hybridfree/eevblog-posts huggingface dataset:
Manual stencil printer frame sizes - Page 1
Forum section: electronics / general

author: pasimasi2
author_rank: Newbie
timestamp: January 29, 2023, 08:53:34 am
content: A lot of Chinese companies selling the similar looking manual printer, Kayo P1000, others with model number 3040.They all seem to have same specifications:Print size:250*400mmWork table size:300*400mmMax mesh frame size:370*470mmThickness of the substrates:0-80mmWhat I don't understand here, is the max size of the frame. If choose 370 x 470mm stencil in PCB houses, they often tell that the actual effective area of 370x470 stencil will be 190 x 290 mm.And this on the other hand is much less than the print size these printers state, 250 x 400 mm.Also when looking at the construction of the printer, I don't see any physical reason there why one couldn't place a frame for example size 420 x 520 mm, which shows effective area of 240 x 340 mm, or even a larger one to cover the whole printing area 250 x 400 mm?I understand with very large frame it comes physically difficult to manually spread the solder paste but for example that 420x520mm would be just 50mm larger both directions.Am I missing here something, I have to admit I have never seen the printer or the framed stencil in action so I might have misunderstood something.

author: pasimasi2
author_rank: Newbie
timestamp: January 30, 2023, 03:01:14 pm
content: I was told by manufacturer that it is the nominal recommended max size but can use bigger frame

author: SMTech
author_rank: Frequent Contributor
timestamp: January 30, 2023, 03:38:01 pm
content: Quote from: pasimasi2 on January 30, 2023, 03:01:14 pmWith limits, the print area in a stencil will typically be centered. So there will come a point where the area you can technically support on the table is outside the center window of a standard stencil. To get around that, you'd need them to make a non-standard frame, perhaps shift the image to one end & well as fix your foil in such a way that the fixing tape and epoxy doesn't intrude into the PCB area. However the OP's 50mm in each direction is probably pretty easy. A full (small) commercial 23" stencil frame might be pushing it..

author: PCBprototyping
author_rank: Contributor
timestamp: March 04, 2023, 01:49:24 pm
content: We made the following frame just for this purpose, fits 3040 area, has 4-sided tensioning to prevent bending of the stencil and provide good tensioning. Compared to framed stencils, you save a lot on storage space, stencil price and shipping cost.Custom sizes on request.https://www.tronstolsmt.eu/products/sf2636-stencil-frame-for-4-sided-perforated-stencils-260x360-mm
MPM Momentum vs Accela? - Page 1
Forum section: electronics / general

author: kynwav
author_rank: Newbie
timestamp: February 11, 2023, 03:42:15 am
content: I recently came across a good offer for both the MPM Momentum (2008 model) and MPM Accela (2006 model). MPM Accela costs $2,000 cheaper, but both machines are in good working condition.I note the Accela seems to be an older machine than the Momentum but twice as heavy, weighing in at 2tons vs only ~1ton for the MPM Momentum.Which one is the better quality machine and better deal? Momentum or Accela?

author: loki42
author_rank: Frequent Contributor
timestamp: February 11, 2023, 05:30:42 am
content: The Acella is heavier than that... I've got one. It's a very nice bit of kit. I bought a used one from Chicago and it was a lot of work to get it working. It was sold "in excellent condition" but I would make sure to see it print boards. Mine had a servo controller that was dodgy when it arrived. Turns out a little bit of soldering fixed it but it took a long time to find that out. Also check what tooling / work holding they have with them. The inspection is very fast and very good. The calibration procedures are quite easy, the paste dispensing is very good. It's very easy to use / program. I had a broken input board sensor but that was a $50 fix. I also had a broken air filter when it arrived. I spent maybe a few $100 to get it all working. Mine had printed a few million panels and I think it's got a few million left.Mine was work to get working but now it's pretty lovely. It's giant, heavy and all the insides are top quality parts. It's fast and staging is handy.
PCB Manufacture - 1 to 2 Working Days - UK Supplier - Page 1
Forum section: electronics / general

author: Matt Coates
author_rank: Contributor
timestamp: January 11, 2023, 12:04:40 am
content: Hi,Im looking for recommendations for a UK supplier of PCBs that is able to produce a simple PCB in 1-2 working days.SpecificationsLayers - 2Size - 50mm x 80mmQuantity - 3 PCBsBoard Thickness - 1.6mm (Not critical)Copper - Ideally 2oz but 1oz is acceptableMask - Any ColourSilk - Any colour, can be omitted if neededMin Clearance - 0.2mmEurocircuits offers a 2 working day service for £155, but at the moment shipping takes another 1-3 days. I ideally need recommendations for a UK company that is able to offer a comparable service and price and who can be trusted to deliver on time.Thanks!

author: Jackster
author_rank: Frequent Contributor
timestamp: January 11, 2023, 12:10:21 am
content: Not used them yet but Express Circuits Ltd can do "from 24 hour". At least that is what they say.I suspect your PCB count will be a problem for the smaller guys to run fast (less likely to pool or run a single panel every day or two)?

author: SMTech
author_rank: Frequent Contributor
timestamp: January 11, 2023, 01:28:11 pm
content: Not sure we've tried ordering 3, but Blackvein, CC Electronics, ALR & Quartz TSL have all done unexpected rush jobs for us in the past including more complex ones.We use Tim athttp://ixpcb.com/for other services and he has quoted for this kind of thing too in the past. Some of these may well broker from others on the list.For bigger budgets or more complex jobs You might also look at people like ZOT & Wrekin, there are of course lots of others the prices will vary and I don't think you could rely on just one always having a 24hour slot for what you need.

author: jc101
author_rank: Frequent Contributor
timestamp: January 11, 2023, 06:28:20 pm
content: Doubt you will get the same price that fast in the UK. I have a local PCB company who could probably do it, but won't be anywhere near as cheap I expect. Might be worth asking them.https://www.cambridge-circuit.co.uk

author: Matt Coates
author_rank: Contributor
timestamp: January 13, 2023, 01:14:11 pm
content: Just as a follow up, I ended up going withhttps://www.pcbpanel.co.uk/for this.I sent over gerbers at 5am on Thursday morning and the boards dispatched the same day for delivery Friday morning by 12.Quality of the boards is great, really happy with the result. As a bonus I got a bunch of extra boards that I'm guessing they had room for on the panel. The team were very friendly and acoomodating - highly reccomend!

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: January 15, 2023, 12:17:41 am
content: Quote from: Matt Coates on January 13, 2023, 01:14:11 pmAs someone not from the UK, after seeing such service actually existed in our modern day in the UK at such an affordable price, if I'm based in the UK, by all means I would definitely try to support these type of companies.
JLCPCB parts service - additional costs - Page 1
Forum section: electronics / general

author: edeca
author_rank: Newbie
timestamp: January 06, 2023, 07:24:50 pm
content: I am using JLCPCB for fabrication & assembly for the first time. It's also the first time I'm having a board assembled rather than assembling by hand with a frying pan, a video of my previous technique is.I purchased the minimum quantity of a part that was out of stock, this was 236 pieces at an estimated unit price of £0.0302.I received an email saying the procurement department advised a minimum quantity of 1000. Not a huge problem as I'll likely use them, so I cancelled and reordered 1000 for an estimated unit price of £0.0156.I have now received a "final quotation" of £0.0487 with a supplement of £33.10. This is still likely cheaper than I can buy the parts, and will be assembled.Whilst I understand that part costs fluctuate, how common is this? It makes planning PCB costs quite unpredictable for anything outside the standard range of components. And this is before I start to use any complicated components like ICs

author: JPortici
author_rank: Super Contributor
timestamp: January 07, 2023, 07:32:29 am
content: This happened to me at least once:- Order a design- There was an error in production files that i didn't catch- order was canceled because you can't just change the production files- reorder with correct files, same BOM- End up paying almost double because the price for most of the passives, and probably something else, have magically increased in priceand this over the course of about three hoursI only do prototypes or oneoffs there, this was a very big board, only two pieces assembled so i haven't lost much time asking myself why prices fluctuate this much, or if they apply surcharges based on your activity, bait you with the very low price on the first order only and the more you wait between oders the less you pay. Even with this the service is good and fast, it just goes from cheap to adequate

author: JLCPCB Official
author_rank: Regular Contributor
timestamp: January 09, 2023, 02:44:04 am
content: friends, just leave your order number here, and we are going to check the extra cost reason. Or you can henry@jlcpcb.com to get the answer clearly.
Can I avoid plugging via in pad with a thin board and 0.3mm via? - Page 1
Forum section: electronics / general

author: OwenH
author_rank: Contributor
timestamp: January 05, 2023, 10:55:52 am
content: Hi,I have a thin 0.8mm board that needs some via's in the pads of a mosfet. Is it possible to reliably use non filled via's in pads with thin boards and tented 0.3mm via's? I would think that the small diameter and the low height of the via would make it difficult for the solder to be robbed from the pad but I do want reliability. My intuition says fill the via's but I would like to avoid the cost.Thanks,Owen

author: Niklas
author_rank: Frequent Contributor
timestamp: January 08, 2023, 10:23:30 am
content: If the PCB is 0.3 mm thick, then it would be approx 3 times thicker than the printed solder paste with a 0.1 mm stencil. Vias placed in the large thermal pad, as the drain of a MOSFET, are fine, but probably not for a single pin as the gate.Solder mask tented vias can come with two risks: droplet/smear and flux residues. Depending on the viscosity, and which side is printed first, there is a risk that the solder mask can form a droplet on your pad if that is on the second side to be printed. 0.3mm holes are probably OK, but I have seen this for 0.4 mm holes in pads for Murata NFM21 EMI filters. PCB manufacturers also recommends to have an opening in the solder mask on the opposite side if the via is placed in a pad printed with solder paste. This is to evacuate flux residues and for outgasing.
My soldering pen died - is there anything that uses Weller RT tips? - Page 1
Forum section: electronics / general

author: qu1j0t3
author_rank: Regular Contributor
timestamp: January 02, 2023, 12:14:10 am
content: Hi,I have been happily using this great little pen for 3 years:https://www.tindie.com/products/vlk/rt-soldering-pen/But first the switches failed and after getting a repairer to replace the switches, it is completely dead.I'm looking for a replacement pen, but since I have a working RT tip and it's great to use, I have been looking for options that also take RT tips. It seems there is practically nothing out there? The only Weller products are long discontinued. And yet the tips themselves seem plentiful online, so there might still be an opportunity for another hobbyist design...Anyhow, should I abandon the hunt for an RT compatible pen and just switch to something else? TSP? I'm just a hobbyist doing undemanding throughhole work and repair. I have a bigger 40W uncontrolled iron for any big jobs.Thanks for any uh tips

author: nardev
author_rank: Unknown
timestamp: January 02, 2023, 07:43:01 am
content: Maybe this:https://pine64.com/product/pinecil-smart-mini-portable-soldering-iron/

author: qu1j0t3
author_rank: Regular Contributor
timestamp: January 02, 2023, 01:59:07 pm
content: Yeah, I ended up deciding to order one of those. Unfortunately not compatible with the tip I have.It may be that only the OLED is dead on VLK pen (since it seems to heat, but there's no display), but I don't like my chances at that repair....Thanks.

author: thm_w
author_rank: Super Contributor
timestamp: January 02, 2023, 10:15:21 pm
content: How is the OLED attached to the PCB?You can buy them for $1-2 so might be worth an attempt.

author: qu1j0t3
author_rank: Regular Contributor
timestamp: January 02, 2023, 11:48:56 pm
content: Quote from: thm_w on January 02, 2023, 10:15:21 pmI'm definitely looking into it! I know nothing about SMT repair (I'm a THT guy) but I'm checking with an expert to see if it's worth a try.
Zebra Strips, Elastomeric Connectors  - Page 1
Forum section: electronics / general

author: dcmeigs
author_rank: Newbie
timestamp: December 31, 2022, 03:53:10 pm
content: I’m looking for a source of supply for Zebra Strips, the elastomeric connector often used on LCD displays. I’ve had no reply from the manufacturer and of course I’ve tried Digikey and Mouser. Any tips would be appreciated.

author: jbeng
author_rank: Regular Contributor
timestamp: December 31, 2022, 04:21:41 pm
content: Have you contacted this manufacturer? If so, it's likely due to holiday season that they haven't yet replied.https://www.fujipoly.com/usa/products/zebra-elastomeric-connectors/

author: dcmeigs
author_rank: Newbie
timestamp: December 31, 2022, 11:26:14 pm
content: Yes, that’s who I contacted. Perhaps they will respond.

author: jbeng
author_rank: Regular Contributor
timestamp: January 01, 2023, 06:58:14 pm
content: I see. Here are some other manufacturers of elastomeric connectors, if Fujipoly doesn't respond:https://www.zaxisconnector.com/https://custominjectedplastics.com/Hope this helps.
torque for ceramic pads (TO-3) - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: December 31, 2022, 01:00:19 am
content: What is the torque required for ceramic isolation pads on TO-3 packages?I am replacing some stuff in a audio amplifier and I have gotten cracks from very modest pressure. Infact, any less and I would be scared of the connection to the body being bad.Infact, I thought maybe to just solder a stud to the top of the TO-3 package to put a wire there with a ring terminal. I know the easiest option is to not use ceramics.Does a cracked pad have any effect anyway? (it will be sitting on a bench, not avionics compartment).

author: coppercone2
author_rank: Super Contributor
timestamp: December 31, 2022, 02:25:57 am
content: also, could thermal grease be the reason they are cracking, since its uneven? I thought maybe to try to tighten the assembly down while its hot, or slowly increasing torque over a time period?could there be a viscosity limit on this type of thermal pad grease?

author: Gyro
author_rank: Super Contributor
timestamp: December 31, 2022, 07:17:41 pm
content: It implies that one of the surfaces isn't dead flat*. Ceramic pads need heatsink compound anyway to fill in micro surface irregularities, they are there for high voltage insulation, not as an alternative to the compound.Edit:*... or the compound is applied too thickly and unevenly.

author: coppercone2
author_rank: Super Contributor
timestamp: December 31, 2022, 08:44:41 pm
content: I used MX4 compound and used a utility knife to flatten it as much as possible during install. I think maybe the pad is a bit too big, because it cracked on the edge near the screw hole.I noticed that the other ceramic pad I had in the other HP amplifier for a TO-3 package did not crack when I tightened it alot, but its slightly smaller. I guess the heat sink plate (back of HP 6000 series) might be warped or something slightly. I think I need a giant lapping plate to make it work properly now..
JLCPCB v-cut additional charge.  $15 Why? - Page 1
Forum section: electronics / general

author: TankSparks
author_rank: Contributor
timestamp: January 13, 2023, 05:18:25 am
content: I keep getting charged an addtional $15 after order is submitted and paid for /reviewed (times 3 orders so $45 so far). I was told its because my boards are too small in the panel. True but I'm only doing vertical v-cuts, routed out horizontaly and my vertical v-cuts are20mmapart I'm pretty sure that is within specs.From their website1. Make sure the single PCB size is bigger than1.5cm x 1.5cm, or we will charge $14.5 for the v-cut cost. Small PCB is hard to v-cut.I did pay the surcharge as trying to get that point accross with support did not work. I hope JLCPCB is reading this post.

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: January 13, 2023, 05:34:17 am
content: Minimum JLC V-cut length is 70 mm.

author: JLCPCB Official
author_rank: Regular Contributor
timestamp: January 13, 2023, 09:07:54 am
content: Quote from: TankSparks on January 13, 2023, 05:18:25 amWould you mind emailing henry@jlcpcb.com to get the answer clearly?
Seeking thermal  sheet for mounting components to metal plate - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: December 21, 2022, 05:28:05 pm
content: Hi,We need to heatsink some components to a flat metal surface, and need a bit of thermal conductor/elec insulator between them....so we want a sheet of say 10cm by 10cm so we can cut it up into the right sizes.But we cant find anything.Everything we find is either..1...way too expensive, like £30+2...Too small eg 15mm x 15mm3...Has holes in it which we dont want.The best i found is these...Thermal pad farnell 3790360, 25mmx25mmThermal pad farnell 2723050, 51x27mmThermal pad farnell 3779118, 100x100mmBut these arent really it.Do you know of any general thermal sheet/film?

author: Kasper
author_rank: Frequent Contributor
timestamp: December 22, 2022, 05:12:28 am
content: I order custom thermal sheets, I think they offer that size.

author: Kean
author_rank: Unknown
timestamp: December 22, 2022, 11:23:56 am
content: Quote from: Faringdon on December 21, 2022, 05:28:05 pmWhat exactly is the problem with those ones you list?The last one at least seems to meet all the listed criteria, and is sold in many different sheet sizes, thicknesses, and thermal conductivity specs.
2oz 2 layer flex pcb flex to fit limitations - Page 1
Forum section: electronics / general

author: OwenH
author_rank: Contributor
timestamp: December 29, 2022, 09:38:25 am
content: Hi,I have a 2oz copper 2 layer flex PCB design with wide traces paralleled top and bottom for current carying ability. The PCB is designed 0.5mm longer than the ideal distance between the surface mount connectors at the ends to allow any dimensional tolerance when mounting to be taken up by the flex pcb. the enclosure is precision machined from aluminium. Once installed the pcb will no longer be able to flex.I realise that 2oz copper and 2 layers with wide over under traces is not at all ideal for flexing a flex PCB. I just need to make one partial radius in the middel of the flex area which will be 20x (12mm) the thickness of the pcb (.26mm). The length of the bend area is about 20mm long and 23mm wide. The radius would be bent before install and allow it to stretch a bit while being installed and take up any tolerances.How rigid will this flexible pcb be? Also how much spring back is there likely to be? I figured I would 3d print a part to aid in making the bend before installation in the enclosure, I assume I would need to add some overbend to make up for the spring back.The images are of the flat pcb before a bend is put in. Two of the images show the assembly with the flex pcb flat and the second connector right of its location to represent the extra length in the flex pcb that would need to be taken up when bent. The bend area would be between the 4 radiuses. The total length of the PCB is 54mm.Thanks!Owen
How to install the loose nozzle for Hot Air Rework Station? - Page 1
Forum section: electronics / general

author: freedomcom
author_rank: Newbie
timestamp: December 17, 2022, 06:05:42 pm
content: I bought a YIHUA 959D-Digital Hot Air Rework Station from Amazon. The nozzle comes very loose. I tried to tighten the screw, but the nozzle still dropped right off. Are these nozzles bad for this batch, or do I need to apply even more force to the screw? (I exchanged the first one that I received, and the 2nd one has the same issue.) Thanks.https://www.amazon.com/dp/B08BK3M6YWhttps://m.media-amazon.com/images/W/WEBP_402378-T1/images/I/81livKb7dnL._AC_SX679_.jpg

author: ataradov
author_rank: Super Contributor
timestamp: December 17, 2022, 06:57:19 pm
content: This happens a bit with those stations. Usually you can pre-bend the clamp with pliers and let the screw do the reset. You don't need much, deform the metal until it just fits over. And then screw won't have to do a lot of work clamping.
Puhui T960 versus Puhui T961S - Page 1
Forum section: electronics / general

author: tomgat
author_rank: Regular Contributor
timestamp: December 10, 2022, 08:50:21 pm
content: So I want to buy another small conveyor oven. I am looking at the Puhui T960 and the Puhui T961s (double the price, but has a rather nice touchscreen). I really like the T961s mostly because it has 4 top heating zones and a 13" wide belt (T960 - 3 zones and 11" wide belt) so that I can double stack boards into it doubling my throughput.However, I noticed on the forum people complaining that the T961S gets overly hot on the top and since the controller is on the top, it messes with the thermocoupler ambient value. In theory, this could be resolved by running blowers on the top vents which I will be doing anyway just to get rid of the excess heat. Anyone using the T961S? Is this still any issue? Are you happy with this oven?https://www.eevblog.com/forum/manufacture/puhui-t960-and-t961-ovens/msg3594338/#msg3594338Finally, since the T960 is half the cost and has the controller on the side, maybe this is a better oven overall? My main concern with this oven is that it does not appear you can actually change the temps from their preset values. Their manual makes no mention of this. Is this possible? Anyone using the T960? Happy with it?Which oven would you recommend?
Anyone here using a GKG G5 Automatic Stencil printer? - Page 1
Forum section: electronics / general

author: seon
author_rank: Regular Contributor
timestamp: December 09, 2022, 07:48:46 am
content: Hey Folks,I'm looking for other people using a GKG G5 stencil printer, as I've just got mine up and running on my line (bought it second hand from China) and I'd like to find people I can talk through board setup and trouble shooting with.I'm sure some of the things I'd like to talk over might be relevant to other fully auto machines, and I'm happy to chat in general, but finding other folks with a G5 would be amazing.CheersSeonUnexpected Maker

author: mon2
author_rank: Frequent Contributor
timestamp: December 09, 2022, 04:51:00 pm
content: We own the Ekra X4 but recall that this printer company is one to watch. Believe that they 'cloned' the original Ekra line years ago in Asia but they have a good reputation.Do post your same request on smtnet.com for other feedback. The vendor should have local reps that can also assist you on any questions.
Auto feeding soldering station - JBC-ALE-210VA - Page 1
Forum section: electronics / general

author: OwenH
author_rank: Contributor
timestamp: December 05, 2022, 09:31:03 pm
content: Hi,I'm looking into a JBC-ALE-210VA auto feeding soldering station but have no direct experience with these. Do auto feeding soldering stations work equally well for pcb soldering and soldering wires in a solder cup? I have a bunch of solder cup wire soldering coming up and would love to have a free hand to hold the wire wile soldering. Are there any other makes/models I should look at?Thanks,Owen

author: thm_w
author_rank: Super Contributor
timestamp: December 05, 2022, 10:48:27 pm
content: Review of earlier unit here, which appears to have a similar mechanism, basically not good for small gauge, OK for thick solder:https://www.youtube.com/watch?v=TNLXSFTBorgWhat is "solder cup wire soldering", you mean tinning the ends of leads? Why not just use a solder cup for that.They have a 30 day trial you can do as well.Hakko equivalent:https://www.tequipment.net/Hakko373-11.html

author: tomgat
author_rank: Regular Contributor
timestamp: December 06, 2022, 03:04:06 am
content: Quote from: OwenH on December 05, 2022, 09:31:03 pmWhile auto feeding soldering irons work great on soldering robots, I have found that using auto feeding soldering irons when hand soldering suck because they rarely put the solder where you actually want it. This is why soldering robots have a rotational axis, but when hand soldering you tire pretty quickly if your constantly rotating your hand when soldering.In my case, I just bought one of the cheap foot type automatic soldering machine (about $50 on aliexpress), and then threw away the cheap 50w soldering iron using only the solder auto feeder. This way I get the best of both worlds. I can correctly position the solder with one hand having it autofeed while rapidly soldering with the other hand. Its also great for drag soldering operations.

author: OwenH
author_rank: Contributor
timestamp: December 06, 2022, 07:11:43 am
content: I'm referring to soldering wires to pins that have a solder cup to solder there wire into. The wire is already tinned so there is no need for a solder pot.

author: mairo
author_rank: Unknown
timestamp: December 08, 2022, 04:21:02 am
content: I own the previous version and LOVE it. Of course it has its purpose use and is not suitable for all applications, although it can be used just as a normal soldering iron as well if you can live with the bended tip options. One big draw back on my older unit, which seems fixed on the newer units is (not sure), is the tip of the solder feeding pipe. On the older units it used to be a plain metal, which sometimes if not carefully used, used to get stuck from molted solder, and actually this is the only reason why the wire would break, or need to change the feeding pipe on my system. The new system seems to have a plastic/Teflon tip that I am guessing should work better.I think for your application might be a good use, can you post some pictures/model numbers as still abit unclear to me the actual use.
European insulation equivalent of Controleo3 reflow kit - Page 1
Forum section: electronics / general

author: soFPG
author_rank: Frequent Contributor
timestamp: October 26, 2019, 12:42:44 pm
content: I am looking forward to build my own reflow oven using the Controleo3:https://www.whizoo.com/buyBut I am undetermined whether I take only the Controleo3 or the whole kit because of the USA-brand insulation material which is not available here at my place.So I am wondering what the european equivalent to "Reflect-A-Gold insulation" or "Floor & Tunnel Shield II insulation" would be? I mean we have fiberglass insulation here but I am not able to find equivalents to the two just mentioned products.Any ideas?

author: Fire Doger
author_rank: Regular Contributor
timestamp: October 27, 2019, 06:38:51 pm
content: With simple fiberglass around the oven I got really nice responce time (6 elements, 2.2kW total, 10lt oven) to make a true curve follower and not a bell curve...The big issue is air, if your oven has a fan then it will be really nice, if not I used the blades from a desk fan (ebay)(*double setpoints are used to change gains and avoid overshoot)

author: SMTech
author_rank: Frequent Contributor
timestamp: October 28, 2019, 03:01:29 pm
content: Quote from: soFPG on October 26, 2019, 12:42:44 pmWell I haven't tried the 2nd one but starting with the first, that comes up in the UK from just about anyone who sells performance car parts like Demon-tweaks and I think the other suggestion is sold by similar vendors. However I wouldn't get too caught up with branding, the key in reflow (no matter the scale) is low mass. You don't want anything in the "hot bit" to be holding on to thermal energy as that will delay both heating and cooling making it more difficult to easily control your temps.

author: stigger
author_rank: Newbie
timestamp: December 07, 2022, 05:31:37 am
content: Quote from: Fire Doger on October 27, 2019, 06:38:51 pmSorry to bump an old thread, but could you please share some details about your build:- are your heating elements quartz or resistive?- how did you manage to install a fan? 10 liters is a pretty small oven.- have you tried increasing the power parameter before installing the additional elements? Or there they already at 100% duty and that was not enough?- how did you distribute the power over the 6 elements? (the Bias setting in the profile, top/bottom vs boost configuration)PS. Also, what tool did you use to plot this graph?
Ersa ERS 250p reflow oven opinion - Page 1
Forum section: electronics / general

author: mtkapala
author_rank: Newbie
timestamp: November 16, 2022, 06:45:57 pm
content: Hello everyone on the forumI am thinking of buying a small quite old ERSA ERS 250p reflow oven for the production of prototypes and small series. Unfortunately, it's hard to find information about this oven on the Internet. Is there anyone on the forum who used this reflow oven and is able to write its pros / cons? The oven I want to buy is used but in good condition.Can you successfully solder BGA elements and small 0201 elements with this furnace?RegardsMateusz

author: tooki
author_rank: Super Contributor
timestamp: December 03, 2022, 02:08:06 pm
content: Why would the component size be dependent on the oven? That depends on the PCB layout and solder paste stencil, and having an appropriate reflow profile.

author: SMTech
author_rank: Frequent Contributor
timestamp: December 05, 2022, 04:49:55 pm
content: Quote from: tooki on December 03, 2022, 02:08:06 pmYes and no, uneven heating could increase the risk of tombstoning on smaller parts. Equally in forced air convection reflow an oven that needs to run the blowers pretty hard to meet your profile might blow things off the board. An older, smaller oven might struggle to produce a decent profile for lead-free processes, that might mean it burns through fans and heaters more quickly, or it just sucks at it.
NextPCB DFM - Page 1
Forum section: electronics / general

author: davekeck
author_rank: Contributor
timestamp: December 05, 2022, 05:33:03 am
content: Hey all, I'm getting ready to order some boards from NextPCB so I wanted to do some DFM testing.NextPCB offers a DFM analysis tool called HQDFM (https://www.nextpcb.com/dfm), but it's very slow on my small 4-layer board. (It takes several hours to do a single analysis, and sometimes hangs forever.)I noticed that hqpcb.com (NextPCB's counterpart that serves the Chinese domestic market) offers a newer version of HQDFM with a lot more features, but I haven't been able to use it because it requires a Chinese phone number to sign up. (I contacted NextPCB's support and they said that the newer HQDFM version is only for Chinese customers. I tried signing up with a temporary Chinese phone number, but couldn't receive the SMS verification code.)Has anyone successfully used either the Chinese or non-Chinese version of HQDFM?
what do you want for christmas? - Page 1
Forum section: electronics / general

author: ansonbao
author_rank: Regular Contributor
timestamp: November 06, 2022, 03:13:14 pm
content: Recently, we are preparing for Christmas promotion. We hope this event could help more people build their projects easily. Could you tell me what you want for Christmas or suggestions? Maybe I can make it happen.Thanks in advance,friends.

author: bidrohini
author_rank: Regular Contributor
timestamp: November 08, 2022, 10:53:25 am
content: I think you can offer a discount on Christmas decoration-related PCBs. For example, Christmas stars like this one:https://www.pcbway.com/project/shareproject/RGB_Christmas_Star_a7fadb41.htmlOr interactive Christmas trees like this:https://www.kickstarter.com/projects/288354188/christmas-tree-pcb-for-raspberry-pi-pico?ref=project_linkA discount before Christmas will be good.

author: ansonbao
author_rank: Regular Contributor
timestamp: November 09, 2022, 07:13:16 am
content: Good suggestion, I can't help revealing one of our plan: Christmas decoration-related PCBs design will enjoy free prototype.Hope you will like it.

author: bidrohini
author_rank: Regular Contributor
timestamp: November 09, 2022, 11:06:24 am
content: Thank you. I believe the offer will be appreciated by all PCB designers who will be celebrating Christmas.

author: ansonbao
author_rank: Regular Contributor
timestamp: December 05, 2022, 04:47:37 am
content: Hi,bidrohininow you could enjoy the free protoype for Christmas theme design,details here:https://www.pcbway.com/activity/christmas2022.html
Ersa i-CON pico anti-static mod? - Page 1
Forum section: electronics / general

author: Karel
author_rank: Super Contributor
timestamp: December 03, 2022, 10:21:25 am
content: I'm considering to buy an Ersa i-CON pico but I would like to know if it's difficult to connect the iron to ground using a 1 meg resistor.Even if the powercord doesn't have a ground terminal, I'm thinking of adding a banana jack in the enclosure which is connected to the iron via a resistor.Before buying I would like to know if one of the wires in the cable between the station and the iron is connected to the metalpart of the iron.Edit: I found the answer here:https://www.eevblog.com/forum/projects/grounding-the-tip-of-an-ersa-i-con-pico/https://youtu.be/ZT8HsC8ewzc
PTF, feeder teach universal instruments  - Page 1
Forum section: electronics / general

author: loki42
author_rank: Frequent Contributor
timestamp: November 25, 2022, 11:44:40 am
content: So I'm attempting to run feeder teach for my platform tray feeder... but I've got no idea what first point I should teach is... normal is the end pin of the feeder but this is for the ptf conveyor... so I've got no idea. If I just teach each corner of the ptf slug it gives me a crazy value. Is there a way to know where the reference fiducial / location is? Has anyone done this? My pick points are currently fine in the ptf but the head is missing the parts on the conveyor.

author: loki42
author_rank: Frequent Contributor
timestamp: December 03, 2022, 01:09:34 am
content: I've got access to the universal manuals / voyager but I haven't found a section that describes the feeder teach setup process, I can pick up the teach slug onto the conveyor and then get into feeder teach but if I teach the corners of the slug as the on screen prompts suggest (bottom left then top right in the feeder location to pick location action) it doesn't give me a valid offset. I have worked out a currently working solution, but I would be keen to know the correct way to do this. I laser cut a copy of the PTF teach slug and tray, then covered the laser cut copy of the teach slug in white board marker. I then ran the teach product in NPI mode with board transport turned off. I measured the offset from the ptf nozzle mark and the high force head nozzle mark, then adjusted the pick position so it picked in the centre. So it works now but it's not as elegant as actually knowing how to do it correctly!
VL822-Q8 Datasheet USB 3.1 Gen 2 Hub Controller - Page 1
Forum section: electronics / general

author: mon2
author_rank: Frequent Contributor
timestamp: October 27, 2022, 01:04:29 pm
content: Hi. Not sure if this is the proper forum to ask but searching for a current and accurate datasheet for the Via Labs VL822-Q8 USB Hub controller.The public earlier datasheet on the internet is not accurate (no surprise here). The factory HQ in Taiwan is useless for support. USA office hides behind assorted firewalls. If you are lucky enough to phone and speak with anyone live, they want to know which extension is of interest. Makes perfect sense to me, first time calling, give us a name.Specifically wanting to know how to mate the VL822-Q8 with an external USB mux to allow for use with a Type C connector for upstream use. Downstream will be the CH569W + a mix of USB 2.0 HS devices (JTAG, UART, etc.).Unbelievable how difficult it is to give business to these offshore brands. Not expecting their product to be perfect as they had massive growing pains with their e-marker IC when PD was starting. However, believe they may be the least evil on defective IPs if we can get over this hump. They claim to have passed the USB IF tests. Already have vendors that can supply us the hub controller component.The Microchip hub devices are not available before we retire our business. Genesys Logic is more offshore flakeware where many are complaining on Amazon that the hubs based on their designs are not detected / working.Thanks in advance.

author: gnif
author_rank: Unknown
timestamp: December 02, 2022, 12:09:39 am
content: I was looking for the Q5 version myself and found this, covers the Q8 also.
Thermal conductivity of  thermal insulation pads - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: November 27, 2022, 11:26:53 am
content: HiPlease advise on the meaning of Thermal conductivity.The units are Watts per (Metre.Kelvin)So if Thermal conductivity is 1, then it means that if a one metre long copper bar of uniform area is in contact with a heat source at one of its ends, then that means that for every 1 watt dissipated, there is a 1 degree reduction in temperature at the other end of the 1 metre bar?And if its 1000W/(m.K), then that means that for a uniform area copper bar connected at one of a heat source, the source would have to dissipate 1000W to get a 1 kelvin drop across the length of that 1 metre bar?

author: jpanhalt
author_rank: Super Contributor
timestamp: November 27, 2022, 12:05:01 pm
content: Understanding the units is important, and I am one who believes it is particularly important to carry them along during calculations as a check. Did you bother to look it up for examples?https://en.wikipedia.org/wiki/Thermal_conductivity#/media/File:Thermal_conductivity.svgJudging from the plethora of recent posts, I am assuming you have a lot of time on your hands again or are you trying to solve real problems assigned to you by a new employer?

author: Kean
author_rank: Unknown
timestamp: November 27, 2022, 09:55:43 pm
content: Someone really needs to stop posting on forums and read some engineering books. That would be me, but even more so the OP.

author: ConKbot
author_rank: Super Contributor
timestamp: November 30, 2022, 01:39:05 pm
content: W/(m k) is in a simplified/reduced form that doesn't make intuitive sense. (W m)/(m^2 K) is the full form and is more intuitive, with distance on top, area on the bottom.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 30, 2022, 02:25:17 pm
content: If you get the units right without cheating, you got the calculation right, too. I often forget formulas or they are sometimes hard to find from a simple Wikipedia lookup, but units are easier to remember. Work out the formula from the units.Unit of length is m, and unit of area is m^2, so if you forget on which sides of division they are, resulting unit ends up wrong. Repeat until units are correct, and your temperature difference does not contain 1/m, m or m^2 in it; unit of temperature is just K. Not 1/K, for example!

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 30, 2022, 02:34:31 pm
content: recap younger dave...

author: Faringdon
author_rank: Super Contributor
timestamp: November 30, 2022, 06:09:36 pm
content: QuoteThanks for this.Yes, you can see that for every 1 metre you go along a bar of unit area........you loose a Kelvin for every watt at the source end.
Manufacturing SMPS boards with odd value resistors? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: November 26, 2022, 08:57:00 pm
content: Hi,Customer has sent us some SMPS to bring up.They are festooned with “weird” value resistors….few are E12 or E24.They are eg 499k, 249k, 13k7, 2k26, 6k04, 33k6 etc etc...Surely such resistors are a bad idea, in terms of cost, nil-stock-likeliness, etc etc?

author: wraper
author_rank: Unknown
timestamp: November 26, 2022, 09:00:41 pm
content: They are OK for feedback voltage dividers. Otherwise it's hard to justify something so specific.

author: Faringdon
author_rank: Super Contributor
timestamp: November 26, 2022, 09:16:19 pm
content: Thanks, do you agree they are more likely to be nil-stock than E24?

author: TimFox
author_rank: Super Contributor
timestamp: November 26, 2022, 09:25:35 pm
content: Those are popular standard resistance values for 1% tolerance, using the series E96.1% resistors are often more expensive than 5%, but the difference is less now than in my youth.They are readily available from the usual vendors.If 1% tolerance is important to the customer, you also need to see what tempco, etc., he requires.A handy chart:https://www.vishay.com/docs/28372/e-series.pdf

author: asmi
author_rank: Super Contributor
timestamp: November 27, 2022, 03:33:54 am
content: These are not weird at all. Nowadays it's not uncommon to see 0.1% resistors in pol dc-dc converters because modern ICs require very precise voltages.

author: Faringdon
author_rank: Super Contributor
timestamp: November 27, 2022, 11:09:32 am
content: Thansk, but this divider is on a PFC output...thats a intermediary rail......only 1% resistors required and E24 is fine.Also, they have been used on non-divider places.

author: TimFox
author_rank: Super Contributor
timestamp: November 27, 2022, 03:21:08 pm
content: If the 1% tolerance is required, then the values will be in the E96 series, which has three significant figures.The E24 series, used for 5% resistors, has only two significant figures.General-purpose 1% resistors are manufactured to the E96 series.If the difference between 499 k and 500.0 k is important to the design (as in a precision voltmeter), then the tolerance will be tighter than 1%.
Unwanted stencil aperture reductions by manufacturer - Page 1
Forum section: electronics / general

author: hcglitte
author_rank: Regular Contributor
timestamp: November 24, 2022, 07:16:09 pm
content: Hi,I'm having repeated trouble that my stencils are modified by the manufacturer - even though I clearly explain that there should be no modifications done.I have already done the correct size reductions and applied home plate design etc.As an example, too much reduction below a QFN ground can suck the part down and cause the other pads to squeeze out, causing shorts.Do you encounter similar issues? If so, how can one explain to the manufacturer that they should not do this?Should I enclose a second gerber readme file as well? Then the engineer would at least open it and read it in his/her gerber software.As of now, I think I need to ask for their production file and validate it before I say "go".This is a continuous issue for me causing headache(!)

author: Mangozac
author_rank: Frequent Contributor
timestamp: November 24, 2022, 10:10:34 pm
content: Quote from: hcglitte on November 24, 2022, 07:16:09 pmI'd certainly be doing that.

author: jayx
author_rank: Regular Contributor
timestamp: November 27, 2022, 03:03:50 pm
content: May be silly / obvious idea, but perhaps you should change stencil manufacturer? Ask the new one for a discount as they have no extra work with apertures modification.To be honest I'm surpriced that it's still expected stencil manuf adjust apertures. Surely it's not the same with the PCBs, it's not expected that PCB manufacturer change pads / tracks (at least without asking for permission).
SAKI AOI BF-Planet-X 2006 - Page 1
Forum section: electronics / general

author: Michael_N
author_rank: Newbie
timestamp: January 12, 2023, 10:42:51 am
content: Hi,I'm considering one these AOI's. Anyone has experince with this model? Pros and cons will be greatly appreciated.The machine will be used in a small EMS company.
Flux remover causes ESD damage? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: December 17, 2022, 10:11:00 pm
content: Hi,Would you agree, this flux-remover with brush applicator can cause ESD damage?...Eg , if brushed over chips....we have a board with what appears to be an ESD damaged LTC3721-1, after brushing over it with this applicator. The brush is on the end of a plastic holder...as can be seen..https://uk.rs-online.com/web/p/solder-flux-removers/2987921?cm_mmc=UK-PLA-DS3A-_-google-_-CSS_UK_EN_Power_Tools_%26_Soldering_%26_Welding_Whoop-_-Solder+Flux+Removers_Whoop-_-2987921&matchtype=&pla-338094537262&cq_src=google_ads&cq_cmp=10914490527&cq_term=&cq_plac=&cq_net=g&cq_plt=gp&gclid=CjwKCAiA7vWcBhBUEiwAXieItoe-NJq24bxvkWqM0WsfuVWHxM0W0hUXB8YSoTCI-WWMi-ETyhhASRoCJe4QAvD_BwE&gclsrc=aw.ds

author: Gyro
author_rank: Super Contributor
timestamp: December 17, 2022, 11:30:16 pm
content: What else can I blame?https://www.eevblog.com/forum/beginners/laying-pcb-in-plastic-box-caused-esd-damage/

author: jc101
author_rank: Frequent Contributor
timestamp: December 18, 2022, 05:57:00 pm
content: I often use something similar to clean flux after modifying prototype boards, never had any issue with ESD damage to any part. It's Electrolube Aerosol Flux Removerhttps://uk.rs-online.com/web/p/solder-flux-removers/2058449I generally given them a squirt with the flux remover that has a stiff brush in the end and a scrub, then a squirt with isopropyl, another brush towards to the edges. After that I give it a blast with compressed air to dry the board off. I have a small oilless compressor rather than canned air, cheaper in the long run.In fact, over the years, despite probably some pretty shocking treatment, I've never damaged anything with ESD that I've been aware of.

author: jpanhalt
author_rank: Super Contributor
timestamp: December 18, 2022, 06:15:12 pm
content: The datasheet doesn't say that particular flux remover is "esd" safe. Time to stop wasting time with hypotheticals, i.e., you can't prove something won't happen, and for Faringdon to do a controlled experiment. The fact a SMPS of his design doesn't work may be consistent with ESD damage, but there are a lot of more likely reasons.

author: coppercone2
author_rank: Super Contributor
timestamp: December 18, 2022, 06:26:10 pm
content: just get a ESD safe brush and don't use the thing on the can, its dodgy
Accelerated ageing tests of electronic products: do anybody know a good book etc - Page 1
Forum section: electronics / general

author: hilper
author_rank: Contributor
timestamp: November 24, 2022, 05:06:24 pm
content: HiAccelerated ageing tests of electronic products: do anybody know a good book etc ?BR

author: jonpaul
author_rank: Super Contributor
timestamp: November 24, 2022, 06:05:18 pm
content: FIT, MTTS, See reliability calculations, MIL HDBK 217most calculation is temp dependent according to the Arrhenius equationhttps://www.jedec.org/standards-documents/dictionary/terms/arrhenius-equation-reliabilityRule of thumb...every chemical reaction doubles with every 10 deg F increase in temperatureEG a lytics cap rated at 2000 hrs 85 Dec C will fail in 1000 hrs if running at 95 deg CJon

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: November 24, 2022, 06:49:54 pm
content: Quote from: hilper on November 24, 2022, 05:06:24 pmAre you fluent in German?

author: hilper
author_rank: Contributor
timestamp: November 24, 2022, 11:05:29 pm
content: hi if the german book is good - I will be a fast learnerBR