Quick Change Indexer

[rebajm]

I picked up a small lathe on sale from Harbor Freight cheap. Rockler woodworking sells one that looks like it called the “Excelsior”, so I purchased the extension for it from them, and it fits my lathe. I fabricated a stepper motor mount by bending the long section of a heavy T-hinge and welding a piece of angle iron to the short section. I then welded a steel tab with long bolt welded to it to the angle iron. It takes just seconds to loosen the wing nut to allow removal of the timing belt so the lathe AC motor can be used allowing sanding or buffing of the work material. This setup has been working just great for me.

[myxpykalix]

looks like you got it figured out! looks good!:D
Now show us something you made on it:eek:

[rebajm]

Used the indexer on the handles, axle, hubs and spokes to make a garden flower cart out of cedar for my wife.

[steve_g]

HA! he fooled you Jack... It's nice to see an indexer actually used! I like the project too.

Steve

[garyb]

Looks good John, what gearing and belt did you use?
Gary

[myxpykalix]

I like that john. I used to like to turn things on my lathe but because of my shoulders and neck had to give it up. Its now a glorified sander, you have your indexer to turn things that look really neat. Good job!:D

[rebajm]

Gary, I used 7.2:1 geared motor with GT2 (5mm) pitch pulleys and belt. The one timing belt pulley has 50 grooves, the other 36. This gave me a final ratio of 10:1. The belt has 90 teeth. Both pulleys have a 12mm bore. I tapped the hollow lathe shaft, took a 12mm bolt, cut the head off, threaded a nut onto it, added a lock washer and then screwed it into the now threaded hole. This provided a shaft for the lathe pulley.

[gene]

how does the shopbot run the lathe ? is there a driver added ? I have seen the wrap around thing in aspire and i know that its for this type thing bit how are the two interlocked?

[myxpykalix]

Gene,
If you look at his picture you see the stepper hooked to the lathe via a gear and pulley. The lathe is simply a "extension" of the stepper in that, if the stepper turns 90 degrees, it turns the shaft of the lathe 90 degrees. His pulleys and motor are disengaged while it is being used as a indexer.

Just imagine that the stepper is hooked to the end of the lathe in a straight line instead of via a pulley. Although i think there may have to be some -/+ rotation reversal in the control software to accomodate the stepper rotation(?)

The indexer rotation in degrees is substituted for the Y movement in the file setup (assuming your indexer is in the X axis)

[gene]

where does the wire go that comes out of the stepper that is mounted to the lathe pulley? :confused: this is like me being in a 12' pond its over my head.

[garyb]

Gene, it goes to the control box to be connected to the board and driver and be designated the "A" axis.
Gary

[rebajm]

The motor connects to a stepper motor driver that must be installed inside the control box just as the x,y and z motor are connected. Also, it is not necessary to remove the belt for the lathes AC motor as it does not affect the operation of the stepper motor. The stepper motor belt does need to be removed if you want to run the AC motor. I keep the lathes AC cord unplugged when the stepper motor belt is in place.

[myxpykalix]

Gene this pic might help. You have a driver for each stepper and one for the indexer.

[mars]

Hi John,
did you have a lot of sanding to do on the handles of your garden flower cart

[rebajm]

Hello Marcel,
No, cedar sands very easily. I machined the handle end down to .5 inch, cut the stub off with a saw, and then finished rounding it with sandpaper.