Tuesday, September 14, 2010

Delta 46-700 Lathe Reeves Drive Warped Pulley

Video at the end of this post.

I noticed last week that my lathe was making more noise than it should. Being a Reeves drive, it already makes a fair amount of noise, so it took a bit for me to catch that it was louder than it should be.

A Reeves drive is a pulley system that allows infinitely variable speeds while keeping the motor speed consistent. It does this by moving the two pulley halves further apart for slower speeds, closer together for faster speeds. The V-belt moves in and out, effectively changing the pulley diameter.

It's a good design and less expensive than an electronic speed control. Being mechanical, it does have its drawbacks. Namely that parts wear and break. When I bought this lathe (for $100) the outboard pulley bearing set was broken. I installed the new outboard gear and it worked fine, but noisy.

I pulled the cover off today to find out why there was so much noise. I found three problems:
  1. Inboard pulley mounted incorrectly-
    The inboard pulley set screw was on the motor shaft, not on the key as it should be. This made it impossible for the key to be fully seated, making the highest lathe speeds unavailable because the two pulley halves couldn't get as close together as they should.
  2. Belt is old and stiff-
    The belt was old and dried out, resulting in bumps preventing the belt from traveling smoothly.
  3. Warped pulley-
    The inboard pulley is warped. This was slapping the belt around, causing a lot of noise and some vibration.
You can clearly see the belt slapping around in the video below. The low resolution of the video doesn't really show the pulley, however.

A new inner pulley is only $15 from www.dewaltservicenet.com, but it's still annoying to have to replace it. Especially considering how slow their shipping is.

At least I've found the problem!

2 comments:

Larry Queen said...

I have the same Delta lathe w/reeves pulley system.
This video and your comments will probably help with
my situation. I am having very difficult time moving the speed control leaver. I don't have much noise, just
normal sounds. If you have had this problem, or heard from someone else who has had this problem, would like to here what was found. Thanks.

Don said...

I would take the cover off and watch the mechanism. Make sure you ONLY move the lever while the lathe is spinning!