How to build an Indexer?

This forum is dedicated to those Hobbyists Interested in CNC machining & 3D Printing in their home shops. (Digital Read Outs are also topical, as is CAD/CAM as it relates to CNC)

Moderator: Harold_V

Post Reply
JimGlass
Posts: 2281
Joined: Sat Jan 04, 2003 8:33 pm
Location: 40 Miles West of Chicago/near DeKalb
Contact:

How to build an Indexer?

Post by JimGlass »

I would like to build a CNC indexer as the 4th axis and wondering if anyone has made one or ideas on how to make one.

First thought is to have a stepper motor run worm wheel and worm gear but what about backlash?

I'm thinking about making an indexer where a stepper motor would be direct drive. No backlash :idea: :idea: . To lock the indexer in position, I was thinking about installing a brake system so the stepper would not do all of the holding.

Does anyone have some better ideas??? Jim
Tool & Die Maker/Electrician, Retired 2007

So much to learn and so little time.

www.outbackmachineshop.com
jutz
Posts: 49
Joined: Sat Nov 25, 2006 2:27 pm
Location: Austin, Texas

Post by jutz »

I found information about one that used a stepper motor through a harmonic drive. The motor and drive fit quite neatly inside the body of the indexer and harmonic drives can be built with zero backlash but they are a bit pricey.
GaryHart
Posts: 63
Joined: Sat Jan 04, 2003 9:40 am
Location: Vancouver, WA

Re: How to build an Indexer?

Post by GaryHart »

JimGlass wrote: First thought is to have a stepper motor run worm wheel and worm gear but what about backlash?
Jim, have built couple using worm gear reducers. Controlled gear backlash by using an eccentric for the bearing on end of worm gear and end play was having a spring washer behind bearing on worm shaft at stepper motor end and the other end with the eccentric is a single ball from a ball bearing that is pushed on by a set screw.

Replaced DC motor on a gear reducer motor with a stepper motor. The gear reducer was like new and had no wear on the gears. Made a new output shaft that matches the Sherline lathe spindle. I use this indexer a lot for making gears and rotary engraving.

Made another larger one from a lever operated 5-C indexer that had. This is too large for my little cnc mill but made it with a long enough cord so it could be used on larger manual mill. Made it few years ago and have yet to use it other then testing it. The small one gets used all the time.

Some pictures of inside of 5-C in photobucket album link at bottom.

Image
Image

http://smg.photobucket.com/albums/0903/ ... 20indexer/
Vancouver, WA
Marty_Escarcega
Site Admin
Posts: 1730
Joined: Wed Dec 18, 2002 8:17 pm
Location: Mesa, AZ USA

Re: How to build an Indexer?

Post by Marty_Escarcega »

JimGlass wrote:I would like to build a CNC indexer as the 4th axis and wondering if anyone has made one or ideas on how to make one.

First thought is to have a stepper motor run worm wheel and worm gear but what about backlash?

I'm thinking about making an indexer where a stepper motor would be direct drive. No backlash :idea: :idea: . To lock the indexer in position, I was thinking about installing a brake system so the stepper would not do all of the holding.

Does anyone have some better ideas??? Jim
Jim, I'm going to take a Yuasa Dividing head and do just as you suggest. It has a threaded spindle and a chuck. Used to be a device called a FROG but I don' think its made anymore. There was another called DIVISION MASTER, I think its still around to program and drive the stepper.

Marty
"Jack of all Trades, Master of None"
JimGlass
Posts: 2281
Joined: Sat Jan 04, 2003 8:33 pm
Location: 40 Miles West of Chicago/near DeKalb
Contact:

Post by JimGlass »

A friend has asked me to make him an indexer so now I need to make two.

From Homosassa FL

Jim
Tool & Die Maker/Electrician, Retired 2007

So much to learn and so little time.

www.outbackmachineshop.com
Marty_Escarcega
Site Admin
Posts: 1730
Joined: Wed Dec 18, 2002 8:17 pm
Location: Mesa, AZ USA

Post by Marty_Escarcega »

JimGlass wrote:A friend has asked me to make him an indexer so now I need to make two.

From Homosassa FL

Jim
Jim, I am going to build this control for my Yuasa Dividing head and will add a stepper motor to my 6" rotary table as well and use the same control. You can by an inexpensive stepper drive controller on ebay from where else, China for under $20

I believe you are well versed in electronics and can build one yourself.
Marty

http://www.cnczone.com/forums/showpost. ... tcount=111
"Jack of all Trades, Master of None"
Post Reply