MT4 to R8 adaptor?

[zzambucca]

Does anyone make an adaptor from a MT4 to an R8? I have a mill that I finally found to be a MT4 with a M12 drawbolt, which seems to be an odd size from what I can find. The mill I have says it is available in MT4 or R8, but I cannot find anyone who knows how easy the swap would be. I have a ZAY 7040FG with a brand name of "White Eagle" I think.

[Climatepro]

Are you sure it's a #4 taper and not an R8? I bought a Rong Fu type dovetail column mill that came with an R8 taper spindle with an odd sized drawbar thread. The thread fit the (awful) drill chuck that came with the machine, but was much smaller than the R8 standard, so none of my other tooling would work.

I tossed that junk in the garbage and bought a replacement drawbar for a Bridgeport, which had the hex head joined to the bar by a shear pin. I cut it to the right length, and drilled a new hole for the pin.

Morse taper in the spindle is a single taper, whereas R8 will be a taper near the tool end and a straight section near the drawbar end, with a groove on the straight part. If it's and R8, you can see a pin sticking into the spindle bore if you look up there with a flashlight.

MT4 machines don't usually have a drawbar, so if that is indeed what you have, I'd bet you will have to make an adaptor with a lathe.

[philbur]

I think an MT4 to R8 adaptor will be an extremely unusual animal. An R8 will not dimesionally fit inside a MT4 so the only possibility would be an extension type adaptor and this would probably leave you with an unhappy looking overhang. In addition the drawbar will need to pass all the way through the MT in order to grab the R8.

I might be wrong but don't get to optomistic.

It looks to me like a change of spindle or find MT4 tooling.

Phil

Originally Posted by zzambucca Does anyone make an adaptor from a MT4 to an R8? I have a mill that I finally found to be a MT4 with a M12 drawbolt, which seems to be an odd size from what I can find. The mill I have says it is available in MT4 or R8, but I cannot find anyone who knows how easy the swap would be. I have a ZAY 7040FG with a brand name of "White Eagle" I think.

[fatal-exception]

I think r8 shanks are pretty common. Maybe you could convert your spindle to r8?

[tauntdesigns]

Here's a link to 3 end mill holders (3/8, 1/2, & 1"), but the draw bar size is 1/2-13.
http://www.use-enco.com/CGI/INLMK32?PARTPG=INSRAR2

I did find a page thru google that had some mills for sale with MT4 spindles but, they're across the pond........ I think.... they had L in front of the price.
http://www.engineerstoolroom.co.uk/turret_mills.htm

If you could find someone here in the states that sell a 7040, see if you can buy an R8 spindle and drawbar from them.
Or maybe find someone overseas that will ship to the USA or maybe someone on the cnczone who will get them for you and ship them here. I don't know how that would work...customs?

Good luck,
Jack
P.S. you might send a e-mail to Little Machine Shop and see if they might have a supplier who makes them. If you don't change the spindle out, you might have this problem everytime you need tooling for your machine.

[andypugh]

Originally Posted by zzambucca Does anyone make an adaptor from a MT4 to an R8?

A bit late, but I found one during an unrelated google search which also turned up your query.

http://www.gizmowizard.com/deckeldap...ter_sleeve.htm