need some guidance, X1 CNC-related...

[WRMorrison]

I'm starting to get frustrated, and I'm not sure where to start looking for answers. I figured that instead of spending (literally) days reading and researching (when "spare" time is rarely found when working 40+ hrs/week and trying to raise a son), I would see if someone here could clear a few issues up for me

I've got a HF X1 clone. Progress so far:

-ordered and installed X/Y extend kits from LMS
-ordered and installed motor mount kit from CNCFusion
-ordered and installed 4 axis dynamo kit from stepperworld (4th axis is going to be saved until later)

I've got everything set up and gave X, Y and Z motors their trial run with the included test program...so far, so good (except they're spinning CCW despite the CW button is checked on the program?).

I'm using the stock leadscrews for the time being (I already have what I need to convert to a larger, precision acme screw later, but I want to make sure everything works first, I can always upgrade all that later).

I have downloaded the demo of Mach3 to use (but will buy the license later when I can see that it will do what I need), but I'm have a few questions.

I suppose that my main questions relate to what else do I need to do before I start making chips? Do I absolutely need limit/home switches before I machine anything? Can't I just work off an origin point on the work, or do I really need a machine zero?

Another thing, some of the parts that I want to machine are basically just flat plates with some holes drilled in them. Since the Z axis moves so slow, can I just install an optional stop between X,Y coordinates and manually work the quill?

Any advice will be greatly appreciated. Right now, it doesn't "click." For the time being, I'll go back to trying to digest the 170+ pg. Mach3 tutorial....sure would be a lot easier to read/understand with a degree in electrical engineering....

-WRM

[zwdeal]

I made a few parts using my own converted X1, I work off an reference point instead of absolute home origin. It is much easier.

Very important note, the Z axis stock screw is 1.5mm pitch, it is NOT the same 20 TPI on X and Y. So when you set up your Mach3, be aware of this fact, else you are likely to plunge your tools into your work piece. I learned the lesson.

[WRMorrison]

Thanks for the heads-up on the screw pitch! I suppose that my main problem at the moment, is that I can't figure out how to set the inputs/outputs for the motors in Mach3.

-WRM

[zwdeal]

Originally Posted by WRMorrison Thanks for the heads-up on the screw pitch! I suppose that my main problem at the moment, is that I can't figure out how to set the inputs/outputs for the motors in Mach3. -WRM

I built mine from scratch, including driver. My driver is half step driver and my motor is 200 steps/rev, hence there are 400 steps per revolution in half step driver. If you are using 1/4 step or 1/8 step mode of your driver, you would have 16,000 or 32,000 steps per inch.

In my setup, the X and Y stock lead screws are 20TPI, therefore, it has 400 X 20 = 8,000 steps per inch. So for your "Motor Tuning" screen, you put in 8,000 for X and Y.

For Z, since 1.5mm pitch means 25.4 / 1.5 = 16.93333 TPI. I am using same set of driver and motor, so there 400 X 16.933333 = 6773.33 steps per inch.

If you are using 1/4 and 1/8 step mode driver, adjust according.

[WRMorrison]

Originally Posted by zwdeal I built mine from scratch, including driver. My driver is half step driver and my motor is 200 steps/rev, hence there are 400 steps per revolution in half step driver. If you are using 1/4 step or 1/8 step mode of your driver, you would have 16,000 or 32,000 steps per inch. In my setup, the X and Y stock lead screws are 20TPI, therefore, it has 400 X 20 = 8,000 steps per inch. So for your "Motor Tuning" screen, you put in 8,000 for X and Y. For Z, since 1.5mm pitch means 25.4 / 1.5 = 16.93333 TPI. I am using same set of driver and motor, so there 400 X 16.933333 = 6773.33 steps per inch. If you are using 1/4 and 1/8 step mode driver, adjust according.

Thanks for the math, that cleared a little of it up for me. I was able to determine that the Nema23 motors that I have are 200 steps per rev., but I don't know what steps my driver (FET4 from stepperworld) uses.

I was able to configure the motor outputs correctly in Mach3, and am able to drive the motors, but they are extrememly "twitchy." I emailed stepperworld to find out if the FET4 board is a 1/2 step driver or what, unless someone here has figured that out already .

-WRM

[Stepper Monkey]

You don't really ever need limit or home switches, even on my machines that have them I don't use them. They are good as "training wheels", but pick an origin point on your work and you will be just fine. That is a habit you will develop anyway as you get comfortable with the machine and don't feel the need for wasting time on the babysitting features in the programs like defining material setups.

Yes, you can get the machine to stop and use the quill manually. For that little machine it would be a lot faster anyway.

[zwdeal]

Originally Posted by WRMorrison Thanks for the math, that cleared a little of it up for me. I was able to determine that the Nema23 motors that I have are 200 steps per rev., but I don't know what steps my driver (FET4 from stepperworld) uses. I was able to configure the motor outputs correctly in Mach3, and am able to drive the motors, but they are extrememly "twitchy." I emailed stepperworld to find out if the FET4 board is a 1/2 step driver or what, unless someone here has figured that out already . -WRM

I went their site and judging from this link from their site http://www.stepperworld.com/FET3dynamo.htm, the sentence "Top speed is approx 24,000 pulses per minute, which equals 120 rpm, no load condition." suggests that your driver is FULL step driver (24,000 / 200 = 120 RPM). It also seems your board is the R/L type -- no chopping because it needs power resistors. But the board does have some DIP switch on them for each axis, I don't know if they are for stepping mode selection or others. The best way is to check your manual.

Another way to find it is, assume the driver is FULL step driver, so you input 4,000 steps per inch in motor tuning screen. Then command the table to move one inch as following:

1. Set all axis's to ZERO
2. Enter G-code "G00 X1"
3. Make sure you have all the clearance -- your tool is not going to ramp into anything.

then run the G-code. If the X table moves 1 inch, the assumption of FULL stepp driver is correct. If X table moves 1/2 inch, it means your driver is 1/2 step driver. If it moved 1/4 inch, and so on.

Do the same to Y and Z axis. If you do not have an indicator to accurately measure table movement, try to move 2 or 4 inches so that you can see it with your eyes -- if it moves about 1/2, 1/4, or 1/8 or what you would expect, that is the stepping mode.

Hope this helps.

[WRMorrison]

ZWDEAL, you were spot on about the 4000 steps per; it moves as close to 1" as I can measure at home (all the DTI's and calipers are at work).

Now, I just need to figure out what the rest of the info on that same motor tuning screen means. Here's what I've got entered at the moment:

X axis:
Steps per = 4000
Velocity (in/min) = 1.0002
Acceleration (in/sec2) = .01328125
G's ?
Step pulse (1-5 micro sec.) = 5
Dir pulse (0-5) = 5

Y axis:
Steps per = 4000
Velocity = 1.002
Acceleration = .005
G's ?
Step pulse = 5
Dir pulse = 5

Z axis:
Steps per = 3386.665
Velocity = 1.002
Acceleration = .005
G's ?
Step pulse = 5
Dir pulse =5

I'm not sure if any of the numbers except "steps per" is correct. Is there a way to figure it out?

Thanks so much for helping me clear this up!

-WRM

[Stepper Monkey]

You can up your velocity, and really up your accel, or else it will take years to cut much of anything! The Z on those units can't handle much speed or accel, but still likely 10 times what you have it at now. The X and Y can go up even more than that.
There really isn't a set way to figure it out, other than to keep running it faster until is makes ugly noises at you. You'll just know. Don't worry, you can't break anything by trying, just make a lot of funny sounds!

[zwdeal]

Originally Posted by WRMorrison ZWDEAL, you were spot on about the 4000 steps per; it moves as close to 1" as I can measure at home (all the DTI's and calipers are at work). Now, I just need to figure out what the rest of the info on that same motor tuning screen means. Here's what I've got entered at the moment: X axis: Steps per = 4000 Velocity (in/min) = 1.0002 Acceleration (in/sec2) = .01328125 G's ? Step pulse (1-5 micro sec.) = 5 Dir pulse (0-5) = 5 Y axis: Steps per = 4000 Velocity = 1.002 Acceleration = .005 G's ? Step pulse = 5 Dir pulse = 5 Z axis: Steps per = 3386.665 Velocity = 1.002 Acceleration = .005 G's ? Step pulse = 5 Dir pulse =5 I'm not sure if any of the numbers except "steps per" is correct. Is there a way to figure it out? Thanks so much for helping me clear this up! -WRM

Now I see what you mean by "twichy". At 1 IPM (inch per minute), your motor is probably making a lot of "clicking" sound, particularly with a FULL Hi-Torque step driver. No offense :-)

Your board is very similar to mine, except mine is half step which makes it smoother. With your setup, I think you can get at least 12 IPM if not 18 IPM, this is assuming you are using 12V power supply. I am getting 18, 12, and 9IPM on X, Y, and Z respectively. On my rotary A I just built, I can get 6 rev per minutes without losing steps, the motor is a 50 oz-in baby one. This is using a salvaged PC power supply and with 12V terminals.

I set acceleration at 0.5 because when motor starting up, it needs to overcome rotor inertia. Also, when you accidentally ramp your Y table to the end, it could get jammed and to pull it out, you need low speed and a lot of torque and that is done at acceleration part of it.

I left all others at default.

On my motor, when it misses steps, it make some high pitch noise, that is when you know missing steps. When cutting, of course, you won't get 12 IPM, but around 6 IPM at 0.025 inch depth with 1/4 end mill.

[WRMorrison]

Again, thanks for all the help folks, I really appreciate it. Without everyone's help here, it probably would have taken days to get this far.

Right now, I only have 5V going to the motors, but I'll have 12V as soon as I get the power resistors wired up (and I still need to tidy up my "rat's nest" of wires).

Does anyone know if I have the correct values entered in the last two spots per axis? (step pulse and dir pulse). I have both set to "5," but I haven't a clue if that's correct.

I'm also going to go ahead and get some limit/home switches and an E-stop, and use 1 switch per axis for a combo limit/home at the far neg. corner for the X/Y, and about midway up the column for the Z. I plan on doing small production runs of various RC parts (among other things), and I like the idea of being able to set multiple part origins.

I just wish that the horizontal 4 axis CNC mills that I operate at work had as many programmable origins...lol. On the larger of the two mills at work, I have ~40 origins to work with, and on the smaller only 6. It can be quite frustrating to use a combo of # signs in a program that requires more origins than the machine can store....still haven't figured out how to use those effectively yet.

-WRM