Converting VH-65 + Indexer Box, to Full 4th Axis on (DC) 1992, 4020HT

[mflux_gamblej]

I am in the middle of getting my VH-65, which came with an indexer box, to be a full 4th axis on my 4020. My machine is pre-wired.

I have purchased and installed:
1010-4 with no limit eproms ele-0021
amp-6 (smaller) axis amp card, and a converter wiring harness for adapting the amp-21 wires to the amp-6
a dummy plug

I have, but have not yet installed:
an air solenoid that will be used to actuate the air brake (M60)
a new motor for my VH-65
a new wiring harness for my VH-65

The big deal is that my VH-65 has the older style MTR-0002, which is a stubby sized (for the rotary) DC motor that has an encoder on it instead of a tach and resolver. This setup is used with the fadal 'servo controller model 1' which is an indexer controller box. The indexer box communicates with the CNC88 control using a contact that it closes to let the machine know the index move is complete. The CNC88 sends a signal (also just a relay contact) to the indexer via M-Code (M20) to tell the indexer to execute the next move. The moves are programmed on the indexer or sent to the indexer over rs232.

I suspect that this indexer setup is quite rare and that FADAL went to full 4th axis' only shortly after the indexer box and strange VH-65 with an encoder was released. I have not seen or heard of another person with the indexer box.

At any rate, it's time to get some full 4th action going for me as I need to do 4 axis contouring for some upcoming parts.

I am working on swapping out the new MTR-0003 which uses a tach and resolver, and is also stubby, so that it can be used with my CNC88 control / 1010 card and amp006. I need to go get a gear puller to get the drive gear off of the old motor. I'll post some pictures of all of this soon.

I noticed that there seems to be quite a bit of backlash on the internal gears that drive the worm gear inside my VH-65. Anyone have experience adjusting these gears? The manual goes through a procedure on how to do it but its a little vague. Anyone adjust the mechanical backlash on a VH-65 before and have some advice?

Another issue is that the previous owner of my machine / rotary table said that 'there is a problem with the brake on the VH-65'. This is second hand info that I got from the machine tool dealer that I bought the machine from. I have not tried the brake at all yet. It could easily be a problem with the solenoid on the indexer box, rather than a real mechanical problem with the VH-65 brake itself. The brake mechanics are buried deep in the rotary table, and I'd have to pull it fully apart I think to get to the brake to inspect it and/or replace parts. I'm going to try and use it with my new solenoid and M60 on the CNC88 prior to going to that extreme. Regardless, anyone ever have an air brake problem on their VH-65? What happened and how did you fix it?

Another potential issue is that I cheaped out and got the amp-006 instead of the larger (and twice the cost) amp-0021. I got a real glentek, not some knock-off at least. The amp-006 to my knowledge is used in the VMC-15, or the TRM as the xyz axis amps. That being said, the amp-006 is listed as being for use with the MTR-0003 which is what is going on my VH-65 (and what is on all DC VH-65's that are used as full 4ths). I don't anticipate trouble, but the guys at ITS told me that I 'should' get an amp-0021 which kind of erks me a little... If they'd give me details on 'why' instead of always just suggesting the most expensive option maybe they'd have my money right now instead of me be being irritated with them.

Another potential issue is that I will not be using an axis inhibitor board. This is on some advice from a 20+ year factory service technician that told me that the inhibitor is really for AC machines, and that DC machines don't need it. The intent of the inhibitor is to shut down the rotary table's motor when its at rest to stop it heating up - which could ware on your amp, and on the motor. we will see what happens.

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[mflux_gamblej]

well I got it all hooked up, and its not right yet.

The A axis spins infinitely at what I assume is it's max speed as soon as the amps get energized (i.e. not in e-stop).

An e-stop stops it, but when you clear that it just gets back to rotating infinately.

any suggestions?

[mflux_gamblej]

so far I've tried reconfiguring the jumper J4 on the 1010 card to check the direction of rotation, and I've tried swaping the tach wires.

changing the jumper made the table just run away in the other direction, but also generated an amplifier fault, error #1

having put the jumpers back, and swapping the tach wires, the rotary table never moves and there is an amplifier fault.

So it's back in the original config that still runs away in the counter clockwise direction as soon as the machine is turned on. the jumper on the 1010 board is 5, and 7 set to on, all others off.

[mflux_gamblej]

I tried all 4 possible combos of motor and tach wiring, none work.

reversed motor, and reversed tach make a runaway in the opposite direction
regular motor and regular tach make a runaway in the regular direction

the two combos of tach swapped with either reversed or regular motor wiring make no motion at all, and have not repeated the error #1 that I have seen just one time.

I took the motor back cover off to have a look at the tach and resolver - both look brand new and its not obvious if there's an issue.

[mflux_gamblej]

well, this morning thanks to some advice from a long time fadal service tech, I found out that I need to plug in jumper J5 on the back plane board (behind to card cage). That is a big deal - it hooks up the tach, and resolver, and 1010 card, to the amp.... duh!

problem isn't fully solved yet - I'm getting no more runaway, but I am getting an amplifier fault, error #3, a axis motor overload. I haven't had time to go change stuff up, but I bet it's either the jumpers on the 1010 card, or my wiring of the tach / motor.

[mflux_gamblej]

Problem Solved - it turned out that my tach was wired backwards (even though I had matched up the colors). The 4th axis works just fine now. Here's a quick video - I'll probably make a proper video with some machining and so on soon.

[mflux_gamblej]

Here's my first test part. Took a lot of learning despite how simple it looks. Also, fadal seems to have uncommon rules about programming the A-axis. This seems typical of fadal - strange programming rules that in their own right make a lot of sense and are pretty easy to use, but, because they're different than the way most controls (i.e. fanuc) do it, most cam software needs a heavy post update which goes far beyond changing some settings. At any rate, here is a video showing some chamfering around all edges on this 4th axis test part.

[Waynno]

Good Job, I got some good paying jobs out the door, and sucked it up and paid
like $7k to have the same unit installed.

What software are you using, I like the multi axis moves this vid made