Pm1228 Spider

Buggy Chief

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Sep 24, 2016
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Anyone make or have one? I was turning some 3' stock and about 2 inches sticking out of chuck and the balance was out the headstock. The portion sticking out of the headstock really was wobbling bad and needs to be aligned. Aides in machine wobbling a little.

Any input is appreciated!!
 
Often one mounts either a dial indicator or test indicator to zero the run out on the spider end. Doing it by eye, doesn't work very well. If using a test indicator you need one with a long indicator point. The mount can be temporary or permanent, this is an example of what I did, but you could also do something with a articulated arm with a fine adjustment.
http://www.hobby-machinist.com/threads/pm1340gt-spider-with-dial-test-indicator.45446/
You need to check the mounting through the range of diameters that fit through you spider, so the spider screws don't take out the mount/indicator. I also use locking collars on the spider set screws, so they do not loosen and go flying across your shop.
 
I've been trying to remember to make a call to PM about this. I think an outboard spider with a flange can be installed by picking up the bolts that attach the spindle drive pulley, but that is based strictly on what I can see in a video of the machine. That PM 12X28 lathe has almost no spindle sticking out past the pully, certainly not enough to grab with a spider on the outer diameter.
 
You are right, now threads to work with. Would be interested what Matt says. Keep us posted.

I've been trying to remember to make a call to PM about this. I think an outboard spider with a flange can be installed by picking up the bolts that attach the spindle drive pulley, but that is based strictly on what I can see in a video of the machine. That PM 12X28 lathe has almost no spindle sticking out past the pully, certainly not enough to grab with a spider on the outer diameter.
 
For long stock, anything after the outboard spider if long enough, still has the potential to whip. In that case you need to support the stock further out. I posted this in a similar thread.
 
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