MT5 to ER40 collet adapter and a few collets. Largest collet is 1" and it appears that will extend about 4" into the adapter. A 3/4" rod will pass all the way through to the draw bar.
Can't wait to get this sucker bolted up so I can quite smashing my finger into chuck jaws!
-Matt
Nice set. You can get collets more than an inch to increase your range.
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I had been considering a 5C collet chuck for my 12x36 but the size tolerance for 5C collets is really small. Anyone know what the range is for ER40s? Actually I had been considering an ER40 with an R8 for my mill too. It would make tool changes a lot quicker.
Mike
Size range for ER40 goes from 2mm to 30mm or if you get an Imperial set - 1/8 to 1 inch with complete overlap whichever set you get but you have to be careful and look closely at manufacturer specs for clamping range. For imperial sets you might have to go to 1/32 inch increments. Usually "on the millimeter" sets overlat or match completely.
The "through" capability on ER's, depending on the collet chuck design, can be more limiting than a 5C setup. 5C collets have limited clamping range and for the purist they do not have complete overlap even at the 1/64th increment level. But, folks have reported clamping them down .020 without a problem.
That's why they make 5C "emergency" collets for off-sizes.
When you overclamp too much a 5C you do not get parallel clamping whereas with an ER collet, you do. As far as precision goes, you get what you pay for. You can get .0002 TIR on either side at nominal clamping. For 99% of what's done here, even if you spring a 5C collet, it ain't the end of the world. I have both systems and there are benefits and detriments to each in terms of setup time and flexibility but either will work well on its own. The only reletively significant con I can think of with respect to a 5C adaptation is that the collet nose might hang out further because you have to have a 3 1/2 inch 5C collet buried inside the actuator assembly so right off the bat you're that far out. An ER system should be at least an inch shorter.
Cheers,
Rich