Mt3 open socket

[Rig Pig]

Anybody know if mt3 x mt3 open sockets are available anywhere? I need the shortest possible extension to fit my milling chuck into my slightly non standard spindle, all my searches have found loads of size changes but no simple standoffs.

 

[Ton-up]

Do you mean a mt3 extension like this, very handy!

https://www.cromwell.co.uk/shop/cut...tension-socket-3mti-s-x-3mt-o-s/p/KEN4824330K

 

[Rig Pig]

I'm after something much shorter to hold an er32 collet chuck as ridgedly as possible, annoyingly the spindle is slightly non standard - it's built for mt3 with a drive dog so the head of the chuck hits the dog instead of going in fully.

 

[Rig Pig]

Anyone?

 

[Ton-up]

I don't think you will find something as it would be thin walled. You could machine the outside of what I posted above down. Silly question, but I don't suppose the dogs are bolted on are they?

 

[Rig Pig]

Most of the available adaptors are hardened which will make adapting one a pain, sadly the end of the spindle is a socket, the dogs need to be on the male taper. I think I will have to buy a soft MT3 arbor and bore it out. I only need about 1/2" more length. It's that or rebore the spindle iso30 but I'm a coward.....

 

[8ob]

I have turned down MT3 drills and converted them into reduced shank ( blacksmith drills), they are a lot softer that a sleeve. It may be an idea to start off with one of those. Just thoughts Mr @Rig Pig .

Bob

 

[WorkshopChris]

I only need about 1/2" more length. It's that or rebore the spindle iso30 but I'm a coward.....

Would the tapper in your spindle have enough length if you were to machine the part that accepts the drive dog off of the spindles length?
Another option may be to machine a mt3 to mt3 adaptor form a Straight Shank to Morse Taper Adaptor Sleeve that way you all ready have your internal taper machined. Start with something like this. https://www.cutwel.co.uk/tool-holdi...tion-sleeves/mtas-morse-taper-adaptor-sleeves
Your er collets holders draw bar would still hold both parts in the spindle.

 

[Rig Pig]

I will have to see what's about to modify, I was hoping to just buy one, I'm not keen to do anything to the spindle as one day I will get someone to put an iso30 taper in it so I want all the meat it's got - 3mt is a bit puny in a mill of this size with (I think!) 3hp.

 

[Rig Pig]

This is the view from below.

 

[vwmark]

This is the view from below.View attachment 115723

Yours is slightly different to mine. Still haven't found what was used originally.

Have you stripped the quill on your mill? Just wondering what is involved if I decide to remove the drive dog recess.

 

[Rig Pig]

I haven't had it in bits, my current cunning plan is to buy a soft mt3 arbor, stick it in my lathes mt3 spindle and drill + bore it out to make a thin mt3 x mt3 sleeve to give me the standoff I need to clear the dogs.
I'm not keen to cut the mills spindle about at the moment because mt3 is a fairly poor choice for a mills spindle taper (hence the drive dogs.....) but I saw an early post from someone who has a similar mills to us but the spindle has been modified to int30, a quick measure up of mine showed enough meat to do the same modifications if I stick with the mt3 for now.