Jet 1014 Tail Stock Spindle Problem

[Dave_M]

I've had this lathe about 2 years now and it's been a great tool. I recently decided to try drilling on the lathe and that's when I noticed the problem. The tail stock spindle has a considerable amount of play. About 1/32" on the horizontal plain and about 1/16" on the vertical plain. It's not as noticeable with a live center but add a drill chuck with a drill bit sticking out there and it becomes very noticeable.

I haven't experienced any out of round issues when turning and drilling on the lathe seems to put the hole centered. What I did notice is when withdrawing the drill bit from the hole and then driving it back in, it doesn't strike the hole centered. Once there is some pressure on the the bit it seems to align back to center. The drilled hole is centered but slightly enlarged because the bit is off center until pressure is applied from the stock I'm drilling.

I did some searching and I really haven't found any info that specifically addresses this issue. I'm not exactly sure where to go with this just yet, but I thought I would start by asking here. Anyone ever experience something similar? If not, I'll be sure to update the thread as I work through the problem so the information is here for someone else to find.

Thanks guys. I really appreciate the help.
Dave

 

[Chthulhu]

A number of possibilities come to mind, but I want to be sure we're talking about the same thing. When you say "play" do you mean that you can move the "spindle" (properly, the part that moves in and out but doesn't rotate is the quill) inside the tailstock casting? That would mean that there's considerable wear to either the quill or the casting, and the larger amount being vertical could be the result of putting far too much tailstock pressure on the work.

If you meant, however, that the tip of the drill bit is misaligned by 1/32" horizontally and 1/16" vertically without the quill actually moving, then you have a misalignment somewhere. It could be the tailstock casting at the ways; there could be some debris in the taper pocket of the quill; the taper of the drill chuck could be bent; or the headstock may be misaligned on the bed rather than the tailstock.

Tailstock to bed misalignment is usually due to either crud built up on the bottom of the casting, or wear of the casting. Release the tailstock clamp and try to twist the casting from side to side (you may need a dial indicator to see any movement). If there's no movement, remove the tailstock from the lathe and check that the part of the casting that rests on the ways is clean and smooth. A tiny bit of crud can cause an amazing amount of misalignment. If the tailstock moves, slide it to a different position on the bed and repeat the process. If it moves by the same amount, the key portion of the casting is worn; you can either rebuild that portion (braze a bead on the side of the key and mill it back to the correct size) or replace the casting.

Debris in the taper pocket is easy enough to deal with, and since you're probably not turning metal there's little likelihood of chips being embedded in the pocket wall, but check that the pocke is clean and smooth throughout. Likewise check that the taper of the drill chuck (and anything else you use in the tailstock) is clean and smooth.

Checking whether the drill chuck taper is bent is a matter of setting up the same conditions you described; then removing only the drill chuck, rotating it 180 degrees and reinstalling it. If the drill bit hits the part in the same place, the taper is not bent.

A misaligned headstock isn't likely based on the design of this machine, but you can loosen all four of the screws holding the headstock to the bed, give the headstock a couple of raps with a rubber mallet, and retighten the screws.

Oh, by the way, hello! I'm new here, and haven't started turning any pens yet, but I spent twenty years repairing machines for Snap-on Tools and thought I could help a bit.

 

[Dave_M]

Thanks Mike,
I am referring to the part that moves in and out of the tail stock casting. It's the quill that's actually moving by that amount. If I draw the quill back into the tail stock and check the alignment using two centers, the centers will meet tip to tip so alignment seems to be good. If the quill is fully extended out of the tail stock, the tail stock center droops and doesn't meet the head stock center tip. It doesn't seem to matter whether I use my centers or the drill chuck. I get the same degree of error. Hard to imagine I'm putting too much pressure on the tail stock. Seems like I would bend the heck out of my mandrels before that ever happened.

Bummer, although I was thinking along the same lines. I appreciate your input Mike. It sounds like you have a lot of experience to offer up. Welcome to the forum!

Dave
Clovis Ca.

 

[KenV]

Dave -- on my Jet 1014 it helps if I keep the quill relatively inside the tube and avoid extending it more than about 1/2 to 2/3 of the travel. When extended there is a lot of cantilever hanging out there.

Teach taught me that bits are pretty much self centering (if ground well) and the tail stock can be loose and pushed ahead to drill. One hand on the chuck and one hand on the tail stock.

Even on my big lathe --- things get more loose when the tailstock is extending all the way.

 

[aggromere]

I think my jet lathe does the same thing. The more the quill is extended the less support it receives from the tailstock casting thus the droop. I purchased a special tailstock nut from Johnny CNC that looks more like what would go on a metal lathe than the big washer that comes on the Jet. it fits precisely between the ways. If i withdraw the quill into the tailstock casting (but leave enough extended to hold the MT2 on the drill chuck) it has no play in it at all. I too can then slowly advance the entire tailstock into my blank for drilling on the lathe. Sometimes this seems to work better than turning the wheel and extending the drill bit. Just my two cents worth.

 

[Chthulhu]

Thanks Mike,
I am referring to the part that moves in and out of the tail stock casting. It's the quill that's actually moving by that amount. If I draw the quill back into the tail stock and check the alignment using two centers, the centers will meet tip to tip so alignment seems to be good. If the quill is fully extended out of the tail stock, the tail stock center droops and doesn't meet the head stock center tip. It doesn't seem to matter whether I use my centers or the drill chuck. I get the same degree of error. Hard to imagine I'm putting too much pressure on the tail stock. Seems like I would bend the heck out of my mandrels before that ever happened.

Bummer, although I was thinking along the same lines. I appreciate your input Mike. It sounds like you have a lot of experience to offer up. Welcome to the forum!

Dave
Clovis Ca.

Dave, then your terminology was correct. Since Ken and Peter suggest the same issue with their lathes, it seems inherent in the brand. The problem *can* be corrected, or at least minimized, but it takes some work (boring out the talistock casting at the front end and installing a sleeve). As the other gents suggest, best in your case to just not extend the quill any further than needed for the job. This will also help to reduce the wear I was thinking of.

I'm assuming that everyone here keeps their tools properly cleaned and lubricated.

 

[Dave_M]

Thanks for all the info guys. I've been thinking about ordering that piece from JohnnyCNC anyway so might as well give it a try. I also found if I lift up on the spindle with my hand it will land dead center.