PCB / Foam and RPM on the nomad

Hi all,

I am looking at the nomad for my personal shop CNC. I need to do reliably and consistently PCBs and I might need to prove the PCB topology. I also need basic foam carving for some molds and some edge cases aluminium.

I see RPM at 10000 which seems low for some woods, PCB and foam. Am I Wrong?

Is proving of work offsets (z prove) and maybe PCB height possible with custom software but with built in controller?

Any opinions welcomed!

We have a collection of customer projects here: https://carbide3d.com/projects/

Wood can be cut with great precision and a wonderful finish, foam cuts quickly and efficiently, and aluminum cuts well:

You would need a depth probe and 3rd party software (bCNC has this feature) to probe and then adapt a G-Code file to a PCB blank.

I was going to reply earlier, but decided wait. The PCB example in the projects page (the thread referenced from the project description page) has lost its images, so is less useful than it might be, but the text is clear.

I will throw in on PCB’s as that is one of my semiregular uses (maybe 1 to 2 dozen a year on the Nomad). The machine is quite good for doing a PCB, but, like any PCB milling process, requires a little setup.

Benefits:

Fast, compared to ordering out. The other day, I ran a medium complexity, single sided board for an industrial controller. Three power busses (so a lot of serpentine traces on a single side, even with through hole components to routing paths), a 20 pin processor, a pile of discretes, power drivers, connectors for sensors and drives, and so on. Size 80X120mm. First shot came out fine, other than two design issues (one a data sheet misread on a pull-up, the other a noise pickup issue you don’t find until until you install. No issues on the bench). Would have been 2 to 6 weeks to order a 4 layer board that would do no better. From firing up Eagle (I have been using it since V2, when it was the only option that was economical and non-proprietary) to the finished board was less than three hours, including drilling. Two of those hours would have been there if I had a commercial service do the fab.

Drilling will be dead on (a challenge with other prototyping methods), and you can choose the appropriate sizes without being bound by the board house (some have… interesting… selections) or paying a lot more for non-rule sized holes.

Drawbacks:

No silkscreen or conformal coating layer.

Need to prep the board before soldering (clean, tin if desired, and so on).

Two sided requires extra care.

Dust control is needed (this is ANY machine, really)

Overall, the Nomad does a better job than any of the other machines i have used for isolation-milling PCB’s.It is more accurate, more precise, and more repeatable than the other current/recent machines I have used (at work, I have no say in what is purchased, so we have a collection of incompatible machines, none of which perform well), and the one dedicated PCB mill I have used did no better, despite having automatic Z probing/compensation.

I can run traces at 0.15mm, with separation of 0.2mm, consistently. For most things (0.75mm scale, trace plus seperation), I use a 90 degree “mill/drill” bit with a 0.05mm tip, as it is stronger the a sharp point graver (less likely to break, stays sharp longer) at 100000RPM and about 175 to 200mm/min feed. I use a narrow angle (20 degree?, IIRC) for finer work (to the 0.3mm scale), as the narrower angle makes it less sensitive to minor variations in the board surface. I really try to keep at the 0.75mm scale, as the success rate is near 100%. It drops at finer scale, most often due to me doing something dumb (dull tool, bad zeroing, etc)

Using the standard Carbide sender (Carbide Motion) is fine for most things, if the copper clad stock is uniform and the mounting is uniform. You can use an alternate sender (I make no endorsements, but there is discussion in several places on this forum) if you need to do surface probing, and several people have had really, really fine results. I tend to design around the process if I can, to avoid the need for any more involved software.

I generally mill a shallow pocket in the waste board before running PCB’s, with a clean alignment point so I can butt the stock in to location. I use an adhesive to hold stock in place (3M 467MP transfer adhesive) that is very thin, very uniform in thickness and holds really, really well. I typically end up within 0.03mm of dead flat, using good quality FR1 (phenolic type… no fibreglass dust, no texture at the surface). The biggest issue is getting the finished board released from the waste board. I need to take care on double sided, as the adhesive holds better than the bond to the board, so if I am not careful, the copper will be pulled free of the bottom side (really annoying after cutting the second side)

I hope this is the type of information you are looking for. I am not the hardest user of the Nomad, I do use the crap out of it, and have had no significant issues (mine is an early Pro, so there were a few teething issues that C3D worked through with me… A couple were me, one was the machine)

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All of those get done often on the nomad. Consider your use case carefully though, the SO3 can do all those things as well, but it’s a larger, open machine. That may be a benefit to you, it may not. If you’re looking for minimum learning curve, nomad all the way.

The SO3 is quite a bit less expensive, but does have a steeper learning curve, and requires a lot more careful setup to be ready for PCB’s.

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Thank you all for your messages,

I appreciate the detailed review. I am looking for a closed machine really. Is Z Probing an option on the Nomad?

Whats An SO3?

Probing yes, built in probe. Autoleveling, not integrated, but can be done with the same software you use now to do it.

SO3 = Shapeoko 3

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Got it!

I like the SO3 a lot but the lab is not ready for an open design…

My worried is actually the 10k rpm… i thought it was a bit slow for foam finish and for PCBs but it seems I am wrong.

Thanks a lot for the info!

z probing requires software other then the standard Carbide3D sender. It has been discussed in a few threads over the last few years, and @WillAdams mentioned bCNC as an option. IIRC, the GRBL control board does provide support. Tool length probing is built in, and quite repeatable.

An SO3 is a Shapoko 3. It is a larger machine, is a kit, allows the use of arbitrary spindles (the design intent is one of several trim routers, and higher power/precision spindles can be obtained). It uses belts, rollers, and vee rails, so the accuracy is a lower than Nomad (but can be quite good… figure 0.05mm or better repeatability for the Nomad and maybe 0.2 or 0.3 for the SO3, 0.15mm absolute accuracy for the Nomad, maybe 0.5mm for the SO3). The footprint is larger.

*** opinions follow, for which no money changed hands. Ranting may be embedded ***

In my opinion, the Nomad is a better machine for PCB’s, the SO3 is is a better choice if you need a large footprint for general milling, the SO3 for speed (due to the higher power spindle), and the Nomad for precision and repeatability with smaller milling jobs.

Looking at the other machines in the price range (<$US3K-ish), there doesn’t seem to be much t compete with the Nomad for precision, and in it’s price range, the SO3’s are at least as good as the competitors. THere are a lot of import machines, and having seen a few in the wild, they do not begin to compete. I ran across one about a year ago that played the game of naming compatibility with someone else’s software (no names here, but it was not C3D’s software. I wouldn’t be surprised if there were imports that did claim that, though) that apparently was… incorrect. Similar to the knockoff Saleae logic analyzers that don’t actually perform in practice (got stuck with one at work. Then we bought the real deal to get some work done as the knockoff didn’t meet spec).

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Thank you so much, I appreciate all the info.

Quick question, tool length probe is included, Z probing (not for bed leveling but for work offsets) is accepted in the controller but not on the software right? So I need a good sender, like CNCJS or gCodeSender to support it, but the hardware has the support built for it.

Has anyone used the thttps://triquetra-cnc.com/ triquetra probe?

Anyways. Thanks for the help!

@KikoLobo Do you have an X carve or Carvey? The SO3 and Nomad are like the big brothers of those machines. They all use grbl and all can be controlled with CNCjs. Probing works the same and you can use a 3 axis probe like the triquetra or a homemade version or, for seamless integration with Carbide Motion (C3Ds controlling software) you can use the C3D probe.
I recognize you from Inventables and CNCjs forums.

Yes! I own an XCarve. But the carvey is no more, and I was thinking on the Nomad…

Thanks for the info!

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