[Torontocnc]

Good day folks,

I am hoping to start doing a KRM build in the new year. I am thinking of doing a mod like this poster: http://www.cnczone.com/forums/diy-cn...-drives-3.html

I do not know if KRM is using Gecko drives G540 or what they suggest, but I would probably use the G540. Here is what I am unsure. I would probably have the A-axis go parallel to the X-axis as I may have need for very long turnings for posts and the like. Since the G540 can only handle 4 motors I am guessing I could disconnect the Y-axis and connect my A-axis? Then have some sort of physical stop and clamp/bolt to lock the Y-axis in place. There isn't a need to have the Y-axis active during a turning right? The Y-axis would be centred on the centre line of the A-axis as I understand and, the X-axis goes back and forth.

So since this seems a little muddle I guess I am asking:

1) Do I need a y-axis active during turnings? Or is there any use to having the Y-axis move during turnings?
2) Can I physically lock down the y-axis for turnings and use that driver for my A-axis?

Hoping to make a decision soon as Gecko has a sale

Thanks,

Jordan

[pippin88]

It's possible to do what you suggest, but a whole lot of hassle, it will also only let you turn round features (like a lathe) when a fourth axis is capable of much more including indexed square cuts etc.

I believe the digital outputs on the G540 can be used as step and dir lines to an extra driver, though they are somewhat speed limited from memory. But should not be a problem for a 4th axis which typically rotate at low speed.

[ger21]

I agree, that it's not worth the trouble.
Just get a G251 or G201X for the 4th axis.

Not sure because you're in Canada, but I think you can usually find G540's for less than Gecko's sale price, especially if you get it in a package with motors.

[Torontocnc]

I agree, that it's not worth the trouble.
Just get a G251 or G201X for the 4th axis.

Would I need to get a separate breakout board? I am guessing I would also need a second printer port or look into USB connection, like the smooth stepper. Should I just get a 5 axis breakout board and buy 5 G251s or G201Xs?

[Devastator]

I am guessing I could disconnect the Y-axis and connect my A-axis?

That's what I do. Not much of a hassle at all. I'm just doing simple tasks on my rotary axis like slotting cardboard tubing and spot drilling for index holes. Since these are very low torque operations, I don't even lock the Y.

I have two different XML files for mach depending on which configuration I need to run. I have to remind myself to load the right one when changing between though.