Where to start and what to avoid

islander261 wrote:

Ok, you are looking at a good reliable piece of kit from people that have been around long enough they won't be gone next week. CommandCNC is a proprietary port of LinuxCNC ( 32bit Ubuntu, LinuxCNC 2.7.??) that uses proprietary CandCNC hardware, works fine but not a true open source build ( you will be dependent on them for support). You actually will not be able to build an EQUAL quality system unless you are good and cleaver at designing/building. Sourcing new materials for much less money is hard, volume purchasing has big discounts in the motion control world. If you have a year or two to watch for good deals on Ebay (which are getting quite rare these days) you can get quality low priced motion control parts. If you need an all in one software solution with commercial support go with a table run by the Flashcut software but you will pay for it.

You can build a quality table yourself and control it with LinuxCNC but it will require considerable mechanic, electrical and computer skills on your part to make it happen.

John

It seems I was under the wrong impression. I did not realize that this came with closed and proprietary electronics. I was assuming I could just use whatever electronics came and just use LinuxCNC with some maybe minor changes.

I had found this page (www.candcnc.net/knowledgebase/source-code/) which led me to believe it was more open than it might be?

Are the boards and hardware they use more closed than the Mesa cards?

I'm assuming I could get it and then buy a Mesa 5i25, 7i76e, Thcad 10 and switch to LinuxCNC assuming the electronics with it are unusable for switching. Does that seem reasonable?

The goal is to be as open as possible while still having a good solid machine.

I'm assuming I could get it and then buy a Mesa 5i25, 7i76e, Thcad 10 and switch to LinuxCNC assuming the electronics with it are unusable for switching. Does that seem reasonable?

The goal is to be as open as possible while still having a good solid machine.

You won't need a 5i25 with a 7i76e as the 7i76e uses ethernet to connect to.

Hi

CommandCNC and CandCNC electronics package will run under straight LinuxCNC, It will take a bit of .hal work and still using their drivers. Until recently it used an 7i92 card to interface with the computer, now they have their own FPGA card (remember open source firmware) so they don't have to buy them from Mesa. The original CandCNC electronics were designed to work with Mach3 and were tweaked to work with LinuxCNC. I have gone the other way as trial once and ported CommandCNC to use a 7i76E and THCad cards with my hardware. Worked ok but I like my custom gmoccapy much better. Because of the Mach3 legacy of their hardware the THC module and some other stuff connects to the control computer through a apparently proprietary ( I bet it really isn't but have never had one in my hands to figure out) USB to RS-485 breakout box.

Please don't take my comments on their system not being open source in a negative way. I mentioned that because some people are truly committed to using open source solutions exclusively. Their hardware works many people have used it. I have never owned any myself. There are rumors of spotty customer service for "problem" users but that is the same every where. Ask about them on plasmaspider.com as there used to be many CandCNC users there, the company owner is a frequent and very protective poster there.

John

Because you have a makerspace gang behind you, just make your own and be done with it.

Grab 3 of these NEMA 34 gear boxes with some matching 1400mm gear rack from aliexpress
www.aliexpress.com/item/CNC-Gear-Box-Rat...&transAbTest=ae803_4

Look for a linear stage something like this for the Z axis. With hindsight, I'd get 200mm travel
www.aliexpress.com/item/Heavy-Load-X-Y-Z...&transAbTest=ae803_4

and 3 of the smallest NEMA 34 steppers you can find and 1 NeNEMA 23 about 269 Oz on stepperonline
Then find some HGR25 rails about 1600 long with 6 carriages

Look for a commercial magnetic breakaway.

Then a Mesa THCAD, 7i76e, J1900 PC, a cheap wfi keyboard and mouse kit, and a USB wifi dongle (or a 2 NIC PC)

You'll need two small DIN rail power supplies, 24 volts, (1 for field power, 1 for Ohmic sensing. and a 10.5 amp 48 volt power supply for the steppers.

On Ebay, grab a bunch of PNP proximity sensors. and some drag chain. Also grab some Longs motor DM542a Stepper drivers a couple of estop buttons, switches and lights. I used 2 bus bars one for +24v and one for -24v but there are some cool DIN rail hardware that would do it much neater.

So now for the gantry find a piece of something like 40x80x3mm aluminum box section.

Go to your local aluminium supplier and get them to cut a couple of slabs of 16mm for the gantry ends for your maker space guys to mill and drill

So from there you got almost everything your need. If you want to cheat with mounting the Y axis rails on each side of the machine, get some 12mm steel laser cut to mount the rails and rack. They should be able to cut holes dead accurate so you can directly tap 6mm which is what the rack and rails expect. Have a series of vertical slots laser cut in these along the top. I drilled a series of holes and tapped them M10 x 1.25mm into 4mm thick table frame. Allow the rails to sit on some grub screws at either end which will pass through nuts welded to the table frame. Once you get the table level, you can tighten it all up.

So there you go, super fast to build and industrial quality

rodw wrote:

Because you have a makerspace gang behind you, just make your own and be done with it.

This one will be for my personal workshop. I hope to get this up and going and get some good experience and knowledge with cnc plasma and then put together a build for the space. There is a nice big mill and some pretty talented people with it there so I think what you describe is going to be the perfect fit for that one... And maybe for my second one

For this one I think I'll just buy something like the star labs machine and probably add a second/redundant electronics box so I can use and learn while converting to the electronics i'd use on the space one.