CNC Rotary table/lathe head indexing

**leem123** · 24-08-2010

thank you for your contribution I'll start gattering the parts and beguin on the project, I do have one question do, how it will afect the table if i use gear reduction or do i have to use it with a straight shaft and no reduction?

**Kwackers** · 24-08-2010

It depends on what you mean by reduction gear.
If you simply mean the worm on the table (i.e. in the case of a 6" vertex which is 90:1 reduction) then it's designed for that.
If you wish to reduce the gearing further by driving the input shaft to the table via a reduction gear then you can do it providing you're not reducing it by too much.

Basically it's down to the maximum number of steps for a single 360 degree rotation of the table. These can't exceed 65535 steps. So with a half stepping (400 step) motor, and a 90:1 reduction ratio the number of steps per 360 = 400 * 90 = 36,000.
If you tried to drive this through a 2:1 reducer you'd need a value of 72,000 which is too high.

Hope this helps
Steve.

**leem123** · 24-08-2010

Thank's Steve, i did mean the worm on the table, i was'nt sure if the controller was designed for that, so it should'nt be any trouble, i apreciate your time.

**petrus** · 17-11-2010

Hello,
Many thanks to everybody for these informations.
I'd like to built an indexing device for my watchmaker lathe.
My knoledge in electronics is not perfect, so is someone able to provide me a printed board ?
Regards, Petrus (France )

**Kwackers** · 29-11-2010

Hi,

Attached to this post V2.12b firmware.

A couple of minor bug fixes, couple of minor new features and a change to the way the worm ratio is entered, rather than enter a worm ratio (and the device 'assume' a 400 step motor) you now enter the worm ratio multiplied by the step ratio.
E.g for a 400 step motor and a 90:1 worm you'd enter 400 * 90 = 36000.

This change allows odd ratios to be entered.
I'll upload updated instructions shortly.

**rooies13** · 09-12-2011

Originally Posted by Kwackers

Hi,

Attached to this post V2.12b firmware.

A couple of minor bug fixes, couple of minor new features and a change to the way the worm ratio is entered, rather than enter a worm ratio (and the device 'assume' a 400 step motor) you now enter the worm ratio multiplied by the step ratio.
E.g for a 400 step motor and a 90:1 worm you'd enter 400 * 90 = 36000.

This change allows odd ratios to be entered.
I'll upload updated instructions shortly.

KWACKERS Do you have the source code of V2.12 and V2.12b?

Thanks

Dennis