Eureka relieving fixture

[tangler]

The original ME article has been reproduced here on the Model Engineer website (page 22 of the PDF).  The original design is for cutters of about 1 1/4" OD.  John Stevenson has doubled up the size for 1" bore cutters.  It is usual, when the button tools needs large buttons, to cut much of the button away before hardening.  The Eureka isn't just for gear cutters of course;  any profile cutter can be relieved.

Nice work Bjorn - I shall be interested to see how you get on with the screw cutting clutch.

Rod

[Bjorn_B]

Thanks for all your kind replies, regarding room for large button tools, Ivan mentions in the book that built according to plans cutters up to about DP 20 is possible in 1 1/4 to 1 1/2 inch diameter. The design is scalable if needed.

A length of silver steel bar is on order at the moment.

[Bjorn_B]

The original ME article has been reproduced here on the Model Engineer website (page 22 of the PDF).

Wow! Great find, never thought I'd see this article and here it is! Right under ones nose..

Have a bit of reading to do now...

[Bjorn_B]

As part of the process I now have a allmost complete set of HSS ME taps and dies.
Fine threads are needed to save some metal for the centre support to run in on the spindle end.. (5/16 40tpi)
20160303_185243 by Bjorn Pettersson, on Flickr

The larger thread on the indexing sleeve have to be fine allso or the smaller nut on the end would have to be smaller still (It's a bit like chasing ones tail). Otherwise the whole thing has to come apart when putting on or removing a cutter blank and that would not be very nice
20160303_185312 by Bjorn Pettersson, on Flickr

The nut for fastening the cutter blank is 1/2 inch 40tpi. I slightly deformed the smaller nut with a pair of pliers instead of using loctite, makes adjusting end float of the indexing sleeve to nil a doodle...
20160303_185018 by Bjorn Pettersson, on Flickr
20160303_185329 by Bjorn Pettersson, on Flickr

[Steamer5]

Hi Bjorn,
You doing a great job on this, & with Tangler 's  input up the videos of his working makes for a great read. It was a guy from my club that started the process rolling on this design, a quick check of the article introduction shows that there was a number of respected guys involved in the design.

Cheers Kerrin

[gerritv]

Doing some research as I plan to make gear cutters in the not-too distant future.

I enjoy digging for original patents and have found one for a very similar device. It was patented in 1895 by S.M. Balzer
It uses 2 gears of same tooth count, but with one gear having a specific number of teeth removed on half its circumference. It might be simper to  make as the only eccentric is the offset centres on which the whole device rotates.

The photo sequence above will be a great help, thank you for sharing them.

Gerrit

[steamer]

Very Interesting!

Dave