buying er32 collets

J

j ferguson

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My Beall Collet chuck arrived and what a work of art it is. now to populate the collet rack.

er32 collets can cost from a little to a lot. obviously "a lot" means different things to different people, but it is not my first choice. So the question is, If one buys moderately priced collets will they all be not so good? My thought was that deep in China there is a machine which churns out collets. The troops measure them and the best ones with 2 temths max runout are sold for high prices and the others are sorted into groups such that the less you pay the lousier they are.

The thing I'm getting at is if you buy less expensive collets will smoe be really good and some not so good or will they all be 6 tenths or worse? In other words, does it make sense to buy a mid-range or a bit less than mid range set indicate all of them and replace the worst. Obviously this only makes sense if most of them are ok. ????

supposing you get a pretty good (pricier) set. there will likely be some runout in the spindle-chuck combination. I assume since the chuck is tightened up against the flat on the spindle it will always have its runout in the same place radially. does it make any sense to compensate the chuck runout with the collet runout by finding the sweet spot by rotating the collet relative to the chuck and then marking it so you don't have to do it the next time. Is this nuts?

since a set of collets encompasses a continuous range of sizes which the chuck can handle, does it really matter whether you get metric or imperial? Unless of course you can't do the conversion in your head.

one of the collet suppliers makes a fuss about how his 2 tenth or better collets induce much less tool wear when used as tool holders. This makes sense but for someone doing mostly one-off things does it make that much difference?

Finally, what is the maximum runout which you would accept in your tool crib?

I guess I'm hoping to get MORE than I'm paying for.

sorry
 
J Ferguson,

Good question! I'm also looking for an MT3 ER32 collet set. Banggood has a metric set from 3mm to 20mm with the chuck for $126. The runout isn't specified. Here's the link: Banggood MT3 ER32 Collet set

Does anyone have any experience with Banggood?

Glen Zoerner
Spicewood, TX
 
I've bought kits to build small electronic devices from them. signal generator and oscilloscope. quality was outstanding. I don't know if this is consistent across all of their products. years ago, '50s maybe, the Japanese countered their reputation for shoddy quality by making everything better than it really needed to be. It could be that the Chinese are doing the same thing with some products.
I know my 6040 CNC router was a whole lot better than I expected. I had planned to completely rebuild it when it arrived, but in the end only needed to ease the sharp edges on parts which I might otherwise have cut myself on.

but collets? I still think there's a chance that they make a whole lot, inspect them and batch them according to precision. but I guess only way to find out is to buy a set and see.
 
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I bought my ER32 collets from TPAC Tools after reading a few positive reports on here, I have been very pleased with the quality , the run out of the ones I tested was ~.0003" ,it is possible that I got lucky and got a good set but I still would not hesitate to buy another more complete (metric) collet set from them .

https://www.ebay.ca/sch/totalcnctools/m.html?_nkw=&_armrs=1&_ipg=&_from=
 
So a few things to consider, I have both an ER32 and ER40 set in imperial, plus a number of metric ER collets.
1. What are you going to use the collets for, to hold endmills or to hold stock? If just endmills, you would do just fine with a 1/8" higher quality set in the specific measurement system you predominately use, I assume imperial. Most endmills come in fixed shank sizes, so you end up only using a few collets 99% of the time. My own experience is that although the collets have a wide clamping range, clamping ability and accuracy (TIR) suffers. This also depends on the quality of the holder and if you use a bearing nut. If you are going to us the ER collets for work holding, then I recommend a 1/32" (0.0312" increment) set which offers a better clamping range then a 1mm (0.0394" increment) set, and is in the more common increment for stock/tooling you will use. Even with this, I have edge finders that have 10mm and 12mm shaft diameters, and the accuracy is improved using a high quality metric collet for each. Manufactures sell 1/32 ER sets, but for some stupid reason they omit a few sizes that they think are not commonly needed. So you may need to back fill several collets.

2. Most manufactures state the maximum TIR of the collets, better ones are usually 0.0002" and the worse usually state 0.005mm (0.0003"), but beyond this is the way the collets is designed and the finish of the collet which can effect the way it seats and the collapsibility of the collet. Higher quality collets are significantly better in this respect at least from my observation. A good bearing or high quality clamping nut can make a significant difference in both TIR and angular skew. We are talking a big difference measured at say 3-4" out. from the collet.

3. I do not believe that collet manufactures have an A and B sorting based on tolerances, they make them to meet different tolerance and fit/finish specs, and maybe the level of QC as to 100% vs say 10%. On ER collets, they tend to be a bit more consistent in TIR then say 5C collets.

4. Brands that I have used, recommend. No name generic, well the QC is often minimal and the collet design may be that when used at it's +/- clamping extremes you will see more distortion. I have seen and others have mentioned this when using metric sets for imperial sizes. I can say that the Iscar ETM (my ER32 set) and Rego Fix (my metric) are super and they all measure under 0.0001" TIR with super finish. I have a few Teckniks (made in Taiwan), that would be my next choice, and 3rd would be a close tolerance or precision set of Chinese manufacture that is guaranteed to meet spec. I have the Z-Live 1/32 ER40 collet set and they are well made and measure well. In order of recommendation below, ETM Iscar (or similar quality), Tekniks, Z-Live (and Shar's), T-Pac or similar. The ETM below may seem expensive, but it includes an R8 holder and you could offer something like$250 and have a super set, or keep a lookout for a set of ETMs, Rego Fix or similar set. On ER holders, it does pay to get good ER holder (and nut), so something like ETM, Lyndex, Glacern (nickle plated), Shar's (higher end models that are nickle plated), etc that usually have a TIR of 0.0001" or better.
https://www.ebay.com/itm/ETM-R8-ER-...ISCAR-Milling-Machine-Lathe-Tool/322808167973
https://www.ebay.com/itm/Techniks-ER25-16pc-Precision-Collet-Set-5-32-5-8x32nds-/381827651388
https://www.ebay.com/itm/ER32-COLLE...ME-QUALITY-TESTED-RUN-OUT-0-0003/332036579878
https://www.ebay.com/itm/ER32-COLLET-25PC-SET-1-16-3-4-by-16th-and-32nd-ACCURATE-NEW/321189862437

5. This all may be moot, in the sense that it the worse set guarantees say 0.0004" TIR and you are machining to 0.001" tolerance, well it is unlikely to make any difference. If just for milling, then better to get a better quality 1/8" increment set in my opinion.

6. No doubt China does turn out very high quality machinery and products, but usually not at the lower price points. Having lived in Japan in the 60's when we use to be a joke about the Japanese quality, the limitation was not the intent willingness to do high quality work, but not having the technology/training and understanding to do so. In contrast to lower end Chinese (and tooling from say India) products, which from my experience there is neither the intent, training nor willingness to do so, nor have any process improvement/QC. Since we gobble their stuff up, I guess there is no incetive to do so. On the high end products produced in China they can meet or exceed products produced in other countries. Just my opinion.
 
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I've had good experience with Maritool ER 32 collets (https://www.maritool.com/Collets-ER-Collets-ER32-Collets/c21_56_59/index.html), especially for the small diameters on stainless steel work pieces (0.084- 0.100"). Here's their description:
ER32 series collets have a capacity of .02-.787 inches. Each ER32 collet has a range of .039 inches(1mm). ER32 Collets .094 and smaller have a range of only .015 inches. The size indicated on the collet is the largest size it can hold and can be collapsed smaller within its collapse range mentioned above. For example, ER32-1/4 can grab a round shank from .250 diameter to .211 diameter. Please refer to our ER32 Collet print for general ER32 dimensions.

They claim their maximum run-out is 0.0003". I bought about 4 specific diameters rather than a set, and they set me back about $20 ea.
 
mksj

Thanks for your thoughts. Your Point 5 is well taken. I'm a hobbyist, not building parts for NASA.

Glen
 
There's also Pioneer, which are supposed to be on par with Rego and some of the other premium brands, and
the price reflects that
 
@mksj has given you excellent input. I just wanted to add a few comments.

The Beall ER chuck can be used on the mill and lathe - same spindle. The part that the chuck contacts when seated is called the register; it and the threads of the spindle must be clear of chips, dirt and debris when the chuck is installed as this can definitely affect run out. Using collets to try to offset run out is difficult and, in my opinion, is a waste of time. If run out is excessive, you can use some Engineer's Blue (like Prussian Blue) on the back of the chuck to see what the contact pattern is like. If contact is uneven, I would return the chuck for a replacement rather than try to correct it. You could try to turn it true but we're talking about run out in the tenths here and a surface grinder is the better way to do it; better to have Beall use his surface grinder for that.

Aside from how the chuck registers on the spindle (assuming the chuck's internal taper is also accurate), the accuracy of an ER chuck depends on collet quality, the fit of tools or work in the collet, the collet nut and adequate torque of the nut. Focusing only on the advertised accuracy of the collet can be misleading.

On the lathe, tenths accuracy is usually not necessary and a Chinese set in 1/32" increments will be fine. The Beall nut is also fine here.

On the mill, things change. The accuracy of your collet system is important for tool holding and I would suggest a decent set of collets and a good nut. Since most milling cutters have standard shank sizes, which system you choose (Imperial or Metric) depends on the cutters you use. If you plan to use mostly Imperial tools then a set in 1/16" increments would suffice and you can buy individual Metric collets as needed. An ER collet will be more accurate than an end mill holder, by the way, and it is most accurate when the tool shank is very close to the size of the collet. An ER collet will collapse and hold smaller shanks but run out increases when you do this.

In my tests, I found that there is a difference between the cheaper Chinese collets and the more established brands like ETM, Lyndex and Techniks. This difference is on the order of double the run out on the Chinese collets, which is a lot when talking about tooling. Consider that excessive run out can have a single tooth of an end mill doing most of the cutting. That tooth will not last long and accuracy and finish will be affected. When using tools that require great precision, like keyseat cutters, excessive run out is the difference between the key fitting and not fitting. So, for collets used for tool holding, I suggest you buy a set of good collets.

As for brands, if I had to choose on the basis of accuracy in light of cost, I would choose Techniks hands down. They are made in Taiwan, are very accurate and are lower in cost than most quality collets.

The nut makes a difference. My most accurate nut is my Rego-Fix nut, followed by my ETM nut. Both are at least twice as accurate as my Beall and Chinese nuts, and the Beall is more accurate than the Chinese ones. I found that a solid nut is more accurate than my Chinese ball bearing nuts, which isn't saying a lot; there are better ball bearing nuts that I don't own. My suggestion is to buy a Rego-Fix nut for your chuck. Cost is about $35.00 so its doable and it makes a difference.

An ER32 nut should be torqued to about 130 lb/ft of torque for max accuracy. Few of us can achieve this with the chuck mounted on the spindle but the Beall wrenches will get you close. You can make a fixture for the chuck and use a torque wrench to tighten the nut if you need to be anal about it.

So, in my experience, the cheapest way to go is to buy a Chinese set of collets in 1/32" increments for use on the lathe and use the Beall nut. On the mill, I would buy a set of Techniks collets in 1/16" increments and use a Rego-Fix or ETM solid nut with them. Buy Metric collets as needed. This will give you the best potential for accuracy for the least amount of money.
 
Thank you all for this really helpful advice. It's such a treat when the guys that really know the stuff can also write so well. I think I'm getting a pretty clear idea of how to go about this phase. You say that the nominal dimension of a collet is the maximum diameter it wil hold. I assume that if i buy a 1/2 inch collet, it will hold 1/2 inch shank mills. Can I alsop assume that the flat which is cut on the shanks of a lot of cutters will not cause problems if they are held in a collet?
 
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