# Set screws!



## bloomingtonmike (Aug 7, 2013)

I have a new to me craftsman 12" commercial lathe Ive had about a month or two. I was using it tonight and the spindle stopped but motor was still turning. What had happened was the top and bottom 4 gear pulleys set screws were loose and had backed off far enough that the set screw was no longer on the shaft. So my lesson for tonight was to tighten those pulleys and all other ones I could see. Check your set screws if you have not done it in awhile. Once tightened I got back to making my Ordbot 3D printer barrel with PTFE teflon tube installed. I went through the procedures of aligning my tailstock and that worked awesome!
Mikie


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## Chuck K (Aug 7, 2013)

Mike, If there's enough room you could run a second set screw in to lock the first one in place.

Chuck


Ok...just looked at the pic...disregard that advice


Now...looking at the pics....I'm not sure what I'm looking at.............


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## Richard King (Aug 7, 2013)

Go to the hardware or auto store and buy some Loc-tite BLUE as it glues in the set screw.  The blue is designed to loosen with only a wrench.  If you buy the green Loc-Tite, you will need to heat up the set screw to loosen it.  The double set screw works too.  I would not like to see you center punch the end of the hole so it can't move out.  (I know you didn't say you did that, but I wanted to tell the others reading this, that that's only done in extreme cases.)

I would recommend everyone check the bolts / screws as they tend to loosen over time.  Just like you did to your bike when you were a kid.         Rich

You can do it again with Loc-Tite or next time it comes loose.  It's just a suggestion and to help another member who has an issue like this.  Thanks for the question!   Rich


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## bloomingtonmike (Aug 7, 2013)

The picture is of the part I made AFTER fixing the pulley. I should go back in and Loctite them. I plan to change out the belts for link-belts and swap to a 3ph motor and VFD. Ill do that when I do that maintenance.


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## wa5cab (Aug 8, 2013)

Mikie,

The 4-step pulleys (and the 2-step) should be keyed to their shafts with Woodruff keys (except the motor shaft usually has a square key). A loose set screw will let the pulley slide axially on the shaft but not spin. If yours slip when you loosen the set screws, you need to remove the belts, remove the pulleys, and install the keys before you use it again.

Robert D.


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## The Liberal Arts Garage (Jul 3, 2015)

Like the grease fittings on your old car------ checking  your set screws is a good 
Excuse to observe ( wiggle? ) everything else.  .........BLJHB


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## spongerich (Jul 4, 2015)

I was about 5 minutes from tearing open the gearbox on my Delta band saw after it mysteriously stalled during a cut.  It ran fine, but as soon as you applied cutting pressure the blade would stop.    Took me a good long while before I finally noticed that the pulley was just spinning on the input shaft.


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