[kccrusher]

We have a Hawk 200 lathe that had the spindle drive motor pulled and checked before we purchased it. Evidently the motor shop lost or broke the drive pulley and replaced it with a 44 tooth pulley instead of the original 42 tooth. This is a 1:1 machine and obviously when trying to do any operation that requires spindle synchronization, tapping, threading, etc it cannot. I see a parameter in the service screen that asks for drive ratio, but it will not accept new entries. Are we stuck with purchasing the correct pulley or ???

[Jim Dawson]

I would say that the motor shop is stuck with purchasing the correct pulley.

Take a look at Ametric to see if you can find the correct one. Ametric - Timing

[maver1ck]

I agree that if possible, you should try to get the right pulley. Cincinnati will still sell you one if you are unable to find what you need elsewhere.

I've never adjusted the ratio on the Hawks, so can't speak from experience ... however, assuming you have the A2100 control, most of those items were configurable. You just had to be at the proper security level to make the changes.

The basic "operator" level minimizes how much can be set.
The next level - "service" let's you make typical adjustments and install software.

However if you need to change some of the more fundamental settings there are two additional higher security levels.

If you want to try to adjust this, send me a PM I'll send you the passwords. I prefer not to post them because in the wrong hands, the machines can be severely messed up (and damaged) in these modes.

I'm sure you will also find the passwords online if you search for them though.

[kccrusher]

Jim,
Yes, you're correct, the motor shop should be responsible, but that was before I purchased it. The previous owner found out after he bought it and tried to thread with it. I bought it with the understanding it was going to have to have a pulley or a parameter change to function properly. At that time the pulley from the factory was $1300 new; double that now. All the off the shelf pulleys for this belt jump from 40 to 44 teeth, no 42. If we can make the parameter change, great, if not then we will just bite the bullet as it needs to function for threading, etc.

[Jim Dawson]

Well that's a bit of a problem. If the parameter change doesn't work out, I guess I would make one before I paid that price. If you started with a bit larger pulley and reduced the OD it would save doing all of the bore work for a taper-loc bushing. I'm assuming you have a CNC mill. Is this a M8 x 50mm HTD? 42 tooth, PD = 4.211, OD = 4.157

[kccrusher]

yes, it is a problem. You are correct, if we can't change the parameter, and the tech we use says we can't, it looks like that's the plan. Its a 14MM HTD type belt with the round tooth. I just have to make the time to produce it.

[Jim Dawson]

This might be of some help Timing Belt Pulleys | Timing Belts | Pfeifer Industries

Or maybe just get a quote from those guys.

Best of luck.

[kccrusher]

we're on the same page! I looked them up today.

I got the ratio change to take in the parameters, but it throws the TPA/ home error on the C-axis now. I assume from the ratio change, it's looking in the wrong spot now?

[Jim Dawson]

we're on the same page! I looked them up today.

I got the ratio change to take in the parameters, but it throws the TPA/ home error on the C-axis now. I assume from the ratio change, it's looking in the wrong spot now?

Great minds think alike

That would be my guess. You may have to change another parameter also, but I really don't know anything about that control. My machine has two encoders on the spindle, one in the motor and one external directly on the spindle. The spindle encoder is the one that it reads for threading and positioning.

[kccrusher]

I believe this just uses the resolver in the motor, nothing attached to the spindle itself.

[coop31]

Just wondering if there would be a mathematical equation you could use to trick the machine into cutting the correct pitch on threads?

[kccrusher]

Just wondering if there would be a mathematical equation you could use to trick the machine into cutting the correct pitch on threads?

Probably, but the other problem is during threading, evidently the c-axis wouldn’t pick up the same start? I haven’t tried threading, just went off of the previous owner’s info. We’re just going to produce the correct pulley and be done; thought if it could be done with a couple quick parameter changes we’d do it.