Advice on a simple single axis setup

Hi all,

this is my first post here but ive been a lurker for awhile.i'm basically building a small custom lathe, which needs (ATM' at least!) a single-axis motion (in addition to the chuck rotation). i just need to true-up a cylinders outer surface- so no 2nd axis needed.

i would like to use a manual control, since adding G-codes for this operation is overkill i feel. now, if im using M3 its pretty straightforward,...

stepper motor-> motor controller-->Break Out Board-->PC-->M3-->G-code inputs

My Question is,.. is there any way to do this without going the Mach3 / PC route?

IE:-
stepper motor-> motor controller-->Manual handwheel type controller

so long as i can set feedrates & specify start-stop limits i think thats pretty much all i need.
end goal is to make this machine Simple & Idiot-Proof. ebay has some handwheels but im not sure if they can do what i need.

PS: To the Mods, if this thread is in the wrong place can you please move it?

Feed rate control...... limit switche(s).....

Seriously, it sounds like you just need a lead screw with a DC gear motor on it. You can easily come up with a variable "speed control", and you can interrupt motion, heck, even reverse motion easy with simple switches and relays. Certainly not anything that needs a CNC control of any sort.

Years back, there was a nice little self standing "motion control unit" called a FROG for just this type of purpose. I was surprised to see it disappear from the market.... Lots of uses for that little thing. I wish I would have bought one.

In the mean time, you can put your cordless drill on the end of the lead screw and just stand there with the trigger pulled properly under "human control" rather than turning a crank handle.

Have you ever used a standard manual lathe? Almost all of them have a variable speed automatic feed driven off of the spindle. It would be perfect for you.

You don't need a stepper, just a DC gearmotor and a couple limit switches. You could control the speed with a rheostat. This is like a power feed on a manual milling machine.

If you want to use a stepper you can google a 555 timer circuit and use that to control the speed, add in a few pushbuttons and limit switches and your problem is solved.

There are many ways to go about it and only you know which is best.

Good Luck
Matt

Quote:

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Originally Posted by keebler303

Have you ever used a standard manual lathe? Almost all of them have a variable speed automatic feed driven off of the spindle. It would be perfect for you.

You don't need a stepper, just a DC gearmotor and a couple limit switches. You could control the speed with a rheostat. This is like a power feed on a manual milling machine.

If you want to use a stepper you can google a 555 timer circuit and use that to control the speed, add in a few pushbuttons and limit switches and your problem is solved.

There are many ways to go about it and only you know which is best.

Good Luck
Matt

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thanks alot matt, this was exactly the kind of info i was hoping for... googling it now... i have never personally used a lathe so i guess that knowledge is somewhat limited. how would you add-in the pushbuttons & limit switches though?

Here is a video: https://www.youtube.com/watch?v=3JhpIQoLZrA
At the beginning you can see a long screw parallel to the spindle, this is the feedscrew which is pulling the carriage toward the spindle, traversing the work.

Is it your plan to use a stepper and 555 type circuit? Knowing your plans will make it easier to provide guidance.

The limit switches could be mounted on a rail with a thumbscrew so you can set them where you want them. When the carriage contacts the switch, it would disconnect the step pulses from the stepper drive so the motor would stop. You can wire it so that it would still go the other way when you tell it to. With a bit of thinking, you could add a jog button to move at full speed and then go back to a slower speed when you were cutting. Keep in mind the simple circuit I am imagining does not include any acceleration or deceleration ramps. It is either go or stop. You could alleviate that partly by adjusting the speed down when you started. It all depends on the features you need/want.

Matt