Dividing head is splitting mine.

[kenny6486]

I am interested in making model camshafts (4 – 8 inches long) for small engines Traditionally it appears you use a dividing head/ rotate table and tail stock on a mill to make camshafts. If so, is it necessary to automate the dividing head or does it work fine hand turning? I want to buy one that can obviously index, maneuver both vertical and horizontal, and have ability to be automated. Regarding automation, I am thinking about attaching a variable speed Sherline motor or CNC with step motor eventually. What I need to know is which rotating dividing assembly are your favorites. It has to enable me to attach a motor though. Also is a 6 inch rotating table adequate for my work or do I need a larger rotating table? My price point is under $900 preferably. My mill (to be purchased this fall) is PM 935 TV

 

[xpylonracer]

Hi Kenny

A 6" rotary table may be large enough but depends on the scale of engines or work you plan to build.
Check this link To Chuck's article about controlling a rotary table with a low cost Arduino controlling a stepper driver.
http://www.homemodelenginemachinist.com/showthread.php?t=17896&highlight=arduino+dividing+head

Follow the article pages and you will find other contributors ideas as well.

Emgee

 

[Cogsy]

I've used Steve Huck's method of using a jig in the lathe to machine a V4 camshaft and it was reasonably simple to do. I much prefer it to using my dividing head. Have a look at THIS POST.

 

[kenny6486]

I cannot tell by the picture but is the chick moving along with the cam on the lathe? Are there offset holes on tail end thats repositioning it? Like 5 holes following a circle diameter? aWhat am I missing thank you for this idea

 

[kenny6486]

Chick? I mean jig [emoji33]

 

[Blogwitch]

Kenny,

If you envisage making LOTS of cams, then really you need to build a cam grinder. There are lots of plans knocking about, from relatively easy made out of bits af angle iron and other odd bits and pieces, to very complicated ones with dials, bellows and gizmos all over the place.

For the odd one or two, as suggested by others, then using the lathe and either ET Westbury's or Bob Shores version (basically ET's design) is about the easiest method to make them.

You could use an RT with tailstock on the mill and use coordinate milling if number crunching and calculating is your idea of fun. You would need to hand finish them as you would have to do on the lathe as well.

John

 

[kenny6486]

Thanks. Will look for EY westburys

 

[Cogsy]

I cannot tell by the picture but is the chick moving along with the cam on the lathe? Are there offset holes on tail end thats repositioning it? Like 5 holes following a circle diameter? aWhat am I missing thank you for this idea

The jig does spin on the lathe. Basically the cam blank is offset to the lathe's axis allowing you to cut one side of the blank only. You make the required cuts (there's a spreadsheet you make - easily - before you start) then stop the lathe, loosen the screws holding the cam blank and rotate it 5 degrees by the degree wheel on the end of the jig. Cut again and repeat. I'll see if I can dig up the thread Steve posted where he explains it properly.

 

[kenny6486]

Thank you for the help

 

[Cogsy]

The good news is that there is a document showing exactly how to make and use the jig and the spreadsheet. The bad news is that it was in the downloads section which currently doesn't exist. Possibly if you PM Steve Huck (from the post I linked to above) he may be able to send you a copy.

 

[MachineTom]

To build a motor controlled dividing head, will take a bunch of money if buying new components, and alot of time making and trouble shooting the result.

Then I use my DH as a simple driver for the work. I take my drill motor, stick a socket on the end, and drive the nut on the handle of the DH. Every DH or RT I've ever seen has backlash in the gearing, depending of what level of accuraty you need locking the head will still be needed with a stepper drive.