Shopsmith Forums

reible wrote:Since the drill chuck fits on either end of the main shaft another simple experiment would be to mount it and the same bit on the non quill end and see if the wobble is still there........

Ed

Good info, tells if it is the chuck or the main spindle!!!
No JPG on top of this, must be Casino night

Have you cleaned it yet?
Did it help?

Is the Cushman chuck made for the Shopsmith? Specifically, it the bore for the set screw at an angle to match the flat of the quill? Easy test, pull set screw and put the long Allen Wrench in it. Is it at an angle?

Why do I ask? Because I believe if the set screw bore isn't angled to match the flat, then any accessory is likely to have run out introduced when it is seated.

I did clean it up last night. Eyebrow brush (genius! the toothbrush I tried was way too big...) + mineral spirits, got all of the visible gunk/crud out of the jaws. Inspected for damage after cleaning, jaws and everything looked OK -- no visible scoring or other damage that I could identify... not that I'm 100% confident I know what I'm looking for. Didn't bother cleaning up the outside yet, figure it should have no bearing (har har!) on runout.

:drumroll: ...

No luck, still wobbly. Maybe a slight improvement, but hard to tell since I don't have any hard measurements. If I had to put a number to it, I'd say the pilot tip of the forstner bit in question is tracing a circle about 1/32" in diameter... maybe 3/64".

I also had the idea to shine a bright flashlight on the spinning chuck body with the machine on slow, and observe the shadow cast by the chuck body several inches away from the spinning chuck; the theory being that any runout of the chuck body that is invisible to the naked eye would be magnified in the movement of the edge of the shadow at a distance. Similar to how if you shine a laser pointer at a wall 6 inches away and rotate the direction of the laser pointer 1 degree, the red dot on the wall will move a small distance; but if you shine it on a wall 10' away, the same 1 degree rotation of the pointer results in a much larger movement of the red dot on the far wall. Rudimentary for sure, but the edge of the shadow cast by the chuck body did appear to be moving ever so slightly; FWIW, the same test with the shank of the bit just below the cutter head showed considerably more/obvious movement in the shadow. Not sure if that tells me anything definitively, but it's another piece of information nonetheless.

I did also discover that with the quill retracted and locked and the bit chucked, if I grab towards the end of the bit and wiggle it around, there is some play/movement in what I believe is the spindle shaft within the quill housing. It's not a lot, but enough that I can hear it "clunking" and barely see it moving. To be clear, I'm talking about movement perpendicular to the axis of rotation. Could this be further evidence that a two-bearing quill upgrade is needed, or at the very least replacement of the existing single bearing and/or other parts of the quill/spindle assembly)?

reible wrote:Since the drill chuck fits on either end of the main shaft another simple experiment would be to mount it and the same bit on the non quill end and see if the wobble is still there........

Great idea! I'll check it at lunchtime in about 3-4 hours and report back with the results.

algale wrote:Is the Cushman chuck made for the Shopsmith? Specifically, it the bore for the set screw at an angle to match the flat of the quill? ...

My understanding is that the Cushman chucks were original equipment with machines of this vintage (mine is an '82, at least one other report of a Cushman with an '83 model). So, I have to assume the set screw bore is at the correct angle.

No luck -- bit still wobbles with chuck mounted on upper auxiliary spindle.

Where to from here? Look into getting the chuck fully apart for a complete cleaning and reassembly? Get a dial indicator to measure runout on spindles and/or chuck body?

mjl5007 wrote:I did clean it up last night. Eyebrow brush (genius! the toothbrush I tried was way too big...) + mineral spirits, got all of the visible gunk/crud out of the jaws. Inspected for damage after cleaning, jaws and everything looked OK -- no visible scoring or other damage that I could identify... not that I'm 100% confident I know what I'm looking for. Didn't bother cleaning up the outside yet, figure it should have no bearing (har har!) on runout.

:drumroll: ...

No luck, still wobbly. Maybe a slight improvement, but hard to tell since I don't have any hard measurements. If I had to put a number to it, I'd say the pilot tip of the forstner bit in question is tracing a circle about 1/32" in diameter... maybe 3/64".

I also had the idea to shine a bright flashlight on the spinning chuck body with the machine on slow, and observe the shadow cast by the chuck body several inches away from the spinning chuck; the theory being that any runout of the chuck body that is invisible to the naked eye would be magnified in the movement of the edge of the shadow at a distance. Similar to how if you shine a laser pointer at a wall 6 inches away and rotate the direction of the laser pointer 1 degree, the red dot on the wall will move a small distance; but if you shine it on a wall 10' away, the same 1 degree rotation of the pointer results in a much larger movement of the red dot on the far wall. Rudimentary for sure, but the edge of the shadow cast by the chuck body did appear to be moving ever so slightly; FWIW, the same test with the shank of the bit just below the cutter head showed considerably more/obvious movement in the shadow. Not sure if that tells me anything definitively, but it's another piece of information nonetheless.

I did also discover that with the quill retracted and locked and the bit chucked, if I grab towards the end of the bit and wiggle it around, there is some play/movement in what I believe is the spindle shaft within the quill housing. It's not a lot, but enough that I can hear it "clunking" and barely see it moving. To be clear, I'm talking about movement perpendicular to the axis of rotation. Could this be further evidence that a two-bearing quill upgrade is needed, or at the very least replacement of the existing single bearing and/or other parts of the quill/spindle assembly)?

reible wrote:Since the drill chuck fits on either end of the main shaft another simple experiment would be to mount it and the same bit on the non quill end and see if the wobble is still there........

Great idea! I'll check it at lunchtime in about 3-4 hours and report back with the results.

algale wrote:Is the Cushman chuck made for the Shopsmith? Specifically, it the bore for the set screw at an angle to match the flat of the quill? ...

My understanding is that the Cushman chucks were original equipment with machines of this vintage (mine is an '82, at least one other report of a Cushman with an '83 model). So, I have to assume the set screw bore is at the correct angle.

That is a bad assumption in my opinion.

FWIW, to my knowledge none of the 10ER arbors including the Jacobs 3326 chuck have angled set screws and the quill has same tapered flat as the MK V. Also not all MK V arbors have angled set screws. I have some here that don't and that includes the Shopsmith branded drill chuck that came with my brand new from the factory 1994 MK V 510.

mjl5007 wrote:No luck -- bit still wobbles with chuck mounted on upper auxiliary spindle.

Where to from here? Look into getting the chuck fully apart for a complete cleaning and reassembly? Get a dial indicator to measure runout on spindles and/or chuck body?

I would replace the chuck and see what happens. Jacobs 3326's are on eBay all the time.

jsburger wrote:That is a bad assumption in my opinion.

FWIW, to my knowledge none of the 10ER arbors including the Jacobs 3326 chuck have angled set screws and the quill has same tapered flat as the MK V. Also not all MK V arbors have angled set screws. I have some here that don't and that includes the Shopsmith branded drill chuck that came with my brand new from the factory 1994 MK V 510.

Sure. In fact when I looked at the set screw on the chuck while testing it on the upper aux spindle, it did not appear to be angled. Nor have I ever noticed the set screw on any of the other arbors/attachments being angled.

I think the more important point, though, is that the Cushman chuck C13LS was indeed original equipment with machines of this vintage, so whether or not the set screw bore is angled is irrelevant -- it should work just fine, since it's the drill chuck that came with the machine.

mjl5007 wrote:

jsburger wrote:That is a bad assumption in my opinion.

FWIW, to my knowledge none of the 10ER arbors including the Jacobs 3326 chuck have angled set screws and the quill has same tapered flat as the MK V. Also not all MK V arbors have angled set screws. I have some here that don't and that includes the Shopsmith branded drill chuck that came with my brand new from the factory 1994 MK V 510.

Sure. In fact when I looked at the set screw on the chuck while testing it on the upper aux spindle, it did not appear to be angled. Nor have I ever noticed the set screw on any of the other arbors/attachments being angled.

I think the more important point, though, is that the Cushman chuck C13LS was indeed original equipment with machines of this vintage, so whether or not the set screw bore is angled is irrelevant -- it should work just fine, since it's the drill chuck that came with the machine.

There are some here that think a non angled set screw is almost a show stopper. I am not one of them and agree with what you said above. My guess is (and it is only a guess) given the SS has been made for almost 70 years with the same flat and spindle diameter that there are more SS arbors in the field without angled set screws than with. I certainly have never had a problem with either.

mjl5007 wrote:No luck -- bit still wobbles with chuck mounted on upper auxiliary spindle.

Where to from here? Look into getting the chuck fully apart for a complete cleaning and reassembly? Get a dial indicator to measure runout on spindles and/or chuck body?

What condition are your bit shanks in? Do you bottom out the bits in the chuck?