cheapo er40 collet chuck + collets

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liveaboard
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cheapo er40 collet chuck + collets

Post by liveaboard »

I read a lot of horror stories, so with some trepidation I put an indicator on my $15 ER40 collet chuck and one of the cheapo collets.

Maybe there are multiple errors that all canceled each other out; but my mechanical Mitutoyo indicator isn't sensitive enough to detect any runout at all.
ER40 collet and chuck test.jpg
RSG
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Re: cheapo er40 collet chuck + collets

Post by RSG »

Nice! But curious to see what happens if you use a DTI at the bottom and sweep the spindle backwards. You might see a difference then. Otherwise it looks good at the top of the collet
Vision is not seeing things as they are, but as they will be.
pete
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Re: cheapo er40 collet chuck + collets

Post by pete »

Sometimes it's nice to have some luck Mark. You do know about snapping the collet into the nut first before placing and threading it into the chuck. ER 40's also have high torque recommendations. Around 130 ft. lbs for the largest size and dropping down a bit as the tool shank size decreases.
John Hasler
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Re: cheapo er40 collet chuck + collets

Post by John Hasler »

Put a precision pin in it and check runout 2 or 3 cm out.
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Re: cheapo er40 collet chuck + collets

Post by liveaboard »

pete wrote: Mon Aug 09, 2021 6:27 pm You do know about snapping the collet into the nut first before placing and threading it into the chuck. ER 40's also have high torque recommendations. Around 130 ft. lbs for the largest size and dropping down a bit as the tool shank size decreases.
I didn't know about snapping the nut in, but I observed the ridge and figured it out.

130ftp! That's a lot of torque.

I don't have any precision pin or shaft.

I should add that I'm not advocating cheapo tools as an alternative to good tools; but for those on a tight budget like myself, the choice is between cheap tools and no tools.
Bearing that in mind, I just wanted to point out that one can, on occasion, be well served by the lower priced option.
John Hasler
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Re: cheapo er40 collet chuck + collets

Post by John Hasler »

You can turn a precision shaft for this purpose. It just has to be concentric and have a diameter within the clamping range of the collet. A small amount of taper won't matter.

I understand about the lower priced option. It's what I go for when I can't locate any suitable junk.
pete
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Re: cheapo er40 collet chuck + collets

Post by pete »

130 ft. lbs would be for the largest 1" shank tools with my imperial set Mark. And I suppose that's to prevent tool movement on heavy high HP roughing cuts. No R8 mill could drive that size of tool hard enough, so as tight as I can get it with the provided too short wrench to get up to that torque level anyway. Precision shafts? Got an old computer printer around or can find one? The shafting in those are very straight and round, almost gauge pin quality for everything but size. There hard as hell so something like a Dremel with a cut off disk is needed to cut them to length and de-burr the ends.

The first set of 123 blocks I bought cost me maybe $25. They measure to size, parallel and square to under the .0002" they said they would. My 246 blocks I bought later not so much. Some times you get lucky, other times ?
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