Making a mandrel/ lathe issues

[Displaced Canadian]

Thinking of buying a collet chuck and making my own mandrel. How does one deal with the 60 degree point in the far end?
I like using a mandrel but I think there might be an issue with the taper on my lathe. When I put the mandrel in the taper sometimes it lines up quite well and sometimes not. I've cleaned it out and it looks clean. It's the black lathe you buy at Rockler. The points line up but when you put the mandrel in the far end wobbles a little when you turn it by hand. Any ideas?

 

[KenV]

Mandrels are "D" sized rod -- a nominal 0.246 inch. Usually available as ground O-1 drill rod (silver steel in the UK)

Most are faced with a metal lathe and bored to provide a dimple. Then threaded if a nut is to be used.

With the "mandrel saver" type live centers, one need only deburr the end and go.

Collet chuck allows easy mounting.

The mandrel runout (deflection) can be caused by "whip" because the mandrel is pretty flexible -- it has a long length in relationship to the diameter and will bend under gravity when cantilevered out more than a few diameters extension. That is why support at the tail stock is needed to hold it in closer alignment.

 

[keithlong]

If you buy a collect chuck, then just buy the mandrel saver and a piece of 1/4 inch drill rod and cut it to the lenght you need. I used my 1/2 inch drill chuck to hold mine. Also if you have an adjustable mandrel, it has a collect chuck, you just need the drill rod and mandrel saver.

 

[jd99]

Is this the lathe?

I have this lathe and never got the centers to line up, I gave up trying to turn on a mandrel a long time ago.

I use TBC Bushings, (My own design) and have never had any out of round issues since.

I would suggest you try turning between centers either with bushings or without but you will find it a lot easier (at least I did) and your pens come out better.

 

[Displaced Canadian]

That would be the one. It has always been just a little off. It's still not a bad lathe for the money.

 

[KBs Pensnmore]

I would say at a rough guess that the head stock is out by a degree or two.
Mount a straight dowell in it and see how far out it is at the end about 12"+ long.
Kryn

 

[jd99]

I would say at a rough guess that the head stock is out by a degree or two.
Mount a straight dowell in it and see how far out it is at the end about 12"+ long.
Kryn

That would be a good fix if the tail stock didn't have all kinds of slop (at least mine does), there is no sence trying to align the head stock, when the tail stock can move .050" to .060" side to side in the ways (if you can call them ways on a wood lathe).

If it was causing me issues I would remachine the ways/bed and fix the tail stock to line up, but it's not worth the time because it doesn't cause me any issues.

 

[Dale Lynch]

You could also do what I did to solve runout.I turn custom mandrels out of wood using a chuck and friction fit the barrels.No need for bushings or barrel trimmers.

 

[KBs Pensnmore]

Get hold of a Morse taper reamer in the size of your lathe (not sure if its #1 or #2) and clean it out, as a bit of dirt, sawdust or ding could cause your problem of run out.
Also using a Mandrel Saver will help a lot. If the tailstock is not in line, using a MS might cause early failure of the mandrel as it will flex at one particular spot.
Kryn