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South bend 9a belt tensioner

Andeo1025

Plastic
Joined
Apr 30, 2022
I recently got a 9a, and found the turn buckle for the belt tensioner was missing. Its an under drive setup. Does anyone know the length of the original turn buckle? I bought one from lowes that fits, but looks longer than the ones I've seen in pictures. Thanks for the help.
 

chipss

Aluminum
Joined
Jul 19, 2020
Quite a pain to get up in there isn't it.

You have to make it so the lever will swing over center and lock which I assume it does.
Then the turnbuckle can adjust tension. As I remember it took me a while to get it setup right with the segmented belt to get the belt pieced together for the right length.

Or, contact Latheman Ted to see if he has the correct one in stock. It could save a lot of dicking around.

Another issue on mine is that when the belt is set to the highest speed, it will lightly scrape against the bed. Look down through the top by the pulleys and see if yours does it too. (Yes I'm too lazy to take the headstock off and grind away at the bed casting where it hits)
 

Andeo1025

Plastic
Joined
Apr 30, 2022
I'll keep an eye out when I reassemble it. I just got the machine home Saturday so I've been making a list of repairs, or maintenance to do.
 

Andeo1025

Plastic
Joined
Apr 30, 2022
Definitely will. I plan on ordering the one with the guide on how to take it apart. Have you tried the threading dials on ebay?
 

chipss

Aluminum
Joined
Jul 19, 2020
^ No as I have an original one. I see no reason the printed plastic ones won't work well. They have no loading on the plastic other than the miniscule forces to turn the indicating wheel. Just don't get torque happy tightening the set screw into the plastic.

There are tons of threads here and on other forums detailing rebuilding a SB9. Nothing to it really and no special tools are needed. There are several taper pins to drive out so just be sure which direction you are tapping on them. You'll be amazed at how much dirt, chips and crap are in the guts of the saddle. IIRC it's been about 20 years for me but pay attention how the drive key is located on the worm gear in the saddle that is driven by the lead screw.

Half a gallon of mineral spirits and a couple days and you'll have it working like new.
 

mjr6550

Aluminum
Joined
Oct 7, 2012
Location
Lansdale, PA
I bought a 3 D printed thread dial kit on ebay recently. It was inexpensive and I thought I would just use the gear and make thread dial. When I received it I was surprised that it looked ok, so I went ahead and put it together. I have not used it, but it seem like it will work. I have seldom used my lathe for threading, so for me it will probably be fine. Otherwise, I will make one.
When you are new to this hobby you can't always buy the best ip front, but for frequent use I try not to go cheap either. If you do much threading the plastic gear would mot be the best option.
 

Andeo1025

Plastic
Joined
Apr 30, 2022
I've already removed a ton of chips from the areas I can access. I figure there will be a ton more I can't see. As far as the threading dial, I don't know how much threading I will do, but i definitely want to learn single point threading. I work on some old equipment and occasionally run into threads that a tap or die is hard to find.
 

chipss

Aluminum
Joined
Jul 19, 2020
I do a lot more single point threading than I thought I would. It gives a better finish than the dies I have. It also can make a more concentric thread as dies can sometimes cock a bit from the torque you need to put on them. It's most handy to avoid the cost of larger dies. A couple ears ago I made a shaft for a guy with a 2 inch coarse thread on the end. I shudder at the cost of the die needed, the torque required to turn it and that for most home hobbyists like me it's a one time use.
 

Andeo1025

Plastic
Joined
Apr 30, 2022
Large sizes and wierd threads are my interest with threading. I got the tensioner fixed and the belt goes in tonight.
 

chipss

Aluminum
Joined
Jul 19, 2020
With a lathe you'll be working on something and encounter a problem with a part. After a minute it'll be I'll just make one. As opposed to searching hours for a part, buying an expensive die or tap etc.

One of my wife's buddies called today and has some old Sears Craftsman riding mower with apparently a worn out blade arbor. ... Yeah ok bring it over... As it's a 30-40 year old turd I'm sure I'll find there are no parts available and I'll be making a new shaft out of whatever scrapbinium alloy round stock I have to mount one of the blades. Threading the top, woodruff key slot, welding a flat blade pad, machining that pad to true it up and so on.

You'll be doing the same things so enjoy your new and fun toy.
 








 
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