[project5k]

so, heres the thing, i have my x3 that i converted to cnc some time ago, and its a great machine, but as i get more experience, my parts get more complex, and i'm at that point where watching my machine working on one part for over 4 hours of continous cutting is getting boring...

so, what has everyone done to increase the 2000 rpm max on your x3 spindle?

I toyed with adding one of thoes $20 air micro die grinders to the side of mine, eh, ok, i should have mounted it better, but still, i lost some usable table area cause its off to the side...

I'm seriously considering something that mounts into the existing spindle and is then spun by an external motor, it just so happens that i have a 2.75Hp porter cable router motor, i was thinking with a couple pullies and a belt, perhaps i could some up with something...

i'm all ears, and i really do need a fix for this, so lets hear it,

if you have pictures of something that you've done, that would be really great too...

[Oldmanandhistoy]

Some thing like this?

http://www.cnczone.com/forums/showthread.php?t=65591

John

[project5k]

yep thats pretty much exactly what i was thinking..

my question is whats the internals look like, and what kinda bearings were used?

i've tried to draw up something like that, but everytime i get to it i run into issues mounting it, and figuring out how to preload the bearings and stuff like that...

i allways thought about using tapered bearings, but perhaps thats not the best idea, i was just thinking it would be the best way to control the runout...

the other question i have is how to make it, so that i can then mount an endmill in it, i can make a cylindar spin, but the collett is my biggest issue... if i could use something like an er spring collet system, that would be fine with me...

[ViperTX]

Well search around someone mentioned that the internals were in Practical Machinist or some magazine like that. I believe the criticism was that the shaft....and I'm assuming pinion was only supported by a bearing at one end and the other end was free.

Google it.....I should have made note if I read it here or on Google.

I had been thinking of ordering the kit, but wanted to know more.

Paul

[project5k]

i'll do some searching,

in some of my other looking around i came across a company that sells 4x speed increasers that will "chuck up" in my r8 taper, so, depending on the price, that would at least get me from 2000 rpm to 8000 rpm, and if i understand the math correctly, that would take me from cutting at 2ipm to 8ipm with a 2 flute HSS .250 endmill. its an improvement anyway...

I'm waiting to hear back from them on the price.

[S_J_H]

Those spindle speeders are pricey. Even used ones are and it's hard to find a R8 tapered speeder.
An easy quick and dirty way to get around 5500rpm or so is just swap the motor and driven pulleys. Very easy job, Only issue is the gears get pretty loud. I ran mine like that for a while. But it kills off your low speed power and I do plenty of steel and iron milling lately.

I made a super high speed spindle with a er11 spindle of near 50,000 rpm. But I find it sort of useless now. Oh well it was a project.
Next up is a belt drive and vfd for my x3. I'm going to put a 1hp 3ph motor and just make a 3 speed belt drive. I figure I'll shoot for around 7500rpm as well as good low speed range for plenty of grunt.
Steve

[project5k]

i'm guessing your right about the speeder thing, cause i've exchanged like 4 or 5 emails with this guy in IL, asking for the price, and he keeps stalling.. and this is a company thats supposed to specialize in spindle stuff....

I wonder about the bearings in the x3 spindle.... turning that fast has to have an effect on them.... swapping the pullies is a "right price" answer for me, so i may investigate it.. my rig is built exclusively for alum... i just dont have a need to cut anything else with it. i cant see needing gobs of torque for a 1/32" endmill.

I've had ideas about cooling the spindle, just not sure if its worth it..

just about everything i cut, i use wee tiny endmills on, nothing any bigger than .250 unless i'm facing the part off before i start... most everything i do is .125, .0625 or .030 endmills. and when thier that small, and micrograin carbide, one oops, and "PLINK" you just spent 8-15 bucks.

[neilw20]

In the space available maybe a variator drive can be adapted:idea:
[ame="http://www.youtube.com/watch?v=2XDqgGFfCso"]YouTube - tmax how variator works[/ame]
http://images.google.com.au/images?q...e=UTF-8&sa=X&o

I have a non motorbike version I might try.
It requires a fork to move the pulley to change the speed, but a small servo motor would work that OK.

I have a big mill with BIG variator drive and 2 speed gearbox, and it runs from 50 RPM - 6000RPM at 3HP. (Very old P&W CNC Drill Mill)

I used a window winder motor to control pulley width fork.
Original machine had a wind the handle speed control.

[project5k]

the variable speed drive is neat and all, but i really dont see the need on a milling machine.

[neilw20]

Sometimes I want 50 RPM with tapping etc, or a 2" MILL, other times I need 10,000 RPM for 0.5mm drills, maybe even on the same job. 3600RPM is too slow. The machine might have all day, but I don't.

[project5k]

i can certanly understand not having all day, i'm having the same issues... thats why i started this thread...

my biggest fear right now about speeding up the existing spindle is the bearings.. i just don't know if they will live for long at greatly increased speeds...

[escott76]

the variable speed drive is neat and all, but i really dont see the need on a milling machine.

Yeah, those guys at Bridgeport and every other milling machine since that used it had no idea what they were doing.
Seriously, it makes a lot of sense when you are running machines on 3 phase and you don't want the added complexity or expense of a VFD. When many of these machines were made it was not even an option anyway.
Electric motors (like most other kinds of motors) have specific torque/speed relationships. In order to get the most power out of a motor at all different RPMs you need to have a series of different gears -OR- relatively complex electronics, although these can only go so far. Variable ratio pulley sets are a great way to get this done. VERY fast speed change, no belts to move from pulley to pulley and no gears to strip and break.
It's not the end all be all of variable spindle speed, but it's an accepted time proven method of doing things.

[dneisler]

I did the pulley trick to my X3 and get 6000rpm approx. I have ran it many hours with no issues. I cut 6061 all the time at 24IPM using a 3/8" 2 FL EM.


Loud, due to the gears, but works great so far.

[project5k]

thats encouraging.. what depth of cut are you running when your cutting that fast?

what kind of endmill HSS? Carbide? Coated?

[dneisler]

Well I have been playing with that, making the rpm that high you loss torque for sure. Last night I was doing some 6061 at 24IPM, .075" DOC with a 3/8" 2FL EM with slight slowing when it was cutting a profile at full width. With side cuts and not full width it did very well.

[Crevice Reamer]

Well I have been playing with that, making the rpm that high you loss torque for sure. Last night I was doing some 6061 at 24IPM, .075" DOC with a 3/8" 2FL EM with slight slowing when it was cutting a profile at full width. With side cuts and not full width it did very well.

At what speed was the spindle running when it slowed?

CR.

[dneisler]

At what speed was the spindle running when it slowed?

CR.

6000RPM, but only when it was cutting full width.

[Crevice Reamer]

Thanks! Have you cut any steel at lower RPMS? Does it still have enough torque for steel?

CR.

[dneisler]

I have not, but it is like a 30 second change to go back to factory gearing if I need it.

[Crevice Reamer]

Great! So what exactly did you do to get that 6K? Got any pics you can post?

CR.