Making Dividing Plates

[T. J.]

I need to make a couple of new plates for my dividing head and I’m wondering what’s the best way to make the holes - about 500 of them . Has anybody done this?

Is drilling only accurate enough, or do they need to be reamed? If reaming is best, I was considering getting a combo drill/reamer to cut down on tool changes. They’re kinda pricey, but if one would do the job I think it might be worth it.

 

[ChazzC]

No personal experience, but per N. Kettle in Model Engineer v142 #3540 (2 July 1976), he used a 1/8" x 5/16" center drill to drill 1,500+ holes in the 4, Ø6" plates for the dividing head he made for a R.T.2 Rotary Table (I'd send/upload a copy of the article, but I'm a great respecter of Copyrights). You may be able to download a copy (or ask for a copy since it was 48 years ago) from ME. N. Kettle also noted that he based his design in part on a Myford Dividing Head; at his request, Myford provided a full set of drawings for his use!

 

[brino]

Two things come to my mind:
1) If the number of holes in a single circle and diameter of those holes is large, you run the risk of drilling a ring right off the disc. If required you can use two circles and alternate in/out to make them fit without "trepanning" the plate.

2) Although drilling is never a precise operation, the offset introduced by any drilling errors should be reduced by the gear ratio of the worm and wheel inside the dividing head.

I hope you post some follow-up of your efforts.

Brian

 

[mattthemuppet2]

Non standard plates or to make missing plates? I have some different assorted dividing head plates, might be one that fits your head in there

 

[cathead]

From my perspective, a center drill would be superior to a drill-reamer combo. I have made several
dividing plates with a center drill and had good results making gears. Center drills are highly accurate
but not so with a standard drill bit. It seems to me that a drill-reamer combo would make accurate holes
in inaccurate places.

 

[projectnut]

You might want to check eBay to see if there are any plates that will fit your dividing head. Last year I bought a new set of #4, #5, #6, and #7 plates for my L-W Chuck Co. dividing head for less than it would have cost to buy the combination drill/reamer alone. The same seller currently has complete sets available for Ellis and Carroll dividing heads. My L-W Chuck Co. uses the same ones as the Ellis dividing heads.

ELLIS DIVIDING PLATES, 7 PIECE SET. | eBay

This a full set of dividing plates for a Ellis dividing head & made of A36 steel. You get 1 of each of following plates #5 51, 53, 63, 73, 81, & 96.

www.ebay.com

 

[T. J.]

Non standard plates or to make missing plates? I have some different assorted dividing head plates, might be one that fits your head in there

I have the 3 standard plates up to 49 holes. My immediate need is to make 3 gears of 57, 63, and 69 teeth, which necessitates a new plate. I figured I would add some other hole circles as well to fill the gaps.

 

[T. J.]

You might want to check eBay to see if there are any plates that will fit your dividing head. Last year I bought a new set of #4, #5, #6, and #7 plates for my L-W Chuck Co. dividing head for less than it would have cost to buy the combination drill/reamer alone. The same seller currently has complete sets available for Ellis and Carroll dividing heads. My L-W Chuck Co. uses the same ones as the Ellis dividing heads.

ELLIS DIVIDING PLATES, 7 PIECE SET. | eBay

This a full set of dividing plates for a Ellis dividing head & made of A36 steel. You get 1 of each of following plates #5 51, 53, 63, 73, 81, & 96.

www.ebay.com

That’s a great find projectnut! My dividing head is an L-W Chuck model as well, and it looks like he has what I need.

I’m going to contact the seller about getting those individual plates. Thanks!

 

[T. J.]

I just purchased the 4, 5, 6, & 7 plates from the same seller for $100 plus tax & shipping.

When considering the time and effort it would take me to make them myself, I’d say that’s a steal.

 

[francist]

Not to mention the anxiety of trying to get through all five-hundred holes without screwing one up!