ER40 Adjust True Camlock Collet Chuck Build

I'm glad I saw this thread. This design gives me an idea. My ER40 chuck gives .0003 TIR on my Lathe spindle, but when put on the dividing head spindle I get a couple thousandths TIR. I could make another chuck for the dividing head using this principal and use it on the dividing head or either of the two rotary tables and could get it to run true.
 
Just a reminder to lube the collets, it might help with extracting the collet when done. This from Tormach:
quote
  1. Lubricate the outside of the collet and the inside of the spindle taper with anti-seize lubricant. These are sliding surfaces and are best kept lightly lubricated. You can use Tormach PN 31273 or any other good quality anti- seize type lubricant. Lubricate sparingly to avoid risk of the lubricant migrating to the inside of the collet.
 

Snip

Where I have had more issues is with the ER40 chuck nut. I now have a collection of about six of them, and most of the imports do not grip the groove on the nose of the collet sufficiently to pull it out of compression when the nut is backed off - the collet simply pops loose from the nut. This one does not grip the recess on the collet nose at all, which was a big disappointment considering the cost. The USA made Maritool collet nut doesn't grip the collet nose firm enough to suck the collet out of the taper if tightened to torque spec. The nut that came with the HHIP collet chuck is total junk IMO. The nut that came on the the Shars R8 ER40 collet arbor I purchased is nicely finished, but isn't ball bearing, thus difficult to loosen, and again doesn't grip the collet well enough to retract it from moderate compression. There are two ER40 collet nuts that I am satisfied with (both ball bearing type), including the one that came on the plain back collet chuck that I adapted, and the Parlec. The Parlec is closest to the original Rego-Fix nuts I have on other equipment where you press the collet into the nut at a slight angle to engage the retract ring firmly into the groove around the nose of the collet. It can be fussy to learn the technique at first, but the collet will not come loose from the nut unless it's angled to the side.

David, another great design and execution.

I have the ER32 ball bearing nut from Arc Euro Trade http://www.arceurotrade.co.uk/Catal...nners/ER-Collet-Nuts-with-Ball-Bearing-Type-B
These are very much like the original Rego-Fix nuts you describe and I'm pleased with the quality and performance. Arc Euro Trade offers a unique set of ER tooling such as ER collet blocks and a 5C to ER32 Collet Adaptor http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Collet-Fixtures
I have their 5C to ER32 Collet Adaptor and use it in my 5C spin indexer. Very handy and allows any size piece within the ER32 range to be held vs the narrow holding range of 5C.

For using ER collets on my PM1340 I was lazy and used the "field expedient method" and purchased an ER32 straight shank collet chuck simmilar to this one https://www.amazon.com/Straight-Shank-Collet-Toolholder-Milling/dp/B00N0M1RKM/ref=sr_1_4?s=hi&ie=UTF8&qid=1504027660&sr=1-4&keywords=Straight+Shank+Collet+Chuck It has a hollow shank that I chuck in my 6 jaw set true chuck. This allows me to true up the ER chuck and I don't need to change chucks.
You design gives more control on axial parallelism, something that I can't adjust easily with just the ER straight chuck.
 
I have the ER32 ball bearing nut from Arc Euro Trade http://www.arceurotrade.co.uk/Catal...nners/ER-Collet-Nuts-with-Ball-Bearing-Type-B
These are very much like the original Rego-Fix nuts you describe and I'm pleased with the quality and performance. Arc Euro Trade offers a unique set of ER tooling such as ER collet blocks and a 5C to ER32 Collet Adaptor http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Collet-Fixtures

Rich, I have so many ER40 collet nuts now that I can't remember when one (if any) came from Arceurotrade. LOL But I do have their square and hex ER40 collet blocks which I quite like. I did buy a 3" 4-jaw chuck from them which I'm not impressed with, and a few other items like dead centers, etc. which have been fine. They do a great job on shipping to the USA - very fast.
 
Nice job David, over the top work as usual and with detailed information. I believe we both have the same ER bearing nuts from Maritool, they are not too common. They work well, just be aware that if you compress a collet to its specification limits, the bearing nut is more likely to fail. I already returned an ER40 nut to Maritool for a replacement a while back, this prompted me to get a fractional 1/32 ER40 collet set and also a 10 and 12mm collet for my indicators. If you look at the better quality collets, you will often see deeper cuts in the splining which probably allows them to compress further and more uniformly.

https://www.maritool.com/Tool-Holde...438/ER40-BEARING-COLLET-NUT/product_info.html
 
Earlier this year I purchased an ER40 collet chuck with integral D1-4 mounting from hhip.com (their part #3901-5042). I wasn't completely satisfied with the quality and it didn't have sufficient stick-out from the spindle nose to get cutting tools to it using my solid tool post. I also had inconsistent registration to the spindle with unacceptable TIR. This is that chuck.

View attachment 240557

I decided to replace it with a better solution - one that was adjustable to the centerline of the spindle rotation, along the lines for an Adjust True or Set Tru scroll chuck.

After some research I bought an ER40 plain back collet chuck from an eBay seller, did some checking of it when it arrived and concluded it was built to decent tolerances. Then I bought a Bison D1-4 camlock backing plate, some 1045 stock from McMaster and set about making a sleeve to join the Bison backing plate to the ER40 collet chuck.

This is the result - it has four M8 set screws around the perimeter that can be used to precisely center the chuck. I'm very happy with the result
View attachment 240558

Here's a nose-on view - you can see the centering adjustment set screws if you look closely.

View attachment 240559

Although a bit expensive, the Bison D1-4 backing plate is exactly what I expected - outstanding quality:

View attachment 240560

I'm attaching the drawing for this implementation in case anyone wants to do the same.

Also, there are more images and description of the build process here:

https://flic.kr/s/aHsm1PtHsq

Hopefully this will be useful to someone here. Enjoy.
 
David: I never fail to be impressed with the stuff you both post and produce. I did acquire a PM1340GT lathe which is still not running due to the hassles associated with getting the VFD up and running (another story). I noted your posts as I'm looking at a collet chuck as something I'll have to acquire although I'm sure hoping I can find something off the shelf, if not your chuck looks GREAT.
Alex
 
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