ER32 collet chuck mods-Arboga mill

[neksmerj]

I have to modify my ER32 collet chuck so I can use it in my Arboga mill.

Basically I have to machine two slots across the body, one each side, to slide a C-shaped washer into.

I figure I can cut the slots in one of two ways.

1. Set the arbor up in a chuck/rotary table, and machine across the collet chuck with an end mill, 5/32" or 4mm, or

2. Similar set-up but vertical, and cut the slots with a 5/32" thick slitting saw.

Attached is a rough drawing showing what has to be done. The large C-shaped washers are a tad under 4mm thick. A new washer will also have to be made, probably laser cut out of 4mm ms.

I'm tending to think the slitting saw idea is the better one, with less chance of breaking, and being useful for other things. I can get a P&N blade for around $45 new.

Last question, how would you transfer the location of the slots from the Clarkson chuck to the ER32 chuck? Doesn't have to be absolutely precise, ie, +/- 0.5mm.

Ken

[pipeclay]

Looking at your drawing it appears that the slot is formed in the Nut.

What then retains the washer from falling out?

What if any thing does the washer bottom out on?

What tollerance is there in where the washer sits,I see you have stated a +/- .5mm is this for the thickness of the slot or the final location that the slot needs to be in?

[Dave J]

Hi Ken,
You will probably find the shank to be hardened or case hardened so a carbide end mill or slitting saw would be recommended and last longer. The tool place in Taiwan where Eskimo bought his boring head had slitting saws in carbide I am pretty sure and carbide end mills are around on ebay and a few stores for good prices.

I would mill it with a 2 flue carbide end mill held in a rotary table set vertical. (good excuse to buy 8-10 inch one with a MT3, LOL)
This way the taper could be locked in the rotary table using a short draw bar and the Clarkson collet chuck could set up first to get the distance out needed for the slot.

Using the Clarkson chuck to set up the distance for the slot could also be used with the table horizontal using the slitting saw if you want to go that way. If set up this way the table would need to be raised off the mill table with spacer blocks to clear the draw bar coming out of the back of it.

Dave

[Dave J]

Looking at your drawing it appears that the slot is formed in the Nut.

What then retains the washer from falling out?

What if any thing does the washer bottom out on?

What tollerance is there in where the washer sits,I see you have stated a +/- .5mm is this for the thickness of the slot or the final location that the slot needs to be in?

The washer sits inside the nut and as it is tightened it pushes the taper in. As for clearances I am not sure and Ken would have to measure it.

Dave

[pipeclay]

I havent seen this type of setup before but by looking at the drawing the groove or flat appears to be on the outside of the nut not the inside.

[Stustoys]

PC,
Forget the nut in the PDF, thats for holding the collet in the ER32 chuck.
There is another nut that holds the ER32 chuck into the mill.
Stuart

[Stustoys]

Ken,
The washer would be easy to make.
Won't you have to turn part the Dia of the ER32 chuck down to 35mm or change the shape of the washer?

Dav,
At a guess, wouldn't the slot be to close to the table to get in with a milling cutter when the ER32 is held by the MT3? You could hold it in a in a 4 jaw on an adaptor though maybe.

Stuart

[neksmerj]

Dave,

Greg cut one of these ER collet chucks, to adapt it to fit his Deckel mill.
I mention this as the metal was not all that hard, and succumbed to a hacksaw blade.

So I'm still thinking that a slitting saw will be the way to go.

Pipeclay, I'm sorry if my drawing is a bit ambiguous, it is an unusual set up, and quite clever eliminating a draw bar. Perhaps I should draw up an assembly drawing of the Arboga spindle, showing how it all goes together.

Ken

[Anorak Bob]

I should have asked a more pertinent question. Is the mill finally up and running?

[Stustoys]

Threre you go Bob
https://www.woodworkforums.com/f65/ar...ml#post1291997

[Anorak Bob]

I deleted my earlier post because I found the photos.

BT

[neksmerj]

Thanks Stu,

I was just off chasing this previous post, when you located it for me.

I'm trying to knock up a very simple dwg showing the spindle/arbor arrangement.

Ken

[Greg Q]

Ken, I think I'd just have the arbor grooved at that location (in a lathe). That way you won't introduce a possible imbalance problem, you won't have to worry about indexing accurately and you can use cheaper tooling.

Thinking about it, doesn't the U shaped washer demand a full circumference groove?

[Dave J]

Ken,
The washer would be easy to make.
Won't you have to turn part the Dia of the ER32 chuck down to 35mm or change the shape of the washer?

Dav,
At a guess, wouldn't the slot be to close to the table to get in with a milling cutter when the ER32 is held by the MT3? You could hold it in a in a 4 jaw on an adaptor though maybe.

Stuart

You are right there, it probably wont have enough room.

Dave

[Dave J]

Ken, I think I'd just have the arbor grooved at that location (in a lathe). That way you won't introduce a possible imbalance problem, you won't have to worry about indexing accurately and you can use cheaper tooling.

Thinking about it, doesn't the U shaped washer demand a full circumference groove?

Sounds like the easiest solution and would be easily done on the lathe. If the lathe has a MT3 spindle even better, or an adapter could be used. The Clarkson could still be used to get the right distance set up.

Dave