.0mm shaft DC motors with (quadrature) encoder strips or discs.If anything actually, the steppers, belts, shafts, and maybe even scan bars out of a couple of identical scanning heads could perhaps form the basis of an axis - more suitable than the ink carriage.

author: Paul Price
author_rank: Super Contributor
timestamp: July 20, 2013, 02:52:04 pm
content: In my experience, the holding motor servo torque of most inkjets is quite high and a takes quite a strong hand to move them away from a static position (by motor-servo with powerful gear reduction), not a stepper motor, you are correct) set rock-solid on by the printer.Try another printer!Keep in mind that the speed of positioning is quite fast, the precision is very good, and the holding torque is quite high..what more could you want?There is no need to use a stepper motor if a built-in indexed servo-gear-motor can do the job very well.From this I would say they could be quite suitable. And the precision of the optical encoder is quite high, using a extremely fine pitched reference ribbon behind the carriange.

author: IonizedGears
author_rank: Regular Contributor
timestamp: July 20, 2013, 03:05:15 pm
content: Paul-For the optical encoders, are the absolute or incremental?

author: PA0PBZ
author_rank: Super Contributor
timestamp: July 20, 2013, 03:09:59 pm
content: Quote from: Paul Price on July 20, 2013, 02:52:04 pmAgreed, but also keep in mind that this is a tuned system designed to spend not a cent more than is needed for the lightweigth printhead. As soon as you increase the mass that it has to move you will find that you will have to decrease the speed or you will loose precision. Or you just found a overdimensioned inkjet printer, but these are rare in a very competitive market where already no money is made on the printer.

author: Paul Price
author_rank: Super Contributor
timestamp: July 20, 2013, 03:12:23 pm
content: I have every reason to believe they position servo uses absolute steps because all of these printers that I've seen all have an optical sensor at the left end of travel that gives the 0-step reference point, and the MCU just counts steps from there to accurately position the printheard carriage assembly.This means that you can easily take precise control of the positioning mechanism quite easily just applying motor power and counting optical pulse encoder output (just 4-wires here, and two are for the infrared LED) and then dithering +- the power to the motor as necessary at the set point to keep at the desired position. Some sort of proportional control would do the job to rapidly achieve position and just for the "I" part just dithering the polarity of the power to the motor.in this simple PID control, while discarding any consideration of a "D" complication.

author: Paul Price
author_rank: Super Contributor
timestamp: July 20, 2013, 03:17:12 pm
content: Paopbz, you say,"Agreed, but also keep in mind that this is a tuned system designed to spend not a cent more than is needed for the lightweigth printhead. As soon as you increase the mass that it has to move you will find that you will have to decrease the speed or you will loose precision. Or you just found a overdimensioned inkjet printer, but these are rare in a very competitive market where already no money is made on the printer."In fact, printers seem an enigma to me, the robustness, quality and precision of all the mechanical parts is truly overwhelming in comparison to their sold price. If I had to buy all the parts of the same or slightly lesser quality to fabricate an x-y positioning setup, it would cost me in the hundreds, if not thousands of bucks.I strongly disagree, as I told you, many manufacturers use quite robust mechanisms. In particular, the older, larger inkjet printers are made this way and also are the ones most easy to find discarded, just adding to your convenience.In fact, many of the older inkjets are so strong they can inflict a wound and a black and blue boo-boo to a hand roaming around and into the printhead's path.Also these printers must need to move the printhead very quickly to achieve high page throughput rates..and they do this without any trouble. And this is not dealing with a feather's mass, the large print cartridges and traveling carriage assembly they set in is a considerable mass to be so quickly ushered around with such precision and accuracy.Keep in mind that this positioning speed is demonstrably there in any printer design, if this aspect of performance was at all really an issue in CNC work like this on a small circuit board.

author: IonizedGears
author_rank: Regular Contributor
timestamp: July 20, 2013, 06:25:26 pm
content: I might be able to design a x-z platform for where the pcb lies (like the plate on a makerbot replicator) with a printer's mechanics even if the frame is as weak as some people have said.The frame work would only have to hold a pcb and a thin wood plate so yes, it could work very nicely.The drill would be stationary on the x-z axis but moving on the y axis.That said, my suggestion with the 5 stepper motors seems to be a better choice if you have no printer to gut out and you get two extra steppers.The x-z frame could be easily made using drawer sliders like the one used in dave's camera boom since the pcb plate will be moving forware-back, side-side and the drill will be moving up and down.Eh, i'll have to test some things when i purchase the parts.

author: mc
author_rank: Regular Contributor
timestamp: July 20, 2013, 06:46:04 pm
content: If you want accuracy and quality while cutting/engraving, then you need rigidity. A printer frame just doesn't have that, and will vibrate and give a poor finish.It may be acceptable for what you want to acheive, and if you are willing to spend the time trying it out, then by all means do so. However don't expect high quality results.

author: Paul Price
author_rank: Super Contributor
timestamp: July 20, 2013, 07:28:49 pm
content: As with everything else, even human beings, rigidity can vary with age.Some older printers and some new inkjets are quite strong, others aren't, one has a choice of the litter.Some printers are quite strong and rigidly built, and there is always the possibility to add an additional cross-member for bracing.

author: WarSim
author_rank: Frequent Contributor
timestamp: July 20, 2013, 10:37:44 pm
content: PCB routers minimums are two positioners (Steppers) and one motor, for a relative depth method.Any more are for compensation for something or adding a non PCB feature.For example mine has 3 steppers just because it I capable of process milling for making faceplates etc.To stay under $150 the router will be comparatively very slow or very crude. The budget would require some very lucky finds. For example the spindle on mine is $300. Also my bits are $10 - $40 each of which a selection is required for any PCB. My router can position to .2mil but I don't route less that .2mm and prefer to stay over .5mm. At 36,000 RPM and 2% boards take awhile, at the less expensive 5400RPM a complex board would take over an hour.I am not telling you this to deter you just so you have some realistic expectations. Without significantly more investment do not expect to used parts with a higher density of a DIP nor speed.There are many DIY projects out there that claim success, but they have large failings. The ones that use a roto tool. The slop and runout which gets worse through use will induce variations. A 20mil trace could easily end up as a 10mil trace. Therefore a trace that needs to be 16mil MIN will need to be 26mil MIN in design. Every trace will need to be over rated which will reduce the pin density you can use.This does not mean you can not use small devices. You will just need to have daughter boards made, which can be pinned or stabbed onto your board. Even I do this on my prototypes. If I need to use an under .85mm pitch package I use my lower life very small router to make a daughter board for it. this way I can use my longer life .5mm mill on the larger board. Anything smaller than .4mm are automatically a manufactured daughter board.Even with these shortcomings a router is my best solution. I refuse to have acid in my home, and explaining what I think is a simple PCB to a manufacture is annoying. Being asked about the orientation of layers in a non symmetrical board is just stupid, especially when there is printing on the top silkscreen which has a board outline, all layers have flood fills and I used the manufacture specific layout exporter tool.Remember you need very strong Steppers. You have to compensate for tool vibration, side load, gantry resistance, and torque loss due to partial stepping. If you are using full steps to overcome micro stepping losses add in the position reduction mechanism losses.

author: David_AVD
author_rank: Super Contributor
timestamp: July 20, 2013, 11:31:21 pm
content: Modern printers (anything in the last 10 years) are all engineered down to a price. I kept a couple of old dot matrix types in my junk pile as they are more heavy duty, but would not use them as a basis for anything that needed grunt or precision.Wooden frames and skate bearings or drawer slides are never going to make a good machine for anything other than wood carving at a hobby level.We're in the midst of making a CNC milling machine at work. Even with a seeming reasonable parts budget in the thousands, I found that I've needed to pour even more money into it to get a good end result. Luckily, a lot of the labour required has been done on otherwise unproductive quiet days.If I knew then what I know now, I probably would have spent $10K on a reasonable ready-built CNC milling machine first up.

author: Stonent
author_rank: Super Contributor
timestamp: July 21, 2013, 12:06:09 am
content: I bet you could use this stuff. They've got that stuff all over the place at work. They make all sorts of stuff out of it. They've got some free CAD-like software where you can mock up the design and they just send it to the maintenance guys and they build it for them.http://www13.boschrexroth-us.com/Framing_Shop/Product/Default.aspx?units=1

author: IonizedGears
author_rank: Regular Contributor
timestamp: July 21, 2013, 12:12:18 am
content: Quote from: Stonent on July 21, 2013, 12:06:09 amI would guess that those frames are way out of my budget. And i decided i want something like the reprap which i know will be killer on calibration but it will make it possible to adjust if i ever need to.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 21, 2013, 09:24:36 am
content: As has been stated by numerous posters already: if you want a hobby-level engraver that leaves you with negligible precision and accuracy, along with sloppy and chattery finishes, an x-y platform rigged up out of printer parts will work. Rigidity and printer carriages, however, do not belong in the same sentence. Having a 20 year machining and mechanical background I can tell you that wih certainty and authority. The "rigidity" in a printer carriage versus what is required for a quality engraver or machine tool is several orders of magnitude apart. It isn't as simple as is being made out, no matter how much certain posters may want to argue that point.

author: Paul Price
author_rank: Super Contributor
timestamp: July 21, 2013, 12:41:45 pm
content: For every word of encouragement on this board there exits a hundred replies that shout No! Don't try this!!What if someone wasn't really doesn't need to machine spare parts for a Swiss watch or a F17 fighter, but just maybe want to make a quick PC for a simple project like a linear power supply, using only a few parts with no trace spacings closer than .2-in?In trying, someone might get a lot of enjoyment. It is possible trying to do this to learn a lot about machines, and machining, and the physics of mechanical couplings and gears and motors and struts, and all sorts of new things about electronics and programming and servo systems and stepper motors and tons of other things about how things really work in this world.Then again, it might even work well enough to show to your friends, make a video and splash it over Youtube or even make that power supply PCB much quicker than you thought.There could be some satisfaction and a feeling of accomplishment in that.Failure can be the best teacher.

author: GeoffS
author_rank: Unknown
timestamp: July 21, 2013, 01:01:06 pm
content: It less 'Don't try this', more 'Be realistic in your expectations'If it were possible to build a CNC router capable of the necessary accuracy using light weight components such as those found in a printer, then there would be no one making CNC routers using much heavier components. The forces needed to move a router or rotary engraver around are much greater than those imposed by moving a print head around.This is not to say that building a CNC router from printer components wouldn't be fun and educational, but you need to be aware of its limitations - and there will be many.

author: Paul Price
author_rank: Super Contributor
timestamp: July 21, 2013, 01:14:28 pm
content: Geoffs, you say, "If it were possible to build a CNC router capable of the necessary accuracy using light weight components such as those found in a printer, then there would be no one making CNC routers using much heavier components"That's not true at all.You are somehow thinking if it might be possible to make a makeshift printer-parts made simple PCB maker and that would somehow obsolete the idea of using more heavier components.There would not be "No one making CNC routers using much heavier components, using so much more capable and yet expensive parts in making million dollar CNC routers to do high quality precision workbecause some few built something that worked just well enough to do what they wanted.

author: ddavidebor
author_rank: Super Contributor
timestamp: July 21, 2013, 01:45:57 pm
content: This topic is damn boring

author: Paul Price
author_rank: Super Contributor
timestamp: July 21, 2013, 02:30:18 pm
content: Of course, not everyone will be interested in this topic, that's why there are so many other different topics posted.I find this topic exciting.That's why I've taken time out of my very busy day to make comments here.I really like to encourage everyone who enjoys electronics to try do something themselves using electronics,this is so much more exciting than to just go out and spend a lot of money and buy solutions and equipment to create something useful.I would really enjoy to learn how someone managed to take up the challenge and see someone succeed in this as well as offer help and encouragement and also have someone share their experience in developing a home-made PCB router.

author: IonizedGears
author_rank: Regular Contributor
timestamp: July 21, 2013, 04:48:42 pm
content: Well, i want to build this but i need to wait for my birthday to get enough money to try to build this. (Birthday is September 4th)And I noticed everybody keeps saying the printer parts will make up the "X,Y" part of the CNC. You guys do realize that X,Y means horizontal and vertical right? X,Z is horizontal and forward/back.So if i was to use printer parts they would only make up the axes that don't have to fight gravity.I realize i accidentally said i wanted the design to function like the Makerbot Replicator but i meant to say i wanted it to function like the Makerbot Thing-o-Matic.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 21, 2013, 05:02:21 pm
content: Gears: In machine tool parlance, X and Y are the axes that are used to position the spindle relative to the origin datum. These can but don't always coincide with "real-world" X, Y and Z axes. Most horizontal spindle machines do coincide, but most vertical spindle machines use X and what one would consider the "real world" Z axis as the Y axis. The "real world" Y axis then becomes the Z axis.On the subject of Paul's protests and complaints: of course one can make any sort of product to an inferior/hobby level. That's exactly why I made certain to say so in my first post. An item made in this fashion will not perform anywhere near the same as a properly made tool. One might be better served in such a case using the laser printer/magazine page/acid resist PCB method. Personally I am not a fan of busting my ass (or doing excess work if that does not translate) to make an inferior product, but I recognize that many people do not care about or recognize quality tools when they see them. (I.E. if they bit you in the ass).I don't see anyone telling the O.P. not to do or try anything. Merely those who are ensuring he is aware that a tool made in such a fashion will have many limitations and that he shouldn't underestimate the difficulty of such an undertaking for a novice.

author: IonizedGears
author_rank: Regular Contributor
timestamp: July 21, 2013, 05:16:25 pm
content: Thanks Kretz, I am not that experienced with machine tool jargon.I have however taken a good look at the machine tool shop at my school (It is a trade school to which i take electronics) and have looked at the cnc machines where they milled metal(2 million dollar cnc) and their CO2laser CNC($200k).I agree fully that printer parts would work; but I can't say anything much for how it will affect the quality of the mill(and neither can anyone else really) unless they have done it themselves and even then, 100 years ago when they had HUGE machines for factory work i bet they would scoff if you showed them a design of the size of the machines today saying that it would be too flimsy to properly work etc.The only proof either side could give is if they tried for themselves. But i will say i am leaning towards the design with the steppers i linked to on the original post because it seems to be the most reliable compared to other low cost solutions. (I bet this project will have a serious case of Deus ex Machina

author: nessatse
author_rank: Regular Contributor
timestamp: July 21, 2013, 09:39:15 pm
content: I don't wish to discourage you from trying, but I would encourage you to take advice from those knowledgeable in this area. You should also head over tohttp://www.cnczone.com/, you'll find a wealth of information there from people who have built their own machine (yes, it has been done before).Speaking from experience, having built an "on the cheap" three axis machine out of hardware store parts, I can assure you that rigidity is absolutely key. From a novice point of view, if you think its rigid enough, it probably isn'tConsumer grade printer parts may look good, but dragging a router along while cutting into copper is not the same as moving a printer head. Any flex in your system will be translated to your engraving/router bit as vibrations and affect your end product. You may get something that sort of works, but it won't be of real use.That being said, you can build a more or less usable machine out of hardware store parts (mdf, skate bearings, etc) as I have, and it is a very rewarding experience. I wouldn't bother engraving pcb's on it though, it is just too slow, bits are expensive and FR4 wears them out quickly and resolution is crap compared to even toner transfer. It's fantastic for drilling them though, providing you get yourself some decent carbide drill bits.

author: Corporate666
author_rank: Unknown
timestamp: July 21, 2013, 11:17:41 pm
content: Not to discourage the OP, but a $150 PCB engraver will never happen, unless a substantial portion of the parts are free, and/or the end result can be so sloppy as to be essentially useless.We've built 3 CNC machines in our shop. In hindsight, I would never, ever buy what can be bought. You can't do it cheaper and better, IMO. The idea of trading sweat equity for $$ savings is more than countered by the added expensive of trial and error and not having any economies of scale.There is/was a post here about a $450 Chinese PCB engraver. It looks like mostly crap (no offense to owners) as it comes from the factory, but is a much better starting point for a PCB engraver.Motion control is fun... but when you need precision and rigidity, home grown for the first try isn't the way to go.

author: Marco
author_rank: Super Contributor
timestamp: July 21, 2013, 11:39:57 pm
content: Quote from: Corporate666 on July 21, 2013, 11:17:41 pmPeople have made usable PCBs on mantis CNCs ... it can be done and when done from the point of view of hobbyism the time angle isn't that relevant.

author: IonizedGears
author_rank: Regular Contributor
timestamp: July 22, 2013, 12:40:37 am
content: Well, i have most of the parts for the engraver listed already at around $115. So if i can build the frame for under 35 dollars which i might be able to do with a reprap frame style design using threaded rods and rods as the frame.

author: IonizedGears
author_rank: Regular Contributor
timestamp: July 22, 2013, 12:51:07 am
content: Hmm, I'm sure this would be pretty sturdy; This could be a possible outcome for my frame.

author: sleemanj
author_rank: Super Contributor
timestamp: July 22, 2013, 01:07:16 am
content: Quote from: IonizedGears on July 22, 2013, 12:51:07 amI rather like the simplicity of that design, some good ideas there with the simple 60*ZZ bearings locking everything in place. The motor positions for X/Y look to limiting the travel of the platform a bit though, could have done with being set below the platforms so they don't obstruct, or further back.

author: Corporate666
author_rank: Unknown
timestamp: July 22, 2013, 02:20:23 am
content: Quote from: Marco on July 21, 2013, 11:39:57 pmI looked up a Mantis CNC. I guess our definition of "usable" must be radically different... I couldn't do anything usable with a "CNC machine" made of plywood and acme screws. If it's just for fun, then people should do whatever their heart desires, of course, but people never seem to be doing it for fun. They want something usable, which a $150 CNC machine won't be, other than as an exercise in just doing "something".I can't imagine how starting from scratch could possibly be better than starting with one of those POS $500 Chinese jobs?

author: GeoffS
author_rank: Unknown
timestamp: July 22, 2013, 02:36:30 am
content: Quote from: IonizedGears on July 22, 2013, 12:51:07 amI built one some time back when I first saw the Instrucatable.It worked as claimed but was only built as a toy and to get familiar with the CNC csoftware.Threaded rods don't give you accuracy or repeatability. The downward and sideways force on the router tool are significant even for light cuts. The support structure is just not strong enough.I didn't try to cut an PCBs where the depth of cut is much smaller so less sideways load on the tool bit but the accuracy/repeatability/resolution would all conspire to give you a less than acceptable result.The hackerspace I'm involved with has a 6040 CNC router and it's been used successfully for creating PBCs. I'm not sure of the details of the board as to what size traces etc, I'll find. out.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 22, 2013, 03:53:29 pm
content: Quote from: IonizedGears on July 21, 2013, 05:16:25 pmThis isn't entirely true. It is pretty easy to calculate stiffness using modulus of elasticity of different material combinations and stiffness and rigidity are extremely crucial to accuracy and repeatability. The maximum speed of a carriage might be super high, but if it can't be controlled to the necessary precision the speed is useless because it can't maintain the proper (read: accurate) toolpath. I think the toolmakers of old would indeed scoff at the machine tools of today; not because they would have thought they wouldn't work though, more because of the ridiculously low quality of most machine tools these days compared to the "old, massive, heavy" machines. Those old machines from the 1940's through the 1980's were capable of MUCH heavier cutting with much more rigidity than pretty much anything made today. As with everything else these days, even machine tools are made to "good enough, as cheap as possible" standards, and have accordingly suffered for it. The machine tools of today mainly try to make up for this by increasing available feedrates (now more possible due to lighter components) and spindle RPM. They mostly use recirculating ball linear guides for their axis travels, which are not at all very rigid, but allow for very high feed and rapid rates with very low friction and stiction. The problem here is the contact between moving parts is reduced to point to point contact which increases the wear rate massively. Machines that used to last decades in the "heavy" days now wear out in years. Some of the more expensive machines still use box ways, but they are still much less rigid than their older "massive" counterparts.

author: Marco
author_rank: Super Contributor
timestamp: July 23, 2013, 11:46:56 am
content: Quote from: Corporate666 on July 22, 2013, 02:20:23 amThat's just a case of PEBKAC then ... other people made usable PCBs with it. If you do the math on the actual dimensional changes of the wood due to humidity it's just not going to impact accuracy to any real disagree on a machine this size ... as for stiffness, it's cutting a couple micron of copper and a bit of FR4.BTW, just to add insult to injury ... plastic AND wood :http://forums.reprap.org/read.php?131,218779

author: ptricks
author_rank: Frequent Contributor
timestamp: July 23, 2013, 11:55:44 am
content: I wouldn't suggest printers as a source for parts, the old flatbed scanners though have very nice sled on bearings rails and stepper motors, the older the scanner the better. The old scanners that are old enough the casing has yellowed are ideal.If you are doing this to make PCB, don't bother though, the photo or laser printer method is faster and more reliable and will give better results.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 23, 2013, 08:52:34 pm
content: The video in Marco's link of the machine in action shows some of the limitations and issues some of us are discussing. The lines that aren't at 90° are clearly zigging and zagging, and I can clearly hear vibration and chatter the whole while that a cut is going on. Not to mention 2 HOURS to make one small to medium sized board! If one were making such a machine for the experience or just to see if one could do it I'd say go for it. If you really want to produce boards it's a waste of time. A machine of industrial caliber could rip one of these boards out in less than 5 minutes. As mentioned in my previous post and by several others, the toner transfer method is superior to doing this. As an experiment to test one's self however, I think it is a neat project.

author: Corporate666
author_rank: Unknown
timestamp: July 23, 2013, 10:54:18 pm
content: Quote from: Marco on July 23, 2013, 11:46:56 amThe dimensional change of the materials (whether it be wood of elasticity of metal) is not where the problems come from. The problems come from the couplings/attachments.Case in point - the black pipe video above. Using aluminum channel screwed to a piece of (what looks like) 0.25" acrylic and using a single bearing pressed against that channel by a single screw on a (what looks like) 0.8mm piece of aluminum is entirely inadequate.When you see what real CNC machines use (which were built to a purpose), these hobby ones - like the wooden one - are so inadequate that they would require constant fiddling to get the most mediocre of results.Like I said before, if it's being done just to say it was done, then that's one thing. If it's designed to be a usable machine that will further one's goal (presumably making quality PCB's), then it won't work. Not when you can get infinitely higher quality boards for such cheap money from dozens of suppliers.Like Geoff said, the forces involved in pushing a rotating bit through FR-4/copper are higher than most folks realize.I stand by what I said earlier... at a minimum, starting with one of the $500 Chinese "PCB routers" (and upgrading the parts) would be a better use of one's time. Even better would be starting with some of that aluminum extrusion, linear rails, ballscrews and ballnuts, axial-load-capable preloaded thrust bearings, and a very sturdy mount for a spindle. Then add home switches, steppers/motor mounts, vacuum, a way to calibrate the table flat and an off-the-shelf controller and Mach3 and you have a usable machine. But plywood and 60 degree screws? It's like learning to ride a bike and starting with a unicycle - way harder and much inferior results.

author: MacAttak
author_rank: Unknown
timestamp: July 23, 2013, 11:26:19 pm
content: The stand in that video doesn't really look any better than the much-derided dremel drill press. Those can be found for $40 on amazon.

author: WarSim
author_rank: Frequent Contributor
timestamp: July 24, 2013, 05:18:42 am
content: Quote from: eKretz on July 23, 2013, 08:52:34 pmYes it would be much faster but not less than 5 minutes.Process speed is limited to 2% or the bits will burn up.Math disagrees with your statement.I also noticed the intended .1mm wasn't actually .1mm but quite good for his setup.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 24, 2013, 08:23:38 am
content: Quote from: WarSim on July 24, 2013, 05:18:42 amI'm not sure what you are talking about. Process speed? Limited to 2% of what? How does math disagree with my statement? I would have to say that a true industrial router could easily complete that board in under 5 minutes. Hell, I could probably do it nearly just as fast with a CNC milling machine (a real one, not a benchtop toy). It would also be using good quality tooling and proper operations/processes, not cheap hobby-level junk and tooling and toolpaths that aren't optimal.I think perhaps you are unaware of the spindle speeds and tooling available for proper routing and milling work these days, judging by your previous post. 36,000 RPM is childs' play these days. There are spindles today with water-cooled bearings running in the multiple hundred thousand RPM range with air turbine motors and ceramic bearings, and these machines are crippled without the use of diamond tooling. They will eat pretty much anything alive, and I guarantee that such a spindle fitted to a proper router would easily be able to make one of the boards shown in the video in less than 5 minutes. Hell, I even have an air router that runs close to 60,000 RPM that I sometimes mount on the milling machine for high speed milling work.

author: ptricks
author_rank: Frequent Contributor
timestamp: July 24, 2013, 11:42:55 am
content: Quote from: eKretz on July 24, 2013, 08:23:38 amYou seem to be knowledgeable about CNC , has anyone cut patterns in glass on a CNC setup ? Any idea on what the minimum hardware would cost ?

author: ddavidebor
author_rank: Super Contributor
timestamp: July 24, 2013, 11:59:47 am
content: for cut glass and stones, at least 30k for a little and basic model

author: WarSim
author_rank: Frequent Contributor
timestamp: July 24, 2013, 01:47:37 pm
content: Quote from: eKretz on July 24, 2013, 08:23:38 amFor less than 5 minutes would require a spindle speed well over 1 million RPM. I have not heard of a mill that can go this fast.Few mills under 1mm have more than 2 cutting edges. Max material that can be removed by any cutting surface is equal too 2% of the mills diameter (a rule of thumb that works). Multiplex by the rotational speed equals the process speed. In this case I ignored cut depth and side load because we are talking about a little over .3mil depths. Significantly slower the bit burns up the material. Any faster it burns up the mill.

author: Watermelon
author_rank: Contributor
timestamp: July 24, 2013, 02:18:10 pm
content: I've built a PCB engraver/mill myself using a stripped down Huntron Access flying probe tester:http://www.huntron.com/products/access.htm. It had all the encoders, steppers, reasonable sturdy frame and RS232 interface card already in it. I got it for free at my school where i followed EE classes, they wanted to scrap it for parts... It has high torgue steppers and high precision encoders which have a resolution of 10um.It is extremely important that your PCB is FLAT, otherwise your engraving widths are inconsistent which you do not want. I copied the system from LPKF that brings the mill down with a solenoid and presses it down onto a depth controller. Guys from EAS in germany sell this. Seehttp://www.easgmbh.de/index.php?area=1&p=static&page=tiefenregler(It's in german but you'll get the point). Tuning the depth is difficult to get right.The software for controlling the engraver is written by my own in Visual basic 6, which handles reading in the G-code files, displaying it, controlling the X-Y movements and some other things. The interface card had custom commands to send over RS232, no standard software was available.Single-sided boards are going OK, double-sided boards is kind of a hell since you have to allign the PCB perfectly.Conclusion: Etching a PCB is way easier.I'll post some photo's soon...

author: RodG
author_rank: Newbie
timestamp: July 24, 2013, 02:37:31 pm
content: Quote from: IonizedGears on July 22, 2013, 12:51:07 amFirst postI actually routed my first PCB today, after a lot of mucking around. @IonizedGears, you should look at these plans for your first CNChttp://solsylva.com/cnc/10x9x4.shtml. I built the 25x25 about 3 years ago and the plans are top notch. There's a basic CNC plan there and it doesn't look too bad. I use HobbyCNC for the controller.The main problem with routing PCBs is the board has to be completely level. You have to etch a consistant .2 - .4 millimeters deep. The way I fixed that problem is by using a free program called "Autoleveller"http://www.autoleveller.co.uk/. The program worked a treat.I'd say go and build a CNC, any CNC and you will learn a lot from it and perhaps upgrade to one that does the job.-Rod

author: IonizedGears
author_rank: Regular Contributor
timestamp: July 24, 2013, 03:15:21 pm
content: Quote from: RodG on July 24, 2013, 02:37:31 pmI really like the look at the 25x25 mill solsylva sells the plans for.That said, why the hell did they give the pdf name of all five plans?I was able to find the file online in one search(not to say i downloaded it).Anyway, I'm just ranting here

author: Corporate666
author_rank: Unknown
timestamp: July 24, 2013, 08:07:35 pm
content: Quote from: eKretz on July 24, 2013, 08:23:38 amWell said.It seems a lot of folks don't appreciate what a real CNC machine can do. With an air spindle, these machines will easily cut at 10,000mm/minute or higher. A small copper board would be completed in a minute or two.But to be able to move at those speeds, a machine needs to be able to position accurately, handle the forces of acceleration/deceleration (often MUCH higher than the cutting forces), and be able to maintain sub-thousandth accuracy through all of that.All of that is even more important when dealing with fine work - like PCB routing. That's why the results from the machine posted above with the 3D printed gears was, I'm afraid to say, total shite.Real machines:

author: Corporate666
author_rank: Unknown
timestamp: July 24, 2013, 08:29:07 pm
content: Quote from: WarSim on July 24, 2013, 01:47:37 pmAny size you could want under 1mm is almost always easily available in a 4FL mill. Harvey Tool has tons of them.A 100k air spindle with a 0.030" 4FL end mill run no problem at 120IPM.What limits these small machines is spindle runout, movement accuracy and Z accuracy. They have to slow way down because the tool motion is not well controlled, which will snap a small diameter endmill in the blink of an eye.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 25, 2013, 01:20:07 am
content: Quote from: ptricks on July 24, 2013, 11:42:55 amMost work in glass is done with CNC grinding machines using diamond grit grinding wheels.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 25, 2013, 01:24:44 am
content: Quote from: Corporate666 on July 24, 2013, 08:29:07 pmAlso well said. It's nice to see someone else who knows what a real machine is capable of. Another thing I noticed in the demo video that would never happen on a real machine with a halfway knowledgeable operator was a ridiculous amount of tool overhang past the spindle. This is just asking for tool breakage also.

author: WarSim
author_rank: Frequent Contributor
timestamp: July 25, 2013, 02:43:36 am
content: Quote from: Corporate666 on July 24, 2013, 08:29:07 pmYes I do not disagree with you statement not extrapolate your figures to the tool used and the specified size and distance traveled for the project. Your calculation is for 30mil the onscreen text states 0.1mm which is 4mil for the outlining. One tenth the size means one tenth the speed. Yes I estimated the path length by estimating my tool path lengths on my projects of a similar size. The tool path distances was much longer than 60". In this case it seems our estimations are polar opposites of the scale.Lastly 30mil is a huge mill. Yes of-course it can speed through FR4 with a bit that big. Kinda useless for a 0.4mm pitch chip though. And yes I think the 0.1mm bit was allot finer than necessary for the board made, but that was the operators choice not the machines requirement.

author: Corporate666
author_rank: Unknown
timestamp: July 25, 2013, 03:29:26 am
content: Quote from: WarSim on July 25, 2013, 02:43:36 amIt's not a 0.1mm mill. Those guys are using V-profile engraving bits (totally the wrong tool) with a 0.1mm tip. And since he's going somewhat deep into the actual FR4, that initial cut is way more than 0.1mm wide. If you look at 3:50 in the video, it shows the finished board. He says he used a 0.6mm (0.031") drill for his through holes. Using that as a size reference, that board could have been 95% done with a 0.030" mill. And if he just moved a couple of traces a hair, the whole board could be done with a 0.030" mill.And that illustrates another problem of these homebrew CNC machines. They have no tool changers... so these guys are trying to do everything with one mill, which takes forever. On my CNC machines, you use the biggest tool possible for as much as possible, before switching to smaller tools. And to use smaller tools, you need rigidity and precise control - neither of which this machine has (look at the zig-zag diagonal traces - there is several thousandths of an inch of error there).As for 0.4mm pitch chips - that is a job for a real PCB router like an LPKF. A homebrew solution with jello rigidity ain't gonna cut it.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 25, 2013, 03:31:36 am
content: Again, as I said before, a proper router with proper tooling would easily get through that board in under 5 minutes. Using a .1mm engraving cutter for a wider track is silly. Proper machines have automatic tool changers and use the proper tooling for the operation being performed.Edit: beaten to the punch by Corporate.Also, the 2% rule you are using for feedrates is more of a ballpark safe starting number, it's easily possible to surpass this with proper tooling and setup.

author: KuchateK
author_rank: Regular Contributor
timestamp: July 25, 2013, 04:15:23 am
content: Want cheap CNC? Take a look at this:http://makeyourbot.wikidot.com/But you know what we say in Poland? "Thrifty pays twice". First to buy what he wanted. Second to buy what he should get the first time.My advice? If you want to actually use your machine to make something stay away from linear motion contraptions and cheap solutions. It has been proven countless times that saving on that is just waste of time and money. Linear motion is foundation for your machine. Wait a little more, save some extra cash, get proper parts. Don't reinvent the wheel.Linear motion is incredibly cheap these days. Get something like that:http://www.ebay.com/itm/linear-rail-SBR16-200-300-450mm-6-supporter-rails-12-SBR16UU-blocks-for-CNC-/171070839849?pt=BI_Heavy_Equipment_Parts&hash=item27d49ddc29Combine it with few flat pieces of MDF/plywood/old shelves or pieces of cabinets, cheap controller, hardware store screws. Basically everything else can be crap and you'll still get good usable machine. Mechanical construction is full of traps. With proven parts construction will be much simpler, you'll get something moving a lot quicker and easier. After some time you can upgrade motors, controllers, screws, frame. Remember, you're buying it for years.Here are few examples of machines built around those parts:http://forums.trossenrobotics.com/showthread.php?4293-Summer-of-Projects-Project-3-DIY-CNC

author: WarSim
author_rank: Frequent Contributor
timestamp: July 25, 2013, 04:54:17 am
content: Quote from: eKretz on July 25, 2013, 03:31:36 amOk so I guess all of us that have 50k spindles and use .20mm mills do not have "Proper machines". I Stand corrected.I believe I used the term rule of thumb. I would not use the greater than 10% feed rate to complete the board in 5 minutes on an expensive mill.Maybe I should be proud if the fact I made the prototypes I have made with such an improper machine. I personal still think I have invested wisely. I'll just have to live with my existence below your standards.Makes me wonder why you would even read a thread of this tittle. The thread is obviously DIY related, not a $70k router or nothing thread.

author: Corporate666
author_rank: Unknown
timestamp: July 25, 2013, 05:37:00 am
content: Quote from: WarSim on July 25, 2013, 04:54:17 amA home made machine is great, and you should be proud that you put one together.But there is a BIG difference between a hobby machine and a production machine. You said previously that you try to stay at 0.5mm or above, and said that these low end machines are capable of making DIP-density parts, but not much more, and that for any detailed work, you have daughterboards made.I think we completely agree about the capabilities of home built PCB routers.There is a huge difference between a home-built hobby machine and something "real". If you don't go below 0.2mm, you aren't using 0.4mm pitch components.I have a few purpose built CNC machines. The fastest has a 24k spindle, will position at over 53,000mm/min, will contour in full 3D at over 30,000mm/min, holds 21 tools that take 1 second to change and will achieve that performance with a 300kg load on it's table and cut aluminum, steel, or whatever else I want.There is a world of difference between that machine and a home built CNC machine... and a world of difference between a home built PCB router and something like an LPKF machine. I've built a few CNC machines - I've tried starting with a manual machine that I converted to CNC with servos (but left the lead screws), then converted it to ball screws. Then converted a bridgeport with ballscrews to CNC, then converted a pick-and-place to a router, etc. There is such a huge difference between "real" hardware (ballscrews, linear guides, a rigid base) that I don't see value in skipping those parts. Besides, you can get ballscrews, linear guides/rails and aluminum plate pretty cheaply - surely it makes sense to use that for a machine instead of stuff like plywood or pipe, no?

author: eKretz
author_rank: Frequent Contributor
timestamp: July 25, 2013, 06:04:07 am
content: Quote from: WarSim on July 25, 2013, 04:54:17 amSorry, now you're just getting offended for no reason. I don't have a problem with your machine, I'm not even sure what it is capable of or how it's made. I have a problem with people spreading inaccurate info though. Saying there's no way a proper 3D router could make that board in under 5 minutes for instance. When I use the term "proper" I'm referring to any machine built by a company that is in the business of building industrial machines made for this purpose. If that bothers you I don't know what to tell you. Just having a 50k spindle and using a .2mm milling cutter doesn't make your machine a quality piece of equipment. The ancillary parts are arguably just as important as or perhaps more important than the spindle, especially in a production environment. Corporate has outlined some of the reasons quite nicely in his last post.

author: WarSim
author_rank: Frequent Contributor
timestamp: July 25, 2013, 06:59:37 am
content: Quote from: Corporate666 on July 25, 2013, 05:37:00 amMy current one is not a DIY, it was purchased. It can go down to 4mil but I meant to say I don't like to go smaller than .25mm. Bits don't last as long and takes longer etc. specs say 0.2mil positioning but in reality it is 0.8mil. I need to have some fudge factor for close tolerance boards.Yes LPKF was considered but I lucked into a better deal. I wanted to stay under 20k, the LPKF option for under 20k was horrid compared to what I got else ware. Spec for spec what I chose was much better, with a sweet deal of under 10k. This is my home machine. Work boards are all outsourced.I am middle ground for my 3d printer also. Not a $400 rep rap nor a 30k objet. Just a 2k Replicator2. There is a reason for the DIY, middle ground and the big budget.I started participating in the thread to offer realistic expectations for a DIY build, but got sucked into defending the DIY option against the DIY bashing.I am not a DIYer on this subject but I am also not willing to spend 40k for your suggested alternative. I guess I am the middle ground.I am middle ground for my 3d printer also. Not a $400 rep rap nor a 30k objet. Just a 2k Replicator2. There is a reason for the DIY, middle ground and the big budget.Yes there are a lot better options that DIY or any sort buy some people are not able to or not willing to pay the money for something else. I still think a DIY mill is a better option than having acid in the house.

author: WarSim
author_rank: Frequent Contributor
timestamp: July 25, 2013, 07:13:53 am
content: Quote from: eKretz on July 25, 2013, 06:04:07 amI was just going by the math and the fastest mill I could find. In hind-sight I guess my delivery could have been more gentle. My apologies.If you have info on how I can get more speed out of a mill like mine without burning bits. Please tell me. I can not get the relative speeds to what you are suggesting.I have tries 90deg 2 flute point, 60Deg 2 flute point, .25mm 2 flute end mill, .5mm 2 flute end mill. I am cutting at 1.8% and 36,000RPM. A board 3x4 board takes over 20 min to mill each side. My faster experiments caused a wavy edge on the cut meaning too much heat and scoring on the bit after about 2000".

author: Corporate666
author_rank: Unknown
timestamp: July 25, 2013, 07:34:55 am
content: Quote from: WarSim on July 25, 2013, 06:59:37 amA $10k PCB router sounds like a very respectable machine. I'm guessing it uses ballscrews, linear guides, home switches, and has a pretty rigidly constructed base? I bet it performs well.There is a thread on here somewhere about a $500 PCB router from China. Not sure if it uses ballscrews, but assuming it does, it's a nice starting point. I think a $150 PCB router is so unrealistic as to be not worth the effort, I think you would agree. That's not to say a home built machine can't be made to work... but on the pro machines, there is a reason they use the parts they do. My Robodrill can do some pretty awesome things (not my machine but..)You can cut corners, but every corner cut results in less performance. So when people are talking about ditching the most basic elements of a machine like the ballscrews, linear bearing rails, balanced spindle cartridge, and sturdy base, and then talking about doing some pretty precise work... the results are likely to be wanting. I don't want to rain on anyone's parade... and I think we would all say doing a project like this for fun is great. It's just that doing it and expecting to get results that are even in the same hemisphere as a pro machine is unrealistic.Just like putting together a "CNC machine" from black pipe and stepper motors won't be in the same galaxy as that Robodrill video.

author: WarSim
author_rank: Frequent Contributor
timestamp: July 25, 2013, 07:47:38 am
content: Quote from: Corporate666 on July 25, 2013, 07:34:55 amThe mill is a two person lift. Very expensive to ship. Haven't been inside in fear of a hernia.I never intended to say the $150.00 budget was reasonable. I personally had issue with the RepRap etc conversions also, but I others have chosen that route. My realm of options started with the mini mill CNC conversions. A 3k budget, now that was slow.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 25, 2013, 02:20:03 pm
content: Quote from: WarSim on July 25, 2013, 07:13:53 amWell, first things first, does your machine use ball screws and linear bearing guides? Can we see a picture? What are you using for a control? There are many ways to get more speed out of a machine, but it often requires expensive upgrades, which you would have been better off buying right off the bat by getting a higher spec'ed machine when you first purchased. There are other ways to improve your speeds though. For instance keeping the tool and board cool. Are you using an air blast now? If not you should be. There are also coolant misters available using MQL (minimum quantity lubricant) techniques that make a bit less of a mess. You also should be running as many flutes on your milling cutter as possible and using the best tooling you can get your hands on. Harvey Tool was mentioned earlier, they are pretty good; Onsrud is a serious player in the routing market, check into what they have available also. It is important to always use the largest tool possible to do the work you are doing to save time; this was already mentioned earlier by both myself and Corporate. What is your spindle's TIR? (Runout). This needs to be kept to as close to zero as possible. This will have the biggest effect on what kind of feed rates you can run. From there you can upgrade your spindle, add ball screws if you don't currently have them, switch to linear guides if you don't have them, etc.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 25, 2013, 02:29:12 pm
content: Quote from: Corporate666 on July 25, 2013, 07:34:55 amMmmm, I love those little RoboDrills. I am always amazed at the smooth control at high speeds these machines are capable of, it starts to look almost graceful, lol. Watching the movements starts to look almost like a dexterous human using a die grinder to shape foam, heh. Only the machine is applying several orders of magnitude more force than any human could with levels of accuracy that are just amazing.

author: WarSim
author_rank: Frequent Contributor
timestamp: July 25, 2013, 08:32:52 pm
content: Quote from: eKretz on July 25, 2013, 02:20:03 pmWhile writing this post I went looking for some figures, and was reminded of a figure of 120IPM. I guess the entire speed discrepancy is the tool-path estimation. For under 5 minutes means the paths are under 600". My estimation was much higher than that. And my current speed is over 200IPM, with a .5mm mill my speed is faster but takes longer.I looked into all the path generators as far as I could and they all performed outlines then fill. I use Design Lab and it takes the approach of outline then concentric fill and/or rubout. I use 2 or 3 mills. First one the largest possible to get through every gap. Second one twice the width. Third if I have a larger mill. Yes my path generator may be less efficient in some ways, automatically using different mill sets for different areas is not supported. For example: If one place needs .2mm then all pads are outlined with .2mm. This is why I prefer .25mm and above. Running a tinny mill around every pad uses up a lower life bit and takes longer.Don't have an auto changer. I don't have LP air in my house and auto changers broke the budget. A $1,200 ring setter wasn't going to happen either. I have a MITS ElevenLab, I am pleased with it. Yes Chinese but 1/5 the cost.I still don't get the time differential. I have exclude the time for my manual tool changes, lower spindle speed and less flutes. Something is still not computing.I would be embarrassed if the time discrepancy was all a perception error. The nozzle to take away the cuttings squeals so much I wear hear defenders, and loud noises do cause changes to time perception. Changing to a quieter dust extraction head is still on the todo list. Making a cabinet is also still on the todo list.Everything is covered up but I can see the Y axis screw it's a machined rod. U shaped grooves with flat tread tops. Has a rotation encoder. Also looks like there is a lateral linkage trough a idler an two fibre belts.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 25, 2013, 10:29:24 pm
content: Well, right off the bat switching from 2 flutes to 4 should halve your time, since you'll be able to run double the feed rate. What brand of tooling do you use now? That can really make a very big difference to max feed rate and tool life.

author: WarSim
author_rank: Frequent Contributor
timestamp: July 25, 2013, 11:27:48 pm
content: Quote from: eKretz on July 25, 2013, 10:29:24 pmI don't know I buy the fromhttp://www.northbaytechnical.com/and he buys them bulk. They call them UltraMills if that helps.I am no longer sure I have a speed problem, do I?

author: eKretz
author_rank: Frequent Contributor
timestamp: July 26, 2013, 12:17:25 am
content: Well that question can only be answered by you. I only offer suggestions for improvement because you asked. I still think you could cut significant time from your processes with a few changes, but whether you actually need to or would benefit from doing so is up to you. Your very first step should be to check your tool runout to make sure you have good concentricity. Again, that has a major effect on tool life and feed rate. Ideally you would want runout somewhere in the millionths of an inch range. Anything higher and you're compromising your tooling and feed rate. If you have high (and by high I mean anything approaching .00005", 50 millionths of an inch) runout you will never approach maximum possible productivity. With close to zero runout and at least 4 flutes you will be able to exceed your 10% by a significant amount. You could also investigate higher speed spindles and diamond coated 4 flute tooling to improve on your current feed rates. You will run into a wall eventually since your machine doesn't use ballscrews. (It sounds like you have either square or Acme threaded rods).

author: WarSim
author_rank: Frequent Contributor
timestamp: July 26, 2013, 03:54:17 am
content: I'll check runout again. Before I could only measure down to .25mil. I have better measurement options so I can certainly check again. All I can say for sure is my runout last time I checked was below what I could measure.I have been using what I have because I haven't found a source for a better option. And I refuse to buy from USA companies that charge double advertised price to cross the boarder. To be honest I stopped looking after 4 months of such dead ends.If you have a recommendation for a .18mm end mill I will try and get one. If I have success I will get .25mm and .5mm end mills also, when I use up what I have.I think machines changes will be effected with a new mill when the time comes.I use Eagle and metric. I can only get imperial exports so there is a double conversion. Therefore I call the .25mm a 2.4mm, so it won't choke on .25mm isolation paths. It was the easiest fix because I use a .1mm grid.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 26, 2013, 06:09:20 am
content: Gotcha. Well, if you aren't willing to order from the U.S. I won't be much help sourcing tooling, as that's where I'm at. Here is a link showing some I the type of tooling you should be looking for though:http://www.harveytool.com/secure/content/documents/HarveyTool_Tablet.pdfOn page 100 of the PDF catalog there are diamond 4 flute micro cutters in your size range. They will also grind customs to whatever size you want. Ideally you should run at least a slight corner radius on the cutter to help tool life also. Most of the cutters they sell are also available in solid carbide with a diamond coating. If you are in Europe you should be able to get in touch wih Onsrud pretty easily to see if they have anything comparable or if they can suggest anyone for tooling if they don't have what you want.

author: Corporate666
author_rank: Unknown
timestamp: July 26, 2013, 06:40:55 am
content: Quote from: WarSim on July 26, 2013, 03:54:17 ameKretz is right about runout... if you are out even by 0.1mm, you could be quadrupling the recommended chip per tooth feedrate when the "high side" of the mill gets buried in the material. 400% of max feed will kill a small bit instantly.It's important to measure runout as you cut... you can do it on the smooth portion of a cutter extended out of the holder a little...but to check runout where you cut, get a gauge pin in the same diameter (or close) as your cutter and use a 0.0001 dial indicator on the table and slowly rotate the spindle. You should be able to eyeball to within 1/4 of a graduation which would be 0.000025 inch, or 0.0006mm. The higher quality the dial indicator, the better... but even something like this will give good results:http://www.ebay.com/itm/PRO-QUALITY-030-DIAL-TEST-INDICATOR-0005-GRADUATION-/121008094933?pt=LH_DefaultDomain_0&hash=item1c2ca4fed5Don't underestimate the effect of crap toolholding. I've got some ER collets on the mill that are wonderfully accurate, and some that are total crap. I only buy Hardinge brand collets now when I can or Kennametal, because even other supposed premium brands like Lyndex have often been total crap. Many people cut corners on tooling, buying Chinese collets and such. Check the runout back to back with a quality part and you will be shocked at the difference.

author: negativ3
author_rank: Regular Contributor
timestamp: July 26, 2013, 01:31:57 pm
content: The option I went for as a PCB milling machine. It does involve a fair bit of DIY to get it all setup/working, but it's worth it. Less than $1500 all-in.A few links to share...HARDWARE3-axis Base Machine, Microcarve MV3:http://www.microcarve.com/mcMV1.htmlStepper control, Gecko G540:http://www.geckodrive.com/geckodrive-step-motor-drives/g540.htmlSpindle, Kress 1050 FME-1:http://www.damencnc.com/en/tools/kress/kress-milling-motor/87Spindle Control, SuperPID:http://www.vhipe.com/product-private/SuperPID-Home.htmLimit Switches, Homebrew with Honeywell Hall Effect sensors.http://www.ebay.com/itm/321052908870PCB Cad softwareCADSOFT EAGLE:http://www.cadsoftusa.com/PCB-GCode ULP for Cadsoft Eagle:http://pcbgcode.org/index.phpPCB-GCODE Wizard:http://www.pcbgcode.com/CNC ControlMACH 3:http://www.machsupport.com/Example PCB...