Need PM1022V/PM1030V Change Gear Advice

[Clif123]

PM lathe users,

I have a PM1030V with the newer adjust-once change gear posts. Up until now, I had the default configuration shipped but today I decided to start single-point threading and needed to reconfigure the gear setup. Just in case it matters, I configured for 20TPI (inch) and noticed some issues. First, the "L" (bottom) gear was making contact with the side of its mating gear. The documentation is a bit sparse so I looked at the manual a few more times and it had a couple useful pictures and stated for the new gear pins that: The thick washer goes on the outside and the thin washer goes on the inside (next to the banjo). Apparently Chinese thin washers are not created equal because one was thicker than the other. I swapped the thicker "thin" washer on the bottom with the upper one and there was some clearance. Next, on the gear contact between the two adjustable gear stacks was slightly off so that one gear was overhanging a bit. I'm concerned about uneven gear wear. Before I start making a bunch of shim washers, etc. I'm hoping that someone has some good advice before I break something.
Also, I use the piece-of-paper method for meshing the gears if that matters.
Thanks for your help!

 

[Jim F]

The clearance between the teeth is what you need to worry about, the side to side has no effect on that gear train.

 

[B2]

First, the "L" (bottom) gear was making contact with the side of its mating gear.

You should not need much clearance to prevent them from hitting. Mine look like they might be hitting, but don't seem to be a problem. There should be so little clearance that even if there was a slight off set between the gear teeth you would not see a significant wear pattern.

Doesn't the center combination pair of gears separate if you take them off the shaft? They should be just pushed together and the key/key way keeps them in constant phase. If so then a thin spacer washer between them will allow you to shim the lower gear position to match precisely.

Have fun.

Dave L.

 

[ivel03]

I put shim stock between my gears to reduce noise from the gears rubbing. It doesn't take a lot to reduce the rubbing from the inside upper gear to the lower outer gear. Also make sure that the bottom gear is backed by a sleeve on the input shaft and the appropriate amount of washers to line it up with the gear above it. In some cases you use a keyed sleeve and in other cases you use the plain bushing without the key.

I don't know what the adjust once style is but the old style had something like an E clip that went on the post and you could slide the gear on and off without undoing the entire stud. You loosen it up to adjust the meshing of the gears but you don't need to remove the stud entirely in fact you don't want to if you can help it.

If you haven't check out the Blondihacks youtube channel for more information about your lathe and some good tips and tricks in general.

I did this a few times and am now finishing the ELS install on my lathe!

 

[Clif123]

I put shim stock between my gears to reduce noise from the gears rubbing. It doesn't take a lot to reduce the rubbing from the inside upper gear to the lower outer gear. Also make sure that the bottom gear is backed by a sleeve on the input shaft and the appropriate amount of washers to line it up with the gear above it. In some cases you use a keyed sleeve and in other cases you use the plain bushing without the key.

I don't know what the adjust once style is but the old style had something like an E clip that went on the post and you could slide the gear on and off without undoing the entire stud. You loosen it up to adjust the meshing of the gears but you don't need to remove the stud entirely in fact you don't want to if you can help it.

If you haven't check out the Blondihacks youtube channel for more information about your lathe and some good tips and tricks in general.

I did this a few times and am now finishing the ELS install on my lathe!

Thanks. I'm attaching an image from the manual explaining the post 2017 special nut operation for people wondering.
It is handy. I have a stack of copper shim washers and I think I'm going to go with that to fine tune the gears. I'm on the same journey as you but I'd like to get comfortable with the change gears before ripping them off and putting the ELS on this unit. The hammer in the original pic is sitting on the ELS control box. Good luck with your install!

 

[type3tim]

I added a .050 shim between the thin washer and the banjo which brought the center gear set out properly. This eliminated the rubbing between the center gear sets and both the upper gear set, and the lower big gear. My machine is a PM-1127 and the gear train is laid out upside down to the way you have yours. For me, big gear at the bottom and back position, attached to the input shaft to the gear box.

The point is...I had to put a shim on the middle axle to get the gears to line up nicely and not rub their sides against each other.