# Er collet Chuck in Bridgeport quill



## Dinwoodie Cutlery Concepts (Nov 29, 2020)

I’m thinking about putting an er x r8 adapter in my Bridgeport. I feel as though for what I do, making a lot of tool changes during my jobs that an er collet system would be faster and more versatile. I’m not worried about the additional length so much as the potential loss of accuracy and runout that might occur. Has anyone done this and what have your experiences been? Thanks!


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## Buffalo21 (Nov 29, 2020)

I have R8 x ER 16, R8 x  ER 20 and R8 x  ER 32 collet chuck set ups for my 3 mills, I have absolutely no issues. The additional stick out is roughly 1-1/4” for the ER 16, 1-1/2” for the ER 20 and  2-1/2” on the ER 32.


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## Dinwoodie Cutlery Concepts (Nov 29, 2020)

Buffalo21 said:


> I have R8 x ER 16, R8 x  ER 20 and R8 x  ER 32 collet chuck set ups for my 3 mills, I have absolutely no issues. The additional stick out is roughly 1-1/4” for the ER 16, 1-1/2” for the ER 20 and  2-1/2” on the ER 32.


No noticeable runout? Does it make the tool changes a bit quicker?


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## Buffalo21 (Nov 29, 2020)

With quality collect chuck and collets, run out is almost nil

I found change is faster and easier, both wrenches are at the bottom of the quill, make loosening and tightening very easy.


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## Ed ke6bnl (Nov 29, 2020)

Buffalo21 said:


> With quality collect chuck and collets, run out is almost nil
> 
> I found change is faster and easier, both wrenches are at the bottom of the quill, make loosening and tightening very easy.


My cheap Collets with quality er32 holder have terrible runout


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## mksj (Nov 30, 2020)

I have a power drawbar, and still end up using an ER32 system in addition to other tooling. If you get a decent R8 to ER32 holder the run out is usually on the order of 0.0001" which is far better than R8 collets. A decent set of say Techniks er32 collets and power nut/bearing nut makes a world of difference. I have checked mine an it is no worse than 0.0002" with the collet. If I need absolute rigidity and for facing or heavy work I use my R8.

Most endmills come in fixed shank sizes, so all you need is a limited set of collets like an 8 piece set. There are no fractional size needed, and do not get a metric set because it clamps 1 MM increments, my experience is that when clamped down their run out becomes terrible. If you have an issue with height, you can always use an R8 collet. When I did not have a power drawbar, I use my ER32 frequently, less so now, unless I have dedicated tooling in holders. With a power drawbar you need to hold the endmill and collet together until it pulls up into the spindle, I always hold the endmill with a cloth rag otherwise it will make a bloody mess of your fingers. 

You have to always snap the ER collet into the nut first and then put it in the holder, and then put your endmill in and tighten. When unscrewing the nut it will first loosen and then take a little more effort to pull the collet down. If you are not careful, the endmill will fall out and break/chip. I always put a box with some cloth or paper under mine so if it drops nothing gets damaged. Sometimes I wish I had several ER32 tool holders with different endmills loaded in them, much easier to switch tooling and maintain heights.


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## ThinWoodsman (Nov 30, 2020)

Got an ER-32 chuck with an R8 shank for the bridgeport. 

No appreciable runout.

I found that it doesn't save me much time - the spindle drawbar is about eye level for me, and I'd rather use one wrench standing up than two tools when stooping down. Plus the ER collet nut is a bit fiddly in a way that R8 collets are not. So the ER-32 is sitting in a drawer somewhere and the collets are gathering dust.


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## Diecutter (Nov 30, 2020)

Since we are discussing ER collets, does anyone have experience with ball bearing collet nuts? (my collet uses ER20A type)   What are their advantages/disadvantages versus  regular collet nuts?


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## Janderso (Nov 30, 2020)

Same here, NT30/ ER40 in my HD BP clone. Works slick.


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## Lo-Fi (Nov 30, 2020)

Diecutter said:


> Since we are discussing ER collets, does anyone have experience with ball bearing collet nuts? (my collet uses ER20A type)   What are their advantages/disadvantages versus  regular collet nuts?



The ball bearing nuts give you more clamping force for a given amount of torque. I like them.

I have an ER32 for my Bridgeport and use it often. Mostly because I don't have a full set of R8, but also because it's more convenient to change, with the collets needing less Z clearance. I find them pretty quick, often favouring over my Jacobs chuck for drill, chamfer tap jobs. Runout is negligible on my setup; certainly no worse than the mill itself. I also have ER32 chucks for the lathe, dividing head and rotary table, as well as square and hex collet blocks.


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## Buffalo21 (Nov 30, 2020)

I have ball bearing nuts on all of the ER collet set ups, IMO, the nuts are a huge improvement or the standard nut.


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## Diecutter (Nov 30, 2020)

Thanks for all the feedback on the ball bearing collet nuts.  Much appreciated.


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## pontiac428 (Nov 30, 2020)

BB collet nut also prevents the collet from twisting in the holder.  Huge improvement.  I occasionally use an ER32 adapter on my mill, it works well.  For heavy stuff I still prefer Weldon shank end mill holders.


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## mikey (Nov 30, 2020)

Dinwoodie Cutlery Concepts said:


> I’m thinking about putting an er x r8 adapter in my Bridgeport. I feel as though for what I do, making a lot of tool changes during my jobs that an er collet system would be faster and more versatile. I’m not worried about the additional length so much as the potential loss of accuracy and runout that might occur. Has anyone done this and what have your experiences been? Thanks!



If you buy a decent ER chuck and use good collets and an accurate collet nut then run out will be minimal. Given that run out has a significant impact on tool life, money spent on good quality tool holding equipment saves money in the long run. 

One thing to keep in mind is that one chuck does not rule them all because access to the part is often an issue. The larger the chuck, the more rigid and vibration-damping it is but the nut on larger chucks can interfere with access to some parts so many of us have multiple ER chucks. I own ER40, ER32 and ER20 to deal with this. Naturally, this can get expensive if you only buy top shelf chucks and nuts. 

Add to this the fact that if you do a lot of tool changes, buying multiple chucks and preload them with tools is a huge timesaver. My ER40 chuck is from ETM; it uses a coated ETM nut and with ETM collets, this chuck has 0.0001" TIR. My Tormach TTS ER32 and ER20 chucks use Techniks collets and they both have under 0.0002"TIR. Many guys, especially the CNC guys, use the TTS system and buy multiple ER chucks to load tooling into; then they change chucks instead of changing cutting tools. The TTS system simply requires you to loosen the drawbar a bit, tap it and the chuck drops right out. Slap in another chuck, tighten the drawbar and you can cut. It takes seconds for a tooling change so it isn't a bad system, and accuracy is pretty good for such an economical system. An ER32 chuck, with nut, cost under $40 the last time I checked. 

Ball bearing nuts are beneficial in that they reduce the amount of torque required to optimize tool holding power without distortion of the collet. For example, a solid ER32 nut requires 130# of torque, while a BB nut requires about 100# of torque to achieve the same amount of collapse of the collet. However, not all BB nuts are created equal. The Chinese nuts that are readily available can actually increase run out on a good chuck. In my personal tests, Chinese BB nuts ran out over 0.0007" TIR compared to 0.0001 for an ETM or Rego-Fix solid coated nut. While 0.0006" difference in run out might seem trivial, that is 0.0003" of actual run out. Given that for each tenth of run out you have, tool life is reduced by 10% so you're looking at a 30% reduction in tool life just from the nut. The point: buy good nuts, either hard coated or ball bearing, and buy them from a good maker - ETM, Rego-Fix, Techniks.

Lastly, buy good collets because like nuts, they make a difference in run out and ultimately, tool life. Bang for the buck, Techniks is the best deal out there. There are better collets from ETM, Rego-Fix, Crawford and others but all will cost more. Like mksj said, you only need the collets for the end mill sizes you use so buy good ones in just those sizes and only use them on the mill for tool holding; do not use your good collets on the lathe for work holding. I also agree that if you use Imperial tooling, buy Imperial collets and buy Metric collets for your metric shanks. Not only will accuracy be better but so will collet life. 

Take a hard look at the TTS system. I use it because it is fast to change tools and the accuracy of their import chucks is actually quite good when used with good collets.


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## ThinWoodsman (Nov 30, 2020)

mikey said:


> Add to this the fact that if you do a lot of tool changes, buying multiple chucks and preload them with tools is a huge timesaver.



Why not just use R8 collets, then, and cut out the middleman?


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## mikey (Nov 30, 2020)

ThinWoodsman said:


> Why not just use R8 collets, then, and cut out the middleman?



Accuracy.


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## ThinWoodsman (Nov 30, 2020)

But that depends on whether the R8 shank of the chuck is more accurate than the R8 shank of the collet.
And if repeatability of tool height is the issue, there's end mill holders instead of basic collets.
Not really seeing how the ER chuck adds accuracy compared to just using an R8-shank toolholder in the spindle.


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## pontiac428 (Nov 30, 2020)

What is the difference between accuracy and repeatability?
Certain clockings of spindle, collet, and tool may be more accurate, but not more repeatable.
Switching to the simpler system of R8 collet and tool, you are going to have more repeatability AND accuracy.
I for one do not want to line up sharpie marks on all of my collets, tools, and holders to make that system repeatable.  I just want to plug and go.  Either that means I accept my measured runout or not... and if I do, that's all good.


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## mikey (Nov 30, 2020)

ThinWoodsman said:


> But that depends on whether the R8 shank of the chuck is more accurate than the R8 shank of the collet.
> And if repeatability of tool height is the issue, there's end mill holders instead of basic collets.
> Not really seeing how the ER chuck adds accuracy compared to just using an R8-shank toolholder in the spindle.



Okay, what is the run out of your mill spindle? If you put an R8 collet in that spindle and put an accurate pin in that collet, what is the observed run out on the pin?

My spindle has under 0.0001" TIR. With an ER40 collet chuck, good collets and a good nut I get 0.0002" TIR, maybe a little less, so about the same actual run out of the spindle. I also have Crawford R8 collets and while they are quite good they are not as accurate as my ETM chuck so they are used only when I have to use larger end mills or other tooling. 

Does any of this matter? Up to you. For me, I believe tool life  is enhanced with a more accurate tool holding system so I have a set up that achieves that.


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## middle.road (Nov 30, 2020)

I prefer using the er32 setup on the mill when I can. With a manual drawbar it saves my shoulder.
So far after a few years it's been fine.
I do want to get a BB nut though. Keep forgetting. 

I believe this is the vendor on eBay that someone in another post recommended. (Though as usual I can't find the thread right now...   )








						NEW - ER32 BEARING STYLE COLLET NUT - ALWAYS FREE SHIPPING - NEW   | eBay
					

Find many great new & used options and get the best deals for NEW - ER32 BEARING STYLE COLLET NUT - ALWAYS FREE SHIPPING - NEW  at the best online prices at eBay! Free shipping for many products!



					www.ebay.com


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## ThinWoodsman (Nov 30, 2020)

pontiac428 said:


> Certain clockings of spindle, collet, and tool may be more accurate, but not more repeatable.
> Switching to the simpler system of R8 collet and tool, you are going to have more repeatability AND accuracy.



Yeah, that's pretty much my point. The more interfaces you add to the system, the more you compound any error.

Now if Mikey found an ER chuck that is more accurate than any R8 collet or end mill holder on his mill, fantastic. But that doesn't make it good advice for someone else - they would have to go through a few ER chucks until they find one that has less runout than their R8 tooling. Given the price difference between an ER and the R8 collets/endmill-holders, it makes more sense to chase down accurate R8 tooling for those dedicated toolholders.


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## mikey (Dec 1, 2020)

ThinWoodsman said:


> Yeah, that's pretty much my point. The more interfaces you add to the system, the more you compound any error.
> 
> Now if Mikey found an ER chuck that is more accurate than any R8 collet or end mill holder on his mill, fantastic. But that doesn't make it good advice for someone else - they would have to go through a few ER chucks until they find one that has less runout than their R8 tooling. Given the price difference between an ER and the R8 collets/endmill-holders, it makes more sense to chase down accurate R8 tooling for those dedicated toolholders.



Just to be clear, I was simply trying to help the OP. He asked about ER chucks and I gave him what I know, that's all. He was concerned that moving to an ER system might adversely affect run out and accuracy and I was trying to reassure him that if he chose good stuff then he has a good chance at a good outcome.


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## mksj (Dec 1, 2020)

Mikey is correct, even with an extra interface of the ER system in most cases the run out is less than R8 collets and it has nothing to do with clocking. ER systems are more accurate, but will probably never be noticeable in a hobby environment. True end mills do wear out faster with increasing TIR, but the 10% per 0.0001" of run-out sited is in a production environment pushing cutting performance to their extremes. If you buy very inexpensive R8 collets or an ER system, your TIR will suffer with either system. My first set of R8 collets was a Chinese generic set, it did not fit my spindle, I ended up with a Lyndex 1/16th set for around $130 and the TIR are quite good but they still rate a maximum of 0.0007" TIR. So still not so good, although mine were typically are 0.0003" or better. My R8 chucks are just as good. If you are trying to align a tough probe with an R8 collet you may have some issues, I use a Crawford R8 collet for setting up my touch probe or I use an ER32 collet which gives comparable results. On an ER system, I use a Shar's ER32 R8 holder and ETM/Iscar collets but other ER32 collets are just as good. A power nut or bearing nut make tightening the collet much easier and will decrease the TIR. So spend a bit more once and be happy with the better performance, you only need a minimal collet set as most endmills shanks fall into fixed diameters 1/4, 3/8, 1/2, 5/8, 3/4 and 7/8". In a pinch you could use a decent chuck.

As I indicated both systems are valid and work satisfactory in a hobbyist setting, an ER system tends to be easier to switch out endmills if you do not have a power drawbar. I often prefer to use an ER32 system even with a power draw-bar, it adds about  2" in height but makes handling the end mill much easier. I do not like to work with the cutting occurring close to eye level.

Example of a 7/8" 6 flute rougher, 3000 RPM 10 IPM 0.4" DOC where rigidity was more important using an R8 collet for the least amount of stick out:



Example with an ER32 system with a 1/2 end mill where it was more desirable to have the added length  and the convenience of an ER system for this cutting profile:



Followed by using a precision chuck where the other two others would be too bulky, it is a self locking chuck but I always torque it with the chuck handle or use a keyed CNC chuck otherwise with endmills can pull down into the work. Chuck TIR is under 0.0007".


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## tjb (Dec 1, 2020)

mksj said:


> Mikey is correct, even with an extra interface of the ER system in most cases the run out is less than R8 collets and it has nothing to do with clocking. ER systems are more accurate, but will probably never be noticeable in a hobby environment. True end mills do wear out faster with increasing TIR, but the 10% per 0.0001" of run-out sited is in a production environment pushing cutting performance to their extremes. If you buy very inexpensive R8 collets or an ER system, your TIR will suffer with either system. My first set of R8 collets was a Chinese generic set, it did not fit my spindle, I ended up with a Lyndex 1/16th set for around $130 and the TIR are quite good but they still rate a maximum of 0.0007" TIR. So still not so good, although mine were typically are 0.0003" or better. My R8 chucks are just as good. If you are trying to align a tough probe with an R8 collet you may have some issues, I use a Crawford R8 collet for setting up my touch probe or I use an ER32 collet which gives comparable results. On an ER system, I use a Shar's ER32 R8 holder and ETM/Iscar collets but other ER32 collets are just as good. A power nut or bearing nut make tightening the collet much easier and will decrease the TIR. So spend a bit more once and be happy with the better performance, you only need a minimal collet set as most endmills shanks fall into fixed diameters 1/4, 3/8, 1/2, 5/8, 3/4 and 7/8". In a pinch you could use a decent chuck.
> 
> As I indicated both systems are valid and work satisfactory in a hobbyist setting, an ER system tends to be easier to switch out endmills if you do not have a power drawbar. I often prefer to use an ER32 system even with a power draw-bar, it adds about  2" in height but makes handling the end mill much easier. I do not like to work with the cutting occurring close to eye level.
> 
> ...


Likely a dumb question, but what's the purpose of the green tape?  I've never seen that done before.

Regards,
Terry


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## mksj (Dec 1, 2020)

Hi Terry,

I use painters tape to protect surfaces that I surfaced from getting damaged when clamping the part, and also use it on the jaws to prevent paint damage when holding a painted part in the vise.  You often see sheet aluminum and stainless come with a plastic protective film that you peel away after assembly. In this case the material is 7075 used for micrometer stops, harder than 6061 but still can be damaged when clamping.
Mark


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## tjb (Dec 1, 2020)

mksj said:


> Hi Terry,
> 
> I use painters tape to protect surfaces that I surfaced from getting damaged when clamping the part, and also use it on the jaws to prevent paint damage when holding a painted part in the vise.  You often see sheet aluminum and stainless come with a plastic protective film that you peel away after assembly. In this case the material is 7075 used for micrometer stops, harder than 6061 but still can be damaged when clamping.
> Mark


Thanks, Mark.  I have quite a bit of both the green and yellow varieties of that tape from back in the days when I was working on hot rods.  I have experienced exactly what you're talking about when machining but never considered using the tape for that purpose.  Next time I'm in the shop, I will move the rolls closer to my mill.

Regards,
Terry


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