Gerrit's Eureka Relieving device build

[steamer]

It's alive. Still have to add a spring for the lower pawl, finish cleaning up surfaces and securing various parts (the mandrel is 3 pieces instead of original 1) but the ratchet works.

<a href="https://www.youtube.com/watch?v=Eou5lnRIGSE" target="_blank">http://www.youtube.com/watch?v=Eou5lnRIGSE</a>

Gerrit

Put her to work!!!!   Looks good from here!

Dave

[gerritv]

I'm working on a mandrel to make the cutter blanks, then the drill guide and the first form bits. First up will be a cutter for T2.5 timing pulleys.

Have to get this done before May as that is when I am expected to build a new 12x16' multi-level deck for summer enjoyment. :-)

[zeeprogrammer]

That's cool to watch! I hope once you get it up &  running that you will show us it doing it thing!

I couldn't have said it better.

 

[gerritv]

A design for the mandrel on which I will shape and face the cutter blanks, hope to get this piece done on Monday:

[gerritv]

The mandrel is finished, mostly per my drawing. I used a 5/16-18 SHCS as it provides for more oomph should I need it to grip the cutter blank better. 6 slits of 0.5mm width and an internal taper of approx. 10°. I added 17mm wrench flats because it is a common size on my lathe.

The mandrel is used to face the cutter sides, do the rough shaping and then the actual shaping before cutting the gashes and relieving. By using it in my ER32 collet chuck I get predictable concentricity every time.

Presently making cutter blanks from 1.250 drill rod that I happened to have 3' of.

[gerritv]

I made 3 cutter blanks with another 4 in the wings. That should be enough for a while....

I centered the drill rod in 4 jaw, getting good at this with all the recent practice. Drilled and bored out to just under .5, then used a .500 reamer to finish the hole.

A cutoff operation, supported by dead centre (yes a live centre is on the -to-buy-real-soon list). Then onto the mandrel for facing both sides and trimming to .250 width.

With the blanks made I decided to see if the device actually would relieve cutter teeth. To my relief it will relieve!

There are 2 more tools to make, a holder for drilling the 12 holes (might do this in the mill with dividing head) and a jig to assist in cutting the teeth gashes (might do that in the mill with slitting saw and dividing head as well). And of course whatever form tools to make the actual tooth shape.

There will be another intermission as yard work is kicking in, have to sand and treat 4 new Muskoka chairs. And have to work on our pond. Plus this coming weekend we (wife ands I both) will be at NAMES.

Gerrit

[mike mott]

This is really interesting, it is similar to the way that some of the watchmakers made their single cut milling cutters work. I made some 48DP cutters by turning the gear blank eccentric to the shaft, then notched the gear at the extreme point of the sweep so that I can sharpen the cutter on the one face and the cutter always has some relief.
I am not in the shop at the moment because I am recovering from emergency appendicitis and on some heavy painkillers. I will look for a picture of the cutter. I know I have them somewhere.

Found them


Mike

[gerritv]

Hi Mike,
Yes, Dean made a mandrel to assist in making 4 tooth ones. I am fascinated by tooling, sometimes I think making an engine model is just an excuse for me to make tools.

Gerrit

[gerritv]

Those look professional Mike, and a proper stand for them as well.

Gerrit

[mike mott]

Gerrit I agree the whole notion of making tools is one of the best parts of these hobbies. Thanks for the kind words about the cutters.

I used them to make these gears



I need to get back to this engine http://www.modelenginemaker.com/index.php/topic,4423.msg90810.html#msg90810

Mike

[zeeprogrammer]

I find this very interesting and I'm certainly enjoying the learning.
Very nifty thread.

@Mike - I hope you have a speedy recovery and get off the painkillers soon.

[90LX_Notch]

Gerrit-

I have been watching this thread with great interest. 

-Bob

[Dave Otto]

Gerrit I agree the whole notion of making tools is one of the best parts of these hobbies. Thanks for the kind words about the cutters.

I used them to make these gears



I need to get back to this engine http://www.modelenginemaker.com/index.php/topic,4423.msg90810.html#msg90810

Mike

That is a great project Mike, I would love to see more progress on it.

Dave

[gerritv]

I found Eureka's little brother at NAMES. 1/4" shaft instead of 1/2" for the cutters. Being used to make cutters for 72 pitch and smaller gears.

[gerritv]

Finally updating my posts, been a bit busy with stuff.
When I last posted the main part of the tool was complete and I had made some cutter blanks.
Next was making the drilling jig. While it is possible to drill the 12 holes in the blank using a dividing head, the jig means it can be done on the drill press without complex setups. The dividing head comes into play just the once to make the jig. Another bit of single point threading to make the 1/2-40 spindle and a trip to the blow torch for hardening.