#3 involuted cutter

Hello
I have a # 3 involuted gear cutter that doesn’t have any depth of cut markings on it. All it says is no3-16p. 35 to 54 t. Does .134 sound like the correct depth? This is only the second time I’ve cut a gear and the first time it was stamped into the cutter. I know what all the other markings mean but I’m not sure why it doesn’t have the cutter depth on it? Anyway any help would be appreciated. Thanks in advance. Tony.

Both 14.5 Composite and 14.5 Full Depth systems have minimum total depth of 2.157 / P

So 16 DP would be .1348" minimum

Ref Volume 2 of Buckingham's Manual Of Gear Design

Ok. Thanks so much for the information.

Tgran said:

Hello
I have a # 3 involuted gear cutter that doesn’t have any depth of cut markings on it. All it says is no3-16p. 35 to 54 t. ...

Click to expand...

Seems like it should also have the pressure angle marked unless it is so old that 20 degree was not in use when the cutter was made. And the maker's name is also often marked on the cutter unless it is foreign.

Larry

Tgran said:

Hello
I have a # 3 involuted gear cutter that doesn’t have any depth of cut markings on it. All it says is no3-16p. 35 to 54 t. Does .134 sound like the correct depth? This is only the second time I’ve cut a gear and the first time it was stamped into the cutter. I know what all the other markings mean but I’m not sure why it doesn’t have the cutter depth on it? Anyway any help would be appreciated. Thanks in advance. Tony.

Click to expand...

who did you purchase the cutter from?
it should of been marked DP,PA & WD (D+F) which pressure angle do you require?
is it in fact what you need?

it should of been marked DP,PA & WD (D+F)

Click to expand...

I have about a hundred B&S cutters that have no mention of PA - they are just stamped INVOLUTE (since there were OTHER tooth forms in those days - such as EPICYCLOIDAL)

The point being 14.5 was so standardized 100 years ago that B&S assumed everyone knew that they were 14.5

Hello again.
I just realized I spelled involuted wrong. My apologies. I got the cutters at an auction several years ago. I’m not sure any two of them are the same maker lol. I do have a couple of pictures of it but haven’t figured out how to post them yet. I will post when I figure out how. It’s a brown and sharp cutter but no mention of pa that I can find unless I don’t know what I’m looking at. Which is quite possible. Thanks for all the replies. Special thanks to johnoder.

Just out of curiosity, and I know nothing about make involute gears so i guess the process is different from making traditional gears?
When making clock wheels ( gears ) one calculates the pcd and adds a addendum to calculate the od of the blank and the proper depth of cut is where ever it cuts leaving a very slim line of the original od between the teeth.

MrStretch said:

Just out of curiosity, and I know nothing about make involute gears so i guess the process is different from making traditional gears?
When making clock wheels ( gears ) one calculates the pcd and adds a addendum to calculate the od of the blank and the proper depth of cut is where ever it cuts leaving a very slim line of the original od between the teeth.

Click to expand...

Cycloidal gearing is very different to involute, most cylcloidal cutters are "topping" where, at least in my experience, involute aren't necessarily. So where with a cycloidal the ogive ends with a point, involute is a flat (or close to it, the od which being non-contact is A-ok being a slight curve).

When I cut gears or pinions for watches and clocks I leave a little on the OD and cut down until it "tops" then procede over say 5 teeth 180 degrees apart until the OD mics out and the do all the teeth.

When doing a sub 1mm 6 tooth pinion cutter alignment and depth of cut have you dreaming about microns at night. Clock gears are a welcome reprieve haha. But true high confidence involute gears in high power and speed applications get right back to those microns. We horologists are lucky with our slow moving gearing, where a bit of gut level tweaking can make the difference of 50 years of service or 250, the stuff Zahnradkopf and others do here- a small change for us would be minutes of service or years.

Newer gears cutters are Identified, as John said older gear depending were and when made.
https://www.ebay.com/i/153484000703...hM6mMR9PCgh-VHBEMpLj1htkrvSIcnXhoCsyEQAvD_BwE

what is the pressure angle of the gear you want to make, don't guess
or cut a gear and roll it with an existing gear if rolls good then your good.