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PM935 and ER tool holders

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kb58

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My PM935 is on the way and I need to order tooling. At first, I was considering a power drawbar for the R8 spindle, but then read about the ER-series tool holding system that negates the need. I don't have any tool holders (R8 or otherwise), so I'm not invested either way. Some threads note that it takes a fair bit of torque to tighten the ER chuck. Is this of any concern on a PM935? I realize those threads don't always mention what machine they're breaking spindle parts on when tightening the chuck. They also don't say how many ft-lbs of force they're applying, but I still wanted to ask.

Oh, and which ER-series do you guys recommend? I know there's a lot of ER32 stuff available, but since the cost isn't much more, is going with the ER40 smart? A few posts note that the ER40 can be a pain because it's physically larger and may interfere with the work.

The mill will be used on all sorts of stuff, but mostly smallish (<12") objects that are not too tall, hobby stuff and car stuff.
 

Bob Korves

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ER40 can be a good choice. It does require a fairly high torque to get the collets properly tightened. If you use two wrenches, one tightening the collet nut and the other restraining the ER mandrel from rotation, you will have no problems with the mill, which will be out of the equation. The chuck will need to have provisions for the second wrench like this one has:
1547739739629.png
 

mikey

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Probably the best way to choose which system to go with is to look at the largest tool you are likely to use. If you're doing mostly small work and the largest tool shank size you're likely to use is 3/4" diameter or less then an ER-32 system makes sense. If you plan to use 1" diameter cutter shanks then the ER-40 is more suitable. Cost is commensurate with size.

Be advised that a good chuck counts; they will have lower levels of run out. Good collets also count, as do the collet nuts you use. A good ER set up will have run out levels in the neighborhood of 0.0002" or less for the whole assembly, including the spindle.

Insofar as tightening the chuck nut, the easiest way to do a tool change is to remove the chuck to a fixture, change tools and use the fixture to hold the chuck while you tighten the nut. Most ER chucks have a flat on the sides so a fixture is easily constructed from scrap aluminum you have lying around.
 
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davidpbest

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IMO, ER collet chucks do not negate the utility of a power drawbar. Drill chucks are best when used with a dedicated R8 tool holder. And you will get better results on concentricity/run-out if you tighten your ER collet chuck in a dedicated fixture out of the spindle. This is particularly important when using very small end mills like 1/8" or smaller, since runout at those tool diameters will quickly lead to tool breakage. So you will probably still be doing a lot of tool install and removal via the drawbar.

I have and use both ER32 and ER40 collet chucks for both R8 and D1-4 camlock, and share the collets between my PM1340 lathe and PM935 mill. There is a huge difference IMO between cheap and quality ER collet chucks and collets, so if you plan to do precision work, you're better off buying versions that are high quality and thus more expense. The same is true for the collet nuts - I have discarded all my prior attempts to employ collet nuts that come with the chucks, and purchased the original Rego-fix nuts instead.

If you're looking for a system that does not involve having to mess with the drawbar for tool changes, a good (but not inexpensive) alternative is the Royal Easychange system. Here's a video example of using the Easychange quick-change tool system for typical multi-tool operations such as spot drilling, drilling and then tapping a hole: https://flic.kr/p/282tf9y This was shot prior to replacing my RF45 with the PM935 (which now has a power drawbar).

This Royal quick-change system has the least stick-out of any non-drawbar activated QC system for R8, and has exceptional runout performance. It's taken me a while to accumulate the full set of tool holders for that system that I need for my routine work, and here's a photo that shows my common mill tooling - the Royal Easychange tools are in the lower front rack, the elevated back rack is for dedicated R8 tools and collet chucks: https://flic.kr/p/2ecfYob
As you can see, I have a few ER32 collet chucks for my Royal Easychange system, and I use these mostly for mounting metric-specific tooling such as 6, 8 and 12mm end mills, and the 12mm spindle of the Haimer edge finder.

Hope this helps.
 

pontiac428

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I use ER32 collets for my mill. It would have cost the same for me to go up to ER40, but my mill is better suited for 3/4" shank tools and under. Big tools and 1/8th-increment end mills go into dedicated holders for rigidity. I really like the collet setup, they hold well and have very low runout.
 

bretthl

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I have and use both ER32 and ER40 collet chucks for both R8 and D1-4 camlock, and share the collets between my PM1340 lathe and PM935 mill. There is a huge difference IMO between cheap and quality ER collet chucks and collets, so if you plan to do precision work, you're better off buying versions that are high quality and thus more expense. The same is true for the collet nuts - I have discarded all my prior attempts to employ collet nuts that come with the chucks, and purchased the original Rego-fix nuts instead.
I purchased a Bison ER40 set w/ an R8 adapter and really like using it on the mill. I had intended to use the ER system on my lathe but have not been able to find a ER40 X D1-4 chuck. What are you using?
 

ttabbal

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I purchased a Bison ER40 set w/ an R8 adapter and really like using it on the mill. I had intended to use the ER system on my lathe but have not been able to find a ER40 X D1-4 chuck. What are you using?

I'm using the Shars chuck. Fits up nicely, and has the set-tru style setup for adjustment. I have no reservations saying it's not Bison quality, but it gets the job done for me.
 

bretthl

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I'm using the Shars chuck. Fits up nicely, and has the set-tru style setup for adjustment. I have no reservations saying it's not Bison quality, but it gets the job done for me.
Is this the chuck you are using? https://www.shars.com/5-er40-zero-set-fine-adjustment-collet-chuck

This is new territory for me. Which back D1-4 back plate should I use?

Perhaps this one? https://www.shars.com/5-d1-4-threaded-black-place-for-er40-zero-set-adjustment-collet-chuck

Yes the Bison set is nice, I lucked out and found it new on ebay 250 USD. It is just a 16 piece set but it is pretty nice.

It sure makes collet change easy on the mill without a power draw bar.
 
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davidpbest

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I purchased a Bison ER40 set w/ an R8 adapter and really like using it on the mill. I had intended to use the ER system on my lathe but have not been able to find a ER40 X D1-4 chuck. What are you using?
You probably bought the same Bison R8 collet chuck I have. It's a great unit.

As for the ER40 collet chuck for the lathe, I started with an an Asian import from HHIP, but I was dissatisfied with it's runout and lack of adjustability. At the time, there were no other Camloc D1-4 ER40 collet chucks with Set-tru like adjustability, so I devised my own. Others on this forum have done the same - search the forum archives. Today, Shars offers a Set Tru version, if you can tolerate that level of quality (I can not). I was also looking to increase the projection from the spindle. The build of my ER40 Set-Tru Collet Chuck, along with plans and drawing can be seen here - each image has a detailed description if you view the images individually:

https://flic.kr/s/aHsm1PtHsq

To increase rigidity, I built a solid tool post for the carriage. It replaces the compound for 90 percent of my work and has made a huge difference is quality of finishes, parting operations, and just overall enjoyment of the lathe. I do replace this with the compound occasionally, but typically only when cutting tapers or doing single-point threading. The solid tool post build can be viewed here (again with descriptions with each image):

https://flic.kr/s/aHsm1cKjPB

This solid tool post was one of the driving factors in my desire for an ER40 collet chuck with longer stickout from the spindle nose.

I've done a lot of customizing my equipment, and most of those projects are fully covered here:

https://www.flickr.com/photos/davidpbest/albums

Hope this helps.
 

bretthl

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The build of my ER40 Set-Tru Collet Chuck, along with plans and drawing can be seen here - each image has a detailed description if you view the images individually:

https://flic.kr/s/aHsm1PtHsq
Very helpful, many thanks! I will pursue this route.

I just recently purchased a "used once" BXA Dorian wedge tool post off ebay for 375 USD (with a Dorian insert tool and holder). Not having access to any other machine tools besides my own for reference, I had some reservation if that was money well spent. Hah! Man what a difference that makes over the unit that came with my PM1340GT.
 

ttabbal

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Is this the chuck you are using? https://www.shars.com/5-er40-zero-set-fine-adjustment-collet-chuck

This is new territory for me. Which back D1-4 back plate should I use?

Perhaps this one? https://www.shars.com/5-d1-4-threaded-black-place-for-er40-zero-set-adjustment-collet-chuck

Yes the Bison set is nice, I lucked out and found it new on ebay 250 USD. It is just a 16 piece set but it is pretty nice.

It sure makes collet change easy on the mill without a power draw bar.
Yes, I believe that's the setup I use. I would email them first to verify compatibility though. I did have to machine the center boss a little, but it's designed that way so you can be sure it's concentric etc..
 
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