Re-grinding spindle for new collet system?

[Stuff-Builder]

Hello,

I recently bought an old Gorton 8D knee mill. It has a 300 DA collet system that will accept a 1/4" dia cutter.

I'm planning on having the spindle re-ground to accept some other collet system that will have a larger capacity. I'm leaning towards a #3 Morse Taper at this point. There's plenty of adaptors and tool holders for this size, and I figure it can handle the 1 hp spindle motor. If I went this way would I need to have the "tang" feature milled into the spindle as well?

Is there a different collet system that would be better? The machine does not have a draw-bar or the capacity to accept one, so systems that tighten at the spindle nose are better (ER perhaps?) Any advice would be appreciated.

Scott

[MrWild]

I may have a large set of collets for your machine. Do you have a picture of your spindle and collet? I picked up a Gorton a long time ago, and after realizing the lead scews and ways were worn out, I parted it out. I still have all of the collets for it. I think up to 7/8" and down around 1/16". I was going to ebay them but it'd be much easier just selling them cheap to you provided they are what you need.

[Stuff-Builder]

Did you have an 8D? It's the little one.

If you still have the spindle, then I might be able to use what you have. I need more then only collets.

What I have now was made to use 300 DA collets (really small) and the tool-holder part of the spindle pretty much trashed and useless. The bearings and the outside of the spindle seem to still be in good shape, which is why I'm considering having it reground.

But if I could disassemble mine and replace the rotating part of the spindle with yours, then that could work out really well.

Let me know what you have.

Thanks,
Scott

[MrWild]

ahhhhh. Well damn, you won't like the answer then. I scrapped out the spindle last summer. And if the 300 DA collets are small, then the collets I hae won't work. The mill was a Gorton Master Mill.

[Stuff-Builder]

Any advice on re-grinding a spindle? Is it not a big deal?

I've got a few calls in to local places that specialize in ID grinding. I haven't heard back much yet.

What about the torque involved? Will an MT3 spindle handle machining forces from a 1 hp motor?

Thanks, Scott

[polaraligned]

MT3 should easily handle your 1hp machine.

Heck, my lathe has a MT4 tailstock which I regularly put taper drills in and send them head on into a hunk of steel driven by a 7.5 hp motor.


Call Wells-Index. They specialize in regrinding spindles for mills. They will regrind it right in it's bearings.

Scott

[Stuff-Builder]

Well, I've pursued a few different avenues, and didn't really get anywhere. So I think I'm going to take a little different tack.

I did some measuring last night - the quill housing on the mill is ground to 3.000". So I think I can get a regular quill assembly for a square column Rong-Fu or an IH mill perhaps, and modify that to fit in my Gorton. This would give me decent runout, and the ability to use R-8 tooling.

Anyone have other sources or suggestions for 3" spindle assemblies?

Thanks,
Scott