R8 automatic tool changer

[N4NV]

Has anyone ever seen an automatic tool changer for a Bridgeport mill with R8 collets? I have looked at some quick change tooling and it looks like an automatic system could ge adapted.

Vince

[ViperTX]

Tormach....I believe still offers one...

[N4NV]

I checked their web site and they do not have one listed.

Vince

Originally Posted by ViperTX Tormach....I believe still offers one...

[philbur]

I have the Tormach system. It is an excellent quick change system but is not designed for an ATC.

I think you will have extreme trouble with an ATC for R8 collets. How would you hold the cutter in the collet until it was drawn into the taper of the spindle, how would you ensure repeatable of the Z-axis location when there is no fixed axial relationship between the cutter and the collet. Lining up the drive key with the collet keyway will also be a bit of a challenge but is probably less of a problem than the other two points. It's never good to say never, as somebody will always prove you wrong, but an ATC for R8 collets is a challenge not worth tackling in my opinion. R8 tool-holders might be another proposition however.

Regards
Phil

Originally Posted by ViperTX Tormach....I believe still offers one...

[N4NV]

http://www.royalprod.com/product.cfm?catID=11

Royal Products makes a quick change system where the R8 collet stays in the spindle, you only change a tool holder. The problem with adapting their system to automatic would be lining up the spindle. That may be possible if you had some type is system that could sense the spindle position.

I have seen other automic systems for smaller mills that did not require indexing the quill.

Vince

[ViperTX]

Oh, I remember Joe Vicars.....for some reason I always think Tormach.

[philbur]

I did say never say never. I've just looked at my Tormach quick change. The tool holder shank is parallel so you would need to add a guide taper to the told-holders to assist with alignment during entry into the collet, and some form of positive assist to eject. The positive eject could possibly be achieved with a spring, internal to the collet. The tool holder also needs to be pushed positively into the collet as you activate the drawbar. This could be achieving with some kind of spring assist under each tool in the carousel.

The Royal products system looks like it could solve some of the problems relted to the paralle shank, looks expensive though. The beauty of the Tormach system is you can make tool-holders on a small lathe, no precision tapers to be ground.

Get the CAD system fired up and go for it. When you have developed a proven system please send me the drawings.

Regards
Phil

Originally Posted by philbur I have the Tormach system. It is an excellent quick change system but is not designed for an ATC. I think you will have extreme trouble with an ATC for R8 collets. How would you hold the cutter in the collet until it was drawn into the taper of the spindle, how would you ensure repeatable of the Z-axis location when there is no fixed axial relationship between the cutter and the collet. Lining up the drive key with the collet keyway will also be a bit of a challenge but is probably less of a problem than the other two points. It's never good to say never, as somebody will always prove you wrong, but an ATC for R8 collets is a challenge not worth tackling in my opinion. R8 tool-holders might be another proposition however. Regards Phil

[philbur]

The Royal Products QC.

It's not clear how the tool holder is drawn into to spindle with sufficient force to ensure the tool-holder taper is rigidly held. I don't see how a locking ring is going to make it. So it looks a bit light weight with respect to maximum radial loading. And look at that price. At those prices it's probably a better bet to change your spindle for a proper quick change system compatible with ATC.

Regards
Phil

Originally Posted by N4NV http://www.royalprod.com/product.cfm?catID=11 Royal Products makes a quick change system where the R8 collet stays in the spindle, you only change a tool holder. The problem with adapting their system to automatic would be lining up the spindle. That may be possible if you had some type is system that could sense the spindle position. I have seen other automic systems for smaller mills that did not require indexing the quill. Vince

[Hood]

A guy called Peter Renolds was working on an auto toolchanger for a Bridgeport, not sure if hes made any progress as his site still says the same as the last time I looked, might be worth an email.
Heres his site http://www.zoomt.com/products.htm

Hood

[daedalus]

for an example of using tormach, you could take a look at littemachineshops tormach based automatic toolchanger for the seig minimills.
http://www.littlemachineshop.com/pro...ProductID=2937

Philbur, if you dont mind could you give a bit more detail of the problems of using tormach with an atc, as i was considering putting something together like the littlemachineshop one, and would like to know if there are problems im missing.

[NinerSevenTango]

I see a problem with that one immediately --

The cylinder is pushing on the drawbar to compress the belleville washers in order to release the collet. The washers have to be sized for enough force to hold the tooling when the cylinder is released. The problem I see is that all of the cylinder force has to be resisted by the spindle bearings. I'm not sure if they are rated for that. My thought on that is that it will probably require a mechanism that squishes the washers to release the drawbar without putting the load on the bearings. It can be done with only a little more complication.

--97T--

[daedalus]

would a suitable solution to that problem be having a mechanical stop for the piston set to only compress the belleville washers sufficiently to release the collet?