Manual Jog needed

[Stevie]

Hi guys; anyone out there with enough electronics experiance to help with a Manual Jog box; I want to have one for set-ups and to "maybe" use with my lathe project
I'm thinking of a small alum box with 3 knobs; 1 will be the jog dial; this will spin totally round but be connected to a pot of some kind and supply impuses to the stepper control; I also want the other 2 knobs for step size and which axis I'm stepping; so both could be 3 position switches
I'd like to step the axis 0.010" 0.001" and finally 0.0001"
I do have some 17 sized stepper motors on hand; could they be used as the rotary control for the main dial; I'm thinking if they pulse as they are stepped; maybe some kind of amp could then increase the pulse to be used by the 43 sized steppers

I'm not to savy with design; but I can solder it all together from a simple drawing

[balsaman]

This is usaully done with encoders with hand wheels on the shafts. I think Mach ll supports this.

E

[abasir]

Stevie,
I am assuming you want pure manual control, i.e., the jog box is not connected to a PC. If that is the case, I believe you need some kind of microcontroller (PIC, AVR, PSoC, etc) to process the jogdial pulse (encoder of some sort), read the switches (axis selection and step size). The controller would then send the relevant number of step/dir pulses to the correct axis. The circuit is trivial but programming the microcontroller is not. Adding an LCD axis readout would be a bonus.

[Edit] Would anyone else be interested in something like the above if I were to make it a kit?

Using stepper motor as encoder is describe in detailed here:
http://www.4qdtec.com/stpen.html

[Stevie]

abasir; you are correct; i want a purely manual set-up; I guess after reading your linked page; the speed of the slave stepper could be upped by a simple pulley set-up; maybe 4X; this would give speed and pulses at a higher rate
What I'm thinking is the lathe first; a jog set-up and steppers on the X and Y axis
After that I'd like it for my mill project; there's nothing like slowly creeping up on your referance points; I have both the 1 way and 2 way magnetic edge finder blocks (one looks like a chair; the other has a grond hole right over the 90dgr point; they are expensive and very accurate) I guess after using the full sized machine with a manual jog it's hard to change

I wonder is there were 2 boxes 1 for X and 1 for Y axis; this would allow for hand forming radi etc

My idea is to get maximum accuracy from a manual lathe; it's hard to get 0.0001" on a dial; or even a DRO

Balsaman; thanks for the reply; however i want this machine to be none PC driven for the first year or 2; too much stuff that would not be CNC productive; after that maybe CNC controled as I will be needing plenty of barrels for my BB model

[abasir]

Just another site on using stepper as encoder (for scavengers like me )
http://members.iinet.net.au/~richardh/Rotenc.htm

[abasir]

Originally posted by Stevie
Balsaman; thanks for the reply; however i want this machine to be none PC driven for the first year or 2; too much stuff that would not be CNC productive; after that maybe CNC controled as I will be needing plenty of barrels for my BB model

Stevie,
IMHO, just buy an old PC (free?) and TurboCNC ($20). It will be probably cheaper (and less headache) than building a separate jog box. Just use the direct entry mode (MDI?), for any movements.

[Stevie]

wish I could understand all that gobbledegoop

[abasir]

TurboCNC (www.dakeng.com) is a software to talk to your stepper controller. In its most basic mode, you can 'interactively' tell your controller to do something by typing some command in TurboCNC (eg. G0 Y1.2345 will move your Y axis to position 1.2345).

It will take sometime to learn but I believe the benefits will be significant.

[Stevie]

actually I ment the page you sent me to the post before

however I just remembered i do have 2 recievers that dont exactly work right anymore; guess the digitl tuner might be torn out