R8 shank with ER32 collet system.

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Richard_W
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Re: R8 shank with ER32 collet system.

Post by Richard_W » Sat Mar 25, 2017 1:42 pm

pete wrote:.......To be honest proper R8 collets that ARE well made with low runouts are better in almost every way. But the ER's excell because of there range. When I want spot drilled holes and drilled locations very accurately placed with a good DRO I don't even use good keyless drill chucks. There's an unbelievable difference in just how rigid spot, center, or any drills are held compared to even an Albrecht chuck. Very slow to use and change drills compared to even a keyed drill chuck though. I don't think I'd use the ER's as a full replacement for a good keyed or keyless chuck. When I do want the extra accuracy then the ER's are in my opinion well worth the extra time.
Agreed ! I was wanting to be able to drill and tap using the ER32 collets. The morse tap collets are all right, but tend to strip out and you need the additional length for the R8 to #3 morse taper. My thought was to shorten up the length hanging out the spindle. Also to be able to use metric end mills and number and letter drill.
pete wrote: My Emco and Bison sets all check out well under the allowable limits but they sure weren't cheap. Using ER's on a mill just depends on the work your doing. Yes as others have already said they eat up a few inches in Z. And just aren't quite as rigid as the standard R8 collets are. I guess only you can judge if the few trade offs are worth it. They would duplicate your tool holding a bit and add cost, but a limited set of R8 collets for your most used tool shank sizes is still worth having in my opinion.
Yes it does duplicate and I have thr R8 collets and a few weldon holders. The cost of the ER32 and a set of metric ER32 collets was less than $100. I wasn't expecting to see that they didn't cut the wrench flats though. I have contacted the seller and they offered to return $5 to me. What a joke. I was disappointed to see the shank was hard turned instead of the normal ground shanks. They just got here this week and I haven't checked them out yet.

Thanks for your thoughts.

Richard W.

pete
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Re: R8 shank with ER32 collet system.

Post by pete » Sat Mar 25, 2017 7:38 pm

When your checking those collets it may be worthwhile to also check for any internal and external burrs on the collet slots. Not only does that throw the collet or tool shank off, but if there's any that intrude into one or more of the slots it will give you poor runout numbers since the collet can't close evenly around the perimeter at smaller diameters. There was quite a long thread over on the Model Engineer magazine forums about ER's. One of the people contacted Rego-Fix who invented the ER collets. Many hobbyist's seem to think runout will get worse as the collet grips towards the bottom of it's holding range. According to them that's not so but they do recommend that the tool shank extends into the full length of the collets bore. If that's not possible then an added length of turned scrap material the same size as the tool shank should be used to prevent the collets bore from tapering as it closes down. That will greatly increase the runout and reduce the grip by a whole lot.

5 bucks eh? Wow. My BP clone has the normal spindle brake up on top of the head but it would be a real pita to have to keep that brake applied while tightening or loosening the collet nut since it can't be locked on like some of the other mills can. My 40 sized chuck is 40 mm across the wrench flats on the chuck body fwiw. Maybe someone here who's got a good 32 sized chuck can measure there flat dimension for you.

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Richard_W
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Re: R8 shank with ER32 collet system.

Post by Richard_W » Sat Mar 25, 2017 9:58 pm

pete wrote: My BP clone has the normal spindle brake up on top of the head but it would be a real pita to have to keep that brake applied while tightening or loosening the collet nut since it can't be locked on like some of the other mills can. My 40 sized chuck is 40 mm across the wrench flats on the chuck body fwiw. Maybe someone here who's got a good 32 sized chuck can measure there flat dimension for you.
Good info. I would think milling the wrench flat until it looks good would be fine. To sick with a cold at the moment to get just to go and do it. I think the wrench flats were intended to be used in a bench vise? That would make more sense to me.

Richard W.

pete
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Re: R8 shank with ER32 collet system.

Post by pete » Sat Mar 25, 2017 11:44 pm

Afaik the wrench flats are just used with the chuck tightened into the mills R8 taper. At least that's how I do it and I've never seen any mention of using a bench vise so far. Although with a set of stepped bench jaws that fit onto the wrench flats it could be used I guess. You do know about snapping the collet into the nut first so the nuts internal ring seats into the collets groove that's just below it's maximum diameter? That's all done away from the chuck. My Bison and Emco chucks were very well made, but it took awhile for the sharp edges that seat into the collet groove to wear a bit and then collet changes got a lot easier. I'd expect the same will be true for yours as well. For tool shanks at the same diameter as the maximum a collet is designed to take then changing tools isn't all that bad. For smaller it's a bit of a 3 hands effort. If it get's to be a juggeling act I'll usually bring the knee up with a rag on top of the mill vise or other to protect the tool and use that to hold the tool at the correct elevation then tighten the collet nut.

Same or even more important when loosening the nut. Any undersized tools have a bad habit of dropping out as soon as the nut is loosened so that rag really helps to protect the tool edges. With the 30,40,50 taper cnc tooling and them usually having an ATC plus the correct bench or cart mounted tool holder they can just do the tool changes upside down or horizontally and away from the machine so it's a lot easier. But unless I need to change the R8 shank for the next tool I don't pull the collet chuck at all. If you've got a power drawbar then you could do it the cnc way a lot easier. But so far I haven't found a quiet one and hate the noise the air ratchet ones make so haven't put one on my mill yet.

In my opinion I think it would be a good idea to clean your mills R8 taper really well, the same for the collet chucks shank. Then install it into the mills spindle without a collet or the nut. Then check to see what runout you have on the chucks collet taper first. That way you have a good idea of what each collet is giving you minus what any small runout the chuck hopefuly has. To my thinking a properly ground chuck should have about or under .0005" runout since each collet will have or probably will have at least a few 10ths as well. I have read about some finding .003" or more but if you don't check you won't know what you have. Mine average under half a thou, some well under, and one about .0006". Since I don't have a good set of gage pins I used tool and drill shanks so some of my tests could be out a bit.

Just in case it interests you, Arc Euro Trade in the UK have some ER tooling most other tool dealers don't. A spindexer, square, and hex collet blocks in the 32 and 40 sizes. Maybe others but I haven't checked there website in awhile. Of course that almost needs a second set of collets so the damn tool buying never ends. :-) They and a few other UK dealers also have backplate mounted collet chucks meant for lathe use. But I think building your own isn't that hard and would probably end up better and more accurate since it's machined on the lathe it will be used on anyway. Given the hardened and ground internal collet nut dimensions and compexity I don't think making the nuts is possible in the average home shop.

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BadDog
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Re: R8 shank with ER32 collet system.

Post by BadDog » Sun Mar 26, 2017 2:12 am

Other than getting it tight enough (certainly a chore even on ER32, much less ER40), I'm not sure what benefit a bench block would be. And it would kill the convenience factor of avoiding the draw bar tango. I think the main point of bench mounting is for pre-setting Z, which holding it mount to mount isn't exactly an R8 strong point as opposed to other systems when bench mounting is common. However, if you have a reason and do want to setup some on the bench, I think I would just setup a "barrel vise" (shop made clamp/collet type affair) to use. Added bene of now having a barrel vise at your disposal. If you are really trying to do a Z setting in R8, probably better to look into a fixed height system (Tormach?), which I suppose Z could also be set based on a properly setup barrel vise?

Now, just spit-ballin', but what I think would be really cool if larger ER collets are to be part of your day to day tool holding plans, is a torque arm holder. I can imagine a few ways one might be made, the the gist is something like the drill press vise which floats free to position, but is connected to the column so it can't rotate with drill torque. Imagine a similar system that could be easily swung clear and back, float up and down to engage the nut regardless of Z location, and quickly locked (over center or cam?) so it holds the spindle from rotating completely hands free while you manage the tool/collet/nut/spanner activities. Reef it down to spec, pop the lock (cam, toggle, whatever) to release the action, and then move out of the way until next tool change. Maybe even a single lock based on the Noga style transfer rods where all free movement is held by a single knob/lever, but the design mechanically locs from rotation without that lock actuating. That means you can "lock it" and keep it in any position you like even if you get into heavy vibrations, but the lock doesn't have to be terribly robust to do that as long as the physical design of the arm/joint can restrain the torque while tightening the nut (can't turn even if not "locked").
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Richard_W
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Re: R8 shank with ER32 collet system.

Post by Richard_W » Sun Mar 26, 2017 8:31 pm

pete wrote:Afaik the wrench flats are just used with the chuck tightened into the mills R8 taper. At least that's how I do it and I've never seen any mention of using a bench vise so far. Although with a set of stepped bench jaws that fit onto the wrench flats it could be used I guess. You do know about snapping the collet into the nut first so the nuts internal ring seats into the collets groove that's just below it's maximum diameter?
Yes i know that. I don't like the idea of putting all that extra force on the spindle tightening and loosing the collet. I prefer to do it out of the machine.

Richard W.

RonnieJ
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Re: R8 shank with ER32 collet system.

Post by RonnieJ » Thu Aug 03, 2017 5:31 pm

I have used this type of set up for some time with great results in both a LMS 5500 and larger mills. The system will allow a bit more Z movement than a drill chuck. Also you will find having a set of metric collects also helps even with SAE sizes. Best of luck with it. Ron

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Richard_W
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Re: R8 shank with ER32 collet system.

Post by Richard_W » Sat Aug 05, 2017 2:07 pm

RonnieJ wrote:I have used this type of set up for some time with great results in both a LMS 5500 and larger mills. The system will allow a bit more Z movement than a drill chuck. Also you will find having a set of metric collects also helps even with SAE sizes. Best of luck with it. Ron

I only bought a set of metric collets. They will hold just over 3/4" and smaller and take both inch and metric shanks. They will take al letter, number and fractional drills in the metric collets. I saw no need for an inch set of collets, especially since the largest diameter they would hold is 3/4".

Richard W.

pete
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Re: R8 shank with ER32 collet system.

Post by pete » Sun Aug 06, 2017 1:14 am

The one issue I found with my ER-40'S is as far as I know they don't make collets that will hold tool shanks smaller than .094". And below .094" in the ER-32's they only collapse .015" for each collet size verses the .039" for the larger ones. If your ever needing to hold real small drills and tooling then a second set in ER-20 might be needed. They do make the series in as small as ER-8's although I've yet to see them in any tool dealers catalog. I bought inch sized collets since it's still a standard shank size but see no real difference between metric and imperial ER collets and the range of tool shanks they'll hold. Imperial or metric tool sizes are all held equaly well in either type.

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Re: R8 shank with ER32 collet system.

Post by RonnieJ » Sun Aug 06, 2017 3:18 pm

Richard_W wrote:
RonnieJ wrote:I have used this type of set up for some time with great results in both a LMS 5500 and larger mills. The system will allow a bit more Z movement than a drill chuck. Also you will find having a set of metric collects also helps even with SAE sizes. Best of luck with it. Ron

I only bought a set of metric collets. They will hold just over 3/4" and smaller and take both inch and metric shanks. They will take al letter, number and fractional drills in the metric collets. I saw no need for an inch set of collets, especially since the largest diameter they would hold is 3/4".

Richard W.

No questions about it, you are correct-I already had the other guys before I found the metric--would go metric with no problem
RON

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Re: R8 shank with ER32 collet system.

Post by platypus20 » Mon Aug 07, 2017 10:25 am

I use a ER32 x R8 collet system on the Rockwell vertical mill, with absolutely no issues. On the Jet and the other mill, I use the Grizzly sourced, Din 6388 style collet systems, again with no issues.
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Re: R8 shank with ER32 collet system.

Post by Ironman1 » Tue Aug 08, 2017 10:00 am

To drag this thread off the beaten path, I am wondering if there is a CAT40 holder available for 1" as I have several 1" shank insert type mills that would be nice to use. I guess the option is to get an ER40 collet system as well.
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