Victor 400x750 lathe timing belt?

[taiwanluthiers]

I just bought a new to me Victor 400 x 750 lathe.

When I opened the cover on the head stock I find timing belts driving the gearbox instead of regular gears!

Any reason why they would use timing belts? Is it so there's no backlash?

There are the standard change gears but it's 25T, 52T, 52T, 70T timing belt pulley, with a chart of various other timing belt pulleys to use in place of a to get various metric threads... (Yes I know one of the drive belt is worn, and it will be replaced).

 

[John Garner]

I'll hazard a guess: Lugged-belt drives are less expensive than gear drives, are generally quieter, don't need lubrication, and aren't as prone to "cogging" variation in their speed.

 

[Laverda]

I have close to the same model lathe other than mine is older as it does not have the emergency stop switch like yours. The only reason I can see that someone would replace the gears with belts is noise. All the gears for this lathe are still available new from Victor, so it can't be a case of needing to replace a worn gear that they could not get.

When the gears are engaged they are noisy even with lube and all the gears on mine were replaced with new ones when it was rebuilt 10 years ago. The new and old gears were both noisy!

Here is what it should look like.

 

[rand18m]

I just bought a new to me Victor 400 x 750 lathe.

When I opened the cover on the head stock I find timing belts driving the gearbox instead of regular gears!

Any reason why they would use timing belts? Is it so there's no backlash?

There are the standard change gears but it's 25T, 52T, 52T, 70T timing belt pulley, with a chart of various other timing belt pulleys to use in place of a to get various metric threads... (Yes I know one of the drive belt is worn, and it will be replaced).

View attachment 347590

Mine is the same, which was sold under the Fortune brand. Fortune in CA still has the timing pulleys in stock, just more expensive than you can buy elsewhere. It's quiet, seems to work flawlessly, or at least so far. Speaking with a timing belt mfg, those are high torque drives, used on machines with much higher torque than a lathe would ever put out. Lathes are actually not high torque machines, compared to say a blower. I need some change gears for metric, will likely use B&B MFG'ing. Hope that helps. Oh, and the belts don't cost much at all.

 

[taiwanluthiers]

Well timing pulleys aren't expensive either. I was able to find all the change gears I need (for metric threads) from Taobao for 1/10th the price the Taiwanese dealer wanted to charge me for ONE gear. The only problem was the 43 teeth pulley was not available with the center hole being 50mm and keyed... but again, I have a lathe, so it's not like I can't just enlarge the hole myself. The key can be machined simply by running a sharp HSS blank into it.

I figure that timing belts had to be reliable considering they're used on cars, where if the belt failed the engine could destroy itself.