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    Default School me on ER collets...

    I'm new to ER collets, I'm well versed in R8 collets. I just bought a couple ER40 collet holders from Glacern for a good price, and a set of collets from Shars.

    So, how do they compare to r8 collets in real life? Do they grip harder or is tool slippage a problem? Realistically, on a rf45 machine, will I even notice the loss in rigidity? What can I do with them? What can't I do with them? Please share all your ER collet wisdom with me

    Mike

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    Chasing tenths is hard...


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    They are almost totally different animals. I have never noticed rigidity difference, except maybe the effective length of the tool tip to the spindle will be more. You can do more because you have a larger size range to work with now. Hopefully you have the horsepower to match.



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    Member awerby's Avatar
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    They work a bit differently from R8 collets. You have to slip the collet into the closer nut until it snaps into place. Then you can insert the tool and tighten it, using 2 wrenches. If you neglect the snap-into-place step, then it will never seat correctly. But at least there's no drawbar that you have to break loose...

    Andrew Werby
    ComputerSculpture.com — Home Page for Discount Hardware & Software



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    Quote Originally Posted by awerby View Post
    They work a bit differently from R8 collets. You have to slip the collet into the closer nut until it snaps into place. Then you can insert the tool and tighten it, using 2 wrenches. If you neglect the snap-into-place step, then it will never seat correctly. But at least there's no drawbar that you have to break loose...

    Andrew Werby
    ComputerSculpture.com — Home Page for Discount Hardware & Software
    So THAT'S why the nut is machined with that weird off center groove in it...
    I already made a few cuts without doing that, but I will do it correctly from now on. Thanks a lot for the tip!

    Chasing tenths is hard...


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    Gold Member BobWarfield's Avatar
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    ER collets are great--they perform better than either R8 or set screw end mill holders. Some complain they're experiencing collet pullout. ER's take a lot more torque than you might imagine. Here are a couple of articles to help along those lines:

    Getting the Best Performance from ER Collet Chucks « « CNCCookbook CNC Blog CNCCookbook CNC Blog

    Toolholding in Collets: How to Avoid Tool Pullout « « CNCCookbook CNC Blog CNCCookbook CNC Blog

    I say they perform better for a variety of reasons. Consider this article, for example, which compares ER collets against much more expensive tool holders:

    What Are the Best Toolholders? « « CNCCookbook CNC Blog CNCCookbook CNC Blog

    Here's a tip--look for ball bearing caps for the collet chucks. I've bought some from Arc Eurotrade on the cheap. They make it easier to torque down the collet and increase their gripping power quite a lot.

    TechniksUSA says it increases the grip 75%:

    ER Bearing Nut

    I use ER collets exclusively for cutters 1/2" or less.

    Best,

    BW

    Try G-Wizard Machinist's Calculator for free:
    http://www.cnccookbook.com/CCGWizard.html


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    Quote Originally Posted by BobWarfield View Post
    ER collets are great--they perform better than either R8 or set screw end mill holders. Some complain they're experiencing collet pullout. ER's take a lot more torque than you might imagine. Here are a couple of articles to help along those lines:

    Getting the Best Performance from ER Collet Chucks « « CNCCookbook CNC Blog CNCCookbook CNC Blog

    Toolholding in Collets: How to Avoid Tool Pullout « « CNCCookbook CNC Blog CNCCookbook CNC Blog

    I say they perform better for a variety of reasons. Consider this article, for example, which compares ER collets against much more expensive tool holders:

    What Are the Best Toolholders? « « CNCCookbook CNC Blog CNCCookbook CNC Blog

    Here's a tip--look for ball bearing caps for the collet chucks. I've bought some from Arc Eurotrade on the cheap. They make it easier to torque down the collet and increase their gripping power quite a lot.

    TechniksUSA says it increases the grip 75%:

    ER Bearing Nut

    I use ER collets exclusively for cutters 1/2" or less.

    Best,

    BW
    Thanks for the info Bob. I'll look into one of those bearing nuts. I really need to be able to hold a 1/2 end mill securely for a project I'm working on, and so far my luck with r8 hasn't been that great. It's good to know I can put a good bit of torque on the er40 chuck. Now I'm off to youtube to see if I can find some vids of the bench setup people use to tighten them...

    Chasing tenths is hard...


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    "so far my luck with r8 hasn't been that great." - You're doing something very wrong.... An R8 collet can hold a 1/2" endmill quite securely through cuts far tougher than an RF45 can handle. How are you torquing the drawbar? For R8, you need on the order of 25 foot-pounds torque on the drawbar. You want the tool shank, and the inside of the collet to be VERY clean, and bone dry. You want a light coat of oil or light grease on the taper on the outside of the collet. If that doesn't give you secure holding, then there is something wrong with the taper in your spindle, or you have a set of cr@ppy collets. Keep in mind too that each R8 collet works for only ONE specific size of shank. You cannot put a 12mm tool in a 1/2" R8 collet, and expect it to hold.

    Regards,
    Ray L.



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    Gold Member BobWarfield's Avatar
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    The bench setup part is a bit disappointing as most of the world don't use R8 or straight shank TTS-style holders for CNC. It's easy to get a CAT40 tightening fixture, but R8 is harder.

    For the time being, I prefer collet chucks that have wrench flats. I can lock them up in a vise with soft jaws and put some serious torque on one.

    Down the road, I was recently over at a friend's shop who has a Romi CNC toolroom lathe. We took some 4140 round and put an R8 taper in it (so easy to do with a CNC lathe). It will eventually become both a tightening fixture and a tool setting fixture as the top and bottom are ground parallel so it can sit on a surface plate while I use a height gage to measure tool height.

    Cheers,

    BW

    Try G-Wizard Machinist's Calculator for free:
    http://www.cnccookbook.com/CCGWizard.html


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    Quote Originally Posted by HimyKabibble View Post
    "so far my luck with r8 hasn't been that great." - You're doing something very wrong.... An R8 collet can hold a 1/2" endmill quite securely through cuts far tougher than an RF45 can handle. How are you torquing the drawbar? For R8, you need on the order of 25 foot-pounds torque on the drawbar. You want the tool shank, and the inside of the collet to be VERY clean, and bone dry. You want a light coat of oil or light grease on the taper on the outside of the collet. If that doesn't give you secure holding, then there is something wrong with the taper in your spindle, or you have a set of cr@ppy collets. Keep in mind too that each R8 collet works for only ONE specific size of shank. You cannot put a 12mm tool in a 1/2" R8 collet, and expect it to hold.

    Regards,
    Ray L.
    Yeah I tried cleaning the collet and tool and applying lube only at the threads, outside surface and under the drawbar nut. Turns out it was just a ruined r8 collet - my fault. I was turning some 1/2" stock a while back and I got too close and nicked the bottom of the collet. I guess I raised a burr in there or something. I was pretty dissapointed, my endmill kept pulling down in what I consider to be pretty light cuts in 4140
    I have since ordered a set of Crawford collets, but I haven't had a chance to test them.

    I think my primary problem is my method for tightening; drop the mill in the lowest gear, and tighten the drawbar with a quick motion until it spins. I usually do this a couple times. What I really need is a spindle lock or a wrench that can grab the splines of the spindle. I'm not opposed to using a torque wrench to tighten, but right now it would be useless without one of the spindle locking tools.

    Chasing tenths is hard...


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    Quote Originally Posted by BobWarfield View Post
    The bench setup part is a bit disappointing as most of the world don't use R8 or straight shank TTS-style holders for CNC. It's easy to get a CAT40 tightening fixture, but R8 is harder.

    For the time being, I prefer collet chucks that have wrench flats. I can lock them up in a vise with soft jaws and put some serious torque on one.

    Down the road, I was recently over at a friend's shop who has a Romi CNC toolroom lathe. We took some 4140 round and put an R8 taper in it (so easy to do with a CNC lathe). It will eventually become both a tightening fixture and a tool setting fixture as the top and bottom are ground parallel so it can sit on a surface plate while I use a height gage to measure tool height.

    Cheers,

    BW
    Well, no wonder I can't find one... I guess I'm going to have to buy a couple wrenches for my collet chucks. My biggest crescent wrench is still to small for the flats on the er40 chuck, and I don't have a proper wrench for the nut. I though it would have come with the collet chuck, but I guess at $40 each, I can't complain
    Isn't it funny how quickly one tool purchase can cascade into a LOT of tool purchases?

    Chasing tenths is hard...


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    Quote Originally Posted by 1HobbyMachinist View Post
    Well, no wonder I can't find one... I guess I'm going to have to buy a couple wrenches for my collet chucks. My biggest crescent wrench is still to small for the flats on the er40 chuck, and I don't have a proper wrench for the nut. I though it would have come with the collet chuck, but I guess at $40 each, I can't complain
    Isn't it funny how quickly one tool purchase can cascade into a LOT of tool purchases?
    If you have a milling machine, you shouldn't have to ever buy flat wrenches again.
    School me on ER collets...-100_3623-jpg
    It took about an hour to design, fixture, mill, file, and give a touch of the belt sander to make a TG 100 collet wrench out of a piece of 3/16 inch 6061 flatbar.
    The best reason to buy a milling machine is so you can make tools for your milling machine.
    If you are going to make a ER-40 collet wrench make the handle about a foot long. ER-40 collets need about 80 foot pounds of torque.
    store bought wrenches are only about 8 inches at best.



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    Quote Originally Posted by Dennis Rech View Post
    If you have a milling machine, you shouldn't have to ever buy flat wrenches again.
    School me on ER collets...-100_3623-jpg
    It took about an hour to design, fixture, mill, file, and give a touch of the belt sander to make a TG 100 collet wrench out of a piece of 3/16 inch 6061 flatbar.
    The best reason to buy a milling machine is so you can make tools for your milling machine.
    If you are going to make a ER-40 collet wrench make the handle about a foot long. ER-40 collets need about 80 foot pounds of torque.
    store bought wrenches are only about 8 inches at best.
    I guess I could do that. I could make a wrench to tighten my ER collet chuck, which I bought to hold endmills better so I could make tslot nuts and toe clamps for my 3 sine vises so I can make straight edges so I can hand scrape them into master surfaces so I can rebuild my mills so I can begin converting them to cnc. What's one more project right?

    Hell, I just started working on a spindle lock since I just can't see paying $120 for one when I've got all the materials just lying around.

    Sooner or later I'm going to get to the root of this project...

    Chasing tenths is hard...


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    Quote Originally Posted by 1HobbyMachinist View Post
    I guess I could do that. I could make a wrench to tighten my ER collet chuck, which I bought to hold endmills better so I could make tslot nuts and toe clamps for my 3 sine vises so I can make straight edges so I can hand scrape them into master surfaces so I can rebuild my mills so I can begin converting them to cnc. What's one more project right?

    Hell, I just started working on a spindle lock since I just can't see paying $120 for one when I've got all the materials just lying around.

    Sooner or later I'm going to get to the root of this project...
    Sounds like we both are preaching to the choir.
    Last week it was making my own thread mills.
    This week its threading fixture jigs with my thread mills.



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    Quote Originally Posted by Dennis Rech View Post
    Sounds like we both are preaching to the choir.
    Last week it was making my own thread mills.
    This week its threading fixture jigs with my thread mills.
    That sounds pretty neat. I never heard of them before I googled it. What are yours made of? Do you heat treat them?

    Chasing tenths is hard...


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    So to those of you who use R8 - ER collets, how do you torque them down?

    I can always just use the old TAF torque spec, but how would I do it properly?

    Chasing tenths is hard...


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    Rigo fix collets are by far the best, they come with a torque spec sheet. Different torque for different size collets. They have a crows foot style wrench and a very expensive torque wrench made for it. Just FYI.



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    Quote Originally Posted by 1HobbyMachinist View Post
    That sounds pretty neat. I never heard of them before I googled it. What are yours made of? Do you heat treat them?
    I made an 11 tpi one out of a broken 5/8 x 11 HSS tap. Cut the broken end off with an abrasive chop saw leaving about 12 cutting edges and ground off two of the three flutes. It worked well except the remaining fluted threads were about 1/4 inch long and the pitch angle left a slightly wide cut thread. Ground off about 1/8 inch of the trailing edge of the flute and thinned the trailing end of the cutting surfaces with a Dremmel with a 1 inch thin abrasive wheel. It now works great. I use it on 1 inch diameter mild steel shafts and matching 1 inch aluminum holes.
    I have a Centroid CNC mill and thread milling is built into the conversational programing.
    I also have made a single point thread mill by milling a 3/8 inch flat on a 4 inch long piece of 3/4 inch diameter drill rod. Milled a triangular pocket into the flat the same shape and depth as the 60 degree carbide inserts that came with some Enco lathe bits. The tip of the insert sticks out about 1/8 inch. Brazed the insert into the pocket. When it breaks off or wears down, I'll just heat it, rotate it 60 degrees and braze it back on. I single point 6 TPI male and female threads on two inch shafts and pulleys with it. Again, the Centroid system includes single point thread milling with multiple passes.
    It took about 15 minutes to grind down the 5/8 inch tap and probably 45 minutes to make the single point one.
    Dennis



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    Quote Originally Posted by 1HobbyMachinist View Post
    Sooner or later I'm going to get to the root of this project...
    I forgot why I even came here in the first place . I wanted to make something.... That doesnt even matter any more.
    I have a ER32 and love it.



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    With my 704, I just hold the spindle in place, and tighten with the spanner wrench. Seriously, you don't need a huge amount of torque if you are using stuff that is within the correct dimensional range.

    With the bridgeport, I just stick it in back, and torque away...

    That said, since I mostly am doing small cutter stuff, I've been using DA300 collets - Just stick the holders in a high quality/low TIR 1/2" R8 holder, and go for it... Main reason for that is that I can get a LOT closer to the workholding while still keeping a lot of tool shank in the collet.



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    Well, I got the bearing nut and a wrench for my ER40 chuck from Maritool. I like it, it definitely feels like I can torque it down better.

    I also finished my spindle lock project. I am sharing a few pics of the complete work, but I admit, there's not a lot to see. I basically copied the idea from Fignoogle's product. I made mine from 1" steel plate though, (just because I had some lying around) and I think mine might be just a little bit stronger...
    Overkill is my specialty






    I have a nice knob on order, it should arrive within the week, but even without it, the spindle lock functions fine.

    Right now I'm trying to decide if it's ok to tighten my ER40 chuck with the spindle lock, or if I should clamp it in a vice. I think the spindle bearings can easily take the strain, and I know my lock can. So I think tightening in the spindle should be just fine... Opinions?

    Chasing tenths is hard...


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School me on ER collets...

School me on ER collets...