Would it be possible or recommended to use only 2 mechanical Omron endstops on a Primo instead of the 4 for dual ends stops, for instance one on X and Y respectively?
I would be using this with the SKR Pro v1.2 board. Would it make any functional difference at all besides less wiring?
With only 1 X endstop and 1 Y endstop, you lose auto-squaring. It’s probably worth wiring everything up, in my opinion.
That said, I’ve heard of folks just using stop blocks and having NO endstops at all.
How experienced a machine builder and CNC operator are you?
As MakerJim indicated, the primary purpose of the endstops is to auto-square the machine, and you need all four endstops to make that work. For the Primo, almost everyone defines and runs their jobs relative to the stock, not to machine coordinates, so knowing home position is not the point of the switches. It is almost all about squaring the machine. Typically, the origin is established as the bottom left corner of the stock or ocassionally the center of the stock.
If you don’t want to deal with the switches, you can leave them all off and square the machine manually. You just need to provide stops to push the axes against before engaging the steppers.
As an aside, a lot of the jobs I do don’t require the machine to be square, so I just manually pull the router or laser to the desired position relative to the stock before running the g-code file.
For full disclosure, there are a few tasks that benefit from knowing home apart from squaring. For example, using a fixture and wanting to return to the same starting position for each run. For me, these kinds of jobs are rare.
I’ve assembled many 3D printers, but am a complete beginner with CNC. Would you recommend any particular mechanical endstop?
I have 3 of Omron endstops that mount perfectly on the parts, but I’m curious if there are better alternatives as the few I have were from an old 3D printer kit.
Thanks for the advice, I think I’ll leave the switches off until I have all four and just try running without them first.
On another note, what laser module are you using or would recommend starting with for cutting cardboard or wood?
I have the NEJE 40640 laser module on my Primo. I put a lot of hours on my laser, and some of my projects have been posted to this forum. The only downside is that it is pretty anemic compared to the more powerful lasers coming out today.
When I purchased my module, it was among the more powerful ones on the market, but now there are 20 watt, 40 watt and even 70 watt diode laser modules. I have not seen these more powerful laser modules being installed on Primo machines. Partly that is because these modules are only sold as part of a laser engraving machine, and partly because the wiring appears to be significantly more complicated and may require special firmware support. For me, the NEJE 40640 was almost plug-and-play with respect to the wiring.
As for your switches. I’ve never seen a forum post indicating the purchase of “better” switches, nor that cheap switches are causing any inaccuracy in the machines. I’m sure the ones you have will work just fine.
I did this for quite a while with the Primo. Print four stoppers that you can push the gantry against before starting the CNC and you are good.