collet concentricity

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MedWoodWorx

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i hope this is the right place to start this thread.
I am stocking up all the tools needed to start making kitless pens. Since my collet chuck is ER25 i had a really hard time finding big collets i.e. sized 18 & 20mm. The thing is that the guy at the shop that is selling them mentioned that these collets are not meant for highly accurate jobs. The concentricity according to the website is 0.02mm. Is that ok for penturning? i suppose that my woodlathe is not the most concentric tool in the world either..what are you guys thinking? maybe more machinist oriented folks among us know more about this? @rherrell ?
cheers, Mike
 
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0.02mm is 0.00078 inches or... less than 1 thousandth of an inch. That is very good for a wood lathe.

My collets are all ER32 and I check them for runout with a mandrel in the collet so that I am checking for runout at the end of the piece I am working on.

Now, this is just my opinion, but for me, that is accurate enough for what I am doing. After all, we are not threading bolts for the SpaceX Starship or a Ferrari F1 Car.
 
The eshop selling them is german specialising in machining not penturning; i suppose they are serious about their stuff..
 
MedWoodWorx said:
i hope this is the right place to start this thread.
I am stocking up all the tools needed to start making kitless pens. Since my collet chuck is ER25 i had a really hard time finding big collets i.e. sized 18 & 20mm. The thing is that the guy at the shop that is selling them mentioned that these collets are not meant for highly accurate jobs. The concentricity according to the website is 0.02mm. Is that ok for penturning? i suppose that my woodlathe is not the most concentric tool in the world either..what are you guys thinking? maybe more machinist oriented folks among us know more about this? @rherrell ?
cheers, Mike
Click to expand...
We use ER32 as well, we did find the Beall collet chuck set to hold collets much better than our previous collet chuck, so it seems a good chuck can make a significant difference. I realize you probably can't get ahold of Beall, but what I'm saying is a good quality chuck.
 
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ER collets were designed to hold tools not work. Good quality ER collets are typically under .0004" TIR. Very good quality are under .0002". The quality of the chuck and how concentric it is on the lathe probably makes more difference in most folks' case.

There are plenty of ER collets for sale that are garbage, though.
 
Oliver X said:
ER collets were designed to hold tools not work. Good quality ER collets are typically under .0004" TIR. Very good quality are under .0002". The quality of the chuck and how concentric it is on the lathe probably makes more difference in most folks' case.

There are plenty of ER collets for sale that are garbage, though.
Click to expand...
True
 
egnald said:
Rick Herrell posted to a similar thread here a couple of years ago. His post includes a video on how to tweak the runout on a pin chuck held in a collet. I think the same could be applied to a blank/rod or other item that is held in a collet. If nothing else the procedure would give you an indication of the amount of runout. - Dave
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Yea i ve seen it and actually tried it. To my dissapointment my chuck is not concentric as it should be. However i ve used it to hold mandrels and have made many pens since with no (noticeable) problems. It seems that i have to work with what i have all the good stuff are in usa and it costs a small fortune to buy them from american suppliers.
 
This is the brand of collet that I own and recommend, very good quality without breaking the bank...

www.ebay.com

1/4" ER32 PRECISION COLLET - .0002" T.I.R Techniks 04232-1/4 | eBay

<p>This precision collet from Techniks is a top-quality tool for your workholding needs. With a collet range of .211 to .250 inches and an ER32 series, it is perfect for CNC metalworking and manufacturing. Made with the highest level of precision, this collet has a T.I.R of .0002 inches...
www.ebay.com

I use collets primarily for holding the work, not the tool, I have endmill holders for that.

.02mm is plenty good enough for a wood lathe, IMO.
 
Hippie3180 said:
We use ER32 as well, we did find the Beall collet chuck set to hold collets much better than our previous collet chuck, so it seems a good chuck can make a significant difference. I realize you probably can't get ahold of Beall, but what I'm saying is a good quality chuck.
Click to expand...
Beall Tool closed its doors/was bought out. Their ER32 collet chucks are very accurate in my experience...much better than a commonly available alternate chuck and collet set. Sometimes, the chuck and collet sets can be found on line from other vendors.
 
.02mm is more than accurate enough for what we do.
However, collet chucks are, normally, only designed to go up to a certain dimension. For example, the ER32 collets I use normally only go up to 20mm. But I have been able to purchase collets put to 25mm off of Aliexpress. They work, but the material in the collet is getting very thin and I'm not sure I trust their repeatability. You will likely run into the same problem if you find the bigger diameter er25's, as they are only intended to go to 16mm.
While it is an expense, I would invest in an ER32 set. While the Beal ones mentioned above, were bought out and now sold by Lee Valley, I have a PSI set and have had no issues using it on my wood lathe for marking kitless pens. It is considerable less money. Then you can purchase a complete set of 3-20mm chucks on Amazon for as low as $70. I paid $140cad for mine. The metric set is better, as there are no gaps in the sizing, which does occur in the imperial set.
 
Penchant 4 said:
Beall Tool closed its doors/was bought out. Their ER32 collet chucks are very accurate in my experience...much better than a commonly available alternate chuck and collet set. Sometimes, the chuck and collet sets can be found on line from other vendors.
Click to expand...
You can still get Beall through Lee Valley.
 
darrin1200 said:
The metric set is better, as there are no gaps in the sizing, which does occur in the imperial set.
Click to expand...

Granted metric would be better for me & easier to use but...

My imperial set is in 32nds through 25/32" and don't understand the gap in sizing. Old-fartitis on my part?

FWIW, at one time I saw the Beall runout spec to be up to 0.005" but never saw that on mine.
 
Hippie3180 said:
We use ER32 as well, we did find the Beall collet chuck set to hold collets much better than our previous collet chuck, so it seems a good chuck can make a significant difference. I realize you probably can't get ahold of Beall, but what I'm saying is a good quality chuck.
Click to expand...
Lee Valley purchased some of the rights to Beall tools when they closed their doors. Looks like they still have the collet chuck:

Beall Collet Chuck Sets - Lee Valley Tools

www.leevalley.com www.leevalley.com

Is this the one you were referring to? I have a collet chuck myself, but it was just one that I found at Woodcraft (probably Wood River brand) and I don't know that its great quality. At some point here I'll be getting into kitless myself, and I've wondered if my chuck would suffice, or if a better one would be needed. I generally like Beall's tools...if this is the same quality chuck you have, I might pick one up.
 
rixstix said:
My imperial set is in 32nds through 25/32" and don't understand the gap in sizing. Old-fartitis on my part?
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I took this chart from the thread below and use as a reference. This shows the differences between imperial and metric collet sets. It shows the imperial collets needed to get the full range. Some imperial sets are smaller (18 piece) and do not contain all of these collets. I believe that is where the gaps are.

Collet chucks

The following table was taken from (Precision ER32 Collets) and has been modified to shows the metric and fractional collets seperate to make it easier to see the overlap in clamping ranges. Notice how the metric collets just cover the full clamping range where there is overlap with the...
www.penturners.org

1725636805799.png
 
hooked said:
I took this chart from the thread below and use as a reference. This shows the differences between imperial and metric collet sets
Click to expand...

The only non-overlap that I see is 0.002" at the 13/16"
If I'm not mistaken, I also have a 1/16" collet.

I still wish that I had a metric set.
 
jrista said:
Lee Valley purchased some of the rights to Beall tools when they closed their doors. Looks like they still have the collet chuck:

Beall Collet Chuck Sets - Lee Valley Tools

www.leevalley.com www.leevalley.com

Is this the one you were referring to? I have a collet chuck myself, but it was just one that I found at Woodcraft (probably Wood River brand) and I don't know that its great quality. At some point here I'll be getting into kitless myself, and I've wondered if my chuck would suffice, or if a better one would be needed. I generally like Beall's tools...if this is the same quality chuck you have, I might pick one up.
Click to expand...

FYI...I wanted the Beall collet chuck without the collets because I already had the collets I want/need. I called Lee Valley and they were able to sell me just the ER32 collet chuck and wrenches. The price was very reasonable.
 
jrista said:
Lee Valley purchased some of the rights to Beall tools when they closed their doors. Looks like they still have the collet chuck:

Beall Collet Chuck Sets - Lee Valley Tools

www.leevalley.com www.leevalley.com

Is this the one you were referring to? I have a collet chuck myself, but it was just one that I found at Woodcraft (probably Wood River brand) and I don't know that it's great quality. At some point here I'll be getting into kitless myself, and I've wondered if my chuck would suffice, or if a better one would be needed. I generally like Beall's tools...if this is the same quality chuck you have, I might pick one up.
Click to expand...
Yes, we just very recently purchased this set and find it works much better for us after struggling with a lot of wobble with our previous entry level collet set.
 
Hippie3180 said:
Yes, we just very recently purchased this set and find it works much better for us after struggling with a lot of wobble with our previous entry level collet set.
Click to expand...
Am I correct in that these appear to have threads, and screw onto the lathe spindle? The collet chuck I have now is actually MT2 and just fits inside the spindle. It has actually never fit entirely snug, even when I really try and WRENCH it in there, which is a bit problematic. For the stuff I mostly use it for, its been fine, but, I doubt it would work well for kitless pen crafting.
 
jrista said:
Am I correct in that these appear to have threads, and screw onto the lathe spindle? The collet chuck I have now is actually MT2 and just fits inside the spindle. It has actually never fit entirely snug, even when I really try and WRENCH it in there, which is a bit problematic. For the stuff I mostly use it for, its been fine, but, I doubt it would work well for kitless pen crafting.
Click to expand...

Yes, you choose the spindle thread you need. I purchased the chuck (w/ wrenches) only in a 1" - 8 TPI for my Jet 1221VS Midi Lathe and love it.
 
jrista said:
Am I correct in that these appear to have threads, and screw onto the lathe spindle? The collet chuck I have now is actually MT2 and just fits inside the spindle. It has actually never fit entirely snug, even when I really try and WRENCH it in there, which is a bit problematic. For the stuff I mostly use it for, it's been fine, but, I doubt it would work well for kitless pen crafting.
Click to expand...
Yes, what @d_bondi said, it's just such a nice set, I don't think you'll have regrets. My only regret is that we didn't get one sooner. I've noticed when I turn nib holders, I get far less chatter and the wobble is gone when working on the tail. We're very happy with it.
 
jrista said:
Am I correct in that these appear to have threads, and screw onto the lathe spindle? The collet chuck I have now is actually MT2 and just fits inside the spindle. It has actually never fit entirely snug, even when I really try and WRENCH it in there, which is a bit problematic. For the stuff I mostly use it for, its been fine, but, I doubt it would work well for kitless pen crafting.
Click to expand...
The chuck you have is usually locked into place using a draw bar.
Here is a link to an article on Beauforts web site.

Beaufort Ink - How to make a lathe draw bar

How to make a lathe draw bar
www.beaufortink.co.uk www.beaufortink.co.uk

You could make one yourself.
 
I just saw an add in Craft Supplies for a Drawbar Collet Chuck. It states that it virtually eliminates problems with concentricity and is very accurate.
Has anyone here had experience with this type of chuck and are they as accurate as claimed?
 
Dustman said:
I just saw an add in Craft Supplies for a Drawbar Collet Chuck. It states that it virtually eliminates problems with concentricity and is very accurate.
Has anyone here had experience with this type of chuck and are they as accurate as claimed?
Click to expand...
As I understand, draw bar collets are preferred because they direct mount into the spindle. This has the advantage of leaving more room between spindles as well as removing extra points of error. However they both need to be kept clean to avoid offset.

Another disadvantage, especially for pen makers, is the allowable clamping variance. There was just a discussion on this over on a machinist forum I follow. Because they collets are only slit from the front end, they only have an "accurate" clamping variance of about .005". As these collets are drawn in, they only clamp at the very front. This means that the smaller you clamp it, the looser the part is in the back of the collet, which does not get any smaller. This is why 5C collets come in 1/128" increments, as well as blank collets that can be custom drilled. After a little looking, the MT type collets are not very prolific and tend to only be available common sizes of 1/8" increments.

The ER collets however, are slit from both ends, so as they are drawn into the collet, both the front and rear collaps to come in contact with the part. The more slits they have, the better the clamping force. But they have more points of possible error, so the quality of the collets, chuck and nut are all factors in accuracy.
Spindle type collets are also limited by the size of the spindle. I believe MT2 is limited to 1/2" (12mm). While with an ER32 collet chuck, you have up to 3/4" (20mm) standard {I have found up to 25mm}. The chuck itself will limit the length of part you can put in. In small lathes length of part is also limited by the spindle bore. Small lathes, the bore can be as small as 3/8" while my metal lathe has a bore of 1".

The other draw back with the type of drawbar at Woodturners, is it does not allow pass through. It's fine if you are only doing small pieces. Larger spindle type collets use a hollow draw bar, so that the material can pass through it.

Bit of a long winded response. LOL
If you just want it for holding your mandrels, with a set tenon size, it will work great. and is an economical solution.
 
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