SM belt changes

[combustable herbage]

This is the belt configuration on my 10 utilathe, Should the top pulley be switched around? when I try that configuration its too big either way so I believe that I have to switch the pulley and find a little smaller belt in order to have the true speeds shown?

 

[Susquatch]

Without knowing anything about your Utilathe, I think one of your pulleys might be reversed. Usually they are stepped in on one end and out on the other. With your configuration there would be very little change from one belt setting to the other.

Also, with your configuration, you might even have to change to a different belt to use the other groove because you might not have the range of adjustment you need.

With a normal set up, one groove gets bigger as the other gets smaller which allows more of a constant belt length and a much bigger change in drive ratio.

 

[YotaBota]

@Susquatch is correct, you need to turn the top pulley around.

 

[YotaBota]

Does the belt have a PN on it? I haven't found a manual for the 2000 series so can't say for sure if it's the same belt as my 1120 but the setup looks the same.

My 1120 uses a "Gates 3VX355 Super HC".

 

[Susquatch]

but the setup looks the same.

With or without the pulley reversal?

 

[YotaBota]

With pulley reversal.

 

[Susquatch]

With pulley reversal.

Gotta wonder how @combustable herbage utilathe's pulleys got reversed like that. Belts must have been a bitch for just one combination let alone both.

 

[YotaBota]

Probably someones misunderstanding or caring of how step pulley's are supposed to operate.

 

[RobinHood]

Agree with above advice : one of the pulleys needs to be turned around 180* on its shaft.

Maybe there is enough motor adjustment for the present belt to work once one pulley is turned around? If not, only a shorter belt will work.

 

[combustable herbage]

So I switched the top pulley, and used some power twist v belt that I had to set it up, I can see the difference in the high and low ranges I'll have to get a tach and check the speeds in comparison, but it cut fine the way it was but this should be better for figuring out speeds and feeds. The belt was in there was a 4l330 from goodyear, it was pretty much at max with the previous setup and way to loose with the pulley switched we will never know why it was changed but I am happy I was able to get it back to full condition. Another question I have is can or should you operate the feed fwd/rev lever with the motor running?

 

[RobinHood]

Another question I have is can or should you operate the feed fwd/rev lever with the motor running?

I would not. There is no clutch system to shift the feed drive onto a running spindle on most lathes.

 

[Cryoine]

https://canadianhobbymetalworkers.com/threads/admirable-nelson-standard-modern-utilathe-10-ld.5780/ from the post that i have about it i think the top pulley needs to be reversed, you had it correct before then reverse the motor pulley, though in the grand sheme of things i don't think it matters much

if you check the video that i how i found the lathe, before tearing it apart
also in the manual lovingly prepared by @Brent H

 

[Chipper5783]

I believe Cryoine has it right. Your top pulley was fine (that is what my 11LD looked like when it came to me). With your switch around, you now have the top pulley on backwards. As others have said, one pulley was on backwards, it is the motor pulley that was wrong. Standard Modern uses what looks like an odd set up, but it seems to work very well. They use quite a large section belt (5L or B), it appears to fit the motor pulley, but looks to be too big for the top pulley - it is not, that was their design. You can easily roll the belt from high/low and back, without touching the motor adjustment - the small to large and medium to medium are very close to the same center distance and with the top pulley having a shallower profile it doesn’t need much belt stretch to change speeds. Also it is only a 3/4 hp motor, it doesn’t need much belt tension.

Anyway, that’s how I run mine and it works well. Using a regular B section belt from UFA, once setup, never have to play with the motor.

 

[Brent H]

Indeed @Chipper5783 and @Cryoine have it as did the other folks. The lower motor pulley needs to be reversed so the larger diameter is out. The wider belt allows you to change the pulleys without any tension adjustment once you get things dialled in. You “roll on” and “roll off” as the need arises.