If those collets weren't even close to matching what's in writing for there run out specifications Baron, then they should have been immediately returned to the vendor. I don't try to re-machine, repair or modify what the manufacturer should have already been producing if that's what there specifying them to. And I fully expected not to do when I chose what I did from there own written specifications and what I was then paying for. Ask yourself this, if you paid with Monopoly money, would the tool dealer be fine with that or instead expect to get real money? Then what's the difference if your not getting what they guaranteed in writing for what you were buying.
Sure those very high accuracy collets are available with a price to match. But then what are the run out numbers on the chuck, it's nut, spindle taper & bearings? Then just how rigid is the whole machine there being used with? To get everything your paying for with those high accuracy collets, then all the rest of the components have to be capable of as good or better numbers as well just like Timo already mentioned.
Yeah you could buy the more specialized cutting tools with a few standardized shank diameters to save buying more of those high cost collets. But think about that from a logical perspective. Cutting tools have a limited life span even if there being resharpened. So your going to have to replace any cutting tool at some point. There a consumable item. All your accomplishing by using that limited number of tool shank sizes is saving on the cost of some collets. And from then on and it won't take long, your then spending more for your cutting tools than those extra collets would have cost. Your literally trading one price for a work around that will still end up costing more. It's just spread out over a longer period of time. Plus you still can't use a lot of off the shelf but less costly industrial quality and performance cutting tools that might have shank sizes outide of what your collets can grip properly. Maybe that idea might work in a production situation, but I honestly can't visualize any scenario where it might since there's more than a few other options. In a home shop? Collet chucks, nuts and collets in those industrial situations and when there not using shrink fit tool holders or other methods will still get replaced after enough use or after a serious crash. In a home shop and with a decent set of collets and chuck, it's highly doubtful almost anyone here would ever need to do so for at least multiple decades or possibly in there lifetime. Even if you had to replace collets, then it should still only be a few of the most used sizes that a large number of your tool shanks were used with. Cnc and machines with tool changers, there using at least multiples of each tool shank collet size, multiple chucks, and the tools get torqued into the collet. Then the tools Z axis height and diameter are entered into the tool progam parameters. At that point, the tool itself would rarely be removed from that collet until it's useable life is gone. How we use collets and without those tool changers is a whole lot different than they do with todays high volume part production.
I'd agree, those extreme accuracy brand name collets, chucks and nuts might well cost a few thousand or even more. Is the rest of what you have for machines and tooling capable of justifying the price, or would most here even gain anything with them? How many members here spotlessly clean the spindle taper, chuck shank, male and female nut threads, ID, OD and slits in each collet, chuck interior, collet and nut extraction rings, and at least lightly lube those nut threads. Anyone think that isn't going to be absolutely necessary with those low miron collets? There's multiple ER collet manufacturers. Rego-Fix is probably one of the better known since they invented the ER collet design, and there also known for producing unquestionable quality that will meet or exceed there stated specifications. When I bought my Bridgeport clone I wanted to use ER collets. The ER 32 series would have held any tool shank size a BP and it's R8 taper could be expected to drive. But I also wanted dual duty out of what I was buying and also use them on my lathe. So I spent a fair bit more and bought ER 40's. I also knew I didn't want to pay the extra for those Rego-Fix or Schaublin ER colets.
And with all the videos I'd watched and dozens of forum posts about just how bad those much cheaper off shore collets, chucks and nuts usually are, I refused to buy those at any price. Yes you might even get lucky sometimes and at least a few collets in a set might or might not turn out to be very accurate. I can't afford to trust that would happen, I buy due to the stated specifications and fully expect to get what that higher price had better provide. I also don't blindly trust anything no matter who's brand name is on it. So whenever I can, I personally verify that I did in fact get what the manufacturer stated. So I did my own research, and after enough of that, decided on Bison as the manufacturer and bought a complete set of there 40 series, collet chuck with an integral R8 shank and the nut came with the chuck. All of mine are under or well under .0005" for run out checked with gauge pins and a very good 10ths dti. Mine cost me a bit under $1,000 in Canadian dollars, and likely anywhere in the U.S., Europe or the UK, prices would be even less than where I am.
Bison's chuck and collets are quite close to what a set of Schaublin ESX 25 collets I also own have for run out numbers, and that set of much smaller collets cost almost as much as those 40 sized collets did. In general and other than maybe those Schaublin collets, as the collet series get smaller, the costs drop much lower as well. The only real deficit that 40 series sometimes has for me is the diameter of the chuck and nut. So one further addition I don't yet have would be a set of either ER 11 or 16 just for the much smaller diameter nut and collet chuck that at times would be useful driving the smaller diameter and shorter tools since it would also allow easier access in or around more confined areas. And fwiw, those 40 sized collets can properly grip either imperial or metric tool shanks, and anything from the .125" Dremel tools on up to 1" tool shanks or any part sizes within that range on the lathe. But if your using just about any mini or bench top sized mills, then you don't need nor can you even use either the 32 or 40 series collets. The 25's should be just about all you'd need. And even most of the better known brand name industrial level chucks and collets really aren't that expensive. For any tooling, I've learned to stick with U.S, Eastern Europe, the UK or Japanese manufacturer's. There's also lots from western Europe, but always at very high prices.
and they do not like beeing dropped, touched or looked at.
