Little Havana pens

[Brad Hammond]

hey all. i was wondering if anyone else was having a "wobble" problem with the little havana pens. it seems like the mandrel is bending or something, but i tried 3 different mandrels.
the center of the mandrel and bushings are not turning on their center. i can loosen the mandrel nut and it seems to help, but the blanks slip a little. kinda makes them out of round. i've been able to get around the problem by shifting them a little for a final fitting and turning, but i wanted to see if anyone else was having this prob.
the bushings are sound. i can place them next to the mandrel and they're round. just seems to be in the center where the mandrel rod tries to bend or something.
thanx ya'll
brad

[Ken Salisbury]

hey all. i was wondering if anyone else was having a "wobble" problem with the little havana pens. it seems like the mandrel is bending or something, but i tried 3 different mandrels.
the center of the mandrel and bushings are not turning on their center. i can loosen the mandrel nut and it seems to help, but the blanks slip a little. kinda makes them out of round. i've been able to get around the problem by shifting them a little for a final fitting and turning, but i wanted to see if anyone else was having this prob.
the bushings are sound. i can place them next to the mandrel and they're round. just seems to be in the center where the mandrel rod tries to bend or something.
thanx ya'll
brad

It would seem to me that too much pressure from the tail stock. Tail stock live center should only be lightly applied to the end of the mandrel.

[Scott Greaves]

Hi Brad,

Ken's suggestion is the most likely. Which mandrel are you using? Where the Havana is a Craft Supplies kit, you want to make sure the mandrel is not undersized. PSI mandrels are a bit undersized at times. Check again to make sure the mandrel isn't bent. One of the weaknesses in turning big pens is having to turn them on a 7mm mandrel. As you spin a bigger, heavier piece of wood it can produce "whip" in the mandrel, or at the very least if there is any variance in how the center bushing fits it will accentuate it. Berea has improved the situation with their larger kits by using the "B" mandrel, which is much thicker and stiffer than the 7mm (not really 7mm) "A" mandrel. Turning at lower speeds while you rough your blank to round might reduce the whip, if that's the problem.

Good Luck!

Scott.

[Brad Hammond]

i have the standard 7mm mandrels like you get at woodcraft. i also have the berea mandrels, but all had the same prob.
i'll double check that i'm not screwing the tailstock onto the mandrel too hard.
i've got a couple of more orders, so i'll have to get it figured out.
thanx alot ya'll
brad