Mill Tooling first choices

[Kevinb71]

I have a mill/drill similiar to a Rong Fu with an R8 spindle. My question for you is, given the fact that I have the R8 would it be best to purchase R8 collets or an R8/ER32 adapter and ER32 collets? Also if i have the collets would their still be advantages to having end mill holders. I am sorry for the newbie questions, but i searched the archives and didn't really find this answered. Thanks!

 

[brasssmanget]

well, I can't give you a positive for sure answer, but I own and use a RF31. I have a few of the larger end mill holders on R8 shanks, and use the collets for most everything under .325 without problems. I do prefer the heavier holders when using .500, .625, .750 etc. I have not used the ER collets, but I used C5 on the lathe. I suppose the collets would do, but I just bought the holders as a package with the mill when I purchased it years ago. Hope this helps a little ?

 

[Redirish]

I haven't used ER collets, so can't speak for them. I use R8 collets for my end mills, fly cutters, and other stub arbors. I don't have any end mill holders, as I see no advantage over the R8 collets.

 

[Tony Wells]

The advantage of holders is only the set screw bearing on the flat of the end mill shank, assuming there is one. Not really an advantage on smaller work. >1.000 is where you need the holding power, and even then only if you have the hp and rigidity for it. I use strictly R8 up to 7/8 and have a single holder for 1.00 shanks.

 

[8ntsane]

On the smaller machines with limited day light between spindle and table, the R8
collets are the first choice, no question. The end mill holder with set screw may be of benifit to you when doing side milling,or your worried the end mill will get pulled down from the collet.

The ER collets add to the versatility maybe for drill sizes, but a good drill chuck would do just as well. I have collet chucks for my 9X42 mill , and dont use them all that much. The first thing I dont like is the force to crank the collet nut tight.
Tightening is the first issue. Now to loosen takes a eqaul amout of force. The process is a 2-handed deal. What allways ticks me off with collet chucks, is when your 2-hands are busy loosening, and the endmill drops out on top of the work piece, or drops on your nice Kurt vise,

I had gotton into the habit of having a folded up towel to put under the spindle to catch the falling endmills or what ever the collet was holding. Collet chucks all seem to take a fair bit of torque to tighten the tooling secure. If you have R-8 now, I would stick with it. No really good reason to go looking at ER stuff. For drilling operations, maybe purchase a good quality drill chuck. It would take up about the same amount of room as the ER collet chuck.

If your thought was you rather not reach up for the draw bar, and rather deal with the ER chuck at a lower level, then I would look at adapting your own power draw bar set up to the mill. Most home brew PDB can be built for a few hundred bucks, and saves time, makes tooling swaps fast and easy. Just a thought.

 

[Hawkeye]

I have both R8 collets and two sets of ER collets. The only advantage of ERs is when you will be changing sizes, but can't wind the work out of the way to get more clearance to change cutters. The ER collets can be changed closer to the work than R8s can. If you can move the work out of the way, R8s are still best.

If you are going to get ER collets, get the set with the 1/16" increments. I started with 1/8" increments, but bought the full set when the chance came up. Common centre drills are sized in 16ths.

 

[Kevinb71]

Thanks for all the replies. I have learned so much so quickly browsing this site! I just have a couple R8 collets now and will get the remainder of a set for now. I just wasn't sure if there was something about the toolholders i was missing other than the set screw. so far I haven't had a tool pull out and it hasn't bothered me reaching to the top of the machine to change things. As I use it more I am sure I will learn those things as well. Thanks again for the point in the right direction.

 

[Robert62]

I have to agree with the positive side of using the ER40 collets. Unlike the ER32, the ER40 goes up to 1". An advantage to this is that the R8 to ER40 keeps from having to undo the drawbar you need to change sizes. On a side note, if you have a lathe, you can get an ER40 chuck for your lathe (I got a MT3 to ER40 chuck) also and then use the collets on both machines. With the ER Collets, I seldom use the R8 collets anymore.

 

[Kevinb71]

Thanks again to everyone for their opinions and suggestions. I will look at the ER40 for future purchase. For right now and to get started i have the R8's. I will probably soon want the additional capacity of the 40, but for right now this is most affordable. Trying to get started with both the lathe and the mill means $ are wanted everywhere at once. Time will build my tool supply!