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Martin Reynolds
03-27-2009, 2:25 AM
I do a number of PCB projects, but if the mechanicals are wrong, the prototype fee is wasted.

So I have started cutting mechanical prototypes in acrylic. I can go from the layout program to Corel.

Here's a sample:

http://mrtn.smugmug.com/gallery/7723670_gfYuo#499170858_rSPYx

Useful to check mounting holes, clearances and connectors. If you have people who do PCB work, they might appreciate this as a quick validation.

Frank Corker
03-27-2009, 7:43 AM
I think that's a great idea! No mistakes to be made and a simple check too. Oh by the way Martin, any chance you can update your profile so we can see what type of machine you have and where you are?

Richard Rumancik
03-27-2009, 12:46 PM
I thought I could get more business doing this type of thing but haven't had as much interest as I hoped. One issue is that PCB prototypes are often very fast turnaround. So once the electrical design is complete, they want to order it. And in 2 or 3 or 5 days (depending on how much they want to spend) they have finished boards in their hands. If attempting to get into this market you need to figure out how to get into the design sequence without slowing down the whole process. It may take a bit of "education" to convince a new customer that it will benefit them and be cost effective.

The board design packages use unique file formats. Martin, what kind of CAD file do you get and are there any conversion issues in getting it into CorelDraw?

Dan Hintz
03-27-2009, 1:39 PM
Any good PCB package will export in DXF or DWG format, though I agree with Richard's assessment that turn-around time is a real issue with this market. If I'm willing to pay a premium, I can get 1-day turns on boards. If the board is expensive enough (muilti-layer, tight trace clearance), I'll be extra careful to measure twice.

That said, such a service may have helped me today (of all days!). I just tried to assemble a 4-layer PCB and found out the stand-off posts were a #4 screw... I designed the board around a #2 <sigh>. Luckily I gave enough clearance around the mounting holes, so I had the machine shop drill them out another 30 mils. Stupid boneheaded move, but the entire cost of the 25 PCBs and components was in the $700 range... it would have to be a pretty inexpensive service to warrant the extra step.

Martin Reynolds
03-27-2009, 2:01 PM
Sometimes, I have to dump the dxf through Turbocad. The trick is setting the colors right, and eliminating double cutting on the outline.

My proto runs are usually about $200 - $300.

Here's a sample of what we do. Laser plastics, UV LEDs and microcontrollers. The board has to fit inside the ship in the video, so clearances are important.
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[URL="http://www.youtube.com/watch?v=kLYZ8LRTO0I"]http://www.youtube.com/watch?v=kLYZ8LRTO0I (http://mrtn.smugmug.com/gallery/7707642_WZXs4#498201594_DYE27)http://mrtn.smugmug.com/photos/498201594_DYE27-M.jpg (http://mrtn.smugmug.com/gallery/7707642_WZXs4#498201594_DYE27)

Martin Reynolds
03-27-2009, 2:03 PM
Actually, Dan - you could have cut your own!!!

Dan Hintz
03-27-2009, 2:59 PM
Actually, Dan - you could have cut your own!!!
I offered to engrave our company logo (my 8-5 job) for free into a new product that was in plain sight on television (SuperBowl) but was shot down for unlisted reasons. I couldn't charge as it would be a conflict of interest, but they wouldn't even do it for free! I often question what goes on at this company...