GEAR CUTTING for the Cirrus V8

[bazmak]

I am almost ready to cut the 2 gears for the V8 but need to make
a few items first so have opened this thread for the prep work
I need to make
1- cutting tool
2- support mandrel
3- Tailstock support centre for the mill
4- deviding plate for 52 increments
When these items are finished i will return to the original thread for cutting the gears

 

[10K Pete]

I like where this is going! I've never seen a tool like that. Must have been
a heck of an interupted cut!!

Pete

 

[bazmak]

Piece of cake really,cut very easily.I wanted a single point tool but grinding the invalute form would be difficult.Cogsy showed me a similar 3 tooth tool
that automatically cuts the invalute form so decided to combine the 2.
Silver steel is easy to machine but 3/8" dia was the largest size i had so came up with this.I ground up a similar tool in HSS for cutting timing gears .See bandsaw mod.So i knew it worked well with alum.Opens up a whole new world
We will have to see how the gears mesh later. Regards barry

 

[steve-de24]

Bazmak, this is an interesting technique but how did you decide on the tooth profile and tooth pitch on your cutting tool? Steve

 

[bazmak]

As previous thread i measured a no of change gears from the lathe and came up with the dia,s for the 26 and 52 t.Made the blanks and trial fit so i know they were close.Then measured the teeth and ground the tool to suit the gear tooth profile.Rough and ready and as the photos shows they dont appear to be far away.As long as the 2 gears mesh and the ctres are right they are not too critical

 

[10K Pete]

I was thinking that the round cutter with the non-helical rack form would be
the way to go, but a single flute cutter like that seems so much easier! I'm
having trouble visualizing cutting those teeth on the end of a tool like that
in the lathe; the ultimate interrupted cut! But you did it, so I'll have to try
it!!

Pete

 

[Swifty]

Bazmak, this is an interesting technique but how did you decide on the tooth profile and tooth pitch on your cutting tool? Steve

When making this type of cutter, the depth and pitch of the teeth is the same as a rack gear for the size required. Searching on the Internet will provide the information required.

Paul.

 

[bazmak]

Making the interupted cut was vey easy.Slow speed,the teeth were only 2mm deep.I actually turned the final few thou by hand to see were i was at it just scraped off.As for the profile being a rack thats why i used the largest gear to shape the profile.Maybe even try cutting a rack in a rack in the near future.
Cant wait for Ivan Laws book to arrive for some light reading and so i know what i am doing.Hardest part was trying to measure the pitch of the teeth from an unknown gear

 

[10K Pete]

Thanks, Baz. I've done some serious interrupted cuts but never on the end
of a bar like that. Just looking for some assurances I guess.

Pete

 

[gus]

Hi All.

There is so much to learn from the ''pros''. Hi Baz. Waiting for your engine video.

 

[Cogsy]

I was thinking that the round cutter with the non-helical rack form would be
the way to go, but a single flute cutter like that seems so much easier!

I'm reasonably sure the 5 'tooth' cutter would provide a better approximation of the true involute profile, especially on the larger gears. Plus I thought just the opposite - this looks a bit tricky for me!

Will be very interesting to see the results.

 

[bazmak]

Next was to make a tailstock support.Raided my scrap bin and came up with a piece of angle and square bar.Rough and ready,no bells and whistles and ignore all the surplus drillings.If i use it a lot then i may make a proper one

 

[10K Pete]

Git 'er done!! I love your RT indexing adaptor Baz.

Pete

 

[bazmak]

Last item on this thread is to make a 52 div plt.When i made the rotary table
the central dovetail groove had 24 hole divisions.When i cut the timimg pulleys for the bandsaw i drilled the top flg 60 divisions.I decided to drill the bottom flg 52 divs.If i need any more at a later date i have tapped holes in the face of the table to be able to bolt on division plts.I marked out on white card 52 devisions ,glued to the table and drilled and csk 52 holes.Another day and fingers crossed
for cutting my first blanks.This thread is now closed and back to the main thread. Regards barry 2_zpsnqhqu20m.jpg[/IMG][/URL]

 

[bazmak]