Belt tensioner on SB 9 model c

Hello all. I've got a model c lathe that was given to me.
It works. But needs to be cleaned up and most likely oiled.
The issue is the tensioner. As you can see in the pics, the previous owner has had to use a bungee to keep the handle down.

I think I know how it works, it's kind of suppose to snap downwards and stay in tension. But I can't get it to do that.

Can anyone tell by the photo is something is out of alignment?


Thanks

Countershaft assembly is in the wrong place. Needs to move closer to the lathe bed. Bottom run of belt should be approximately horizontal when on the largest step of the countershaft pulley if the countershaft carrier is bolted direct to the bench. Gawd knows what the extra bit of ply under yours is supposed to achieve. Top run and tensioner link will be pointing up a little. Somewhere on the internet there is a diagram of correct position with numbers for a "standard" belt length. Some editions of How To Run A Lathe have a suitable side on picture to give a reasonable idea of geometry, Fig 16 in my 1966 edition. Can't give you link as the reference went missing some years back long after I moved on from SouthBend lathes.

When I set my first one up I didn't have a belt or a copy of HTRL so merely arranged the countershaft in what looked to be a sensible position with the belt line about horizontal on the middle step of the cone pulley. Then adjusted the turnbuckle to get the tensioning lever at full throw so it rested against the link and measured how long the belt had to be by passing a tape round it. Bit more faff to get things right with an existing belt but quite doable.

In your position I'd go for a new serpentine / multi-Vee endless belt. Being endless means pulling the countershaft and spindle to fit but once done you have a better drive and no belt worries for a long time. Plenty of choice in lengths so just bolt the countershaft down where seems sensible, I'd go couple of inches closer to the lathe, and measure up.

Clive

actually his issue appears to be someone has replaced the adjusting turnbuckle and arms with a hardware store one like would be used for fences.

can be made to work but as it is there is just a bolt holding it to the tension lever bypassing the "over center" action that locks it in tension.

Random web pic of correct parts...you should be able to bend the 90 degree elbows and drill for cotter pins on what you have and make it work fine.

http://www.repair--parts.com/Meta-Discussion-/9-south-bend-metal-lathe-horizontal-tension-lever.php5


Pretty good pic of how the rod should go to the lever..

http://www.lathes.co.uk/latheparts/page3.html

Hardware store fence wire tensioners worked just fine for me on both my SB 9's. Best to chop the eye off and bend the end of course, but that's what the BFH is for, or weld L cross piece on. Think I did one one way and one t'other.

Your countershaft foot is wrong way round too. Should be two bolts at front, motor side,and one at back. Judging by internet pictures a goodly fraction of folk do it the wrong way round putting the single bolt directly under the motor where it's a pain to get at.

Clive

Simple fix, Put a small bend in the front turnbuckles screw, at the tensioning lever. This will allow it to go beyond Straight, and allow it to lock into place. As long as the rest of it is working fine, don't change it.

Stay safe and have fun.

Joe.

Thanks all for the advice. I'll work on readjusting the countershaft to see if it helps. If not I'll modify the turnbuckle parts. Thanks again. Very helpful.

do what Joe said...all the adjusting in the world won't matter if the rod can't "snap" in to the slot in the lever...the other end where it attaches to the countershaft isn't a big deal.

At the lever side it has to have that 90 degree bend so the lever can push back and go over center(past straight) to lock in, a bolt though an eye will not work.