Whats happening here????

[Rob Littleton]

I got back from a buddys house tonight and spent some time turning some pens on his lathe. He has the Mercury (Teknatool) mini lathe from Woodcraft and a regular mandril. With all the pens whe made tonight, from 7mm to cigar pens, once they were assembled, the rings in the middle seemed off center on one side. This is true for the nibs and the pen clips. Strange considering this thing should be spinning in a circle??

Screws up the appearance of the pens after they look so nice polished and buffed.

What should I help him check for? Anyone seen this b4?

Cheers for your help.

[Ken Salisbury]

I got back from a buddys house tonight and spent some time turning some pens on his lathe. He has the Mercury (Teknatool) mini lathe from Woodcraft and a regular mandril. With all the pens whe made tonight, from 7mm to cigar pens, once they were assembled, the rings in the middle seemed off center on one side. This is true for the nibs and the pen clips. Strange considering this thing should be spinning in a circle??

Screws up the appearance of the pens after they look so nice polished and buffed.

What should I help him check for? Anyone seen this b4?

Cheers for your help.

It appears one of two things are amiss. Either you have a slightly bent mandrel or you are apply too much pressure from the tail stock, actually putting a slight "bow" in the mandrel. Ease off on the tail stock and check the results.

[Larry Gottlieb]

Rob,

Ken is right. You have a bent mandrel. I have tried to bend a mandrel by applying too much tailstock pressure while using a dial indicator to determine if there was bending and this probably is not the cause.Jim Heusinger from Berea Hardwoods told me to try this.
Too much pressure while turning or sanding is more likely.

To check this:
Put a pencil on the tool rest and just touch the tip to the mandrel (in the center of the mandrel)
Rotate the lathe and then check to see where the pencil line is.
That is the side that is bent toward you. A small amount of pencil line indicates a large bend. A steady uninterupted line would indicate no bend.

To remedy:
Turn the pencil mark away from you, put a finger on each side of the mark and bend the mandrel toward you.
Remove pencil mark and repeat this until you have as close to a continuous line as you can get.

If you have a dial indicator, of course, use that.

I check my mandrels often and am surprised that, even though I observe the precautions to prevent bending, I find my mandrel going over .003" out of round.I bend back until they are below that figure.

I hope that this is clear. If not let me know.

Larry

[David Spicer]

I was having the same problem as you. What I found out with the drill press table was not square to the bit. It was off by 1 degree. I thought that it is spinning why should it work. I have yet figure this one out.

Dave Spicer