Hardinge CHNC4 Retrofit

[lavrgs]

Sounds like an Acorn would be a better te$t device...

[lavrgs]

At the end of May my X-Axis motor shorted and took the ALLIN1DC with it. I've had both X and Z motors rebuilt, the X motor was newly rewound. The ALLIN1DC board was repaired in less than two weeks but the X motor took almost two months.
I took the "time off" to pursue a couple different projects including getting a high end 3D printer and poke at some of the constant field of unfinished or un-started projects.
I have rewired the power lines for both Axes and will soon put the board back in. This morning I mounted a new cap and board and when it's wired up and tested I will remount the ALLIN1DC with the intent to be back where I was before "the incident" ...meaning there is still a lot to do...but I was making a few parts when it died and I will get to that point and work on all the other stuff.

One question about encoder mounting - the encoders are directly mounted to the ball screws and I am wondering if they need to be timed...? They have an index pulse and some rotational adjustment. I have swapped the x and z encoders as part of the trouble shooting for the x axis failure and always had a mark that I realigned to. Now I'm not sure the marks of the X and Z encoders are still valid. Part of me says "it shouldn't matter"...thoughts?

[cncsnw]

The encoders do not need to be clocked to the servo motors in any way.

The location of the index pulse, relative to where the limit/home switch trips and clears, is somewhat important. You want the ballscrew to turn between 1/8 and 7/8 of a turn (and preferably between 1/4 and 3/4 of a turn) after clearing the limit/home switch, before the index pulse comes around.

That gives you a pretty wide margin for mounting; but there is a zone (the 1/4 to 1/2 motor turn surrounding where the switch clears) that you should avoid in order to ensure repeatable homing.

[lavrgs]

I recently had the main fuse 25A blow out and I believe it may have been due to the cut off post on the new cap and board shorting to ground - now protected by an end cap. I have removed it from the circuit and am checking the resistance of the wires, from the transformer, that supply the voltage >>0.40 ohm does that sound correct?

[centroid467]

Unless you are seeing something larger than an ohm, the wires are probably fine. Up to an ohm is possible from the contact resistance of the meter probes to the wires.

[lavrgs]

Is there a procedure to test the cap and board? The new unit I received had a stud on the bottom that was cut and it seems to have shorted to the chassis

[cncsnw]

Connect it to any AC voltage you have handy, with no load on the output side.

It should not draw any significant amount of current (and should certainly not blow any supply-side fuses or breakers).

You should see a DC voltage on the output side, approximately 1.4x the AC voltage on the input side.

You can also test the board without the capacitor. In that case, I think the DC output voltage will measure approximately 0.9x the AC input voltage.

[lavrgs]

cap and board seems to be faulty 8-( I connected it to the ac line leaving the DC open and it blew the breaker. I removed the board; same deal blew the breaker. It seems the bridge rectifier is not working....

[lavrgs]

I received an updated (i.e correct) cap and board assembly. I have a cap (?) across the 200v terminals on the transformer. I assume that it is integrated into the new board and no longer needed.

[cncsnw]

That black device is a transient voltage suppressor, not a capacitor.

Just to be clear, without re-reading the last 180 posts in this thread:
Is the cap board that you have, a "CAPBRDLO" with two screw terminals for AC input, and with a square bridge rectifier?
Or is the cap board that you have, a "CAPBRDHI" with two large stud diodes and soldered-on input wires?

The transformer in your picture would be used with the CAPBRDHI. The outer taps (with the TVS across them) feed the wires to the stud diodes. The center tap between them goes to the DC minus terminal of the CAPBRDHI.

In my August 30 reply above, I was assuming that you had a CAPBRDLO.