# Tool holding on a Bridgeport



## SamI (May 18, 2019)

I’m sure that this has been asked many times before and I’m sure I’ve read up on it a few times but can I find the information I want now?!

As some of you may know from another thread I have recently bought a Bridgeport mill. With it came a few boxes with probably a couple of hundred end mills. Unfortunately though nothing to hold them other than a fee R8 collets. 

Now my budget is quite limited just now but I am wanting to get some tool holders for it. I know there are various options from R8 collets, an R8 to ER32 adapter or even some of the quick change variants. 

I like the idea of a quick change system but as I said before my budget just now is limited. I don’t however want to invest in one system now just to replace it all down the line. 

So my question is, which is the most convenient and / or versatile tool holding solution for a Bridgeport? Are there any trade offs for a quick change system? Presumably rigidity could suffer but is this really a problem given that the R8 collet itself would possibly be the weak link?

Thanks in advance!


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## ddickey (May 18, 2019)

The R8-ER32 is nice because you are not reaching up and changing R8 collets all the time. You can even eliminate the drill chuck mostly. Changing ER collets a lot can get tedious as well. Also Rigidity suffers some because of the longer lever. For example my mill has a full size Bridgeport style head and I can not run anything larger than 1/2" in this option. Will be a bit more expensive than just buying a set of R8 collets.

If you don't mind reaching up and changing collets every time you want to change a cutter go with the R8s.

Quick change would be the ultimate in my opinion. I've seen them in action and looks very nice although I can't speak of rigidity as I've never personally used them.


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## BGHansen (May 18, 2019)

I bought an R8 to ER32 collet chuck with ER collets like this one off eBay.  Don't remember my seller, I've had no troubles with mine.  Lots easier to change collets at the spindle than at the draw bar.  I have a set of R8 collets too but haven't used them much.  Have Weldon end mill holders that have been used on occasion when there was a clearance issue (smaller nose holding the end mill than the collet chuck).  I occasionally use an electronic edge finder that has a 20 mm shank, have a specific 20 mm ER collet for that one too.  I have a number of Jacobs chucks with straight shanks (3/8", 1/2" and 5/8") for drilling.  Have the multiple shank sizes to avoid changing the ER collet.  My set up is in the bottom picture.

Bruce


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## ddickey (May 18, 2019)

Didn't even think about the straight shank drill chucks. Duh


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## projectnut (May 18, 2019)

If money is your highest concern the first thing I would do is check the shank size of the end mills you have.  Most end mills cone with standard size shanks.  Those under 1/4" usually have 1/4" shanks.  Those from 17/64 to 3/8' have 3/8" shanks.  Those from 25/64 to 1/2" have 1/2" shanks, and so on.  If your end mills fall within these parameters you'll need a minimum of collets.  You can generally get by with half a dozen or so collets to cover the range of end mills the machine can handle.
As for drill chucks you can use either an R8 shank, or straight shank the size of one of the collets you already use for end mills.  Personally I use R8 collets with the standard Bridgeport drawbar.  If you're working within the machines parameters they will hold either a drill, end mill, or drill chuck with no problems.  I have been using the R8 system on Bridgeports for over 30 years.  I've yet to have an end mill, drill, or chuck slip.  Then again I don't overload them by taking oversize or over depth cuts.  The R8 system is by far the least expensive.  It may not be the fastest, or most convenient, but it is certainly adequate.
If speed or convenience is more of an issue you can always invest in a power drawbar, or go to the ER system mentioned by Bruce.  

As a side note the company I worked for had 3 full time machine shops and maintenance shops in over 30 production facilities.  The full time machine shops used Tree brand milling machines with their own proprietary collet system.  All the maintenance shops used Bridgeports with the factory R8 collet systems.  In all the time I worked there I don't recall having more than 1 set of collets for each machine regardless of brand.  From time to time we did have to purchase specialty collets, but for specialty tooling not because the standard R8 collets were not up to the task.


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## ttabbal (May 18, 2019)

If you have limited budget, and don't already have ER collets, the cheapest option is to stick with R8. Just buy the ones you need for the bulk of the tools you have. That way you can get nicer collets with less runout, which helps with tool life. The sets are handy for odd sizes, but get expensive fast for good quality. 

I usually run ER40, but I had already purchased them for the lathe. My Bridgeport came with a small set of R8 that I use with larger endmills or deeper cuts to improve rigidity. 

Quick change looks nice, but I don't want to be locked into having a holder for each tool that I have to buy from one manufacturer. For a CNC or production shop, it's probably worth the price. For my hobby, not so much. I'd rather sped that money on cutters and materials. But to each their own. Whatever makes your enjoyment of the hobby improve is worth something.


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## ThinWoodsman (May 18, 2019)

The middle road for convenience and rigidity is probably an ER system. If you already have one for another bit of tooling, use that size; otherwise get an ER 32 or 40 arbor with an R8 shank.

As others have pointed out, you don't need a full set of R8 or a full set of ER. That sort of thing is more helpful in a lathe, where the stock being held can be of odd sizes, but tooling has a few standard shank sizes.

I tend to use ER collets for most milling, and R8 collets or shanks for dedicated tooling: drill chuck, boring bar, and the larger end mills (should probably be in end mill holders but a dedicated collet seems to work).The ER is nice when you're going to be swapping tools out a bit, e.g. a 2-flute for plunging then a 4-flute for widening then a chamfer mill.


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## MrWhoopee (May 18, 2019)

Start out with the R-8. Make sure you have 1/8-3/4 by 1/8 increments. This will cover 99% of what you will need at the lowest cost. Straight shanks on chucks, boring heads and fly-cutters will reduce the number of collet removals and knee cranking. I use 3/4 shanks if possible and shorten them to about 1-1/2 inches for ease of insertion. Once you figure out your needs, you might go with ER, but you may never need it. Learning to remove and install R-8 tooling with a bump of the power (NO WRENCH!) speeds things considerably. Quick-change tooling is more suitable for production situations. In my job shop, we had 8 vertical mills. All were strictly R-8 tooled, no ERs or quick-change.


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## ttabbal (May 18, 2019)

I would like to know more about this power R8 removal...


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## SamI (May 18, 2019)

Thanks for the advice guys.  I’ve got a run of 10 parts with various holes and threads in them coming up and the thought of changing a tool that many times makes me shudder! But yes I agree, having a dedicated tool holder for each tool will probably make the system too expensive on the mill. 

A power draw bar may be on my project list! 

I have a small selection of R8 collets so I’ll have a look through the tooling and see what fits what and try use that for the short term before I can invest in different tooling at a later date. I might get an ER32 holder as I have the collets already but I shall have a ponder!

And yes, I’m curious by this power removal too!


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## MrWhoopee (May 18, 2019)

I was referring to using power to unscrew the drawbar. It still takes a wrench to break it loose and a tap to release the taper. I made a wrench/hammer similar to this for the purpose.



 Might not be worth it for some, but I got pretty quick with it. Just be sure to remove the wrench before bumping the power,  just in case.


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## f350ca (May 18, 2019)

I started out with a ER32 collet chuck not knowing they made R8 collets (pre internet), used it for years. Since I found out about R8 collets I could count on one hand the times I've used the collet chuck, a set in 1/8ths will as said hold 99% of your end mills, I have 2 out of hundreds that are 7/16 and 9/16th. Though you have to make room to install it I use R8 shanks on everything else, 
I have a 10 inch riser in the mill, climbing up there got tiring, made a power drawbar a few months ago, think I posted it in the "What did you do today thread", its a god send. With it I could see no reason for quick change tooling.

Greg


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## Mitch Alsup (May 18, 2019)

While I have an ER-40+R8 attachment like mentioned above, I am looking towards a set of R8 collets directly.
There are 3 advantages:
a) lower runout
b) more nose height
c) more rigidity.


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## BGHansen (May 20, 2019)

ddickey said:


> Didn't even think about the straight shank drill chucks. Duh


My clue was from the sheer volume of straight shanked chuck's sold by eBay seller "stm_surplus 2".  I figured Morse taper was for lathes, R8 for mills. Then dawned on me to put the straight shank in a collet. 

Bruce


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## chips&more (May 20, 2019)

I totally understand the reasoning behind the use of straight shank tooling. BUT, when using straight shank tooling into a collet you have increased the runout uncertainty. The less you have going on to hold your tooling the better the accuracy. For this reason, I do not use straight shank tooling into a collet. I go from R8 directly to chuck or whatever. And I do not have and don’t see the need for an R8 to ER32, very sorry to say…sorry guys. And for some reason, I did buy a metric set of R8’s. I don’t know what the hell I was thinking? It has just been collecting dust! I also have several sets of Bridgeport R8 back-up sets too. They also have been collecting dust. One set of Bridgeport collects well cared for will probably last your lifetime. And you really don’t need a back-up set(s)…Dave


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## Illinoyance (May 21, 2019)

I have R8 collets and R8 endmill holders, but the ER32 collet chuck probably gets the most use.  It is more convenient to change tools at the spindle nose than by using the drawbar.  A big advantage of the ER collet system is the clamping range of the collet, about 1mm.  They cover sizes for which R8 collets are unavailable.

I can not use a power drawbar because I have some attachments that clamp to the quill.  That requires a socket wrench to reach the drawbar.  The power drawbar setup would prevent that.

Each toolholding system has its advantages and disadvantages.  Figure out what works best for the way you want to work.


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## Firstgear (Jun 19, 2019)

I have no problem reaching my drawbar.  I started out with a wrench and then went to an electric ratchet from HF.  I really like the electric ratchet.


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## jdedmon91 (Jun 20, 2019)

Firstgear said:


> I have no problem reaching my drawbar. I started out with a wrench and then went to an electric ratchet from HF. I really like the electric ratchet.



That’s what I ended up doing myself. I don’t have enough space to build a power drawbar using air impact wrench. I did purchase a Milwaukee just to cut down on batteries and chargers 


Sent from my iPad using Tapatalk


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