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...

Some thing like this?

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

John

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...

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

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.

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

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.

In the space available maybe a variator drive can be adapted:idea:
YouTube - tmax how variator works
http://images.google.com.au/images?q=variator&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=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.

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

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.

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...

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.

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.

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

what kind of endmill HSS? Carbide? Coated?

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.

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.

At what speed was the spindle running when it slowed?

CR.

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

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

CR.

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

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

CR.

Here is my site, with part #'s.
http://www.donald-neisler.com/index.php/2008/07/quick-sieg-x3-belt-rpm-6000-rpm-upgrade/

thats not a bad idea.... if it didnt require me figuring out how to get the keyway cut, i'd be all over it.

On my custom x2 spindle assembly, I simply drilled and tapped the pulley for a set screw - the set screw then engages the keyway on the shaft. No broaching necessary(not an option for me, given the pulley bore for my specific application). :)

now thats an interesting idea.. and something well within my abilities...

something else i saw, that i was currious about, and i dont remember the link off the top of my head, it might be one of the ones above, but i saw one, where someone in the houstin area took one of the little air powered mini die grinders and made up a special drawbar, and was able to mount the thing in the big spindle.. i'm wondering about doing somethng like that... It woul be better than the way i have it mounted now, definately stronger and with less flex.. and would also put it in the "middle" of the table rather than off to one side...

one other thought that i had was to find a r8 taper blank, one of thoes make your own collet kinda deals, and make a bearing support, and a custom drawbar and power it through the original spindle, then mount a collet rig under that.. then i could spin that pretty fast, and use whatever motor i wanted to.. and end up with basically the same thing...

thats not a bad idea.... if it didnt require me figuring out how to get the keyway cut, i'd be all over it.

Cutting a keyway should not intimidate you - You can make a keyway broach in about 10 minutes using a length of steel round stock, and a small HSS lathe toolbit. Cross-drill the rod so the toolbit slips in the hole, then end-drill for a setscrew to hold the tool in place. Put the in the quill of your mill, and you can cut a nice keyway in a few minutes by just working the quill up and down as you move the toolbit into the work a few thou at a time. I've done it dozens of times, and it works great.

Regards,
Ray L.

Almost as simple as putting a parting off tool on it's edge.
Put the pulley in the chuck, orient it,and DON'T TURN ON!:nono::eek:
Just move the carriage left and right and feed it in a bit at a time, like an old shaping machine.

ok, i think i understand that.. so basically i'll be working the quill up and down lots and lots of time, each time cutting just a little bit.. never thought of that..

i can see that working on larger stuff, but what if i need to do one in somethng thats smaller than the lathe bit will fit into?

the other thing that i would wonder about is if i could write some code so that the mill would do this automatically, rather than me standing there working the quill by hand.

ok, i think i understand that.. so basically i'll be working the quill up and down lots and lots of time, each time cutting just a little bit.. never thought of that..

i can see that working on larger stuff, but what if i need to do one in somethng thats smaller than the lathe bit will fit into?

the other thing that i would wonder about is if i could write some code so that the mill would do this automatically, rather than me standing there working the quill by hand.

In 6061, I can usually take about 0.003" per pass, so it goes quickly. Won't work for very small holes, but I've used it down to about 0.1" keyways in 3/8" holes. To go smaller, you'd probably have to use a shaft that just fits the hole, and move the tool out further for each pass, to avoid the shaft bending as you try to cut. It would obviously take longer, but still work just fine. No reason you could't write some simple G code to do the moves for you.

Regards,
Ray L.

Z Axis Broaching

leave it to hoss to have a video of what i'm thinking about trying!

see, now that i can do!

and then when it comes to making the keyway in a shaft, i can just mill it in, and i'm done...

so i'm still tryingto figure out what it is that i'm gonna do... and i found this.... i'm really not too sure how to read these specs, specifically where it sais horsepower 1 / .12 or something like that... can someone translate for me? do you think that this would work?

http://www.surpluscenter.com/item.asp?UID=2009022013541698&item=10-2200-B&catname=electric

or maybe something like this??
http://www.surpluscenter.com/item.asp?UID=2009022013541698&item=10-1785&catname=electric

so i'm still tryingto figure out what it is that i'm gonna do... and i found this.... i'm really not too sure how to read these specs, specifically where it sais horsepower 1 / .12 or something like that... can someone translate for me? do you think that this would work?

http://www.surpluscenter.com/item.asp?UID=2009022013541698&item=10-2200-B&catname=electric

Depends on your intentions for its use. This is an AC motor that can be wired at 2 different speeds 1 hp 3450 rpm and .12 hp at 1725 rpm.

Rick

ohhhh is that what that means... ok, well i'd definately use it on the faster stronger setting....

heres another one i think i like.. i have 220 handy, so this might be the way to go.....

http://www.surpluscenter.com/item.asp?UID=2009022013541698&item=10-2197-K&catname=electric

oh no wait... i think i just found it.... run this thing at a pretty high rpm, and gear it down some... hehehe

on ebay:
120V AC/DC HIGH SPEED ELECTRIC MOTOR 1.5 HP TOOL Item number: 230324097111

ohhhh is that what that means... ok, well i'd definately use it on the faster stronger setting....

heres another one i think i like.. i have 220 handy, so this might be the way to go.....

http://www.surpluscenter.com/item.asp?UID=2009022013541698&item=10-2197-K&catname=electric

A 2HP spindle in an X3 would be a little ridiculous. You don't have anywhere near the rigidity required to be able to use that kind of power. I'd guess the stock motor has all the power the rest of the machine can really make use of. It's RPM that's the problem, not power. Also keep in mind on those two-speed motors, you'd need to sequence the power - they MUST be started in low-speed, then switched to high-speed once they're running.

What is the actual motor RPM of the stock X3 motor? On the X2, the motor is 6K RPM, so swapping for another 6K RPM motor accomplishes nothing.

Regards,
Ray L.

i really dont know what the stock rpm is, if i'm luckey, on sunday i can go out and measure it...

i'm thinking that the last one is the best.. easy to control, and high rpm... i just dont know about thoes bearings in the head.. but i would think that with something like that, one could bypass the gearbox and get after it.

the other thing to think about is that i'm really not needing masive rigidity.. i need rpm, 90% of what i do is with 1/8 endmills and smaller, and taking fairly light cuts, in the neighborhood of .01 to .05DOC

i really dont know what the stock rpm is, if i'm luckey, on sunday i can go out and measure it...

i'm thinking that the last one is the best.. easy to control, and high rpm... i just dont know about thoes bearings in the head.. but i would think that with something like that, one could bypass the gearbox and get after it.

the other thing to think about is that i'm really not needing masive rigidity.. i need rpm, 90% of what i do is with 1/8 endmills and smaller, and taking fairly light cuts, in the neighborhood of .01 to .05DOC

But why are you trying to change the motor? You need increased RPM for small cutters. Small cutters don't require a lot of power. So, just change the belt on the existing motor to increase the spindle RPM. Maybe put a two-speed belt on, if necessary.

Regards,
Ray L.

yea, but then i'm still driving the old gearset, and thats just one of the parts i'm worring about.. i could put a couple different pullies on it, or if they will fit, even swap the pullies that are already on there and just see what happens..

so.. whats the plan if the bearings cant handle the speed? or if i figure out that stuff isnt balanced, and i cant get it any more balanced? I have a magnetic balancer, and i have converging wheel balancers, but they can only handle so much weight, and they are only so sensitive...

Project5k,

Take a look at the Proxxon, it is really nice and very affordable.

You can pick one up for about $110.00, and make a simple mount like the one in the attached PDF.

For small 1/8 end mills you cant beat it.

Jeff...

now thats nice.. only problem is i would loose usable work area by being off center to the table.. but i guess i could allways make an add on plate.. hmm well if i'm gonna do that, then why wouldnt i just use the 30k rpm router motor that i already have???

Project5k

Can you find a 1/8 inch collet for your router?

Jeff...

A 2HP spindle in an X3 would be a little ridiculous. You don't have anywhere near the rigidity required to be able to use that kind of power. I'd guess the stock motor has all the power the rest of the machine can really make use of. It's RPM that's the problem, not power. Also keep in mind on those two-speed motors, you'd need to sequence the power - they MUST be started in low-speed, then switched to high-speed once they're running.

What is the actual motor RPM of the stock X3 motor? On the X2, the motor is 6K RPM, so swapping for another 6K RPM motor accomplishes nothing.

Regards,
Ray L.

The stock x3 motor is a 4k rpm, 110v motor. Labeled 600 watts. The mill could use more power and definately more rpms. It takes a fair amount of power to get the spindle moving on the x2 head with any torque left over (I use a 2HP motor on mine, actually, though it is not an x2 mill and I have PLENTY of power with the setup) - I imagine the x3 spindle needs even more than an x2 spindle. I don't think either of the linked motors is ideal for the job. Leeway found a 180v tradmill motor on EBay that he is happy with on his x2 based mill. This is similar to mine (though mine is a 90v motor). I think in order to make the stock x3 spindle spin at a decent speed with any authority, you will need a reasonably torquey motor (not just HP, but torque). I wouldn't even consider a motor with a smaller length or diameter than the stock motor when trying to make the thing go faster and retain some power(larger diameter will generally make more torque).

well.hmmm i hvent looked for an 1/8th collet, but your right, that would be important for thoes small mills i'm using.. i'll have to look around and see what i can find, i have the 1/2 and a 1/4...

i'll probably get a chance today to go and investigate the pullys that are on it stock, and just see what i learn from that...

well after getting the top covers off, i gotta say, man whats the point of that one cover being soooo heavy?

anyway.. so i got to looking at it, just standing there and stairing at it for a little while, and i got currious. so i pulled the pullies off, swapped them, and tried it.. 2500 rpm max on low gear, and 5100 rpm max on high gear.

the gears are screaming loud, but its sure book'n now...

i havent tried to cut anything like this yet, but i'm sure currious to try it just to see what happens...

Did you have to do anything to make them fit?

Rick

no not really, the motor shaft had a couple burs along the keyway, so i turned on the motor and ran a little sandpaper on it, turned it off, and drug a flat blade screwdriver up and down the slot just to clean it out, but the shaft diameters were the same.. just have to re-arrange some of the washers and things to get the gears at the same height.. thats it..

video to come in a few min

ok, heres the video..


YouTube - x3 motor pully swap demo

ok, heres the video..


Great video! I always like to see videos over still pictures - wonders of the Internet. :) Sure would like a video of the testing too - how much you can increase the feedrate. The smallest popular size I use is 3/16 and it is VERY popular in my projects and I would surely like to work with it faster and deeper.

Keep a close watch on the motor and spindle heat when you test. The main issue with just swapping pulleys is that it still has to drive the gearbox which I would imagine takes quite a bit of power from the spindle and might make the motor a bit hot.

Rick

yea, i'm plann'n on keeping up with the temps to see what they come out like.. and i will make sure to have the video camera with me as well... i might even get inventive and set up both vid cameras, and then shoot a few ultra high rez stills... i dunno.. as for right now i gotta figure out what i wanna try and cut to test it with.. ofcourse i still havent figured out my feed rates, but considering that i more than doubled the spindle speed, i would think that i could double the feed rates...

if someone will, check my math, but i'm conning up with 2 flute 1/8th inch endmill at 5000 rpm is 7.5 ipm feed rate.. does that sound about right?

yea, i'm plann'n on keeping up with the temps to see what they come out like.. and i will make sure to have the video camera with me as well... i might even get inventive and set up both vid cameras, and then shoot a few ultra high rez stills... i dunno.. as for right now i gotta figure out what i wanna try and cut to test it with.. ofcourse i still havent figured out my feed rates, but considering that i more than doubled the spindle speed, i would think that i could double the feed rates...

if someone will, check my math, but i'm conning up with 2 flute 1/8th inch endmill at 5000 rpm is 7.5 ipm feed rate.. does that sound about right?

7.5 IPM is probably a little on the fast side. 6 IPM is more like it, assuming you're slotting up to 0.125" DOC. With an endmill that small, if you push too hard, first thing that'll go wrong is it'll snap off.

Regards,
Ray L.

Depends on your chip load. With .001" chip load, you'd be right at 10ipm. Like Ray said, I'm not saying it won't snap, but that's what the math works out to.

so, heres what i ended up with...

You can see the difference in the finish of the 3 speeds i ran...
1/16th HSS endmill, .100 DOC 2 IPM is rough and wavy
1/16th HSS endmill, .100 DOC 3.5 IPM is better, but still a little wavy
1/16th HSS endmill, .100 DOC 5 IPM is just pretty darn good

Spindle speed was 5050 during cutting.....

http://www.jpcustomcrafts.com/cnc%20machining/shows%20surface%20finish%20small.jpg

I also shot a little video, but i dont have time before i go to work to edit it and post it.. so maybe i'll remember to do it when i get home tonight...

a few other details...
the head of the mill got up to around 120F and the motor was around the same.. the cutting time for all 6 slots was around 20 min.

Thanks for the great experiment!

Is it me, or does the 5ipm look better?

5050rpm with 1/16" end mill = 82.6 sfpm

5050rpm with 2 flute endmill & 2ipm = .0002 chip load (really tiny!)

5050rpm with 2 flute endmill & 3.5ipm = .00035 chip load

5050rpm with 2 flute endmill & 5ipm = .0005 chip load


Now here's my newbie question:
Isn't .001 (note the TWO zeroes...not three) more typical for finishing passes? If so, it makes sense that getting CLOSER to this (his 5ipm pass vs. 2ipm pass) would give a better surface finish?

ETA: Although it makes sense that if you are running a surface cut speed of only 80fpm (instead of 350+), that you would have to reduce your chip load as well.

Thanks!

-Caleb105-

well, i'll be honest, i dont know the math that well for this, but looking at it, the 5 IPM is the best... so thats what i'll be using for that endmill from now on.. I'm planning on making myself a little chart so when i'm programming parts in the future, i know what settings work on my machine...

Project,

Thanks again for taking the time to do this!

Did you happen to try any higher feed rates (above 5ipm)?

-Caleb105-

your quite welcome, the fastest i went was 5 ipm .100 doc.. just looking at the math that i know how to do, i figured that 5 was about the top end of what i felt comfortable with, and i didnt wanna push too hard and break another cutter...

I'm planning to run the same tests again with other cutters so that i can fill in my chart.. i'll be sure to post my results so that if anyone else is interested, it might give them a starting point.

I'm really excited about my results..

I am seriously considering bypassing the gearbox totally and seeing how that does for me.. i think it would reduce the spindle and motor temps some, and give more torque to the cutter and make it a bunch quieter, cause as it is now, it screams(gear whine) and if i were working on a car motor with a blower i would think it was music, but for this, not so much...

oh, i guess i should also include that it was a niagra cutter, double ended, but i'll have to get the actual # tonight when i get home... i'd like my chart to have order #'s so that in the future i can make sure to order the same thing so that my chart remains accurate.

Thanks for the great experiment!

Is it me, or does the 5ipm look better?

5050rpm with 1/16" end mill = 82.6 sfpm

5050rpm with 2 flute endmill & 2ipm = .0002 chip load (really tiny!)

5050rpm with 2 flute endmill & 3.5ipm = .00035 chip load

5050rpm with 2 flute endmill & 5ipm = .0005 chip load


Now here's my newbie question:
Isn't .001 (note the TWO zeroes...not three) more typical for finishing passes? If so, it makes sense that getting CLOSER to this (his 5ipm pass vs. 2ipm pass) would give a better surface finish?

ETA: Although it makes sense that if you are running a surface cut speed of only 80fpm (instead of 350+), that you would have to reduce your chip load as well.

Thanks!

-Caleb105-

Faster works better because of the higher chipload. Heat is carried away from the tool by the chips. With a low chipload, there is less heat transfer, and the tool heats up more, which leads to "gumming" and poor surface finish. Too high a chipload will lead to, in order: poor surface finish due to flexing and gumming, followed closely by damaged cutting edges, due to chipping, followed closely by a broken tool. Chipload should NOT be scaled with SFPM, only RPM should. Feedrate will then scale with RPM, but it is important to maintain chipload, or the tool will heat-up. Chipload SHOULD be scaled by tool diameter - a large tool can handle a much larger chipload than a small one. A reasonable rule of thumb for chipload for HSS tools is 0.006" per inch of tool diameter. So, 0.006" for a 1" tool, 0.003" for a 1/2" tool, 0.0015" for a 1/4" tool, etc. For very small tools, 1/16" and below), even this sometimes proves too aggressive, and will exceed some manufacturers recommendations.

With small tools, it is particularly important to keep the tool clear of chips, as re-cutting chips is VERY hard on the tool. A strong blast of air directly on the point of cut will usually do the trick.

Regards,
Ray L.

thats good to know, i'll figure that into my math and see what i end up with..

I'm actually running full flood coolant, so that should help control the tool heating to a degree and help carry off the chips as well.

wouldnt it also be safe to say with too low of a chip load that the cutter is rubbing more and cutting less, so theres more heat, and less actual usefull work getting done?

thats good to know, i'll figure that into my math and see what i end up with..

I'm actually running full flood coolant, so that should help control the tool heating to a degree and help carry off the chips as well.

wouldnt it also be safe to say with too low of a chip load that the cutter is rubbing more and cutting less, so theres more heat, and less actual usefull work getting done?

"wouldnt it also be safe to say with too low of a chip load that the cutter is rubbing more and cutting less, so theres more heat, and less actual usefull work getting done?" - Correct.

ok, cool, thats kinda what i figured.. so then that takes away from tool life, quality of part output, and increases my time and my costs per part... so getting my cutting speeds right really will effect my bottom line. good to know.. i figured it would, but i didnt think that it would as much as it does.

so running my speed tests, and getting my chart together just got a bunch more important.

one other thing that i found yesterday, i was on the niagra cutter website, and they have a free thing that you can download to a palm based device(in my case my cell phone) and it will help you calculate feed rates, and rpm's and stuff like that.. pretty cool little free thing....

this i like :) hadn't checked this thread in a couple days and i like what i see. a lot :)

I would be curious to see how running it above say 3.5k/4k rpm is for the stock components but hell even that would be 2x stock :)

sorry everyone, i wasnt able to do my next set of testing last night, something came up.. but i've got a 1/8th test drawn up and ready to go.. I'll get that done and post the results in the next couple days.

Ok, so i got off the couch and ran the 1/8th inch endmill cut test.. and the results are a little puzzeling...

Its a altin coated 1/8th inch endmill, turning at 5000+ RPM cutting at 3, 5, 6, 7 IPM.

My math sais 7.5 IPM and not wanting to break my cutter, i didnt push it too hard, i dont think, but at 7IPM i could definately hear it cutting, but i couldnt hear any motor slowing, so i'm still not worried about not having enough torque.

anyway, heres the full length video.. oh, and Hoss, I'm just having some fun calling you out in this, no malice intended...

http://www.youtube.com/watch?v=uhoza1JlNX4
http://www.youtube.com/watch?v=uhoza1JlNX4
http://www.cnczone.com/forums/<object width=

and heres the still.....

http://www.jpcustomcrafts.com/cnc%20machining/Img_0512_with_text.jpg

Now what i dont understand is why it is that they all look the same to me... Am i still going too slow?

What plunge speed should i be using? I'm currently plunging into the part at 1.5 IPM with this 1/8th endmill....

oh, and i learned by running the circle test, that apparently i do have some backlash.. so i'll be working on that soon as well...

It wont let me insert the video clip, i dont know why...

Ok, so i got off the couch and ran the 1/8th inch endmill cut test.. and the results are a little puzzeling...

Its a altin coated 1/8th inch endmill, turning at 5000+ RPM cutting at 3, 5, 6, 7 IPM.

My math sais 7.5 IPM and not wanting to break my cutter, i didnt push it too hard, i dont think, but at 7IPM i could definately hear it cutting, but i couldnt hear any motor slowing, so i'm still not worried about not having enough torque.

anyway, heres the full length video.. oh, and Hoss, I'm just having some fun calling you out in this, no malice intended...

http://www.youtube.com/watch?v=uhoza1JlNX4
http://www.youtube.com/watch?v=uhoza1JlNX4
http://www.cnczone.com/forums/<object width=

and heres the still.....

http://www.jpcustomcrafts.com/cnc%20machining/Img_0512_with_text.jpg

Now what i dont understand is why it is that they all look the same to me... Am i still going too slow?

What plunge speed should i be using? I'm currently plunging into the part at 1.5 IPM with this 1/8th endmill....

oh, and i learned by running the circle test, that apparently i do have some backlash.. so i'll be working on that soon as well...

It wont let me insert the video clip, i dont know why...

Joe,

Not too surprising. Cutting too slow will often not have any visible adverse affect. It will reduce too life. When you start going too fast, surface finish will suffer, followed, sometimes very shortly, by the tool breaking. Best thing to do is push it until something goes obviously wrong, then back off 20% or so next time. I spent several days doing this to learn the limits of my machine, and broke several tools in the process, but it was well worth it.

Plunge speed should generally be roughly 1/2 the cut speed. So, for 1/8" tools running 8200 RPM, I normally run 10-12 IPM feed, 5-6 IPM plunge.

Regards,
Ray L.

Call me out will ya.:boxing::)
I added it to my favorites, now i'm famous.:D
you didn't mention exactly what type of 1/8" endmill you were using.
For aluminum, you want to use a high helix 2 flute endmill.
"A high helix angle, generally around 45 degrees is desirable. The helix helps move chips up and out of the cutting zone and also generates an excellent surface finish. The angle also helps soften the impact at the entrance of the cut, resulting in a smoother, quieter cut."
Hoss

i read the entire endmill label on the video.. i even mentioned where i bought it...

ok, so ounds like tomarrow, being payday, i need to order a couple more endmills, cause this is my last 1/8th, and i'll run the test again cutting faster...

so now whats the rule, altin coated solid carbide i can cut faster than HSS, but how much? just to give me an idea of where to start and stop the new test....

Hoss, yep, i called you out, mentioned you by name, and you know why? cause i'm jealous as hell.

not proud of it, but its the truth. :)

has anyone seen this?

http://bbs.homeshopmachinist.net/showthread.php?t=20585

i believe that someone pointed me towards thoes pictures at some time in the recent past...

I've actually thought about doing mine the same way so that i could bypass all the internal gears in the head, thus reducing the noise, and the drag on the motor that i really dont use..

oh and sorry everyone, i havent had time to do more cutting speed tests, its been a crazy couple weeks... I'll get back to it soon....

Based on your photos I'm assuming that you making one slotting pass and then looking the results. I consider slotting a roughing operation and would consider metal removal rate over the appearance. If you want a better surface finish make the slot w/ a smaller end mill and then follow up with a finish pass to take off another few thou. Overall I’d consider your results very good for a one pass slot.

Most manufacturers recommend against using AlTin or TiAln coated tools on aluminum because those coatings work best above the melting point of Al and the Al content can cause galling. I have seen some end mills for Aluminum with AlTin and TiAln coatings so maybe the jury is still out on it but the big manufacturers recommend polished uncoated, TiN, TiCN, or ZrN. At 83sfm is doubtful that the coating is doing much and uncoated aluminum specific end mills are often sharper. http://www.moldmakingtechnology.com/articles/030401.html

I've been running 1/16" 2fl carbide end mills at 5000rpm in my Tormach and I'm considering adding a 30k secondary spindle. I'm sure it will be an improvement but I'm guessing that acceleration is going to be the real limiting factor. When I'm working w/ small cutters usually the part is small and full of details. I already have a few tiny pockets where the machine spending most of it's time at 3ipm on a 6ipm cut.