Vertex HV4

[kiwi2]

Hi,

I have a vertex 4" rotary table. There are a couple of spots during a full rotation that appear to be binding so I thought I would pull it apart to see if there was an obvious reason. I took the bottom plate off but it wasn't clear how to proceed from there. I suspect that the plate needs to be driven out but a couple of light taps seemed to have no effect.
Before I get a bit more vigorous, has anyone here pulled one of these apart?
If so, do you have any tips or advice?

Thanks,
Alan C.

 

[Blogwitch]

This is a bit of a common fault with this type (but not typically make), and I suffered it at one time on my Vertex 6" RT.
It all boiled down to wheel part of the worm not being exactly centralised, and try as I might, I couldn't improve on it when I converted it to stepper drive.
You can alleviate it by moving the worm slightly out of mesh (the tiniest amount you can envision) but then you do actually introduce a minute amount of backlash.
Because my RT was at least 25 years old, and has never has enough use to 'wear in' the worm and wheel together, in fact, I reckon you wouldn't be able to do that after 50 years of use.
So I took a major decision and stripped it down, cleaned it out and reassembled with a tiny amount of grinding paste on the worm.
It was then run under NC control for about an hour, then thoroughly stripped down again and cleaned out. After reassembly, it is smooth as silk with no tight spots at all.

This link should help you with your strip down

http://medw.co.uk/wiki/index.php?page=6inch+Rotary+Table+Conversion+Guide

Hope it helps

John

 

[kiwi2]

Thanks John.
I'm not sure I follow the procedure shown in the link.
I've put my back out so I'm reluctant to start pulling it apart in case I have to stop half way through. I'll give it a go in a few days when hopefully I'm fit again.
Regards,
Alan C.

 

[Blogwitch]

Basically, you remove the worm out of the side, take off the nut underneath, you might need a pin spanner, but I didn't, and when you turn the RT upside down, the table should fall out of the bearing.
It really is that simple.

John

 

[rodw]

Thee is a small set screw in the side of the housing that needs to be removed. Did you find it?

 

[kiwi2]

Hi,
Thanks for all the suggestions. I had a crack at pulling it apart this afternoon - success at last!
The reason I was getting confused is that there are no bearings in it - which doesn't tie up with either what you guys were saying or the drawing in the manual.
I've attached a couple of pictures to show what I found. I guess I bought the super economy model. I'm not too fussed - it's probably not suitable for a busy shop but it's OK for my occasional use.
If you look closely at one of the pictures, you can see why there was a tight spot during rotation. The grease doesn't go all the way round the gear!
I greased it put it back together and it seems fine.
Thanks again for all the help.
Regards,
Alan C.