Units of measure in Gear cutting

[David Paterson 4Participant @davidpaterson4]

[David Paterson 4Participant @davidpaterson4]

G'day,

I have been re-reading the workshop practice gear cutting book with a view to actually doing this.

One of the tables describes the dimensions for the button tools for creating cutter profiles. The dimensions used in this table are 'Ins'. Can anyone help me identify what these are please?

clearly they are not inches. Elsewhere in the book there is some advice the 1/4" material is sutable for maiking most small cutters – this would appear to be specified as '4' in the table, but any scling from that seems silly.

happpy christmas to the lot of you

Dave

[Graham WhartonParticipant @grahamwharton]

The numbers in the tables are for a 1DP cutter

For other DP cutters, you must divide the number by the DP of the cutter you are making.

e.g if you are making a 20DP cutter, and the value in the table is 4, then the measurement you need is 0.2"

This is explained in more detail on the last page of the book. (Might have been nice to include a footnote on the relevant pages though)

[David Paterson 4Participant @davidpaterson4]

Excellent, thank you.

I now have enough information to have a go at this.

Are you aware of any similar references that would let you generate cutters for clock making? I understand that these are cycloidal and they seem to have a much greater depth of cut than would appear feasible through use of button formers.

dave

Edited By David Paterson 4 on 15/12/2013 23:56:29

[Thor 🇳🇴Participant @thor]

Hi Dave,

if you should want to make metric gears – using the module system – you have to multiply the numbers with the module and the result will be in mm. I have made module cutters using John Stevenson's table and description. Here's another description.

Thor

[David Paterson 4Participant @davidpaterson4]

Thor,

Interesting read – makes you wonder about maths.

I needed a thin woodruff key cutter so have stepped through the process of a fly cutter and using the index plate last night for 10 teeth. looks pretty much like the ratchet wheel i need to do that has much more materials and time invested than a 3" length of silver steel

next for the tooth profiles. first project might be an orrery based on Furgussons paradox. There is enough info around to see how a few of the problems have been solved, andit is only 5 gears.

[Sub MandrelParticipant @submandrel]

Hi Norman,

The link should now take you to the host – it obviously took a day or so for DNS servers (the things that find a website for you when you type in teh name or click a link) to update.

I have to set up my business website first, but when I get a bit of spare time I will put up a holding page with a nice pic on it.

Neil

[John Stevenson 1Participant @johnstevenson1]

???????

You got the right thread Neil ?

[Michael Cox 1Participant @michaelcox1]

Posted by David Paterson 4 on 16/12/2013 23:42:39:

Thor,

Interesting read – makes you wonder about maths.

I needed a thin woodruff key cutter so have stepped through the process of a fly cutter and using the index plate last night for 10 teeth. looks pretty much like the ratchet wheel i need to do that has much more materials and time invested than a 3" length of silver steel

next for the tooth profiles. first project might be an orrery based on Furgussons paradox. There is enough info around to see how a few of the problems have been solved, andit is only 5 gears.

If you want to see the maths behind the tables see:

**LINK**

Mike

[David Paterson 4Participant @davidpaterson4]

Thanks Mike

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