ER11 Adapter for the CT

[farmer]

Jeff and bergerud I have been reading this and decided to get a ER=11 I bought mine from Bass Tool it is a Iscar EMT, with a 1/2" X 4" shank I would like to know how much to cut off it look like I need to cut about 3" off that would leave about 1" above the threads. I attached a pic of the kit it came with all the adapter and the wrench in a nice case.

[bergerud]

That looks very nice. Where to cut it off is a good question. There is, I believe, 1 inch of 1/2 inch bore in the CT. How long you leave the adapter shank depends on how you want to use the adapter.

If you want to use the ER11M as a chuck, loosening and tightening the ER11M to change bits while it stays in the CT, you would want to leave more than an inch of shank so the shank of the ER11M adapter hits the top of the CT before the ER11M nut hits the bottom.

On the other hand, if you want to use the ER11M as an adapter which you take in and out with the bit in it, it might be better the have the shank just short of an inch so that the nut hits first. (This would be more accurate for repeatable bit depth I think.)

My thought was to use the ER11M as an adapter to be tightened outside of the CT and so I would cut it off just under an inch.

Please keep us updated on how this goes. I worry about run out. How well does the shank fit in the CT?

[farmer]

I will want to use it as an adapter and take it out to change the bits. I will try it this weekend and let u know!
Thanks Steve

[bergerud]

I will want to use it as an adapter and take it out to change the bits. I will try it this weekend and let u know!
Thanks Steve

How did it go? Did you get a chance to cut down the holder and give it a try?

I have a guy in China making adapters for $15 each (with wrench) and another China source for collets at $3 each. After I give these a try, I will report.

[badbert]

How did it go? Did you get a chance to cut down the holder and give it a try?

I have a guy in China making adapters for $15 each (with wrench) and another China source for collets at $3 each. After I give these a try, I will report.

Looking forward to that report!

[farmer]

I cut 2 1/2 " off it work good but sticks out to far I am going to cut another 1/2" off and try it again this weekend I will not home to try it until this week end. It went up in the chuck about 1". If I cut another1/2" that will leave about 1" above the threads. Dowse anyone know what the RPM is of the spindle?

[bergerud]

The spindle is up to 20000 rpm.

On the ones I have made, the exposed threads (about 1/4") also go into the CT until the nut hits. The nut itself is almost 1/2" thick and this is all the room there is between the CT and the board at the bottom of travel. I would think that your holder, being of higher quality, should have less free threads.

When you get it the way you want it, it would be useful if you could post a picture.

[farmer]

Here are the pics I took I tried it and its runs smooth not much run out. Will take my indicator home this weekend and check it. The nut does not hit the CT it is about 1/8" away. The shaft bottoms out in the CT so it will always set in to the same distance.

[CNC Carver]

Farmer that looks great. Nice work. Keep us updated on how well it works.

[bergerud]

That does look nice. With that extra 1/8", you have to be careful. The ER nut could hit the wood if you have a short bit going deep.