MT3???????

[rake60]

OK all of this taper talk has gotten me into the chance taking mode again.

As most of you know I bought an R8 shank ER32 collet chuck from the eBay
vendor 800Watt for a very low price and found it to be a great deal!
The story behind that purchase can be seen HERE

The spindle taper of the import 9 X 20 lathe happens to be a MT3
Already having the full collet set I just bought THIS from the same vendor
for use in the lathe.

Now all I need to do is find a qualified machinist to make a draw bar for it once it
arrives. I do know where such a guy lives, but he drinks a bit.
I'll have to catch him early in the evening!

Rick

 

[Mike of the North]

A quick and dirty way to do it is use a pice of threaded rod, a washer and nut, you can make the washer with a step to fit the ID of your spindle to keep it centered.

Mike

 

[Cedge]

Rick
Now if you can just find a sober engineer to draw it up for you...(grin)

Steve

 

[bentprop]

Rick,my bolt supplier actually has long bolts in 2" increments that are often used as drawbars.
I bought one slightly over length,so i could cut off any surplus,rather than be short.In my case this was 12mm thread,but I'm sure they make them in imperial sizes as well.
Mine is only galvanized steel ,which I believe is a bit softer than normal bright ones,but since I never remove the collet chuck,it's not a problem.

Hans.

 

[Hexbasher]

drawbar???

i dont understand

this is for your lathe?...ie in the tailstock (cbores, reamers...) or in the head stock (milling set up)

you dont need a drawbar...do you mean something that screws on as a 'tang' to knock the taper out?



phil

 

[Bogstandard]

Phil,

Just to explain.

Most lathes have a MT bore behind the chuck.

By using MT collets, you can treat the lathe spindle just like the quill on a mill. But you need to be able to tighten the collets so they grip the cutter or workpiece (a cheap option compared to a collet chuck), hence the drawbar to go thru the lathe spindle, to tighten up as you would on a mill.

Hope it is now a little clearer.

John

 

[bretk]

Rick,

Do you (or anyone else who has one) find yourself using the ER32 set for everything including drills on your mini mill? By the looks of things it gives you more clearence than the drill chuck too? Also are the collets long enough to use double end mills in?

Thanks, Bret

 

[rake60]

Bret the collets themselves are 1.570" long and a tool can pass through them.
When using a collet holder for a tool, or stock, the limiting factor is the depth of
the holder. If your using a double end endmill and push it into the chuck until it
bottoms out you'll most likely destroy the inboard end when you tighten the nut
and the draws in to the taper. You have to leave a little room there for that.

Grabbing on 1-1/2" of an end mill with a spring collet is more than enough.

The only time I use the drill chuck in the mill is when I need to drill several different
size, noncritical holes. Changing collets 6 times on one part just doesn't appeal to me
but a cheap collet will drill a much closer to size hole in most cases than even an
expensive drill chuck can.

Everything critical is done with a collet, and ALL endmills are mounted in collets.

Rick

 

[rake60]

My new MT3 ER32 collet holder arrived today.

For $28 including shipping it was taking a chance.

But, I stuck it in the lathe for a quick check on run out.

That picture shows the high spot in the T.I.R.
I believe I can live with that!

Rick

 

[tel]

Yep, looks like you got a good 'un.