Tail stock side play repair

[Gordon Stump]

I center drill lots of short dowels. My lathe tail stock is off center enough at the center points (side to side) to see a noticeable angle when inserting hanger bolts as well as being off center. Twisting the tail stock clockwise before clamping mitigates the problem but I am often not consistent in my twisting!

There is not any visible play at the ways. Gluing on extremely thin brass shim stock to the tail stock sides seems like a problem waiting to happen. I am thinking about drilling for brass rod in the sides of the tail stock ways and fine tuning. That way I could replace it if it wears out.

What do you think about this? My tailstock sits flat and there is no twist in the casting. It is a Rikon mni lathe.

Thanks for reading.

Gordon Stump

[John Keeton]

Have you checked the level of your lathe bed in all directions including diagonally? That typically is where this problem occurs.

Winding sticks work well for the diagonal process.

[Gordon Stump]

Thanks John. I checked that out first thing. I just checked it again. Suffice to say that casting is as flat as it is going to get! I know the Rikon is not a high end wood lathe but it is better than some other entry level ones. Manufactured wood doweling is not really round. I sell lots of these so turning them perfectly round is not cost effective. Adding the side play slop adds to the out of roundness.

Thanks again for your reply.

[John K Jordan]

Thanks John. I checked that out first thing. I just checked it again. Suffice to say that casting is as flat as it is going to get! I know the Rikon is not a high end wood lathe but it is better than some other entry level ones. Manufactured wood doweling is not really round. I sell lots of these so turning them perfectly round is not cost effective. Adding the side play slop adds to the out of roundness.

Thanks again for your reply.

If you slide the tailstock up close to the headstock with points in each do the points align or is one off horizontally? If off, crank up the leg leveler on one of the legs to align. I usually adjust one of the front legs - raising the front right leg will push the tailstock point away from you. If that fixes it but puts something out of level it's not important. I've aligned a lot of lathes that way.

[Richard Coers]

The head must be bolted to the ways. Have you thought about opening up the holes a bit to twist the head slightly? You might also be able to twist the bed by using a shim under one corner to bring the head and tailstock into alignment.

[Alex Zeller]

On my Grizzly the tailstock I believe is machined to fit into the bed ways. It doesn't fit as tight as I would like so my plan was to drill and tap holes so I could put set screws in from the side in all four corners. By adjusting how much each one sticks out I think I can dial it in. For now I do the same as you, twist it. Mind you it's not much play but I can be fussy about stuff.

[Gordon Stump]

My Rikon is a bench top mini lathe. It sits on rubber feet. So I cannot image how it would be twisted or stressed since it is not bolted down. I could try added distortion by bolting it down and shimming but that seems like a solution looking for a problem. The reason I did not want to use steel grub screws was to avoid wear on the ways. But tapping for brass grub screws is a good idea and better than my idea of inserting brass rod and fine tuning with a file.

[Kyle Iwamoto]

If you follow what JKJ says and test your alignment at the headstock and they are straight in line, bolt your lathe down with a washer under the foot to twist it back to level/flat. I have that lathe and that is what I did. I washered up the tailstock end though.

[Gordon Stump]

I want to follow what JKJ says. My headstock has been adjusted and meets the live center tailstock accurately on the vertical & horizontal. It can also swing 1/64 left or 1/64 right of the head stock. That is the play in the machined ways. I am dense in head regarding eliminating slop by adjusting the feet.

[John K Jordan]

I want to follow what JKJ says. My headstock has been adjusted and meets the live center tailstock accurately on the vertical & horizontal. It can also swing 1/64 left or 1/64 right of the head stock. That is the play in the machined ways. I am dense in head regarding eliminating slop by adjusting the feet.

You might have several things going on. I would not want 1/32" lateral play in the tailstock and would devise some way to fix it. Shims are a mess but the set screws could help. (Years ago I shimmed my tailstock before I learned about the leg adjustment method.) I wouldn't worry much about steel set screws messing up the ways since you would always need to leave enough play to slide but the brass set screws should work. Cast iron is usually easy to drill and tap. You can also buy set screws with brass inserts that might be better if the tailstock is hollow and you can adjust a screw from the inside. This could be tricky to get it right, sort of like aligning a sliding table on a table saw.

Even if the points align perfectly the axes of the headstock and tailstock may not be aligned. If there is play in the headstock and/or the tailstock you might want to hold things straight while eliminating the play. Nova makes an alignment shaft with morse tapers on both ends to align their lathes with the swiveling headstock - put one end in the headstock and the other in the tailstock. https://www.amazon.com/71001-Lathe-A.../dp/B07GFR2ZVY It's not cheap but maybe someone in your club has one.

A lathe does not have to be fastened down to twist the bed. Just the weight of the bed on uneven feet can do it, especially if it's a heavy lathe. It seems unbelievable, but cast iron is actually flexible and the bed can easily twist even on a massive lathe if one leg is a bit out of the plane of the others or if there is a manufacturing variation. Adjusting one leg will twist the entire bed back into position. Such alignment is not much of an issue when turning a long spindle but can be a real problem with precision work, small work with the tailstock close, or even bowls/platters when held by the tailstock. If the bed is twisted but the lathe doesn't have leg levelers shimming should work fine. I check this alignment every time I move a lathe since the floor surface might be different. Maybe try locking your headstock down with the points aligned perfectly then pry one foot off the bench a bit and see if it changes the alignment. (Note that aligning the points with this method has nothing to do with eliminating the slop.)

We had Mark StLeger in for an all-day demo at our club and just before the break he noticed the headstock/tailstock misalignment on our Jet 1642 and said it was going to make his next step difficult. During the break I lifted the end of the lathe to take the weight off and turned the leg leveler on one of the legs with my finger - it took all of 30 seconds to fix the problem.

I'd definitely want things aligned when drilling. And if you haven't tried them, starting holes with a center drill bit can eliminate lots of problems. I paid less than $10 for a set like this:
center drills.jpg
I keep one in a Jacob's chuck all the time for starting holes at the lathe. For shallow holes and just before drill deep holes I use a screw machine bit after the center drill. These are stubby to prevent flexing.

Another thing that has improved my drilling on the lathe is using taper shank bits instead of putting normal bits into a jacob's chuck. Taper shank bits have a morse taper on the end that fits directly into the tailstock and eliminates the length and precision issues with using a jacob's chuck.

taper_1_IMG_20160919_094408.jpg


JKJ

[Gordon Stump]

Thank you John for taking the time to address my query. I am definitely going to do the twist! I am also going to drill and tap for the small grub set screws. A small deviation from a linear plane gets exaggerated the farther out from the hole you go. I had a few come back in the last 10 years. Not bad out of several hundred but it still drives me crazy.

Thanks again.

[Leo Van Der Loo]

The tailstock is usually a rather loose fit in the wood lathe ways.

I had a Delta Midi lathe (LA 200) where I found the fit too loose for my liking, as I could wiggle he tailstock left to right, where the alignment was pretty good but could be off some by twisting the tailstock to one side or the other.

So I got out my assortment of shimming stock and found one that would eliminate pretty well all play while still have the tailstock slide smoothly in the ways.

So I cut a strip just as wide as the foot and long enough to be able to bent around the front and back by about 3/16”, glued it on the foot and drilled two small holes in the ends that were bent around the corner of the foot, and inserted small brass nails I had, I just used medium CA to glue the shim to the foot, stayed on just fine, picture shows the shim on the foot.

Shim on tailstock foot.jpg

[John K Jordan]

Thank you John for taking the time to address my query. I am definitely going to do the twist! I am also going to drill and tap for the small grub set screws. A small deviation from a linear plane gets exaggerated the farther out from the hole you go. I had a few come back in the last 10 years. Not bad out of several hundred but it still drives me crazy.

Thanks again.

I may have missed where you mentioned it - what is that thing you make??

Maybe sell enough and get a better lathe! I see no play in my larger lathes.

JKJ

[Gordon Stump]

I may have missed where you mentioned it - what is that thing you make??

Maybe sell enough and get a better lathe! I see no play in my larger lathes.

JKJ

You got me there John! That thing is a cylindrical bore piccolo peg on a single flute base. I am a wind player who sells to other wind players. We are all kind of dizzy but we get along!!

[Gordon Stump]

Update: Tailstock drilled and tapped for set screws; feet leveled and casting flat. No more play. Thanks