CNC bound
finally was able to order the steppers and controllers to CNC my Mini Mill, just going to do 3 axis for now (hope to do 4 then 5 in the future)
Also ordered a copy of Howard Buckley’s book, hope to see that in a couple weeks.
Already have some good software, just need to learn how to use it 😳
once I get the mill setup and also get up to speed on the software I hope to make next gen version of my stock as well as a full air rifle 😯
(don’t really need CNC to make the air rifle, will be a nice exercise though)
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encoders are rather expensive, not something you tend to find on low end chinese mills
I’m running 36v and half steps, and I can literally hang off the table while its moving a 108 IPM without it missing a step 😯 😀
I still have some issues with my X GIB, got some brass to make up a new one at hopefully take care if the issue (loose in the middle, to tight on the ends)
Still trying to figure out a good setup to cover the Z ways, might have to get some bellows as well.
If you have encoders the computer will know and wont hope that the sent instructions were carried out so it will compensate for missed steps.
It really only happens when your doing something you shouldnt (heavy cuts or too fast) or the machine isnt set up properly…
I haven’t had it happen during normal use after I adjusted it.
Is it a regular thing? Sounds like software to confirm what the mill is doing is a very good thing to have.Would that automatically ‘re-do’ the missed step/s
I’d have to stop, figure out why it missed the steps and then reset the tool in the correct position and start the program from whatever point seems appropriate (usually just before it started missing steps I guess…)
I’ll make a video later of what it sounds like.
What do you do if it misses a step? Pause the run, rewind a bit then prress go again?
I mean one command sent to the stepper motor to move 1 step or a fraction of a step depending how its set up.
My Steppers have 200 “steps” in 1 full revolution, the controller allows 1/8th steps (and 1/4 and 1/2 steps too). So if I have the controller set to 1/8th steps, then the stepper can move 1/1600th of a full rotation – each one of those would be a step.
the torque available is less with the 1/8th steps, so I use 1/4 steps for 800 steps per rotation.
If it just misses one, you might not notice, but you’ll hear the change in the motor if it bogs down and misses a few.
With Steppers the computer sends the signal and just assumes that the stepper acted properly so missed steps are bad because they will mess up your accuracy at best and cause tool crashes/damage at worst. Which is why I just run the steppers way slower than I could.
I’m vaguely aware of encoders, which send feedback to the computer to make sure that the instructions were carried out.
Servo’s, which are more expensive than stepper motors are from what I’ve read regular motors, but with encoders built in so the computer goes by the encoder’s feedback on where it is rather than hoping its in the right place with the steppers.
I have seen a guy on youtube who was using steppers and hooked up a DRO to the software to provide position feedback.
How can you tell it has missed a step? When you say “step” are you talking about a complete command string? Like is it moving to the next command before the last one has finished completely?
Shit happens.
Like the big apron. I’m going to have to make covers for my X and Y motor mounts, probably just some plexiglass over the top and sides. and some bellows for the column which is covered in wood dust from all the MDF stuff I’ve been doing.
108 IPM is insane…. I took the handles off and turned mine up to 50 on the X and that seemed wicked fast for the few inches it went before it missed steps.
well I went and destroyed my test indicator today 😳
noticed that my backlash settings weren’t quite right so i started making some new measurements, noticed I had a bit too much play in the X, started playing with that but didn’t move my indicator out of the way and poof 👿
oh well, went and ordered a nice Mitutoyo
Got the X and Y finished, 108 IPM on each, .001″ backlash on the X .002″ on the Y, hope to get the last conversion parts for the Z made this weekend
Coupler came today, its a bit long so I’ll need to make some mods to my X axis drive plate, also got a nice piece of rubber to cover the front of the Y ways 8)
from what I’ve read and what I’ve seen I’d say : yes
But I’ll verify that when I have my X back in shape, if it proves to be better than the Y I’ll just have to do it the way YN did.
Is the accuracy the same running it through a belt over going direct drive?
with these kinds of speeds I’m going to have to start seriously thinking about limit switches 😯
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finally finished the Z axis, took a bit of fiddling.
anywho, getting a nice reliable 36 IPM 😀 Much better 8)
