Thread: Which Chuck

That's only true if there's no wobble at the back of the chuck.

eg. if the deviation is exactly the same at both ends of the chuck, then the chuck is still running parallel to the axis of rotation, even though it's not central on the axis. So even a foot or two away the blank would have the same deviation.

An unlikely case, but it shows that you can't extrapolate from one set of readings...

Further, if the body of the chuck is running true at both front & back & it's only the jaws that are out, then your blank will spin true. Reverse chucking would be a nightmare though.

My mind hurts.

Frank, as best I can make it out your figures are right for deviation from the axis but the wobble would be double ie. measured at a bowl rim the range of movement at right angle to the axis.

Still negligible.

Originally Posted by Skew ChiDAMN!!

Further, if the body of the chuck is running true at both front & back & it's only the jaws that are out, then your blank will spin true. Reverse chucking would be a nightmare though.

This is a very real possibility as the jaws are made seperately to the chuck. To achieve the least runout possible the jaws should at least be machined on the chuck they are to be used on, to go to extremes they actually should be machined on the intended lathe to eliminate all possibility of runout. However the reality is with so many "special purpose" jaws available from a multitude of manufacturers plus inserts from just as many manufacturers all with (probably) different tolerences plus the wear on an old chuck..................... I think you can see where I'm going with this, I'd live with 0.005" runout.

yep...I'm ready to get the duct tape also, all this math is taking it's toll and the mind is glazing over big time.

Keepin' the fingers crossed that Craft Supplies comes thru with a sweet running insert.

Ed just got off the phone with Adrian at Trend Timbers getting a 1x10 adaptor sent out today may as well try see what happens.

What size is your adaptor insert not sure if you have said or I didn't read the thread of what lathe its on

Adrian mentioned he is only having trouble with certain sizes inserts

Whellin' ...My lathe is a Nova 1500, it has 1 1/4 x 8tpi ...thought buying from Tek that everything would just "snap" into place and run true and fine - NOT .

Just a thought and GJ maybe could give some knowledge here

You fit the adaptor nut to the chuck there is a slight play between the threads, you tighten up then tighten the grub screw ..........but in doing so the grub screw is actually putting pressure on one side which is then tilting the nut and chuck to an untrue balance.

forgot to mention also ordered a set of Pin Jaws from Trend also

My SN2 has 2 grub screws, diametrically opposed.

But then again, I bought mine back when Teknatool cared about quality.

Originally Posted by wheelinround

Just a thought and GJ maybe could give some knowledge here

You fit the adaptor nut to the chuck there is a slight play between the threads, you tighten up then tighten the grub screw ..........but in doing so the grub screw is actually putting pressure on one side which is then tilting the nut and chuck to an untrue balance.

forgot to mention also ordered a set of Pin Jaws from Trend also

It is possible that the single grub screw could cause the chuck to r/o slightly.

Originally Posted by Skew ChiDAMN!!

My SN2 has 2 grub screws, diametrically opposed.

But then again, I bought mine back when Teknatool cared about quality.

3 grub screws would be better.

Ok John

way's of testing I can think of for actual fit is mic both ends of the nut external, mic the internal make sure they are square and not tappered, bearing blue or plastigauge.

Try the fit of a pre-Chinese made nut and check balance of chuck and visa versa

Originally Posted by wheelinround

Just a thought and GJ maybe could give some knowledge here

You fit the adaptor nut to the chuck there is a slight play between the threads, you tighten up then tighten the grub screw ..........but in doing so the grub screw is actually putting pressure on one side which is then tilting the nut and chuck to an untrue balance.

forgot to mention also ordered a set of Pin Jaws from Trend also

or you don't bother with the grub screw. None of mine have ever been fitted.

I was gunna add some more here but I'm over it

Time to head to the shed and fix boot rocker on my touring skis. New bindings have left the boot heel 30 mm above the plate it should sit on. Wedge shaped shims had to come from Utah with no guarantee they'll be enough. All the key screws were epoxied in and have to be heated to depoxy.

Don't ya just hate Yank QC?

Anyone else had boot rocker?

Originally Posted by rsser

I was gunna add some more here but I'm over it

Time to head to the shed and fix boot rocker on my touring skis. New bindings have left the boot heel 30 mm above the plate it should sit on. Wedge shaped shims had to come from Utah with no guarantee they'll be enough. All the key screws were epoxied in and have to be heated to depoxy.

Don't ya just hate Yank QC?

Anyone else had boot rocker?

You're gunna need a height gauge and a set of AAA slip_gauges to measure any errors Ern .

Cool.

I could get back to Utah and whinge about their gear being 0.000002 of an inch out!