[neptunier]

hello all,

i am setting up manual tool change on my converted zx45 with mt3 (mk3) holders. i was wondering if these holders are repeatable height holders? if not, does anybody know how much they vary?

i am runnung mach3 with machstdmill, a nice screenset. there i can choose whether i measure each tool after tool change or whether i use repeatable height holders and dont measure. that would make tool change much faster. usually i dont need high accuracy, a few thou's should be no problem.

thanks,
michael

[109jb]

You cold use a 3/4" bore MT3 collet with TTS style tooling and it will repeat fine because the TTS references the spindle nose.

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Otherwise, set up an indicator and test it.

[neptunier]

do you have a link of a 3/4" mt3 collet with tts style tooling? i know tormach uses this tooling. somewhere i read someone made himself mt3 to tts adapter but i did not find a place to purchase this adapter.

[dertsap]

I have mt3 er holders and the height is always dead nuts . Keep things clean and you won't have any problems

[neptunier]

i found a link, here: 30251 - TTS-MT3 Adaptor Collet. i read there are chinese tts style tool holders out there, does anybody have a link. i did not find anything. the tormachs would be great but since i am in germany it would be quite expensive with shipping and taxes.

[mactec54]

do you have a link of a 3/4" mt3 collet with tts style tooling? i know tormach uses this tooling. somewhere i read someone made himself mt3 to tts adapter but i did not find a place to purchase this adapter.

A MT3 should repeat and not be a problem, if using a draw bar, the same pressure would have to be applied each time

Here is a link for a 3/4"-MT3 collet, they are getting very thin at 3/4" they normally don't go above 5/8" the 3/4"-MT3 also may have a lot of the collet outside off the spindle so would not be useable with the TTS system

Buy Collet Mt3 3/4in. at Busy Bee Tools

[neptunier]

i may have found another solution. here in germany you get the mt3/16mm collets and you could use them with a c16/er25 tool holder. the collet is a little bit to long, maybe 5mm, but i guess you could easily shorten it. the back of the er25part would need to get a precise 90° edge on the lathe and the shaft needs to get shortened.

the collets are like 15€ and the cinese tool holders like 15€. would that be a possible solution?

[neptunier]

so i tried out a mt3/16mm collet with a c16/er20 tool holder. i had to cut the collet 6mm in the front, that left inside the collet little more then 10mm where it was ground to 16mm. that was a little short so the tool holder has about 6/100mm. (2-3 thou) runout. i think that is too much. maybe i can find another collet that is ground inside deeper to hold the tool. attached a picture of the inside of the collet.

but thanks for your help, i will stick with mt3 for the moment.
have a happy new year,

michael

[mactec54]

so i tried out a mt3/16mm collet with a c16/er20 tool holder. i had to cut the collet 6mm in the front, that left inside the collet little more then 10mm where it was ground to 16mm. that was a little short so the tool holder has about 6/100mm. (2-3 thou) runout. i think that is too much. maybe i can find another collet that is ground inside deeper to hold the tool. attached a picture of the inside of the collet.

but thanks for your help, i will stick with mt3 for the moment.
have a happy new year,

michael

This is what I posted, that the collet would stick out of the spindle, you can't machine the 3/4 collet any deeper, as there will not be enough material to hold the collet together, it would be to thin, you would be better with an ER to 3MT tool holder, or you could add a spacer to the front of the spindle, and leave the collet long

[neptunier]

This is what I posted, that the collet would stick out of the spindle, you can't machine the 3/4 collet any deeper, as there will not be enough material to hold the collet together, it would be to thin, you would be better with an ER to 3MT tool holder, or you could add a spacer to the front of the spindle, and leave the collet long

yeah, i did not quite get what you wanted to say, i did not think it would be a problem to cut the collet in front, that there would be enough surface to hold the tool holder inside the collet.