Shars R8-ER40 Chuck

ttabbal

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H-M Supporter Gold Member
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I decided to try this one out as it is mid priced and has a reasonable TIR spec. The claim is 0.0001" at the collet face. I figured if I wasn't happy I would send it back and spring for a Bison or similar.

Prior to installing, I thoroughly cleaned the taper in the Bridgeport and tested it with the same setup. 0.0004" TIR. Not perfect, but I'll take it.

I tested a known good ground rod in an R8 collet. The collet came with the machine and any markings have worn off, so I can't be sure what it is. About 1" from the collet face I measure 0.0007".

The first test with the Shars chuck was terrible. I have to assume user error with some dirt or something getting in there. After cleaning everything again and reinstalling I measured the ER40 taper. This was surprising at 0.0004". With the same bar in a Techniks collet I have tested on my lathe, 0.0005" 1 inch from the collet.

I repeated the tests and got the same results a second time. Tests were done with a Compac 1 tenths DTI in a Noga arm.

After the tests I looked up inside the taper and I think there is a little cleaning still possible in there.

The chuck has a nice heavy feel and the machined areas are very smooth. Like the lathe ER40 chuck I got from them, the threads have some small chips in them. Nothing that doesn't clean up easily with compressed air. No burs or other signs typical of junk tooling. At this price point, I'd rather they cheap out on cleaning than machining, so I'm fine with it.
 
I decided to try this one out as it is mid priced and has a reasonable TIR spec. The claim is 0.0001" at the collet face. I figured if I wasn't happy I would send it back and spring for a Bison or similar.

Prior to installing, I thoroughly cleaned the taper in the Bridgeport and tested it with the same setup. 0.0004" TIR. Not perfect, but I'll take it.

I tested a known good ground rod in an R8 collet. The collet came with the machine and any markings have worn off, so I can't be sure what it is. About 1" from the collet face I measure 0.0007".

The first test with the Shars chuck was terrible. I have to assume user error with some dirt or something getting in there. After cleaning everything again and reinstalling I measured the ER40 taper. This was surprising at 0.0004". With the same bar in a Techniks collet I have tested on my lathe, 0.0005" 1 inch from the collet.

I repeated the tests and got the same results a second time. Tests were done with a Compac 1 tenths DTI in a Noga arm.

After the tests I looked up inside the taper and I think there is a little cleaning still possible in there.

The chuck has a nice heavy feel and the machined areas are very smooth. Like the lathe ER40 chuck I got from them, the threads have some small chips in them. Nothing that doesn't clean up easily with compressed air. No burs or other signs typical of junk tooling. At this price point, I'd rather they cheap out on cleaning than machining, so I'm fine with it.

It is always good to know the Chinesium stuff is getting much better in quality. Even my neighbor (a professional machinist) has stated the Chinese Bridgeport clones are okay for beginners and folks who don't require accuracy, though he couldn't suggest buying one (could be out of habit, or a "not quite good enough").
 
Chinese can be good, or crap. It just depends on how much the customer was willing to pay. Better importers pay more and end up with better gear as a result. That's one reason I don't buy the cheapest stuff on ebay.

I have no illusion that this chuck is as good as Bison or another big name. So far, it seems to be good enough for a home guy like myself though. If even 2 tenths is a problem for me, I'm doing great.
 
Hi, just wondering? Is this for a milling machine? I totally get the toolaholic side of having to have every tool in the world. I have a Bridgeport Series I milling machine. And have a set of regular collets for it. How would this ER set-up compare to what I already have. Thanks in advance…Dave
 
Hi, just wondering? Is this for a milling machine? I totally get the toolaholic side of having to have every tool in the world. I have a Bridgeport Series I milling machine. And have a set of regular collets for it. How would this ER set-up compare to what I already have. Thanks in advance…Dave

Yes, it's in my Bridgeport mill. I have a small set of R8 collets that came with the machine. I have some pretty big gaps though. In addition, I already own a nice set of ER40 collets that cover the range the Bridgeport would need nicely. So it's partly using what I have rather than buying a set of R8 to fill in the gaps.

ER collets also clamp over a wider range than R8. So I need fewer collets to cover the same range. They are also a bit faster to swap for me as I don't need to fiddle with the drawbar and I'm already used to ER.

My ER collets also seem a bit more accurate, which helps tool wear. Though the difference is small with the tests I performed.

If you have a more complete set of R8 and they work well for you, this might be something you would pass on. Particularly if you don't already have ER40 collets for other uses. This setup also uses some of the vertical space, about 3", which might be a problem for some work. I'm all for spending your money, but might as well spend it wisely.
 
Yes, it's in my Bridgeport mill. I have a small set of R8 collets that came with the machine. I have some pretty big gaps though. In addition, I already own a nice set of ER40 collets that cover the range the Bridgeport would need nicely. So it's partly using what I have rather than buying a set of R8 to fill in the gaps.

ER collets also clamp over a wider range than R8. So I need fewer collets to cover the same range. They are also a bit faster to swap for me as I don't need to fiddle with the drawbar and I'm already used to ER.

My ER collets also seem a bit more accurate, which helps tool wear. Though the difference is small with the tests I performed.

If you have a more complete set of R8 and they work well for you, this might be something you would pass on. Particularly if you don't already have ER40 collets for other uses. This setup also uses some of the vertical space, about 3", which might be a problem for some work. I'm all for spending your money, but might as well spend it wisely.
Thank you for getting back to me. Looking over my use of collets and your ER set-up. Maybe a big difference is the need for 3 more inches of head room and a possible loss of some rigidity. When I use a collet the head room is at minimal requirement. And because of this, rigidity is at its best. Yes, the ER can hold a range in sizes. Not sure if that comes into play though when holding cutters? Also, there is additional tolerance uncertainties with the ER addition compared to just a simple “one” piece collet. All my cutters have nominal shank sizes. And none of them are metric either. I have a full set of R8 collets. Some get used all the time. Some not so much. Some not at all. Can’t recall ever needing a collet I didn’t have in the set? Some folks have noted the cutter spinning and or moving up/down in the collet? I have never had those problems. But, any who’s it’s. Glad you are happy and glad we had this topic chat. I’m going to just keep the ER thing on the back burner for now. Thanks again…Dave
 
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I have an ER32 Chuck on my BP and use it over R8 collets for quicker tool changes. Just prefer a spanner wrench at chest height over rip-roaring up on the drawbar. Maybe a power drawbar in my future.

Bruce
 
I have an ER32 Chuck on my BP and use it over R8 collets for quicker tool changes. Just prefer a spanner wrench at chest height over rip-roaring up on the drawbar. Maybe a power drawbar in my future.

Bruce,
I did the same thing on my last mill that did not have a power drawbar. On my new mill with a power drawbar, I have yet to use my R8 ER32 chuck. They make life a lot easier, that and I would need a step stool to get to the drawbar on my new mill. I do have the Shar's ER40 nickle plated chucks (R8 and MT3) and I have found them to be accurate (0.0001" TIR).
Mark
 
I haven't used mine yet. I purchased a small set of ER40 collets and an mt3 chuck. I must say. the fit and finish is outstanding IMHO.
Regarding hardness and durability, only time will tell.
 
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