Help identify the mystery set screw

[MHW]

I would like to see if someone knows what this set screw does and what it should look like. I am working on a 101.28990 craftsman lathe with a under slung motor on a craftsman stand. The part number for the set screw is 102725 and the nut is 102634. This is located on the exterior of the lower cabinet next to the belt tension handle and I will assume that it is some sort of a stop for the belt tension handle. The set screw looks like it is sheared off at the end that protrudes into the inside of the motor compartment. I will attach some pics for your viewing pleasure.

BTW this was a very nice score as it was a freebie if I promised to give her a good home and show her some love. At first thought I said no way as I would have to explain to the Mrs why I was bringing home the 4th lathe in the last couple of months. But I figured if I showed it to her and explained it was sitting out in freezing cold and rain had no one to spend X mas with she would melt. BTW all went well.

 

[brino]

Glad to hear that you survived the adoption!

I have no answer to your question, but there is a tradition around here........when someone gets a deal that is way too good to be true, and that the rest of us would search for years and never find then they have earned a special message.

It goes like this:


However, be assured it is not meant in malice....... only in jealousy!

-brino

 

[MHW]

You know it is tough to be out on the road 2000 miles a week but it sure helps to find stuff like that. It is all about being in the right place at the right time. What is more interesting was how i got it stuffed into the back seat of a Nissan Altima. You know what happens when those deals come up and you dont act instantly. He He.

BTW here is a pic of the the last lathe that just seemed to follow me home with no strings attached. You know it like sometimes you get on a roll and it just keeps popping up left and right.

 

[7milesup]

BTW here is a pic of the the last lathe that just seemed to follow me home with no strings attached. You know it like sometimes you get on a roll and it just keeps popping up left and right.

NO! I have no idea what that is like. BTW, holy crap that is a big lathe.
I have no idea either what that set screw is for but glad to see you saved that machine from being alone and out in the cold.

 

[Jim F]

Looks loke a part the screw was holding got sheared off.

 

[MHW]

Here is a pic of how i found that big old lathe. It was sitting in a barn in Salinas Ca. A friend of mine who passed away had saved it from the scrap metal people who were tearing down the building it was in. This is a Schumacher Boye & Emmes and is dated 1899-1906 production and has a 20" swing. It was in the maintenance shop of the Spreckels Sugar Plant in Spreckels Ca. They used this a lot to turn rollers for conveyor belts as evidenced by the large conical tooling and HUGE Lathe dogs that came with it. My brother in laws wifes dad used to run this lathe a long time ago when he worded as a maintenance man at the plant. After my friend passed away it was destined to go to the scrap metal again when i found out about it and rescued it from the barn. It had been sitting under a trap for many years just waiting for a fresh chance at life again. I loaded it with a 6000LB forklift and it was all it could do to pick it up to load on my 24000lb goose neck equipment trailer. After inspection the ways are in great shape and it feels tight. My plan is to bring it back to operational glory as it once was.

 

[kcoffield]

I would like to see if someone knows what this set screw does and what it should look like.

It is sheared. On the inside of the cabinet on the same shaft as the lever, there should be another lever arm. That screw is the stop for when the belt tensioner goes over center and holds it in the engaged position. On mine, it wasn't sheered but was bent at 30 degrees. It's amazing what ham-handed people will do. The reason mine was like that was because the shaft was seized in the bushing that mounts it to the cabinet wall because it was never lubed so the bushing was actually spinning in the cabinet wall, not the shaft in the bushing.

I removed the mechanism, pressed out the drive pins, pressed the shaft out of the bushing, cleaned it up, lubed it with oil and put it back together. The original bent piece was a fully threaded slotted set screw a couple inches long. I just cut the head off a bolt, used the unthreaded end as the stop, and the threaded end to mount it. It's not really something that needs to be adjusted so you won't miss the slotted head.

Once this was done you can adjust the belt tensioner and engage that lever with two fingers. There's a good picture of the mechanism in the manual in the down loads section of the forum.

Best,
Kelly

 

[MHW]

Kelly
Thank you for confirming what i thought. I will look for the pics
Mike

 

[kcoffield]

The file I saved from the downloads is entitled "Atlas Lathe 12 3996 12x36 1975 Rev12". This was the pedestal cabinet model. The other 3996 manual is the bench top version and wont have the illustrated parts reference you are looking for.

Take care,
Kelly

 

[MHW]

Kelly
When tensioning the belts do you pull the handle up or do you move it down to tension. I googled pics and see the handle in both of the postions. I will assume that to tension you pull up and move down to release.