Re: [CAD_CAM_EDM_DRO] DRO FOr lathe Cross Slide

Hi

Here is an idea for a low cost encoder for a MANUAL lathe or mill, which may
be of use to someone.

Take an old PC and load dos and Qbasic
Other parts are;
- a small stepper from a printer
- an equally small stepper driver, or use original from stripped mechanism
- two optical slots
- a 6 or 8mm threaded bar

The principle is to have the stepper driven by the basic program.
One side of the 'encoder' is the stepper directly driving the theaded bar,
and on the threaded bar is a nut with a 'flag' or interruptor attached.
On the lathe slide is the optical slots, next to each other

When in operation, the motor will step, and feed the flag foward until it
interrupts the optical slot. It will then back off, and do it again,
continuously. (duck, duck, duck, duck......)
Whenever the slide is moved, manually, the software will seek it's position,
counting the steps accordingly.

A Qbasic program will display the latest reading, and do the direction
hunting and scaling maths. On a manual lathe, it's usually short relative
distances that matter, so the threaded bar linearity is not critical.
Also, considering the speed at which manual turning is done, the stepper
should be able to keep track of the movements.

Regards
Roland

PS, the problem with a roller is the low resolution obtained. Now a 6mm
threaded bar is 1mm pitch, and a small stepper is 200 step/rev, giving an
inherent resolution of 5um



2009/1/4 friends000ever <friends000ever@...>

> Dear friends
> I wants to make single axis DRO for my lathe with Encoder & hardened
> roller, Can any one suggest how to do this one low cost .
> Best regards
> Kalpesh
>
>
>

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