G0704 (sort of) CNC'ing

[Dr.Fiero]

Well, the above seemed to work quite well. Not the 'tidiest' of jobs, since it's REALLY (!!) hard to hold it dead level while manipulating it under the mill end.
But I got it pretty close (and unless someone gets really nosy with the underside of my table - it'll never be seen anyhow! ).
I think I took 80 thou off on average (since it's rough cast, my numbers were all over the board when I measured it up).

Aaaaaanyhow, I also remembered someone (?) saying that when they went to put the X nut on, it jammed up into the end plate, so they had to go back and make a collar to space things out. Knowing this in advance, I thought I'd make up a special nut. This kills two birds (poor birdie!) since it's also hard to get the nut to not back off. So, added a set screw too! Only took about 10 minutes to make.



Now I can just zip the nut down, set it, and forget it.

 

[Dr.Fiero]

It moved! And yes, under it's own power.

Nothing set up, tuned or tweaked - but still.

[video=youtube;ek1fmNQ7n4Q]http://www.youtube.com/watch?v=ek1fmNQ7n4Q[/video]

 

[fretsman]

Excellent, good for you, my friend, now it's the fun of tweaking her out.


Thanks for sharing!
Dave

 

[jumps4]

nice job so far
i'm helping a friend with the same g0704 build right now.
i had the same problem on my zx45 mill and it was because the couplers were spiral cut. they unscrew when under high load. the aluminum cross cut and steel plate type couplers work good. i have the steel plate type on my zx45's 4200 oz/in motor with no problems. i stayed away from lovejoys because of backlash.
steve

 

[Dr.Fiero]

Re: G0704 CNC'ing

Well, one thing I *think* might be an issue at this point is voltage. Or lack thereof.

When I bought everything from the manufacturer, they supplied the 24v 350W power supply with the package. It looks like this is at the really low end of the usable voltage. So I've ordered up a 48v 600w supply.

Hopefully I will see it within the next couple years. Ha!

With any luck, this will let me kick up the speeds without getting all the stepper stalls I'm seeing. X/Y are stalling at anything over about 80, and Z will stall above 30.

 

[jumps4]

what microstep setting are you using on your controllers?
and if you post your xml file in a zip file i can take a look at it for you
steve

 

[kd4gij]

nice job so far
i'm helping a friend with the same g0704 build right now.
i had the same problem on my zx45 mill and it was because the couplers were spiral cut. they unscrew when under high load. the aluminum cross cut and steel plate type couplers work good. i have the steel plate type on my zx45's 4200 oz/in motor with no problems. i stayed away from lovejoys because of backlash.
steve

What no love for love-joy. :rofl:

 

[Dr.Fiero]

what microstep setting are you using on your controllers?

I've got them set at 400 right now. Did a crude steps setting in Mach (ie, I cheated and just used a ruler instead of doing it right!) just to get things rolling.

X &Y are dialled back to 80in/min. Z is dialled waaaay back to 20.
I'm not missing steps now. It's just painfully slow to watch.

I've got to tear a few things apart - I get the feeling something is binding on the Y. It just doesn't feel as nice as the X, which could be easily turned by hand (when the motor wasn't installed of course!).

 

[Shepherd]

Very cool...just picked up a busy bee round column mill I want to CNC, Thanks for the great step by step...

did you build or buy the motor mounts? We're the components bought as a kit or piece by piece? I'm trying to finalize a shopping list but am running on info overload from the interwebs surfing and reading I've been doing....

 

[Dr.Fiero]

Re: G0704 CNC'ing

It was mostly built up from scratch.

You can see in the pictures above that the nut mounts were definitely hand made! I could have bought some off the shelf ones, but this got me more involved in the project, and gave me more seat time on the lathe I already had but almost never used.

The motors and drivers were bought from one place. Same place that gave me a too small power supply.... sigh....

The box and wiring was clearly all me.

Lead screws and nuts were from linearmotionbearings2008 on eBay.

Motor mounts were from Billy (aka BDTools on eBay).
He also does the nut mounts if you want to just buy them.
(Bear in mind that his stuff is for the G0704 only)

This is just ONE of the million routes you can take. Some people elect to stick with the existing lead screws. This does make it a lot cheaper if you can do your own lathe work, to modify the ends of the existing screws to take a coupling. If you DO decide to keep the existing screws, look up dumpsterCNC and his zero lash nuts. I used those on my CNC router project (look up the user dr.fiero on YouTube) and was quite impressed.

Did I leave anything out? Ask away....