Saturday, June 18, 2011

More on the Delta 46-700 Lathe

The top photo is the "before" shot. You can't tell, but the pulley half closest to the motor is warped. The thing was CAST warped! The bored hole is not square to the face. Grrr... It caused some vibration as mentioned in my previous post about this lathe.

I ordered a new pulley half and belt from ($50 for the two with overnight shipping!)

I installed the new pulley half and found I have to practically disassemble the headstock to replace the belt. ARRGGHH! I decided to see what the new pulley would do with the old belt.

I gave it a quick run through the gears and was happy with what I saw. Much improved. But something that bothered me the last time I did this got me again. The two pulleys are not aligned! As you can see in the top photo, the tail half of the headstock pulley is further upstream than in the bottom photo.

I loosened the set screw and the pulley slammed south. That spring is pretty darn strong. I stuck a large open end wrench between the casting and the pulley to lever the pulley back north. I did this several times, tweaking the alignment, as it changes a bit depending on the RPM setting. I decided I wanted it rock solid at the highest setting, when I'm taking my finishing cuts. So it's aligned for 2500rpm and a bit off at 500rpm.

I'll tell you, this made a HUGE difference. I can still feel some vibration, which I attribute to the belt, but it's very minor, and doesn't seem to translate to the spindle at all.

I've read about others who have used link belts with this lathe. I was surprised, as I thought the pulleys would crush the link belts. I may have to give one a try and see how it goes. If a link belt works, it may solve both the tiny vibration that's left, and the tear-the-bloody-headstock-apart-just-to-change-the-belt issue.

1 comment:

Anonymous said...

I have the same lathe, and my issue right now, is that the inside pulley closest to the motor keeps moving left. No matter how tight I try to make the set screw without cracking that cheap white metal pulley. I can move it, turn the lathe on for about 4-5 minutes, then I hear a loud rattling and the speed drops down as the pulley half shifts left and rattles against the motor housing. I've tried to fix it like 4 times so far. Can't seem to get it to stay. How did you get yours to stay? I'm not even sure how far the key and pulley should be from the end to line up right.