R8 Tooling for Warco Super Major Mill

Hello Guys

I've just recently bought myself a new Warco Super Major mill direct from Warco and I'm looking for some advice on buying an R8 keyless drill chuck and R8 collets to hold my end mills.

APT in Glasgow is my main supplier for HSS/carbide milling cutters, I have noted that on their website they sell R8 drill chucks with TIR 0.05mm, I’d like people’s opinions on this, would this be classed as a low amount of runout for a drill chuck. My knowledge on this subject is a little bit limited, so any feedback would be appreciated.

Also, I haven’t decided if I’m gong to use R8 5C collets to hold my end mills or use an ER32 R8 collet holder.

What would be the most optimum setup for this mill? I like the idea of maximizing vertical space with the R8 collets instead of losing a few inches with the ER32 system. also what about runout on collets is there a particular brand that i should look to buy either ER32 collets/holder and the direct R8 collets?

Thanks for your help.

Martin

If enough head-space, I would likely opt for an ER collet chuck.

R8 collets every time. I bought a set from MSC when I got my VMB and they are excellent, grip like the proverbial, don't eat daylight. I've got 2 keyless chucks, one 13mm Vertex the other 6mm Albrecht, both on standard R8 to taper arbors. I haven't measured their runout but not noticed any issues.

Adapters are not ideal but Morse into R8 goes satisfactorily, so you can use what Morse stuff you have. I have an ER32 collet chuck in R8 for my mill, but also use an MT2 Jacobs chuck with adapter sleeve for drilling. Obviously (for milling) you will need to check the drawbar thread is suitable for your chuck of choice, and if necessary make sure it goes through the adapter to engage the chuck directly.

Martin,

I use an ER25 or ER32 collet chuck in my Warco VMC mill. When daylight under the quill is in short supply, I use R8 collets directly in the spindle, but I don't suppose I've used them more than a handful of times in my ownership of the mill, about 7 years and even then I've think I've only used one or two out of the set. I'd go for an ER collet first and buy R8 collets as dictated by the particular job requirement. I have to admit that I work to tolerances way over the NASA requirement and ER25/32 works fine for me. Never checked for run out.

John

That is much better than the runout I measure (5x) on any of my chucks when installed in the mill and measuring off a milling cutter shank.

I'm collecting R8 collets/arbours as I need em. Great (if you tighten them up ). Some need fettling to fit at first.

Maybe there is a time saving between R8 and ER to consider if changing a lot ... I don't know which way though.

I only use the R8 or MT3 collets when the job means I run out of head room to use ER collets. The biggest downside I find with direct collets is being able to see what you are doing or getting in close when clamps or say the spin indexer are used when using small cutters. Here is an example of a 3mm cutter in the SX2.7 held in a 6mm R8 collet.

Can't get to my R8 mounted chuck at the moment but I get 0.05mm with my MT3 one from ARC, this is a commonly quoted figure from many of the top brands but like a 3-jaw lathe chuck a drill chuck is not as accurate as collets would be and you should be able to get 0.005mm with collets as I do without splashing out.

A drill chuck is intended to hold drill bits....which are not high precision. Their purpose is to make a hole, not necessarily a round hole and not to an exact size. You don't want the drill bit to wobble about but a tiny bit of runout in the chuck isn't going to affect the making of a hole. If you want a more precise hole you use a center drilling end mill in a collet.

I use R8 collets all the time, I think I may have an ER collet system also but haven't used it as yet.

Tony

If you go for R8 collets then get yourself one that is Ø16 and you can then get an ER16 collet holder with a Ø16 parallel shank for when you need to get in close with cutters or drills up to Ø10. This uses up far less space than a drill chuck and can be fitted into the R8 at different heights to suit the work that is being done.

Martin C

Back in the 70s I worked a Bridgeport which had a small drillchuck with an R8 mount. I used to use it for co-ordinate drilling jobs amongst other things, and some of these had tight tolerances. Before I got to trust wobblers, I'd set it up against a datum edge with a .2500" dowel. My close-in eyesight was sharp then, and I think that on a good day that gave me a bit better then 0.002"/0,05mm TIR.

My guess is that APT are quoting the runout they (or their supplier) can guarantee, and most setups where careful practices are followed will give better.

Use collets where you can - the benefit of R8 collets isn't just space-saving, it's stiffening the resistance to any sidestress by shortening the leverage.

Edited By Mick B1 on 11/12/2022 11:54:55

R8 collets every time. I bought a set from MSC when I got my VMB and they are excellent, grip like the proverbial, don't eat daylight. I've got 2 keyless chucks, one 13mm Vertex the other 6mm Albrecht, both on standard R8 to taper arbors. I haven 't measured their runout but not noticed any issues.

We got a full set of R8 metric collets with the drill mill at the museum, and after several years, most of them are unused. They have little or no tolerance for missmatched diameters, I have had to buy 4 imperial ones. It would be best to only get the sizes which match the cutter shank diameters that you intend to use.

With an er collet system, either er25, (up to 16mm) or er32, (up to 20mm), it would be advantageous to have a set especially if you fancy using then on a lathe as well using a Morse Taper adaptor or a collet plate, as a set can cover every size if workpiece.

With sets of er collets, it would be better to get quality ones from Cutwel or APT, they specify the runout tolerance, I have a couple of Chinese sets which leave a lot to be desired in that respect.

Edited By old mart on 11/12/2022 14:36:04

Guys

Thank you so much for all the feedback on the R8 collets and ER 32 system.

I'm going to mix and match to get the best of both worlds as they say. I've ordered a set of ER32 collets and chuck from APT. I'll get a few R8 collets also.

Thanks again guys

Martin

Best of both worlds!

If you get a 12mm R8 collet then you also have the option of buying an ER11 or ER16 straight-shank chuck later (both sizes are available with a 12mm shank you see) to give you *even better* visibility when doing jobs requiring small milling cutters, the "chuck-on-a-bar" jobbies are about 15-25 quid should you find you do need that in the future.

If you are going down that route why not just get an R8 ER16 rather then risk combined runout of R8 collet and ER holder as well as the thinner straight shanks not being as rigid as an R8

You can extend an ER11 straight shank somewhat lower than you can buy an R8 ER16 holder, giving the best visibility.

Other than visibility there's no reason to go down to a smaller ER as you can get collets down to 2mm for ER32, so you might as well maximise the visibility you're getting in a trade off.

Straight shank collet chucks are also cheaper and more easily available than R8 ones due to widespread use in CNC machines.

On the accuracy/repeatability point.

I've previously bought 2μm TIR ER11 straight shank holders to use with bearings shrink-fitted onto the shank to make a high speed spindle for an engraver, so in a small knee mill I would consider the impact of the holder minimal.

Admittedly you would need to buy a similarly good collet to really make the best of that and you could potentially see additive effects, but even if the collet was 12μm TIR then you'd still be under 0.0005" (half a thou) which would be pretty good still.

Edited By Jelly on 13/12/2022 16:50:25

I have a Cutwel 13mm/1/2" R8 integral keyless chuck which holds 0.01mm with any size I care to put in it. Just pure luck, the 0.05mm is good for a drill chuck and all the rest of our chucks at the museum come into this range.

It may just be because Cutwel's site has a dreadful search facility [besides being appalling to navigate generally], but apparently there is no Cutwel R8 drill chuck for sale any longer.

Hello Guys

Thanks for the further comments, I was a little confused following some of the later comments, but now I’ve decided to go along the route of a ER20 collets. I’ve spoken to APT and will change my order.

The reason behind this change is that I use milling cutters all from APT 4, 6 ,8, 10 & 12mm.

I like the idea of having a smaller size chuck for visibility, chip clearance and having easy access to allow coolant into and around the work piece. I had a look at the dimensions of the ER20 holder and I agree with the above it’ll allow good visibility and I like the slenderness of the chuck compared to the ER32.

I believe this will work well for my applications going forward.

APT have a great selection of the collets that I’ll need, and they also state the TIR, I’ll begin with these and see where I need to go from there onwards.

If I need a larger milling cutter, I’ll be looking at a fly cutter or an R8 face mill of sorts.

Thanks for all your help.

Martin