Looking for US shop/fab for small (~50 pcs) run of copper bar w/holes,taps - Page 1
Forum section: electronics / general

author: wb0gaz
author_rank: Frequent Contributor
timestamp: May 11, 2025, 02:47:00 pm
content: Have an upcoming project that would be built in part from soft copper bar (approx. 1/4" square cross section, each piece about 1" long) and has two 3mm thru holes and two M3x0.5mm screw holes tapped on one (of the 1/4x1" flat) side.This would be done in US (no appetite to tackle the current tariff drama) and is cost sensitive (hobby application) so not looking for an aerospace project. Would be open to a home machinist/hobbyist that would like to take this on.Any suggestions as to a fab/shop that could take this on (if so, name or contact info appreciated, PM if you wish.)Thanks,Dave

author: TimFox
author_rank: Super Contributor
timestamp: May 11, 2025, 06:11:24 pm
content: Quote from: wb0gaz on May 11, 2025, 02:47:00 pm"Send Cut Send"https://sendcutsend.com/materials/copper/does copper up to 0.25 inch thick.

author: wb0gaz
author_rank: Frequent Contributor
timestamp: May 11, 2025, 06:40:24 pm
content: Thank you - there is extensive information on their website and it appears my requirement is at least potentially compatible with their mechanical requirements. Finding (and learning) a suitable design program is another story, but you've given me a starting point!Dave

author: TimFox
author_rank: Super Contributor
timestamp: May 11, 2025, 08:31:43 pm
content: Quote from: wb0gaz on May 11, 2025, 06:40:24 pmThey accept standard CAD files. Since I didn't have Autocad or equivalent, I sent them a carefully-dimensioned drawing and (at an extra one-time cost) they converted it to an appropriate file.

author: wb0gaz
author_rank: Frequent Contributor
timestamp: May 11, 2025, 08:44:02 pm
content: I think this will be the nudge to get me started on Freecad (I've had a Axiom CNC machine since last fall but not learned Freecad (I chose that one as it would let me write small software programs to generate 3D designs in the future) to put it into service yet - it can't do the hole tapping but otherwise I figure I can learn-by-doing this time around, with sendcutsend handling the "production" and handling the tasks with hole tapping that fit their other criteria.)Thanks again!

author: dcarr
author_rank: Regular Contributor
timestamp: May 11, 2025, 09:02:13 pm
content: Consider 2D CAD software for this task as well. I find it has a lower learning curve, and it’s ideally suited for this kind of part. QCad is a good free option but there are many.

author: coppercone2
author_rank: Super Contributor
timestamp: May 12, 2025, 12:07:53 am
content: 50 pieces is not that much I think you can do it yourself. I would use the proxon chop saw, a disk sander (to true the edges), drill press (after manual layout with caliper and punch) and manual tapping. Buying a M3 drill that is angled for copper would help. I built my own bus bar projects, is not that bad. I think the key for copper is to get fresh taps. Or to use tellurium copper if you can (less conductive but its a bit easier then electrical copper). That is 50 cuts and 100 holes1/4 inch is easy. Deeper holes in electrical copper get harderMmm I need to try those 135 degree drills. I have 90 degrees for plastic and 118 standard. Supposedly 135 is better for copper and also very hard materials like stainless steel. I spent 20 min reading and it loooks like opinions are all over the place for thisI guess I am going to have to try it

author: wb0gaz
author_rank: Frequent Contributor
timestamp: May 12, 2025, 11:39:34 am
content: Somewhat "back to the drawing board" at this point ---A rep at send cut send was kind enough to engage a dialog via e-mail on the project. In a nutshell, the minimum size (of 1/4" thick copper sheet) they can accommodate during the tapping stage is slightly less than 1 x 1-1/2" inches (much larger than the need). I suggested an option would be to make copies of the (small) layout in a grid on a larger piece of material then cut that into sections (like a PCB would be panelized); they said their process did cutting as a first (or one of the first) steps would be done before the tapping stage, so a panelized approach was not possible. Unfortunately, that precludes use of their service, which otherwise would have been a good solution overall. A possibility remains that they could make a grid of copies on a larger sheet, but that would leave me with a second task (subdividing the copies), which would entail finding another service to do that step.I'm not geared to take this on internally - there would be tooling and expertise requirements, both which would be stranded following completion a single small task of this scale. Hence, my original posting remains unsolved.Thanks for the discussion and ideas!Dave

author: Poroit
author_rank: Frequent Contributor
timestamp: May 13, 2025, 07:38:54 am
content: G'day wb0gaz,You require 1/4" x 1//4" x 1" Copper Bars.I see the Square Copper bar is ready available so why not contact some of your local Sheetmetal/Toolmaker companies.https://www.onlinemetals.com/en/buy/copper/0-25-copper-square-bar-110-h02/pid/1659I used this company many times for similar small jobs in Oz , so I would be surprised if there were not similar companies in your part of the world.https://www.sheetmetallasercutting.com.au/services/laser-cutting/

author: jduncan
author_rank: Regular Contributor
timestamp: May 13, 2025, 12:06:12 pm
content: Even with the tariffs (now only 30%?), your best option is JLCCNC or PCBway. Even a hobbyist in the USA is going to have to charge you way more for this to be worth their time.

author: TimFox
author_rank: Super Contributor
timestamp: May 13, 2025, 07:35:44 pm
content: Tapping copper is doable, but a pain in the neck.Have you considered counterboring a through hole, then pressing a press-fit nut, instead of tapping the copper?

author: thm_w
author_rank: Super Contributor
timestamp: May 13, 2025, 09:12:13 pm
content: https://www.xometry.com/

author: eugene
author_rank: Frequent Contributor
timestamp: May 14, 2025, 04:02:08 pm
content: In the medium size city I live in there are dozens of machine shops that would not consider 50 pieces too small of a job. Have you tried calling around and getting some quotes? They will required a detailed drawing, but your part sounds simple enough that you could probably draw something by hand with pencil and paper just to get quotes.Machining and drilling copper is pretty easy. If you're willing to accept 1/4" bar stock cut to length and faced, then it might not be too expensive.

author: jduncan
author_rank: Regular Contributor
timestamp: May 14, 2025, 04:54:23 pm
content: Sure, if it's 50 pieces of $100+ parts.At the $5 OP probably wants to pay for these, there's more admin cost in quoting than money in the job.

author: eugene
author_rank: Frequent Contributor
timestamp: May 14, 2025, 07:43:15 pm
content: You must deal with different machine shops than I do.In any case, quotes are free.

author: wb0gaz
author_rank: Frequent Contributor
timestamp: May 21, 2025, 12:52:04 am
content: Thanks for the replies and discussion - I'd been out of access to eevblog.forum for about a week, so now catching up.The problem of small production run probably makes creating tooling no-go as far as a commercial supplier would be concerned (NRE costs across 50 pieces.)A discussion with a friend about this problem led to an interesting DIY thought - something that would allow a drill press to perform a tapping operation. He described a device which when driven by a drill (rotation) transformed that motion into a series of rotary impacts. Unfortunately, I didn't think to ask for a brand or product name. Nonetheless, a drill press (and suitable way of holding the workpiece in position) would be a step towards reducing the risk of tap breakage.

author: Weston
author_rank: Regular Contributor
timestamp: May 21, 2025, 02:05:03 am
content: Look into thread milling. M3 threads are a bit small to cut on a hobby level CNC machine, but it's doable.Do you need a nice surface finish on any of the edges? or is this as simple as cutting copper bar with a bandsaw and putting 4 holes into one face, two of them tapped?Do you *actually* need copper? Aluminium is not that much worse and copper is a lot more expensive and more difficult to machine.Either make it out of aluminium and send it out to some Chinese CNC service or check out local makerspace type places. I would offer but I am currently in the process of rebuilding my CNC machine.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 21, 2025, 03:51:02 am
content: The advice about going to China in spite of the tariffs has merit. I don't know how they do it, but their cost after tariff is likely to be below the cost of the raw material here in the US.If you still want to go US you might try Desertec Engineering (https://desertec-engineering.com/) It is a small operation operated by my son out of his garage. I can promise that he does good work. Don't know how his pricing compares to other shops, but am sure that it isn't cheap. As others have mentioned many small shops will work with anything from napkins on up, but they charge for their time in developing proper drawings and charge US labor rates in doing so.

author: wb0gaz
author_rank: Frequent Contributor
timestamp: May 21, 2025, 02:17:55 pm
content: Weston - the spec of copper was mostly to set an upper bound on project complications (that is, if I could solve this for copper, that would imply a roadmap for aluminum.) That said, the piece I describe was to be soldered to other parts of a housing, so copper would make that easier.CatalinaWOW - thanks so much for the referral - I've got some homework to do (creating a usable mechanical drawing/template, to allow a fab shop the basis for a quote); desertec (absolutely no qualms about son-in-garage idea!) perhaps could guide me as to the preferred form of a specification.Thanks to you both, more helpful ideas and points to consider!Dave