X3 questions (again!)

[binfordw]

I think Ive got my cnc'd X3 working well now, one of the next things Im interested in was the spindle speed. Ive read that there is an upgrade that allows a much higher RPM, not sure what that is though.

1. What components do I need to buy to allow Mach3 to control the spindle?

2. What needs to be done to allow higher spindle RPM's?


Thanks for any help!

[jalessi]

A C6 board from CNC4PC will work with your X3 to control spindle speed from Mach3.

http://www.cnc4pc.com/Store/osc/prod...products_id=58

http://cnc4pc.com/Tech_Docs/Sieg_X3.pdf


A belt drive conversion and a pulley change will increase the rpm.

http://www.donald-neisler.com/index....0-rpm-upgrade/

Jeff...

[Teyber12]

i did a quick write up on how i, for free, doubled the rpm's of my x3. its towards the end of my cnc build thread... do a search by "teyber" not teyber12.

cheers

[binfordw]

Im still having troubles with bad chatter. I bought a pile of endmills from Maritool.com, and tried to cut some steel this evening. I was using a 1/2", 4 flute carbide TIALN coated mill. I noticed troubles while slowly plunging .050" into the stock (roughly 2-3 ipm), bit wobbling and such just like before with cheap endmills. I started interpolating a circle at 4-6 ipm feed, and noticed chatter when it was mostly moving in the Y.

I then tried just cutting on a straight line on the X axis, and had lots of vibes and chatter unless I ran at very very slow 2-3 ipm feeds.

What is wrong with my mill? I have a feeling its the Z axis gib, but the only adjustment is that screw at the top that I saw. Its tight enough it stalls the Z now if I try to rapid 100+ipm.

What else do I need to check?

[Teyber12]

try doing a 3 degree zig zag ramp into the material.

its a PITA but slide your mill out so you can stick your hand up under the base and feel the 2 screws that hold the y ballnut block in. Are they loose? mine work themselves loose and destroyed my first 5 parts or so. i felt like crying after months of getting my x3 up my parts looked awful. realized it was the loose y ballnutblock.

slow the z rapid to about 80 ipm. thats plenty fast.

cheers

[binfordw]

I had cut a couple test pieces programmed to ramp instead of plunge a few days ago and it worked well. I thought the new endmills I bought would handle plunging- the were listed as "center cutting" which I thought was what that meant.


I'll check the Y ballscrew mount, I havent checked that since I assembled the mill so its very likely its loose. Something has to be loose somewhere.

[Teyber12]

taken from www.mini-lathe.com
What is the difference between 4 flute and 2 flute end mills? Is one better for Aluminum?

A 2 flute cutter (or slot mill) is designed for "plunge" milling, ie you can plunge the mill directly into the work. If you look at the business end of the cutter, you will see that the two blades are of unequal length, one of the blades goes right across the middle. This allows the cutter to mill directly under it. It can be used to cut vertically or horizontally, but the horizontal cut is not likely to be as good as the 4 flute cutter. The 4 flute cutter (or end mill)is not designed to be "plunged". Again, look at the cutters and you will find that they are all the same length, but there is a hole in the middle where nothing can be milled. This type of cutter can only be used to mill in a horizontal direction. Graham

Um... That's (sort of) the difference between center cutting and non-center cutting, but not really between 2 and 4 flute end mills. Some 4 flute end mills are center cutting (usually two flutes meet in the middle and two don't). And, though I've never seen one, there's no reason a 2 flute end mill couldn't be non-center cutting. (Never saw a end mill with one "blade" longer than the other either... Not sure what that's about.) The real difference has more to do with feeds, finish and such. Bascially a cutters RPM is based on its composition and what you're cutting with it. So how much is taken off per flute is, more or less, a "fixed" rate. How fast you can take off how much material is a function of how many flutes you have. The fewer flutes, the slower the feed must be. The more flutes, the faster the feeds can be. Also... I read a bit a while back that explained how 2 flute end mills were better for slotting and 4 flute end mills were better for finishing. The former had to do with the fact that the 2 flute cutter bites into both walls at the same time and, when cutting to the front, cannot cut the sides. Conversely a 4 flute end mill will cut both the front and sides at the same time and the front cut will cause the cutter to flex, varying the depth of the side cuts making the finish rougher. Don't claim to understand why a 4 flute cutter would give a beter finish unless it's simply because it's stiffer...? As for aluminum... Though "regular" end mills will work with aluminum, there are end mills specialy made for aluminum. "High helix", I think they're called. They claim to produce a better finish. Haven't messed with them much myself. But I'm heading that way for some finishing work. I've only ever seen 2 flute versions of them. I'd love to find some 4 flute versions so I could increase my feeds...

[binfordw]

I purchased 3 or 4 of the 4 flute's and 3 of the 3 Flute, High Helix aluminum endmills, as well as a 1/2" 3 flute rougher. I havent had a chance to try them yet, but judging from the issues Ive been having with chatter, I dont think its a tooling problem as much as something must be loose or needing adjustment.

The 4 flute I was using should have been perfect for mild steel, but it cut like crap. I hope its just some loose screws.

[Teyber12]

only 1 way to find out if something is loose

[binfordw]

A C6 board from CNC4PC will work with your X3 to control spindle speed from Mach3.

http://www.cnc4pc.com/Store/osc/prod...products_id=58

http://cnc4pc.com/Tech_Docs/Sieg_X3.pdf


A belt drive conversion and a pulley change will increase the rpm.

http://www.donald-neisler.com/index....0-rpm-upgrade/

Jeff...

I can't find the info on your site now, Could u post the site and part numbers of the gears again please?

[jalessi]

The upgrade was originally done by Donald Neisler.

http://www.donald-neisler.com/?m=200807

This was copied from his Blog:

Here is a nice quick little upgrade that will let you select several RPM ranges (0-1000, 0-2000, 0-3000, and 0-6000) in less than 30 seconds. These numbers are educated guesses as I have not gotten my Tachometer working yet. When I get more firm numbers I will post them. To do this upgrade you need to order 3 parts from SDP-SI.

* 1 – Timing Belt Pulley, GT2 (5mm) Pitch, 32 Grooves, 12mm Bore, 2 Flanges / With hub for 15mm Wide Belt. Material – Aluminum alloy, Finish- Clear anodize. (Part#: A 6A55M032DF1512)
* 1 – Timing Belt Pulley, GT2 (5mm) Pitch, 19 Grooves, 6mm Bore, 2 Flanges / With hub for 15mm Wide Belt. Material – Aluminum alloy, Finish- Clear anodize. (Part#: A 6A55M019DF1506)
* 1 – GT2 (5mm) Pitch, 82 Teeth, 15 mm (.591) Wide Neoprene Belt (Part#: A 6R55M082150)

Once you have those parts you will have to machine the 19 tooth so that it has a 12mm bore. It comes with I believe a 6mm bore. Then have someone broach a 4mm keyway in each. Once this is done, you can actually use the gears if you need to though I recommend a few more steps myself.

<Insert pics here….>

In this configuration you will get about 0-1000 RPM in L, and 0-2000 RPM in H. If you swap the 19 and 32 pulleys then you get 0-3000 RPM in L, and 0-6000 RPM in high. Again, these are educated guesses for RPM. I have machined some 6061 aluminum with a 1/8� 2 Flute end mill @ 10IPM and .0625 DOC and the swraf was being welded back to the stock, so I need to up the feed to run at 6000 RPM. I tried a ¼� 2 Flute end mill at 6000 RPM and 24 IPM and it made some very nice cuts with ease. I think I could have gone faster easily; I just have not had a chance to do much testing yet. I ran my mill for 30 minutes at the 6000 RPM setting and I took the temperature of the motor and the spindle head case. The motor temp was around 120 degrees F. The spindle head case was around 108 degrees F. To me those temps seem fine. I could be wrong and welcome any feedback.

But wait, it is not complete. To really make this better, you will need to machine a spacer to go under the pulley on the spindle side. This is where I am at and to date had not done it.

Hope this helps,

Jeff...