Holding End Mills?

I have all of the above. The most recent addition is the endmill holders, probably about a year ago. They get used the least because I tend to forget I have them. I find that the collet chuck holds more securely than the R8 collets. The collet chuck is the British equivalent of the ER40 style. They hold well and an added advantage on a round-column mill is that the chuck sticks out about the same as a drill chuck. There is less need on a project to change the height of the machine head.
 
Use both the R8 collets and end mill holders . I've never used ER collets other than on machining centers and have never needed them on any of my Bridgeports .
 
I hold end mills directly in R-8 collets, R-8 end mill holders and an ER-32 collet, so not helping you much with your decision . . . . Advantage of the R-8 collet directly is a little more head space over the table if that's a concern. I use an ER-32 collet chuck on my Bridgeport to avoid reaching up to loosen the draw bar, nice to change tooling at waist level. Bottom line is there's no "right way" and you'll find needs/advantages of all methods.

Biggest problem with round column mills is your Z is limited by your quill travel. One advantage you would see with multiple tooling set ups is maybe gaining some Z by default with the different tooling set ups. The collet chuck or end mill holder extend more out of the spindle, so you'd start with your tooling a little lower. Then if you drill a hole and go with an R-8 drill chuck you'd be at about the same point with the drill bit vs. the end mill in Z. That was always the biggest pain for me with my round column mill; would do some cutting with an end mill mounted in an R-8 collet then switch to a drill chuck and drill and had to crank the head up to get clearance.

My work around back in the day was multiple edge finders fastened to various lengths of drill rod. Finding center is a basic fundamental technique and shouldn't be feared, it just adds a little time to the job. If I had to crank the head up/down, I'd refind center by popping in a 1/2" R-8 collet and the appropriate drill rod piece with an edge finder attached and reset the hand wheels.

Bruce
 
ER32 is too large and restricts your view. I use ER25 with a R8-ER25 collet chuck on a similar mill - no issues
Never have needed to use a drill chuck as the collets handle all sizes.


I do use ER32 on my lathe for the large capacity

Get the full ER25 set, you will eventually need every size, they are under $30

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Make or buy a hex/square collet block to use in your vise etc:
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The general consensus seems to be that I should buy everything! Well naggona happen. I have to pick between a set of ER collets, R8 collets or R8 end mill holders. Time to order. Help[ me out here!
 
I would like to have all the above also. IMHO YMMV, etc.
I have R8 collets on the mill. They work great. Since my mill (PM-25V) isn't very tall, operating the drawbar is not a big deal. Buy a set of R8 collets to use on your mill/drill. It will easily run at feed and speed with a 1/2 end mill. I run larger end mills and achieve great finish and respectable accuracy. With little effort, I can make chips faster that I wish to remove them. You have to learn your machines limitations. They all have them.
If your lathe is a new-ish asian lathe like mine, you might EVENTUALLY go with collets (ERxx), but until then, stick with the 3 and 4 jaw and learn from that process.
To get more productive on the mill, get a drill chuck on a shank so that you can easily change from drill bit to end mill of a certain size shank (say 1/2 inch), an edge finder of the same size and the tap center / assist. With that, one can easily locate, drill and tap holes in a lot of parts. In certain cases, having a 1/2 inch shank end mill holder to allow quick change to a smaller end mill might be a good thing.
While you could share collets between the lathe and the mill, you might always find (or not find) the collet you want because it is on the other machine.
For bar stock work on the lathe, I am looking seriously at ER32/40 to reduce runout. I find it unlikely that I would go with ER collets on the mill
 
epanzella said:
The general consensus seems to be that I should buy everything! Well naggona happen. I have to pick between a set of ER collets, R8 collets or R8 end mill holders. Time to order. Help[ me out here!
Click to expand...

The implication here is that you are going to make a one-time choice. That is "naggona happen"!

I know you're anxious to use your machine but the time to think is before you spend your money. I wanted to give you some food for thought:
  • Any tool system you choose will add to the run out your current spindle has. You need to check your spindle run out and document it so you know where you're starting from. A stock mill drill with stock spindle and stock spindle bearings would do well to have run out under 0.001". Ideally, you want it closer to 0.0001" but that probably won't happen with stock bearings. Just remember that any tool holding system you use will add on to the run out of your spindle.
  • Really good R8 collets can be really good. Hardinge R8 collets can run out under 0.0002" TIR but these are big bucks. Cheap collets can be really bad; how bad is hard to know. Most Chinese collet makers will claim a low run out number but the reality is often much, much worse. As usual, the best option if you go with R8 collets is to pick a good maker and buy once, cry once. In my opinion, Hardinge is the best, followed by Crawford, Lyndex and I'm sure there are others I have no experience with. I use Crawford. The good thing is that you don't need a full set for end mill holding; you only need sizes to fit the tools you use - 3/16", 1/4", 3/8", 1/2", 5/8" and maybe 3/4" - so you can buy just these sizes from a good maker and do fine. Use a drill chuck for drills instead of using R8 collets to hold drills. Of all your options, R8 collets give you the most headroom in Z because you have almost no stick out of the collet. This sounds good, right? However, most mill drills will have something like 12-14" of Z so headroom is not usually a problem regardless of the tool holding system you use.
  • End mill holders: I don't use these anymore but they are a good option for larger tooling. I don't care for them because they use a set screw or two to hold the end mill in the holder and this shifts the end mill off to the side, thereby increasing run out. There are end mill holders that are made to reduce this offset but they are more expensive.
  • ER system: For a hobby guy, I think this is the best option. A decent ER chuck from a good maker is not that expensive, nor are decent ER collet sets. For example, an integral R8-ER 25 or 32 chuck from Glacern is under $90.00. Couple that with a set of Techniks collets that give you the best bang for the buck and you're off and running. ER25 and ER32 sets are available on ebay or Amazon and many other places. It does not pay to use cheap Chinese collet chucks or collets on a milling machine; run out is too high and that affects accuracy, finishes and tool life.
Rather than go through all the pro's and con's of each tool holding system, I'll just add to the other opinions and tell you that after using R8 collets and R8 end mill holders, I prefer the ER system on the mill. I have ER40, ER32 and ER20 chucks for my mill and good collet sets for each. If you have to economize, get a cheaper chuck and spend money on good collets and collet nuts - that is where the real differences are.
 
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I have 3 vertical milling machines, I have R8 collets, end mill holders, ER 32 and EOC 25 (Din 6388) collet chuck systems for all 3. I rarely use the end mill holders, about 30% of the time is R8 and the rest of the time it’s either the ER 32 or the EOC 25 collets. I do a lot of machining using carbide end mills, for me the collet chuck systems seem to be the most convenient.
 
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