Denford Triac VMC w/ ATC conversion

[JAZZCNC]

Yes, thats a 30Year old machine. they used bergerlahr 5fase steppers, with a strange driver as well.

Even stranger then because 5 phase steppers give much lower Step angles due to having 10 poles. This is why they were used because the gave greater resolution and lot smoother running because of smaller rotor steps. They also increase in torque when Ms rather than loose torque like 2 phase steppers do.
The down side being more PPR required compared to 2 phase motor.

The first Smaller leadshine Hybrid Servo motor used 5 phase steppers for this reason. 2Nm Hybrid servo motor gives a 3nm 2 phase motor a run for it's money and is lot smoother.

[Gary]

they were 3 phase actually, leadshine dont make 5 phase drivers.

[JAZZCNC]

they were 3 phase actually, leadshine dont make 5 phase drivers.

Ye had brain fart on that one Gary for some reason I had it in mind they where 5 phase motors but on reflection it was obvious given U V W wrote on top of drive. .

[uli12us]

Don't misunderstand me, I want to change the control Unit of My Boxford machine. The Emco with the
strange Motors should be original. And only for the Boxford I need eventually the 2000 µstep from a
leadshine driver.

[stallone]

So I was able to get a little time with the machine this last weekend, but not much. I started to test the backlash on the Triac but I think I was doing it wrong. I am too inexperienced!! However, I did notice the end of the leadscrew (I think it is that) with the pulley, it moves back and forth approximate 2 degrees before engaging. I am not sure if this tells me anything.

Pic below of the end of x-axis pulley.



I did have time to measure the position of the stepper pulley on the shafts for the new stepper. The new steppers for x and y are much larger than the originals, but they fit!



Thanks for your help,
--mike

[andy_con]

you can easily get rid of backlash on a triac by just tightening the tab nut on the end of the table. getting the right preload on the bearings can be pretty tricky.

ive gotten he backlash on my triac down to 0.02mm, which im pretty happy with.

[stallone]

Hi Andy,
Where would I find this tab nut?

you can easily get rid of backlash on a triac by just tightening the tab nut on the end of the table.

...and what steps would I take to adjust it correctly. ...without screwing things up!
Thanks,
--mike

[andy_con]

you remove the pulley to reveal the tab nut and tab washer.

fold down the tab washer leg which stops the tab nut from rotating, then you can tighten tab washer.

only way ive found to do it, is to tighten put back together and check back lash, if still there remove everything and tighten even more. back lash should be checked using a test dial indicator

you remove the pulley by undoing the grub screw located in between the teeth

[Chaz]

you remove the pulley to reveal the tab nut and tab washer.

fold down the tab washer leg which stops the tab nut from rotating, then you can tighten tab washer.

only way ive found to do it, is to tighten put back together and check back lash, if still there remove everything and tighten even more. back lash should be checked using a test dial indicator

you remove the pulley by undoing the grub screw located in between the teeth

Ye, that's what my poor PM was trying to explain.

[andy_con]

Anywhere where there are angular contract bearings requiredpreloaded and there are two in the end green part of the table