Cross Slide dial Debacle

[cathead]

That is the beauty of the universal dividing head, you do not need high number plates, it is done by differential indexing, where the spindle is geared to rotate the index plate. That is how prime numbers are divided, such as 127 for metric transposing gears.

I don't undersand how a universal dividing head works apparently. My rotary table is 90 to 1 and the universal dividing head is usually a 40 to 1 ratio.
How does this differential indexing work? How can it make large division numbers with a small numbered hole plate?

 

[jcp]

Check the pictures in the last post of the link below. The gear train engaged with the crank handle is the differential gearing for indexing as bemychree said. The stack of gears are used to tie into the table lead screw for spiral cutting.

http://www.practicalmachinist.com/v...niversal-semi-universal-dividing-head-157388/

 

[Uglydog]

Mark_f original post was inspirational. And set me on the path of building an OEM knock off tool holder for my Cincy Slotting Attachment.
The holder specs a similar graduated dial wheel.

Cathead,
I planned on using my DH on the mill.
What did you use for a cutter?

Thanks,
Daryl
MN

 

[cathead]

Mark_f original post was inspirational. And set me on the path of building an OEM knock off tool holder for my Cincy Slotting Attachment.
The holder specs a similar graduated dial wheel.

Cathead,
I planned on using my DH on the mill.
What did you use for a cutter?

Thanks,
Daryl
MN

I machined a point on the end of a broken 3/16 carbide end mill. Maybe adding a flat on it would improve the cuts but
it seemed acceptable as it was. In that case, you would have to be sure the mill head would be locked so it wouldn't turn.
You would be using the mill as a shaper I guess.....

 

[benmychree]

I don't understand how a universal dividing head works apparently. My rotary table is 90 to 1 and the universal dividing head is usually a 40 to 1 ratio.
How does this differential indexing work? How can it make large division numbers with a small numbered hole plate?

For dividing, the head has a extension center that comes out the back end of the head and change gears are set up to tie the spindle shaft to another shaft that rotates the dividing plate while the index crank is being turned; if you look in the dividing tables for B&S in either the "Practical Treatise on Milling and Milling machines" or in Machinery's Handbook, you will see the diagram of it as set up and the change gears required.

 

[cathead]

For dividing, the head has a extension center that comes out the back end of the head and change gears are set up to tie the spindle shaft to another shaft that rotates the dividing plate while the index crank is being turned; if you look in the dividing tables for B&S in either the "Practical Treatise on Milling and Milling machines" or in Machinery's Handbook, you will see the diagram of it as set up and the change gears required.

John,

Perfect, I will be studying the Machinery's Handbook tonight so I completely understand the concept. I knew there was
more to it than I was seeing. Thanks a bunch!

 

[Uglydog]

I machined a point on the end of a broken 3/16 carbide end mill. Maybe adding a flat on it would improve the cuts but it seemed acceptable as it was. In that case, you would have to be sure the mill head would be locked so it wouldn't turn.
You would be using the mill as a shaper I guess.....

I like the idea of the taper on a broken endmill or center drill. Lots of build in stability!
I should be able to do that on my PW TCG.
I'll probably make an engraver type cutter and run at high RPM.

Daryl
MN

 

[cathead]

Daryl,

Maybe try some of those carbide circuit board end mills (less than.5mm) from Alibaba or Banggood. Very inexpensive
and work really well for small applications...