Newbie needs help with Logan 200 spindle runout

[SuperTroye]

Hi All,
I bought a Logan 200 last year and finally getting around to getting it set up as life has caught up. I'm having a problem with spindle runout and I don't know how to fix it. I measure 0.001" runout on the outside of the spindle but 0.015" runout on the chuck..

The previous owner mentioned he changed a bearing, but I don't know if it was the front or back bearing. Perhaps there could have been an issue when he reassembled it? He included an extra and can post the brand if necessary. I will probably remove the spindle next and inspect all surfaces to see what the problem is.

Any advice would be appreciated. I'm hoping the lathe is not totally shot.

Here is a video showing a dial indicator on various chucks and in various places.

 

[Kernbigo]

check the register of the chuck it looks like that may be your problem and needs to be re cut

 

[markba633csi]

It's possible that the lathe has been crashed so hard the spindle threads have been "pulled" but I have never seen that. The spindle seems to indicate correctly so the only thing left is the threads. Or...
All of the tooling you have is damaged or wrong somehow, but I am tending toward something wrong with the spindle threads.
Hopefully a Logan expert will shed more light on this
Mark

 

[markba633csi]

Ah I see your problem now- none of your tooling is seating fully on the spindle- is that the correct spindle or has it been replaced?
Your chucks and faceplate should screw all the way up to the shoulder on the spindle- you should take some measurements. Don't try to modify the spindle yet! Measure first- check with Scott Logan for the correct dimensions if needed
Mark
ps It looks almost like the shoulder has been cut back too far, I'm not versed well enough with Logans to ascertain that

 

[SuperTroye]

It's possible that the lathe has been crashed so hard the spindle threads have been "pulled" but I have never seen that. The spindle seems to indicate correctly so the only thing left is the threads. Or...
All of the tooling you have is damaged or wrong somehow, but I am tending toward something wrong with the spindle threads.
Hopefully a Logan expert will shed more light on this
Mark

Thanks for your help. It's possible about a crash but I don't see any other damage. I tested with another chuck I have (that didn't come with the lathe) and the same result. So, I don't think it's the tooling.

 

[SuperTroye]

Ah I see your problem now- none of your tooling is seating fully on the spindle- is that the correct spindle or has it been replaced?
Your chucks and faceplate should screw all the way up to the shoulder on the spindle- you should take some measurements. Don't try to modify the spindle yet! Measure first- check with Scott Logan for the correct dimensions
Mark

Ok thanks... I just spin them until I can't spin anymore. so they are tight. It's the correct spindle for the Logan 200 = 1 1/2" x 8TPI. What other measurements should I take?

 

[markba633csi]

You'll need to determine what the correct register (unthreaded portion) diameter of the spindle is supposed to be and the profile of the shoulder from where the threads stop- what is the correct distance there. You may have to make a spacer if the spindle has been "modified" by an "unauthorized person"
M

 

[markba633csi]

I think Terrywerm has a 200, maybe he could measure his for you, I believe quite a few members have them

 

[Rooster]

The back of the chuck or face plate should seat against the back of the spindle. Perhaps the previous owner turned down the register too much trying to correct run-out. May-be try getting a spacer to fit between the chuck and spindle register, the threads are just for holding the chuck on.

 

[T. J.]

Mark and Kernbigo have identified your problem. Pre-finished chuck back plates with 1-1/2"-8 threads will need to have the threads relieved and the shoulder square up to seat against the shoulder on the lathe spindle. I can post some pics of mine this afternoon that may help you.