Digital Dividing Head and Slide

[MachineTom]

I've put a video on Youtube showing my conversion of a standard dividing head to digital operation. I removed the dividing handle and quadarant, as well as the divisions disk. I added a stepper motor and 3:1 reduction, with the normal worm drive of 40:1 that 120:1. This is a Micro Stepper drive so 1 revolution is 25,000cpr. Multiply that times 120= 3,000,000cpr. When the number of divisions is inputted, the program divides the 3M by that number, yielding the number of steps for each step on the dividing head. There is a limit switch set as a trigger on the slide, near the end of the return travel, the trigger tells the controller to advance the stepper the required steps.

RP240 display is used, as they are available on internet for $100-200. No need to built one. The Extended Basic programming is not the tough to learn, and that controls the drive and display unit.

The slide came from another purchase, This one has double roller bearing slides. The foil was only temporary, I've not yet installed rear covers to keep out the chips.

Video.http://https://www.youtube.com/watch?v=fwyUKCLQQtI&t=20s

 

[MachineTom]

As there were no comments about the Digital Dividing Head as finished. I thought maybe some would like details of the build.

As mentioned I based the operation on the use of industrial Compumotor Micro Indexer.There is a free download of a compiler called Motion Architect from the Parker website. If anyone wants my program, I'd send it, but only works for 'Basic Extended' controllers.

An enclosure i had just fit the two Controllers, I added plug in's as cable needs may vary depending on what the controllers are hooked up to. The RP 240's sit on top, the front unit tilts forward to provide access to the rear unit. A Pancake fan keeps things cool.
https://photos.google.com/share/AF1QipMsNBvWEaTbMvXak9sHePKAqgkWKUhI5JMuHvNxDlQx_oNFuf0UdW2q253nyB9MxQ/photo/AF1QipOdmEfbhrST-jfypD-I-Nuy-1zqJIlHpljCsfo_?
key=d1JHQmJ1YnI0RW10M1FaZFM5dTFlT3dodVRneTNR

Inside the Box

 

[MachineTom]

As there were no comments about the Digital Dividing Head as finished. I thought maybe some would like details of the build.

As mentioned I based the operation on the use of industrial Compumotor Micro Indexer.There is a free download of a compiler called Motion Architect from the Parker website. If anyone wants my program, I'd send it, but only works for 'Basic Extended' controllers.

An enclosure i had just fit the two Controllers, I added plug in's as cable needs may vary depending on what the controllers are hooked up to. The RP 240's sit on top, the front unit tilts forward to provide access to the rear unit. A Pancake fan keeps things cool.


Inside the Box

Top removed

 

[joco-nz]

Its an interesting system. I tried putting the image url into a browser but got a 404 error. Maybe I'm copying it wrong but its not bringing through the image to posts. Some more details/pics/drawings on how you put thnigs together, where you sourced parts from etc along with performance characteristics would be interesting.

Looks like your mill is manual? And this component is the only cnc style element in use?

Cheers,
J.

 

[DICKEYBIRD]

Very interesting Tom; the light bulb just lit up over my head. Now there's yet another project added to the "round tuit" list hanging on the shop wall. I have a Kuroda precision slide & a spare stepper motor lying around. Thanks to you I know exactly what to do with 'em now!:thumbup: (One of these days.)

 

[lohring]

I would be very interested in the details of your build. As was noted, the images won't load.

Lohring Miller

 

[MachineTom]

I have corrected the links for the photos. I hope.

These units as mentioned are Compumotor, which is Parker Automation. This series is a Zeta6104 Micro indexer, designed as a stand alone controller. Two of the units along with the stages I got with a Harig Grinder. I had posted a thread previously on this site.
The other RP240 and 6104 and some stepper motors are all Ebay buys. Pricing is from $100, 200 for the RP240's, and the Indexers from $60-250. So not so cheap , but within reason. There guys quoting big numbers for these items, but many are still reasonable.

Most of the Stages I see around are not suitable for the work of milling. Exposed slides, unprotected lead screws, poor rigidity. So I couple covers were added to cover the exposed areas of the unit, as seen here.
http://www.homemodelenginemachinist.com/attachment.php?attachmentid=88166&stc=1&d=1491760170

The long piece of AL on the side is the seal to keep SWARF away from the roller guides.http://www.homemodelenginemachinist.com/attachment.php?attachmentid=88168&stc=1&d=1491760170

There is a piece UHMW strip designed for drawer slides, that is used togive a slick surface for the seal material(white Strip) The brown seal is for debris for keeping chips from entering from the top, so no slide action there.

http://www.homemodelenginemachinist.com/attachment.php?attachmentid=88167&stc=1&d=1491760170

There is a home switch on the left side, and a Trigger on the Right. The trigger is what tells the indexer to advance to the next position.

The stepper drives a 5TPI ball screw, The home switch is used at the beginning and end of a each program set. Meaning when the program starts The first move is a setup move, forward 1 turn, backup to Home which sets the RPS to zero counts, then forward one turn, stops, And then the cutting cycle begins. This is so any small errors of position to not add up to a large error, as well as slide movement manualy, or with another program run on the same unit. As there is a second program for drilling on the same slide. Don't need any crashes do to overtravel.

 

[MachineTom]

There is a subplate I made some years ago. There are rows of threaded holes for bolting stuff down to it. This piece is now been added to the slide setup. To this I will mount a steel plate made to fit the keyed base or the dividing head.

This subplate will allow me to very quickly add a vise, or direct bolt down.
Recently I had a job needing 49 holes drilled .250" spacing. A precission vise was bolted to the plate, indexer set for .250 spacing, using a trigger button on a cord, each press on the button, moved the drill .250" every time it was pressed. The DRO made the mill easier to use, the slide will make some jobs much quicker.

My intention is to use the Indexer for other operations, like tailstock feed, and tracing type movements on the X lathe axis.