Vertical Machining Centre Retrofit with Chinese Servo Drives Build Thread (NZ)

Becksvill wrote: Clive I can make a video. But I'm not a expert myself. 2 weeks ago I had never tuned a servo drive before lol. But I have it pretty good now.

All I am going for is low following error and minimal overshoot.
The Z axis was actually giving me some issues. It has a lot more friction and I'm getting ballscrew twisting causing issues. Also I can't find a parameter for dead band so it's hunting or something.


What is your setup? Eg 7i77 or 7i76 etc
I'm happy to help if I can

Regards

Andrew

Yes this is the thread I started
forum.linuxcnc.org/24-hal-components/381...al-mesa-7i76?start=0

I have the manual for the drive. The motor is just on the bench with the encoder and step/dir on a 7i85s connected to a 7i76e

Peter and others have been very helpful . But I gave up I still have it at the moment I was trying to learn how to close the loop without a following error. If I remember Peter said that it might not be a good candidate because the manual is a bit vague.

I don't know what I should be looking for the the plots.

Clive can you email me.
Find my email at
Carbidecutters.co.nz
I'll have a look at your manual

Regards

Andrew

hey guys

I have made heaps of progress on the cnc lately.

and will make some decent updates showing how to setup several things later on
here is a partial list of what has been done recently
1 fixed my grounding issues I was having I think after lots of help on the email list
2 have connected up my new chinese MPG from aliexpress up to the mesa 7i76 card mpg counters.
3 increased the acceleration on spindle vfd
4 tuned servo drives I think pretty well now. still doing accuracy tests to check how good it actually is but initial tests are pretty good and Halscope is showing about .01mm following error at normal feed speeds



anyway as I know everyone loves videos and photos here are some from this morning.



here is the toolpath on the controller



and here is the roughing part finished



and the broken endmill I just broke while cutting them out! (happened 5 mins ago lol better get another one from my stocks)



regards

Andrew

here are some more photos of the finished parts

they are definitely not perfect and I would change how I did it next time but the mill worked without a fault. pretty happy with it.







and here is a screen shot of the fusion 360 cam




I will try upload heaps more photos as time goes on just to show what linuxcnc can actually do on a decent sized cnc mill. I think it will be pretty cool

regards

Andrew

more photos


I know how much everyone loves them. if you don't have photos it didn't happen lol

I did a accuracy test today to see how my servo tuning was. I have since found out that I actually need to change some parameters but the accuracy was still pretty good.

at 300 mm/min finishing speed with a 0.05mm cut 20 mm deep and a nice ultra sharp carbide endmill for alloy I milled a 110 mm circle and measured it afterwards.

It came out definitely within 0.01mm but possibly within 0.005mm of round when measuring all over with a mitutoyo mic

basicely it was close enough that it was hard to decide which side was the largest so pretty happy with that.

at 2000mm min the accuracy was still about 0.015 tops

Very nice, indeed.