Shopsmith Forums

Quick way to make a post to handle your dial indicator and all done on the Mark V. You need about 5" of 3/4" drill rod, 3/4 stop collar and a ¼x20 bolt and washer.

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Ingenious! Thanks for the idea.

Yes, very neat solution. It can even be used to measure runout (wobble) at the blade.

Incidentally, what is your measured runout?

dusty wrote:Yes, very neat solution. It can even be used to measure runout (wobble) at the blade.

Incidentally, what is your measured runout?

At the spindle about .001 and with a ½" collet a tad over .002. I am in the process of getting a collet made to go from 5/8 straight to a shortened MT2
dead center for some BTC turning.

Okay. So once I have measured it what do I do with the information?

db5 wrote:Okay. So once I have measured it what do I do with the information?

Each of us sets a tolerance for the project, this tool simply tells us if the machine will perform within that tolerance. I for one am getting old and the Shopsmith always has much tighter tolerance than I.

db5 wrote:Okay. So once I have measured it what do I do with the information?

Excellent Question!

My suggestion, don't just measure runout, but also measure "play."

Set the dial indicator against the spindle, and "push and pull" the spindle, to see if the needle moves, and how much. Set the indicator to hit the side of the spindle, and push against the spindle, then pull on the spindle, to see how much the bearings let it move. Push as hard as you'd push a piece of wood through the table saw, a piece of wood into the sanding disc, or how hard you'd push a lathe tool into a piece of wood also accounting for the rotational or tangental loads. In other words, put some WEIGHT into it. Now, extend the quill, and do the same thing.

On a Model 10, I'd not be afraid to put enough pressure to lift the front or rear wheels. Of course, YMMV.

steve

skou wrote:My suggestion, don't just measure runout, but also measure "play."

Set the dial indicator against the spindle, and "push and pull" the spindle, to see if the needle moves, and how much. Set the indicator to hit the side of the spindle, and push against the spindle, then pull on the spindle, to see how much the bearings let it move. Push as hard as you'd push a piece of wood through the table saw, a piece of wood into the sanding disc, or how hard you'd push a lathe tool into a piece of wood also accounting for the rotational or tangental loads. In other words, put some WEIGHT into it. Now, extend the quill, and do the same thing.

On a Model 10, I'd not be afraid to put enough pressure to lift the front or rear wheels. Of course, YMMV.

steve

Excellent suggestion, Steve. On a production metal lathe, that measurement is called "spindle lift", and is used to determine if the front bearings need to be replaced. It's called "lift" because a prescribed force is applied upward at the spindle nose, opposing gravity and any chain/belt tension. On the machines that I'm familiar with, the allowable lift ranges from 0.0000" to 0.0002" if the machine is up to operating temperature, and 0.0002 to 0.0004" if the bearings are cold.

All that said, I don't have a clue what acceptable numbers are for a Shopsmith!

For wood working tasks, I have seen quill spindle shafts with up to .005" play and still do a fair job of cutting and other tasks. I personally reject all quills with more than +-.001" play. I send a few dozen rejected quill shafts to the salvage yard recently along with more 2000 pds of rusty and corroded Shopsmith parts (2 pickup truck loads). I cleared about 25% of my storage shed.