How-To Use a Dividing Head (or Indexing Head) Ellis - Bridgeport

No matter what brand of dividing head you have, here is the technique and charts for the most commonly found 40:1 and 90:1 devices. In this video we use the Ellis Dividing Head(40:1) on our Bridgeport Mill. Charts for both 40:1 and 90:1 devices can bit.ly/3c8qEmd
Timestamps
0:00 Intro
2:07 Charts
3:45 Indexing
5:46 Assembly
7:47 History
8:15 Plates
9:40 Milling a Gear
Practical
The universal dividing head (also called indexing head) adds many new capabilities to a machine tool like a Bridgeport Mill, or even a drill press if it has a sufficiently large table. With some math and creative setups, the complexity of parts you can make with your conventional mill is significantly expanded.
History
Jesse Ramsden built one of the first high quality dividing engines in the 1700s to accurately divide circles for marking instruments. We walk through the Ellis Dividing Head, how to use it, and as we cut an external spur gear.
See our blogposts on the Ellis Dividing head and many other Mechanical, Historical and How-To topics here; bit.ly/2LjzCCB
BTW Free downloadable charts are in this article, and below:
Charts: cdn.shopify.com/s/files/1/042...
USED on eBay or at your local used machine tool dealer
A used Dividing head. Search phrases for eBay
Dividing Head Used
Dividing Head Universal
Dividing Head Mill
USED There are many manufacturers for these devices, expect high quality from some of the finest American Machine Tool Makers:
Brown & Sharpe
Kearney & Trecker
Hardinge
Cincinnati
NEW
A new quality Dividing head by Precision Matthews amzn.to/38bJ6sJ
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[@ActiveAtom]

Great the Ellis got a lot easier to see for us once you placed it on the mill, we also think if you have to work between a couple of obstacles, it might as well just be a pair of Wilton Vises. Nice brass example results of your #2, 21 plate use on that El Monte, California made (we believe) Ellis dividing head, we only have there 6.00" vise, great share and lesson, we needed that here, always learning. Lance & Patrick.

[@johntinamostyn4044]

Great Video. Just bought a rotary table that came with 3 plates. Now I understand how to use it better than any other video I have watched. Thanks guys

[@EvolventDesign]

Glad it was helpful.

[@robertdebusk6157]

Very enjoyable. Your explanation makes understanding what you are doing, very easy. Thank you for sharing your knowledge. Be Careful and Stay Safe Bob

[@EvolventDesign]

Many thanks!

[@ShoeOnaWire]

Hell yeah! Looking for something like this, such a big help

[@taylorfarnham6123]

Great video guys!

[@EvolventDesign]

Glad you enjoyed it!

[@craigtate5930]

What a cool setup. I haven't seen 1 like this before... The unit I got is a bit different then everything i have seen (backwards i think) but nothing as cool as this

[@mimimmo219]

Merci, le sous titre en français aide bien !

[@EvolventDesign]

Je vous en prie. Merci d'avoir regardé.

[@johnwenzel9252]

Great videos!

[@EvolventDesign]

Glad you like them!

[@andrewevans1658]

Nice video! I just found your channel and subscribed today. I have the same Ellis dividing head , except mine has a 6 jaw chuck and only the standard base . I have all the plates and dividing head also. I need to find those charts and print them !!!

[@EvolventDesign]

Hey Andrew! Here's a link to our Ellis Dividing Head guide where you can download the charts and some other helpful info: bit.ly/3hNcuIN

[@ryanodonnell8752]

Cool!

[@cruzcontrolmfg4730]

Super helpful stuff, thanks for the info! Any downloadable charts or other tables?

[@EvolventDesign]

If you "SHOW MORE" and scroll down there is a link to our Blog Article which has free downloadable charts for 60:1 dividing heads like the Ellis. Here is the link; evolventdesign.com/blogs/history/how-to-use-a-dividing-indexing-head

[@ghulamhaider9548]

I love you

[@tracylemme1375]

You are Lucky to have the chart. But if you don’t, the number of divisions divided by forty is the number of holes you have to move. IE for a 70 tooth gear, 40 /70 would be the number. But there isn’t a 70 hole plate. A 4/7 would work. But wait. There isn’t a 7 hole plate either. Any number that is divisible by 7 will work. It just so happens that 21 is divisible by 7 3 times. The solution then is to use a 21 hole plate, and move the handle pin 12 spaces ( 7x 3= 21, 4x3=12) .Now, if you adjust the wings so there are 12 holes showing, you will move the handle only 11 spaces because you are starting at zero count. Thirteen spaces must show. The edges of the wings are severely beveled to help operating the handle. They should be adjusted so that the pin moves from beveled side to beveled side. In the 14 space example one edge should be against the pin . And 19 spaces around the circle the other beveled edge should be just visible. It is important that the handle is turned in only one direction ( usually to the right) to prevent backlash errors, and maintain accuracy If one overshoots the hole, one must back up and return to that hole from the intended direction. Been using dividing heads for over 5 decades.

[@EvolventDesign]

WOW, thanks for sharing with the channel. This is exactly the type of clear minded experience that we are all looking for.

[@sarahdelacruz5208]

I have been told that gears made on a mill with a dividing head are not as good as gears made on a hobber. Can you shed some clarity on that?

[@EvolventDesign]

From both a quality and cost standpoint, the vast majority of gears are made with the hobbing technique. Milling gears is also done and practiced frequently in smaller job shops when an individual or low quantities are required. As long as it fits the service milling is very acceptable. Hobbing machines have a proven and high quality drivetrain that insures there are no tooth-tooth indexing issues, it is very fast at scale and produces a very high quality gear.

[@santopezzotti730]

Hi can you let me know where I can get the charts,

[@EvolventDesign]

The link is in this article for an Ellis. bit.ly/3hNcuIN

[@raymondsilveira1936]

it's a shame they trying to dumb down such an intelligent articulate educator

[@danphillips8530]

So is this a 6 axis machine

[@EvolventDesign]

Yes, but it is a very manual 6-axis and the Ellis needs to have the ability to Index, rotate in the X and Z axis. This is why these older indexers like the Ellis are found in most manual job shops -