Daughter board for x and y axis'

I need a way to remove the x and y axis ( 4 drivers) on to another board. Possibly even have it handle the endstops and everything else. I’m thinking like an uno as a secondary daughter board. Catch is lag in sending and receiving info and extra computational power to communicate through USB protocol. Isn’t there a more direct way to communicate through separate boards?

This might be better asked in the Arduino forums, but I’m starting here.

This is for my needs to develope 5 axis. I’ve found several examples of five axis printers and some hobby level cnc machines, but due to the double axis’ it’s more complicated on the mpcnc.

Ive had a couple of rouge thoughts about maybe sending x and y (dir and step) plus one pin a piece for endstops, and have the nano split this into two drivers per axis and dual endstops. It would just send back info as one enstop activated once it completed hoping per axis, then drive them in parallel.

Obviously I’d need something like the cncsheild for the other drivers.

Maybe an uno is a better option.

Any good coders see a problem using the nano route to free up two axis’ on the main board?

Can’t work on mechanics till bearings arrive, so might as well figure out how to drive them. Linuxcnc and a 7 axis board then buying 7 independent drivers is kinda much for a hobby machine… I’m trying to think easy and accessable to more than just fanuc programmers.

Both rambo’s have extra motor headers built in, A few other boards do as well. Alex just posted about adding drivers with the cnc shield. Should be easy.

Great. I need to do some research on the Rambo boards memory as well. There are a few options on making 5 axis cuts and I was hoping to bury a large part in the firmware. This would allow more of a 3 axis approach to the front end user. Give me a bit to research the Rambo cause I was only dealing with Arduino at the moment. Unless anyone else has experience in what I described.

Again. There are options. They’re just not great options at the moment. I am probably overcomplicating things.

Damn… I think I marginally need the extra memory, but now looking I couldn’t shave enough moving the axis’ off board. Still ramps.

Man, now I’m in the save money pool. Started this saying, well if I spend more I get more. Well. That depends on a lot of factors. I applaude you Ryan, but I’m still gonna bury my head in the sand… look I’m an ostrich!

Not saying Rambo is an option yet. Possible cause I counted available pins in ramps and memory plus techniques to relieve some actions. I’m just saying I want more verses ramps.

Previously I didn’t care about price but now I’m suggesting things cheaper since now that we have increased mechanical prices plus now add extra electronics.

Where’s the balance I do not know.

If I may, I think you should start the easy way. You are building a 5 axis machine, so you’ll face a lot of complex challenges, just start with making a quick and dirty prototype to see if this could work.

So, instead of using the new firmware with endstops and perpendicularity correction which needs 5 drivers, why not simply using the previous version, with all motors axis mounted in series or parrallel (I’m still running my machine like this and it works well enough). You’ll have 2 motor drivers slots available, which should be perfect.

This way you can postpone the complex electronic issues, make sure that this works fine mechanically and then, maybe come back at this later if you feel the need to do so.


I don’t understand that logic, completely.

I have free time available now, where as sometimes with work, I have none for months.

I do intend on running it with just basics to test with. But after that i really need to get dual endstops, touch probe, endstops on 4th and 5th axis, and pwm speed control. Otherwise changing tooling would be almost impossible.

Interesting issues with this. I have never put too much thought into it until now. With 5 axis I am pretty sure you will have to use encoders on the tool head. And software that can be aware to prevent crashes with itself, or really careful CAM.

I wanted to code it into the firmware which can take up some space and computational power. That’s why I want to pull as much off of the main processor as possible.

As far as encoders on the tool head… I was going to use a limit switch. Very similar to the bridge boy.

Does anyone else think, that if we had a cheap easy to use 5 axis machine that you could build anywhere you could get electricity that it would be revolutionary?

First thing I can say about my endeavor is we will lose some accuracy. Secondly, resolution diminishes the further you get from Central point. Can we mill aluminum 5 axis.

With proper programming yes, shouldn’t be much extra flex. I’m designing the 5 axis mpcnc to split losses by only adding one axis to the gantry and turning our parts on a rotary table. I can get the cutter really close to where we are already cutting.

Programming wise it’s a nightmare. We are turning this axis at 45° from x and z. Easy enough if you program a stationary extra axis’. But that’s not all…

Your right it a difficult new endeavor, and applying it in this way poses a few new challenges.

I say, challenge accepted. Maybe I’m ahead of myself on programming. Maybe this will be like, if you build it, they will come… and someone smarter will be like you guys are doing it wrong.

We are not only milling metal with plastic, we are going to mill it from all angles!