High speed spindle for milling

[thackman]

I have a CNC'd Super X3 and it just isn't fast enough for small cutters. Has anyone had any success milling with a high speed spindle? I've read a lot of posts about secondary spindles like the Proxxon rotary tool for engraving but I need to do a lot of deep slotting and pocketing in both wood and AL. It looks like my options are eiter a Proxxon rotary tool, a DeWalt laminate trimmer, or a specialty spindle like the ones made by Wolfgang Engineering.

The DeWalt laminate trimmer is the cheapest option, single speed (30k rpm) and should have plenty of power but only has a 1/4" collet and I'm concerned that the runout might be to much. The Proxxon is variable speed and has plenty of collets to chose from. I'm sure it's a great option for engraving but I'm not sure it has enough power for slotting and pocketing. Without a motor, the Wolfgang spindle still costs 50% more than the Proxxon and I have no idea what it's capabilities are.

For AL using a 1/16" carbide 2 flute cutter, ME Consultant recommends 32k rpm, cut depth .0625, cut width .0625, 32IPM for a chip load of .0002
I have no idea what feeds and speeds I'll be using for wood. But I'm looking for any combo that will give a clean cut.

Anybody have any first hand experience.

[acondit]

I am not saying this is the best way to go, but I have had pretty good luck with a rotozip 1/4" to 1/8" adapter in my router. It is called "Chuck Adapter" and is part number CH 01.
I think I paid about $8 or $9 at home depot.

Alan

[MichaelHenry]

There's also the Sherline headstock with 10k rpm pulley and motor, but I think that the set runs several hundred dollars and the speed may not be enough for you. How deep do your slots need to be?

Mike

[LeeWay]

I haven't installed it yet, but I bought a long die grinder from HF. I think it was $49. It should be very easy to mount to my mill. It has a long shaft, so mounting would be easy. If there is too much run out, bearings appear to be easy to replace with good quality ones. It's actually only $30 now. Only 25000 rpm, but a bunch cheaper than the other you mentioned.

As for laminate trimmers, I killed one of the Dewalts already using it by hand. I really like the little Ridgid model that I picked up. I think those rotozip collets fit these trimmers and the grinder.

http://www.harborfreight.com/cpi/cta...emnumber=44141

[thackman]

LeeWay,
At $30 that die grinder is worth a shot. Is is variable speed or fixed? I also considered a RotoZip but heard some people complain about the runnout.

MichaelHenry,
I'm looking for final depths of 1/8 - 1/4" with a 1/16" end mill. I expect I'll end up having to do it in multiple passes of 1/32" each because the endmills are so small.

[LeeWay]

It's not variable speed, but one of the cheap router speed controller works fine with it. It will get you in the speed ranges that you can't get on the X3.
My mill has an X2 spindle head, so I have the same problem.

The thing with cnc is multiple passes don't wear your arms out.

[tsalaf]

You need a spindle with much less runout than the typical wood router. Even good quality routers are going to have radial runout of .003" to .005". This amount of runout will likely cause a .0625" cutter to break as soon as it touches hard material, such as aluminum.

[grinderdust]

Is it possible to turn the workpiece or the spindle 90 degrees and use a keyseat cutter or a slitting saw? This would give you a larger dia cutter and many more teeth to do the work. I know this doesn't solve the spindle speed issue but I have tried to cut long 1/8 deep slots in aluminum with a 1/16 endmill and it is very time consuming. Also, if the tolerances are tight, tool breakage can wind up making alot of $crap.

[thackman]

The head on my mill can turn to 90 degrees but I need to mill curved slots which the keyway cutter would have some issues with. I also interpolate counter bores for small screws to avoid tool changes. One little endmill that takes twice is long is easier for me than dealing with one or two manual tool changes. I guess I'm just going to have to try a few different spindles.

Someone in the Syil forum recommeded this spindle:
http://www.macrotechnologies.com/spe...ir_spindle.htm
Don't know how much they run but it looks pricey.

[Trey54]

I have an X3 that is too slow also. How do you attach a Dremel or Rotozip to the Mill; and is it accurate without flex - they don't exactly fit into an R8 Collet do they?

Keep me updated Thackman as I'm having the exact same problem right now trying to mill Aluminum with my X3. I looked at the Syil Spindle upgrade to 3600 rpm, but this doesn't seem like much of an increase when looking at that High Speed Air Spindle at 30,000 rpm.

[Harryman]

I use a 25K NSK w/speed control, quiet and overall a nice spindle, but a lot more $$$ than you're looking at for a router. I generally run bits with .003" tips so it's got to be accurate.

[thackman]

I think I'm going to go with a Proxxon rotary tool. Their website is very informative and it looks like a very solid tool for the price. I'm not sure of the model yet. The IB/E is the most popular, it's self contained like a Dremel but they also offer a 50E which is smaller because it uses an external transformer. The 50 and 50E are listed as "Precision Milling/Drilling Machines" while the IB/E is listed as a "Professional Rotary Tool". Now I need to figure out which one has more power.

I've seen a lot of sites claim that these are suitable for continous duty unlike a Dremel. Of course they will never have the durability or runnout of a NSK spindle but these typically sell for around $100 so I can afford to take the risk.

Trey54,
KDNTool shows how the Proxxon can be mounted along side your primary spindle. From what I hear you can switch between the two by by using G54-G59 fixture offsets.
http://www.kdntool.com/_sgt/m2m1s15_1.htm


Hoss has some info on his site about mounting a laminate trimmer to a mini-mill.
http://www.hossmachine.com/images/en...03_360x480.jpg
http://www.hossmachine.com/projects.html