Can You Change the Position of the Headstock Lock Wing Nut?

getnby41 · Post by **getnby41** » Fri Feb 10, 2012 7:48 pm

[quote="JPG40504"]Since the wedges are free to rotate in the bore, they can get cocked if the wedge is slightly worn(remember that 0.02") on one side.

Loosen and rattle may reorient the cocked wedge, but since it got cocked before, it could get cocked again.

Here's hoping yours does not!]

I also have the problem of the 4 / 8 position of the headstock lock knob. I understand the function of the locks. They have to put pressure on the casting and the tubes to lock. Would there be enough room around the wedges to slide a small shim around the bottom of them to reposition the knob?

JPG · Post by **JPG** » Fri Feb 10, 2012 8:05 pm

getnby41 wrote:I also have the problem of the 4 / 8 position of the headstock lock knob. I understand the function of the locks. They have to put pressure on the casting and the tubes to lock. Would there be enough room around the wedges to slide a small shim around the bottom of them to reposition the knob?

The wedges squeeze 'in' not 'up'. The fit is too tight anyway..

getnby41 · Post by **getnby41** » Fri Feb 10, 2012 10:13 pm

JPG40504 wrote:The wedges squeeze 'in' not 'up'. The fit is too tight anyway..

The shim will close the opening in the casting causing the wedges to move in with less turns on the knob if they will fit. The casting holes could have signs of ware.

billmayo · Post by **billmayo** » Fri Feb 10, 2012 10:22 pm

Maybe the wedges did get cocked each time. I will try a different headstock tommorow making sure the wedge flat are flat on the tubes. I agree the turning the wedges should not make any change in the handle position.

JPG · Post by **JPG** » Fri Feb 10, 2012 10:47 pm

Never say never until you try!;)

I added a double layer of pop can(about 0.008") under both front and rear wedges, and that changed the wingnut lock position about 90 degrees!!!!!!!!

I would not have thought that would be enough, but it was!

My 'shims' were only about 3/8" wide.

Making them long enough to bend down inside should prevent them from getting 'lost'.

The shims should not be so tight as to prevent the wedges from sliding in the bore.

Trial done with a greenie carriage and those quills mounted in an end casting..

dusty · Post by **dusty** » Sat Feb 11, 2012 7:10 am

This is one of those threads that for some strange reason captures my interest. I don't know why but it does. Even though it will probably lead no where.

I have two Mark Vs to play with and compare.

On one, with the headstock lock finger tight, there is NO push pull movement at all. On the other, there is about 1/8" movement. I view the exposed wedge lock (on the operators side) to see this.

On one machine, the handle is at 3:00/9:00 when tight and on the other it is at 4:00/10:00 when tight. (only finger tight now, did not crank down on it)

Wonder what would happen if I could change the location of only one wedge lock while leaving the other as it is. In my younger years, I would go take the headstock off and try this. No more. I don't like to move the jointer anymore either.

I think it would result in some push/pull movement in one direction when locked but not in the other. (wedges tight against only one tube)

JPG · Post by **JPG** » Sat Feb 11, 2012 9:59 am

dusty wrote:This is one of those threads that for some strange reason captures my interest. I don't know why but it does. Even though it will probably lead no where.

I have two Mark Vs to play with and compare.

On one, with the headstock lock finger tight, there is NO push pull movement at all. On the other, there is about 1/8" movement. I view the exposed wedge lock (on the operators side) to see this.

On one machine, the handle is at 3:00/9:00 when tight and on the other it is at 4:00/10:00 when tight. (only finger tight now, did not crank down on it)

Wonder what would happen if I could change the location of only one wedge lock while leaving the other as it is. In my younger years, I would go take the headstock off and try this. No more. I don't like to move the jointer anymore either.

I think it would result in some push/pull movement in one direction when locked but not in the other. (wedges tight against only one tube)

If you can cause movement by pushing/pulling, the wedges are not in locked position. Both wedges must be 'squeezing' the way tubes to 'lock'. If the wingnut is feeling 'finger tight' and motion is possible, something else is providing tactile feedback(cruddy threads or wedge bore).

Again moving either wedge independent of the other will not alter the wingnut 'lock rotational position'

FWIW BTW As clarification, a Greenie carriage lock is identical to a headstock lock.

Pop can(thin) shims can be inserted from the outside without removing the headstock from the way tubes.

robinson46176 · Post by **robinson46176** » Sat Feb 11, 2012 10:55 am

This might be a good solution for some folks (I didn't chase down prices). These are black oxide finished steel in diameters up to 3".
More info:
http://www.northwesterntools.com/-c-344_27.html
Lots of places carry similar in various materials.
They are also easy to make from the wood of your choice on a Shopsmith making the notches with a Forstner bit.

[ATTACH]16162[/ATTACH]

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mountainbreeze · Post by **mountainbreeze** » Sat Feb 11, 2012 2:03 pm

Well, I tried Bill's proposed solution of rotating one of the wedges one turn and it resulted in no change in the "tightened" position of the wing nut (as predicted by JPG). Oh well, it was worth a try. Now I'm intrigued by the shim solution offered by JPG but I don't get how to add a shim that will stay put and not interfere with normal operation.

JPG · Post by **JPG** » Sat Feb 11, 2012 3:36 pm

mountainbreeze wrote:Well, I tried Bill's proposed solution of rotating one of the wedges one turn and it resulted in no change in the "tightened" position of the wing nut (as predicted by JPG). Oh well, it was worth a try. Now I'm intrigued by the shim solution offered by JPG but I don't get how to add a shim that will stay put and not interfere with normal operation.

Getnby41 is the originator of that shim fix.

I also was doubtful: Until I tried it!

I doubted there would be enough slop in the bore for a shim. I doubted there would be enough in/out change by shimming vertically.

I tried it anyway and lo and behold!!!!!!!

The wedges do not contact the outer edge of the way tube, but below that and on the curved surface. The wedges are at a 60 degree angle from vertical. That means it takes less movement vertically to equal the effect of horizontal movement(.866/.500)[Sin60/Cos60).

I measured the pop can shims and they were actually 0.003.

So 2x0.003x2 = 0.012 is about equivalent to 0.02 horizontally.

If you 'pre curve' the shims they slide in easily from the outside. Being at the bottom, they should stay put(until raised to vertical). Need to watch for sliding 'out'.

Dusty: I think we have gone somewhere in this thread!

JMHO!:)