Tailstock Quill Binding!

Tailstock Quill Binding! · 11-06-2009, 07:27 AM

Okay, so I had some free time last night (which is rare for me lately!) and I wanted to try turning a travel coffee mug:

Anyway, I got as far as boring out a starter hole on the inside when I noticed that my tailstock was binding badly while I was trying to bore the hole with a fostner bit mounted in a jacobs chuck. I had to use both hands and all my strength to get the hole bored and then to retract the bit. It seemed to get worse as I went. Worried that the threads were damaged or gunked up I decided to pull the tailstock apart. The threads looked fine and with the quill out of the tailstock casting I was able to easily thread the quill the entire length of the threaded rod. When I tried to put the quill back into the tailstock casting I discovered my problem. It just doesn't want to go into the tailstock even with lithium grease lubricant! What could be causing the binding? The lathe is in my basement where the temperature is in the mid 60's. Could the casting be contracting more than the quill when cold? I am kinda stumped and am looking for suggestions on how to fix this.

flyrod444 · 11-06-2009, 07:47 AM

Sounds like you need to take the quill out of the tailstock and clean the threads and check them out as well. If the threads are still ok some of your grease on them will insure that they stay that way. To take the quill out their is a small screw infront of the knob that tightens it down you need to loosen and it should screw off the screw inside the tailstock and slide out.
Good Luck,
Jack

timf67 · 11-06-2009, 07:52 AM

Originally Posted by flyrod444

Sounds like you need to take the quill out of the tailstock and clean the threads and check them out as well. If the threads are still ok some of your grease on them will insure that they stay that way. To take the quill out their is a small screw infront of the knob that tightens it down you need to loosen and it should screw off the screw inside the tailstock and slide out.
Good Luck,
Jack

Jack, I got that far with it. The threads are fine, but the quill just doesn't want to slide freely in the tailstock casting. Seems like the quill is "swollen" or the tailstock casting has "shrunk". I don't want to affect the alignment by messing with it too much, so I am looking for ideas on how to "fix" the problem.

woodArtz · 11-06-2009, 08:24 AM

Ok, let me see if I understand you correctly. Are you saying that the tailstock ram is binding as you attempt to run it in or out? If that is the case and the threads seem ok, I wonder if the ram twisted on the set screw. If this happened while you were drilling, that may be the case. Back out the set screw and check it for damage. Also, disassemble the tailstock and look at the outside of the ram and the inside of the casting in the area of the set screw. If I'm way off base... never mind

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timf67 · 11-06-2009, 08:36 AM

Originally Posted by woodArtz

Ok, let me see if I understand you correctly. Are you saying that the tailstock ram is binding as you attempt to run it in or out? If that is the case and the threads seem ok, I wonder if the ram twisted on the set screw. If this happened while you were drilling, that may be the case. Back out the set screw and check it for damage. Also, disassemble the tailstock and look at the outside of the ram and the inside of the casting in the area of the set screw. If I'm way off base... never mind .

You're not off base, but I checked that too. The set screw is completely removed and I checked inside to see if there was any protrusion from the set screw hole - nothing that I could see/feel. Now I did notice that there were sharp edges on the set screw channel cut in the quill/ram. I may try filing these down smooth to see if it helps.

timf67 · 11-06-2009, 09:55 PM

Solved! After filing off the "burr" around the channel in the quill, it moved much more smooth in the tailstock. It appears as though the rotational force on the quill pushing on the locking screw as I was advancing the quill caused a burr to form on the lip of the channel. Lesson learned.

Gotcha6 · 11-06-2009, 10:14 PM

Most wood lathe tailstocks aren't made to transfer the axial loading from boring a large hole. You might check your setscrew & see if you are able to file a flat on it or file off the threads where it rides in the slot. There should be some type of jib or adjustment mechanism there to let it ride on instead of the raw edge of a screw thread.

woodArtz · 11-06-2009, 10:41 PM

Glad you got it!