Shopsmith Forums

I have a SS 520 and recently I have been having problems horizontal boring pen blanks. I have adjusted the tailstock to lineup as perfectly as I can get it using a pen mandrel and a mandrel saver. Problem is when drilling, with drill chuck in the headsotck, the hole is centered going into the pen blank but is off center as it exits. Problem really shows itself when spinning the pen blank and moving the blank into a drill bit being held in the tailstock. Bradpoint on the drill is not in the center of the blank which results in a hole be much to oversize. Pictures attached show the tailstock angled toward the headstock. With a Wixey gauge the difference is only .25 degrees from vertical. Using the below setup will show the gap at the bottom of the square to be 11/64". If I put pressure on the tailstock it will set square so with a pressure from the quill will square it up. With drilling pen blanks not a lot of force is required or needed so the "elements" are not square. Question: Seems I may have heard that this is normal so the tailstock is square when there is pressure on it. What do you experts say? Regards,
Dwight

WHY are you using the tailstock when 'horizontally drilling the holes'?

As for the tailstock wiggle, is there clearance between BOTH ends of the knurled 'handle' and both sides of the hinge casting? That insures BOTH mounting tubes are equally clamped.

JPG wrote:WHY are you using the tailstock when 'horizontally drilling the holes'?

As for the tailstock wiggle, is there clearance between BOTH ends of the knurled 'handle' and both sides of the hinge casting? That insures BOTH mounting tubes are equally clamped.

Correct me if I am wrong, but without any wiggle the cast surface of the tail stock is not a reference surface that is necessarily perpendicular to the table.

When you wiggle the tailstock you should be able to see where the play is coming from. Only two places it can occur which is at the clamp or at the point the way tubes enter the casting. Either should be an easy fix. I agree with John that the flat surface of the eccentric bushing on the tailstock is probably not a great reference point. The only other thing I can think of that might cause a misalignment of the tailstock to the quill would be a problem with the eccentric bushing in the tailstock. If that bushing is not aligned perfectly, whatever you fit in the #2 Morse hole would not be aligned parallel to the quill. It might be possible to reverse one of the chuck arbors and chuck it up on the headstock and see how the Morse end slides into the tailstock bushing. That might give you an idea of how parallel things are. I'm not home or I would try it. Not sure if the taper grind on the tailstock chuck arbor will interfere with tightening it in the chuck. It also would require the 5/8" chuck.
Paul

Not sure if I am out of place here,,,,, however,,,, there is a SS hands on video on youtube that says the arbor on a MKV can wobble .005 " could that be the issue?

Another thing could be ,,,depending on the depth of the drill cut ,,the bit may be following the grain ,,,,.what happens if you slow way down on the speed of the cut and increase the drill speed ?

I have not attempted to do a measurement but I do know the tail stock moves without a lot of pressure. The movement is between the tubes and the openings in the tail stock. I heard of several "fixes" but I have not attempted to apply them.

I like to use a pen chuck and then the drill bit in the drill chuck on the tail stock. You do need to made sure the centers align, best done with a point in the chuck and the drill bit. You can preload the tail stock with a little hand pressure back away from the headstock direction when doing the alignment and see just how far back it is going to move..... This might be a more accurate way to see what is happening.

I try to limit the pressure I use to do the drilling. Letting the bit do the work and feeding lightly seems to help, just don't go to slow.

Ed

If you want to solve the issue there is a way. Some time ago I needed a perfectly solid tailstock solution and the play in the stock tailstock was an issue and has been a point of discussion before. I purchased a stripped down headstock with just a quill and put it on the tubes in opposition to the headstock and it provides a rock solid tailstock. I still haven't mastered the art of posting links to previous posts but the title of the post was " It Works ! " which has some photos of the setup. It works very well.
Paul

Assuming the quill with drill chuck and tailstock adapter will reach the tailstock MT2 bore, I think that is an good way to get the tailstock eccentric 'aligned' to the quill. However there is not a precision fit between the eccentric and the tailstock.

I consider the tailstock to be adequate for it's intended purpose(support a center). As a chuck/drill bit mount, a bit less so.

To me the important thing is the centers be on a LINE coincident with the quill axis of rotation.

Here is "it works"
http://www.shopsmith.com/ss_forum/woodw ... 9-s10.html

On my Mark V 520, the tailstock has noticeable wobble when installed in the usual position, i.e. the right end. Once, when experimenting with alignment, I installed the tail stock on the left end and was shocked to discover that the tail stock was rock solid when installed there. Not sure why the difference, but it was so apparent that I made a mental note of it.

algale wrote:On my Mark V 520, the tailstock has noticeable wobble when installed in the usual position, i.e. the right end. Once, when experimenting with alignment, I installed the tail stock on the left end and was shocked to discover that the tail stock was rock solid when installed there. Not sure why the difference, but it was so apparent that I made a mental note of it.

Check the clamps for clearance at both ends when 'clamped'?