Anyone know about CAD files or how to have custom machine shop work done?

[Rick Lee]

I need an amp part made. I have one piece, but need a second one, which is surely not worth the minimum job size of any machine shop. Since no one else makes these and Marshall stopped making them 35 yrs ago, I wouldn't mind ordering a bunch and then selling the extras on eBay to recoup my outlay.

I went to eMachineShop.com, but they need a CAD file, which I absolutely do not have the skills to create. Their free software might as well be written in traditional Chinese. I cannot figure it out. They want $150 just to create the file for me, before anything else. I have one piece I can send to anyone and just need them to make another identical one or, if it makes it more worthwhile, another 20 or 30 of them. It's a small piece of stainless steel, but its finishing is nicer than anything I could do with a piece of hardware store steel stock and a drill and Dremel. How to do this?

[fanaudical]

I'll do the CAD work for you and supply files (just to help a guy out). I think I can connect you with a couple of different shops that can make those for you. I'll PM you a shipping address.

[stomachmonkey]

Not a difficult shape to work out with a set of quality calipers.

Or.

Put it on a piece of paper.

Trace the outline as tight as you can get it.

Scan it with a flatbed.

Drop it into a raster to vector convertor like this.

https://vectormagic.com/

Dump that into a simple CAD utility and do an extrusion.

Export CAD file.

Give file AND the single piece to machine shop and I'm sure they will tweak any minor stuff it needs.

EDIT: or send it to fanaudical.

[Rick Lee]

Thanks. Going in the mail tomorrow. Pelican comes through again.

[unclebilly]

I was in a jam at Christmas time to get some fairly complicated parts made for a downhole tool. I used Xometry for the first time.

They were expensive but I got my parts in 10 days over Christmas. All of the local shops capable of making this part were 4-6 weeks out due to the holidays and work load. These had wire edm slits 0.005” - 0.007” wide so not any shop could do this.

Upload your cad file, select the material, get an instant quote with various cost options depending on your urgency.

https://www.xometry.com/?utm_term=xometry&utm_campaign=PB:G%7CNT:SN%7CAN:Manufacturing%7CCN: Branded&utm_source=adwords&utm_medium=ppc&hsa_acc=3789459769&hsa_cam=608070446&hsa_grp=67613041575&hsa_ad=425504589745&hsa_src=g&hsa_tgt=aud-300504215006:kwd-297018084385&hsa_kw=xometry&hsa_mt=e&hsa_net=adwords&hsa_ver=3&gclid=CjwKCAiAioifBhAXEiwApzCztlTodI1ONfTbqgg7C9ei uUlBj-Vqya3OG8L2G2OXWQr_M44K2rdSVBoCQKYQAvD_BwE

[Captain Ahab Jr]

If that is a flat part with just countersunk holes I'd be inclined to have it waterjet or laser cut and then the csk surface done using a pillar drill

For 2D profile cutting a DXF file of the profile curves is used instead of a 3D CAD model

If you want a run of 20-30 parts the above manufacturing route should work out a lot cheaper than making using CNC milling

[Rick Lee]

Thanks. I mailed it to Fanaudical today. I'm sure he'll know the best course of action when he has it in hand.

[fanaudical]

I'll be on the lookout for that in my mailbox.

I have used Xometry for some metal 3D printing and small-run parts. I agree that water-jet or laser cutting flat stock may be the way to go on this item (assuming it is indeed flat and thin - can't quite tell from the photo). I'll post screen shots...

Just out of curiosity - Where does that fit on the amp? I'm kinda familiar with older Marshall amps, but don't recognize that piece.

[Rick Lee]

These are chassis straps for a 4010. It's a JCM800 50w 1x12 combo, a rare bird. Far more common is the 2x12 version of this amp and those chassis straps are cheap plastic that always crack.

Here's the current one. Obviously, I can reuse the existing straps. But this cab, up close, looks like it was dragged behind a truck.


So this is the next one and I want to use something a little different, but still somewhat original looking. Also, I plan to sell the old cab and those original straps will help the value.

[Rick Lee]

Truth be told, I could just as easily use $.50 washers. But that one custom chassis strap I have looks like a work of art and so I want to match it.

[stealthn]

I would have tried a local technical college, my son is milling a Sterling Engine from scratch for his Engineering classes.

[Yorkie]

https://www.emachineshop.com/ Never used them but some in the old motorcycle world swear by them. Cheap and easy.

[dw1]

There appear to lots of skilled CAD guys on this forum - and I'm one if them.

If you give me the overall length, thickness and a good "straight on" photo, I can scale the dimensions from the good photo, generate the CAD file you need and e-mail it to you. PM me if you are interested.

Did the vendor you want to use for this express a preference for CAD file format (SoildWorks, Autocad, or one of the "neutral" file exchange formats like ACIS, SAT, DXF, IGES, etc.)?

Btw, I am a mostly-retired technical guy, and in working on a similar team on a recent projects it became obvious that there are few things in the world more powerful that bored retired nerds.

[Rick Lee]

Thanks, but I already mailed it off to Fanaudical and, while measured every bit of it with digital calipers, I only entered those numbers into the eMachineShop template and did not write them down. They emailed back that that's no good and they need a CAD file, then sent me a link to their free software, which is just beyond me. This is the link to it:

https://cad.emachineshop.com/#/

[Rick Lee]

Finished the build today and used the old chassis straps, but I will replace them when I get some more made by a machine shop.

[fanaudical]

That looks very nice! I like the wood finish.

I found the package in my mailbox this afternoon (along with your contact info, Rick). I have a few things to and then will try to get that modeled tonight or tomorrow. Will post screenshots / pics here and will e-mail you CAD neutral files.

[Rick Lee]

Thanks so much.

I made a mess of this, but you can't really see it in the photo. Really hard to measure this stuff while sliding that 40 lbs chassis around and trying to use masking tape, a pencil and calipers. I'll have to dowel the holes and redo eventually. But the chassis straps should cover the trauma up.

[908/930]

Rick Lee, Possibly Fanaudical can confirm, but that part really looks like anodized aluminium to me and not stainless steel.

[stevej37]

It's in nice shape.

[fanaudical]

Rick - Here's a screen shot of your part:



I'm measuring 5.00 inches between center of holes, have rounded thickness to 3/16 thick, diameter of the ends of the dog bone are 0.875, and left 0.485 across the thin part in the middle.

I did find that the original part was a bit "lazy" with the tangent blending around the periphery. I fixed that in the CAD model. You'll want to make two from the CAD model so they match.

This orignal part is carbon steel (magnetic and has rust forming). The face with the countersinks has been grained and is close to a #4 brush finish. The sides are milled (piece looks to have been bolted to a table at the ends and then milled around the outside - CNC, 3 passes). The sides are not as "clean" as the grained face.

I have already submitted an RFQ to emachineshop.com with the STEP file and your contact info, Rick. I specified qty 30, 304 stainless steel, buffed satin finish on the appearance face and sides. You should get an e-mail from them. (They didn't have an option for grained finish, buffed satin is potentially more economical.) I'll e-mail you the STEP file and you can submit an RFQ for different options / quantities if you don't like what they have to say.

Let us know how that turns out!