Newbie needs help with Logan 200 spindle runout

Did you align you machine bed with a level first? The machine is not new, so you can't expect perfect. Oh buy yourself a .0005" indicator. Take off the chuck and back plate and run the spindle at high speed for about 30 min. shut it off and lay your hand on the spindle housing and see if it is almost to hot to touch 140 F to 150F. Then mount the mag base on the spindle headstock and put the indicator on the top of spindle and slide a 2 x 4 or 2 x 6 under the spindle and slightly pry up on the spindle say put 20 pounds pressure up. the indicator should not have any movement or less then a tenth (.0001") Then put the mag base on the face of the spindle and check lateral movement. Again you should not have more then a tenth. Look on page 75 - 77 and see what I mean. https://cdn0.grizzly.com/manuals/g4003g_m.pdf. If that checks bad then tighten up the spindle spanner nut a 1/16" or 1/8 turn.
I know the manual is not your machine, but they have good manuals and a lathe is a lathe.

Like the others said remove the face plate and check for burrs. stone any with med grit Indian lapping stone wipe everything off with your hand and screw it back together. If you were a bit more experienced i would say to blue up threads and taper. check the outside face of the and if it's with in .001" put your chuck back on and snug up the bolts but not super tight. Then check the OD of the chuck and tap it with a dead blow hammer and get it spinning on the spindle axis like you do with a 4 jaw chuck. Get that less then .001". Have to be a detective and test and retest before taking something apart. SKF bearing company says that many times one makes things worse then leaving the bearings alone.

If you do remove the spindle we can talk about how and what to do later. Rich
 
Ok thanks to everyone who replied. Let me digest the comments and will report back on what I find. Here is another video where I indicate on a 3MT to 2JT drill arbor. I'm trying to figure out where on the spindle is the issue. I hope this helps in diagnosing the problem.

 
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


Mark is correct: your tools aren't seating on the spindle nose properly. This is what it should look like:

DSCF7310.jpg

Here's a pic of a Model 200 spindle. The total length is about 1 inch and the unthreaded portion is around 1/4".

DSCF7309.jpg

If you can post a pic of your spindle it would help, but it looks as though your tooling is bottoming on the threads rather than bearing
against the shoulder on the spindle.
 
It's quite possible that none of your tooling was ever properly fitted to the spindle nose in terms of cutting away (relieving) the internal threads to allow full engagement up to the shoulder in which case you simply need to do that and you'll be off and running. But it would be good to know if your spindle shoulder has been cut back enough to make it non-standard.
Mark
 
I can't explain why your faceplate does not fit properly if it is indeed a Logan original part. It may not be.
Mark
 
If you need some guidance doing the thread relief let us know- you'll need a boring bar and you'll need to machine a temporary spacer
Mark
 
I can't explain why your faceplate does not fit properly if it is indeed a Logan original part. It may not be.
Mark


Could be tooling from another lathe: a number of lathes came with that thread. They also could be backplates that were partially machined
and needed finishing, which was never done properly.
 
I found this for you. Page 4 of the instruction manual says it has 3 rows of sealed bearings. If you do take it apart check the spindle by setting it on precision V blocks and indicate it to be sure it's not bent. Also when your ready to install new bearings we can talk about Instaalling them so the TIR run out is at the low side. Near the bottom of the first PDF shows the spindle assembly in 2 pictures. If you can You could donate something to them as it's an .org.

http://www.vintagemachinery.org/pubs/2093/3353.pdf
http://vintagemachinery.org/pubs/2093/3377.pdf
 
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