Bueller

Hello, all..
I’ve got it about half apart, but I was wondering…how loose is too loose for a timing belt? Before disassembling, I was observing needle timing with a 15x1 needle. First couple of spins it would hit the hook case, then it was fine (all turning by hand). The belt seems really loose…like a good 1/2” deflection. Had no issues taking it off of the sprocket.

Couldn’t find a spec for it on the online service manual. Anybody have any insight? Planning on replacing it regardless, just curious.

Frank

OurWorkbench

Welcome to QB, Frank. I'm guessing you have read about most of those machines take a 206x13 needle system. I don't know the particulars on it and hard to find or replicate the timing belt. I know there is a parts list at this link, but not sure how helpful it would be. There is also there is an after market one at https://www.vintagesingerparts.com/c...+Related+Parts
just went back to that link and says it is sold out.

Bueller

Thanks! Yea, I’m aware. I’m modifying it to run the 15x1 needle. There’s several places that show the belt available on the interwebs, so not too concerned with that yet. Still gotta get everything apart and cleaned up anyways.

1.41

FWIW there's at least 1/2 deflection on the belt of my 319. If one grabs the belt at the bottom pulley, there's a fair bit of movement side to side. It won't come off the bottom pulley, but there is movement.

I have an idea that one of the purposes of the cleated belts is that they can run really loose and that way they put a minimum amount of strain on the motor and on the bushings. Again, FWIW, the old Pfaffs had these type of belts and on at least one or two of their models, Pfaff had an adjustable idler pulley that could be used to take up slack on the belt. Again, it's clear that they intended the belt to run as loose as possible.

These belts are easy enough to find, though a bit pricey. The new style of belt looks like it's made out the same type of stuff that car timing belts are made out of. I suspect that they'll last 100 years by the look of them.

There's a guy in Turkey making cleated belts for Pfaff machines. I suspect that if one gave him the specs he could easily make one for Singer machines.

Bueller

Yea, I’m with ya on that..one seeming affirmation is how loose the motor belts run. I’ve played around with a few of my machines, and found that even though the motor belts seems too loose, it’s not loose ‘enough’ and the motor won’t turn the machine very well.

I ended up ordering a modern style timing belt, so we’ll see how that will turn out. I’m kind of wondering if it is marked like the original, so you can get it in time properly, but I’m sure it is.

I appreciate your feedback! It’s good to stir some thought 😎

Frank