Fooling around with Solidworks - Page 1
Forum section: electronics / projects

author: Unknown
author_rank: Unknown
timestamp: July 31, 2012, 05:08:05 pm
content: After themarvelous work by robenzI tried to design a Kelvin clip of sorts for my own amusement. This is not intended for production, it is just a mental excersise and I have no idea if it would really work in real life. As I said I was just fooling around.Design criteria- Absolutely minimalistic design- start from scratch, do not use pomona clips etc.- simple to make using workshop tools- no mechanisms, use the flexibility of the material (which is intended to be teflon btw)- current capability greater than pomona clipsAs you can see from the criteria this is an exercise, not an actual design. For the real deal go here:https://www.eevblog.com/forum/projects-designs-and-technical-stuff/video-of-making-the-ultimate-kelvin-connection-%28major-hacking-of-a-pomona-clip%29/

author: robrenz
author_rank: Super Contributor
timestamp: July 31, 2012, 07:04:11 pm
content: Very nice work and a great idea HAL-42b! I think Delrin (Acetal), PET, or Ultem PEI may be better candidates for the plastic. I did my design to be the most practical way of making a few for myself. If I was going to make a few thousand my design would be different. Don't stop here, make some chips and a video.

author: Unknown
author_rank: Unknown
timestamp: July 31, 2012, 09:06:04 pm
content: Quote from: robrenz on July 31, 2012, 07:04:11 pmThank you! You inspired me.QuoteTeflon too mushy for frequent handling right? It would loose its springiness after a few times but excellent dielectric properties otherwise. As you say, another plastic may work better, needs a test.QuoteI don't have a workshop of my own, which is a shame, so no chips for this one. Used to have free reign over production machinery at the old work but at the new place it is paperwork only. Besides, I have something more substantial in the works which will require not only making of chips but also some advice from an experienced machinist who also happens to know a thing or two about electronics

author: nukie
author_rank: Frequent Contributor
timestamp: August 02, 2012, 12:22:14 am
content: Hi, it's pretty cool. How many hours of work is this? Trying to learn to use it myself.

author: Unknown
author_rank: Unknown
timestamp: August 02, 2012, 06:25:02 am
content: Quote from: nukie on August 02, 2012, 12:22:14 am3 hours or thereabouts

author: ivo.knutsel
author_rank: Newbie
timestamp: August 26, 2012, 08:31:53 pm
content: This looks really nice. Have you considered having the plastic part made by shapeways or ponoko ?I have been modeling some stuff in sketchup and i am curious about alternatives. People keep mentioning Solidworks.

author: Unknown
author_rank: Unknown
timestamp: August 26, 2012, 09:35:45 pm
content: Quote from: ivo.knutsel on August 26, 2012, 08:31:53 pmNot really, I haven't even made a prototype. Unless I make a prototype and prove it to be really useful and long lasting in use there is no point in offering it in any shape.QuoteI am a big advocate of SketchUp. I use it every day since version 2.3 long before google bought it. One of the best computer programs ever written. There are a few of my doodlings with SketchUp on this forumhere is oneSW is too cumbersome to design with but otherwise excellent for preparing a design for production.

author: free_electron
author_rank: Super Contributor
timestamp: August 27, 2012, 12:55:43 am
content: Sketchup seems to be owned by trimble now...One question i can't find answers to : does sketchup have the ability to read and write step and stl files ? And how good is it at that ?I'm looking for a good program to do mechanical design ( injection molding , but protos will be stereolithography )

author: robrenz
author_rank: Super Contributor
timestamp: August 27, 2012, 01:14:17 am
content: Tough to beat Solidworks if you can justify the price and yearly support. I am a one man operation and I gladly pay the $1400.00 yearly support. But my work is mainly mechanical.

author: Unknown
author_rank: Unknown
timestamp: August 27, 2012, 01:54:42 am
content: SketchUp won't do step .iges .stlPro version will do .3ds .dwg and .pdf however and very satisfactorily.It is not a good choice for mould design. The main thing about SketchUp is that it is designed to be a direct bridge between your mind and the computer environment. As such they tossed all gimmickry and concentrated on plain unobtrusive workspace which is all about unobstructed "flow" of the design process, it is one of the best user interfaces ever made imho. But it is for designing and fleshing out an idea, not for drafting.One thing to keep in mind is that SketchUp does polygonal modeling only, therefore curves and complex surfaces are approximations. Not necessarily a bad thing actually, I've done my graduation project with it (sports venue as part of a university campus).So SketchUp is for designs that are more out of the blue sky so to speak. Solidworks et. al. are for structured designs with dependencies and hierarchy .Once you are done in SketchUp you then go to a more bells and whistles program to make something that can be manufactured.Quote from: free_electron on August 27, 2012, 12:55:43 amVery sad. I was expecting google to port it to Linux and open source it. This will kill the community and the warehouse. They murdered it.

author: free_electron
author_rank: Super Contributor
timestamp: August 27, 2012, 03:15:45 am
content: I really like Rhino. Very intuitive to use and it reads and exports almost any 3d format out there.To design the case i first have created step files for all elements. There is the multiple circuit boards ( case needs display cutout , molded studs where threaded copper inserts will be pressed so i can screw in the board, battery clips, door , several complex , to be machined, metal parts. I have all that stuff available as accurate step files.To do the case i have placed all the components in 3d space. I now want to make a blob around this and start sculpting. Eventually i will make 1 slice as to get the top and bottom shell. And then there is a rubber overmold ( a kind of sleeve ) where the entire case goes into ( kinda like the holster on a fluke multimeter )So i need a tool where i can easily sculpt the outer shell and then flip to a kind of add/suntract mode to make remove bits and pieces inside the shell.At a certain point i will hand it off to a real company that does the final adjust for the mold making.However i want to reduce the amount of man hours they need to spend tweaking it as they charge per hour.

author: Unknown
author_rank: Unknown
timestamp: August 27, 2012, 09:55:05 am
content: You need Solidworks then.

author: djsb
author_rank: Super Contributor
timestamp: August 27, 2012, 10:18:15 am
content: I use Alibre Design Pro. It's reasonably priced and works well with Altium Designer. I have access to Solidworks at work but only use it occasionally. It's too expensive for me to buy my own copy.David.

author: Unknown
author_rank: Unknown
timestamp: August 27, 2012, 01:06:56 pm
content: Quote from: djsb on August 27, 2012, 10:18:15 amNever used Alibre. It is like SW by the looks of it. Got to try it some time.

author: dfnr2
author_rank: Regular Contributor
timestamp: August 28, 2012, 02:40:04 am
content: @free_electron. Sketchup cannot understand STEP files. There are third party plugins for this, but they don't work well.Take a look at SpaceClaim. It's kind of like Sketchup on steroids. It supports a large number of 3D formats, and can read in broken 3D files (like the STEP files exported by Altium) and write back good files. I have been using it to clean up Altium STEP files for my mech. colleagues. It's not a parametric modeler like SW, but is really handy at creating shapes. It's not exactly cheap, but is cheaper than SolidWorks and its brethern, though somewhat more than alibre.

author: free_electron
author_rank: Super Contributor
timestamp: August 28, 2012, 12:34:47 pm
content: I have a demo of alibre right now. Strange program. Very counter intuitive.Like i want to draw a rectangle. No way to enter length and width. Something you can do when drawing a line ...It is also annoying that there is only one viewport. In Rhino i have 4 ports. And i can grab an edge and drag it in any of the ports. Grabbing an edge highlights it in all 4.I think alibre may work well when you have all exact coordinates. I don't have any coordinates.I have a maximum outer dimension , and then i have accurate step files that show me where i need a hole , where i need a stud and where i need a cutout.So i need a visual tool where i can place a cylinder , align it with an existing hole in a placed object , add a bit of material here , remove a bit there. All visual and without 'numbers' or calculation on my part. I simply don't have numbers. Thats what the program needs to give me. I start with known elements that come from various cad programs. There is 2 circuit boards that have accurate models including the parts that go on them. There is a touch display (psp style) , there is a wound coil ( that needs to fall in a circular slot i have to create , the coil will drop in and will then be epoxied in the slot ) there is a sideways opening where pogo pins will be inserted so i can slide in a lipo battery pack etc.I don't know all the exact placements yet , apart from what is my maximum working volume and the shape of that volume , and where the display needs to sit on that volume.Rhino works really well for that. I can simply draw two basic objects ( cylinder, ball, torus , come , trapezoid , cube ) and say : execute an 'or' or an 'xor' between these . And it builds the element on the fly.My only fear is that , at the end of the design , people will say , oh rhino .. Thats a modeler , we can't use those files.Years ago i played with solidworks and i found that very intuitive. I liked the fact that you could place a hole in two parts and tell the tool : these are linked. Move one and hole on the other part follows. SW understood that these need to line up. But right now SW is too expensive... Rhino is 1000$ that is acceptable. Alibre is also 1000$ but works 'weird' for what i need to do. Other tools are problematic because they cant read or write many formats. In the end i need two files : a step file and an stl file.The step file so i can reimport in altium to verify everything. The stl file so the thing can actually be made. I'm going to use a 3d printer , but not the extrusion technology like the makerbot. It's a powder based machine as the mechanical strength is far superior to that of an extruder.

author: robrenz
author_rank: Super Contributor
timestamp: August 28, 2012, 01:07:38 pm
content: Find out who your Solidworks VAR (value added reseller) is in your area. Tell him what you are trying to do and ask if he will give you a limited time license to evaluate and do this particular project. You only need the standard package. Also keep in mind that if you get to the purchase stage that the yearly support price goes up with each higher level of SW. The standard package costs about $1400.00 for yearly support only. When you buy it I am pretty sure you will pay the software package costplusa year of support up front.You might as well get used to putting initial dimensions on what you are doing. Sooner or later it is going to happen. You can build your models so they are driven by the underlying/mating part dimensions so any changes will ripple into all the other mating parts. Sounds really neat and it is, but you better really know what you are doing or you can end up with a mess that is just about impossible to fix.

author: ivo.knutsel
author_rank: Newbie
timestamp: August 29, 2012, 05:37:44 pm
content: Quote from: HAL-42b on August 26, 2012, 09:35:45 pmI'm using Sketchup more and more because of using and expanding EagleUphttp://eagleup.wordpress.com/. Aside from the new SketchUp owners I'm a bit worried about tolerance issues described here :http://forums.sketchucation.com/viewtopic.php?f=15&t=25175&p=219030&hilit=precision#p218989. Have you ever bumped into this ?

author: Unknown
author_rank: Unknown
timestamp: August 29, 2012, 06:21:56 pm
content: Yes I've run into dimension problems in the past but these days I simply choose an appropriate unit so to avoid decimals if possible. If working on something extremely small I might choose microns instead of millimeters as a base unit.Wasn't aware EagleUp btw. Thanks for that.