TTS Tool Holders- Collets

[rwm]

I know TTS systems have been discussed extensively in the past. I am thinking about converting and I have a specific question about tool holders that I need to ask. I know there are pros and cons to each but I want to see if there is a consensus. I will be using a TTS collet in an R8 spindle. For end mill holding, do I want:
1. Weldon type holders with set screw
2. ER 32 collet holder.

Our old friend Mikey has previously advocated for ER collets due to runout of set screw type collets based on this diagram:

This makes sense but how much runout does this really add for a precisely machined holder? Would an ER collet have less?
How much issue is tool pull out in the ER system? The ER system is obviously a little more expensive but lets put that aside for now.
What do you favor?
As a secondary consideration what about ER20 vs ER32?

 

[Nutfarmer]

It all depends on what you are doing. If you’re running a commercial cnc you could go all the way to shrink fit tooling. The ER system is an improvement over the R 8 collet. For most of us with manual machines R8 with a Weldon shank works just fine. It is all about how much money you want to spend and what your needs are.

 

[rwm]

Hobbyist with manual machine. I hate tool changes. Trying to speed that up and be able to set the Z height. I have not had any pull out issues with the R8 collets. Is the ER series better in that regard? Why is the ER an improvement?

 

[RJSakowski]

I have been using the TTS system on both my Tormach and my manual mill. I use both collets and end mill holders. My current inventory is 15 collet chucks and 7 end mill holders. The sizing on the bores of the end mill holders is such that an end mill with the matching size shank is within a 1/2 thou or better and I am not concerned about any runout . OTOH, using an end mill holder with an end mill with a Weldon shank will prevent pullout during aggressive milling operations.

I use the ER20 collets. The chucks and collets are less expensive than the ER32. If I need to run larger end mills, I have my set of R8 collets and end mill holders to fall back on. I have multiple collets in the standard end mill shank sizes and a full set of metric collets for use with any special shank diameter.

 

[rwm]

@RJSakowski -Super helpful as always!

Any improvement in rigidity going from ER20 to 32 or not worth the gain?

 

[coolidge]

This makes sense but how much runout does this really add for a precisely machined holder? Would an ER collet have less?
How much issue is tool pull out in the ER system? The ER system is obviously a little more expensive but lets put that aside for now.
What do you favor?
As a secondary consideration what about ER20 vs ER32?

I went from R8 set screw type collects to an ER32 collet chuck and holders on a mill years ago. The same ER32 collet chuck and collets was the first thing I ordered for the new mill this year.

ER tool pull out, never had that issue. ER are more precise than set screw type collets but you might have to be a production shop to notice or care. Basically the lack of concentricity can result in one side of the tool doing more work and reduce the life of the cutting tool.

Had an R8 power drawbar setup for a while, that was also good for fast tool changes. Really a must have on a knee type mill unless one is tall enough to change manually without a step stool.

 

[mksj]

I use primarily ER32, should have better holding power than ER20, but with ER collets proper nut type/torque is important. I had some pullout early on with my ER32 and most likely it was because I did not clean the oil off the collet and not enough torque on the nut. I now use a better ER nuts. An ER32 may also have less stickout than a weldon type. I use a R8 3/4" weldon type for my annular cutters, it requires flats on the tooling, many of my endmills do not have flats. With a TTS system I would think ER collet system is more common vs. weldon.

 

[rwm]

Hey, what is up with the ER32 nuts that have wrench slots on the wrong end???



Unless you use a semicircle wrench you can't get the wrench off? I hate those semicircle wrenches. I can never get them on.

 

[WobblyHand]

Hey, what is up with the ER32 nuts that have wrench slots on the wrong end???

View attachment 505751

Unless you use a semicircle wrench you can't get the wrench off?

Makes a full circular wrench useless, doesn't it? For an ER-32, I use a hook spanner. For my ER-40 I have a half circle wrench, they work fine.

 

[rwm]

One thing I learned on line: The ER32 system has such a large OD that it is hard to use with short/small endmills. It obscures the work and makes chip clearance difficult. Imagine a 1/8 end mill with .500 stickout. You wouldn't even see it!
I just didn't want to end up with 7 different collet systems. I now have 5C, R8, some ER32 and now I guess ER20....