Rotary milling table repair

Has anyone made a replacement crown gear for one of these rotary table. It is a 6" table made in Asia & bought on the internet from an importer in Australia who cannot supply spare parts. I imagine that I will have to machine a new one.  Paul.

Edited By Paul Lousick on 14/10/2015 09:57:14

I'm intrigued, Paul

Is it really a Crown Gear that you need to make ?

... I would have expected to find a WormWheel in there.

MichalG.

Paul and Michael,

I've had mine to pieces [for other reasons] and it is indeed worm and wormwheel drive in these tables.

Regards

Brian

What is wrong with the gears? Could they just have come loose on the shaft?

Looks like what U K users would recognise as a Vertex branded product? If so, possibly, could any U K Importers such as RDG, Myford, Warco, Chester or Axminster , supply spares?

Howard

Look up http://cdn0.grizzly.com/partslists/g1049_pl.pdf, will show parts numbers for very similar table.

.

**LINK**

Link inserted, for convenience

The gear teeth are machined into a cylindrical inner part which is bolted to the rotary table. (appears to only be mild steel material and not hardened)

My table is similar to the Grizzley g1049 in the parts list which you called up but does not have ball bearings. Everything else appear to be the same so gear may be interchangeable.

Thanks for your feedback, Paul

Edited By Paul Lousick on 14/10/2015 11:32:34

Edited By Paul Lousick on 14/10/2015 11:34:57

I don't think it is a Vertex - my 6" Vertex only has three slots, and there is a very prominent nameplate on the body at the top in the picture. Also I would expect that Vertex parts would be available, and judging by the pristine condition in the photo I couldn't imagine a Vertex product needing a new anything at that stage of it's life. My RT is 10 years old and is as smooth as silk.

Roger

Paul,

It looks identical to the one supplied by Myford which I bought some years ago.

I know it is a silly thing to mention but is the problem you have just simply sloppy meshing and are you missing the obvious in that the worm is on a cam to set the meshing? I can't really see why damage to the worm wheel will have taken place, the drive is so slow and lightly loaded and it looks well greased in your photo.

Regards

Brian

Paul, I couldn't see any damage to the gear in your photo. I take it you are aware the worm is carried in an eccentric sleeve so that the mesh between the worm and gear is adjustable. If the gear has slipped against the worm and damaged the tops of the teeth, there should still be enough material left to clean up without replacing the gear.

Dave

.

Dave,

There are about six teeth very badly damaged [roughly in the 310-340 degree area] ... should be clearly visible if you click on the image to see it full size.

MichaelG.

Edited By Michael Gilligan on 14/10/2015 12:37:38

This is a generic style and there are going to be umpteen versions sourced from different factories in India and China, each with minor differences to improve the profit and compensate for errors in the patterns. Unlikely anyone would ever stock spares. Even a major importer probably wouldn't be getting them consistently from the same suppliers though their buyers wouldn't realise there were differences inside as long as the overall spec and price were met.

I should look at the options for grafting in a new worm and wheel from a standard gear supplier - if even remotely cost effective. Otherwise DIY or convert to a simple indexer.

I think it is going to be a DIY.

Will have to make a cutter the same profile as pinion and a jig to hold a new gear blank. Should be able to hold cutter in lathe chuck and mount gear jig on the cross slide. (a project which I did not plan on making)

Paul

Edited By Paul Lousick on 14/10/2015 13:21:37

I was given a rotary table the same as this one that had suffered
from some professional industrial vandalism and was slightly
worse than in Paul's photo .I cut away the damaged wormwheel
and loctited on a replacement ring and hobbed a new 1 module
90 tooth gear .Hobbing unit in MEW 193 article ,similar hobbing
system also in ME 108 by Brian Thompson. Cut away worm from
original shaft new piece loctited on ,milled new worm in lathe
using small cnc file and this cutting head ,no fiddling around with
changewheels required. Lathe cnc convertion MEW 207 to 212.
Photo's in album " Rotary table".

John

Could you silver solder a bit in place and machine that?

That's what I was thinking. You could make an index to lock the wheel (?) on the side opposite the bit being machined. The big problem is its size and jigging it up to present the surfaces to the cutter properly.

Frank