Group Project: Rotary Broach-- Building complete, all shipped out!

[ErichKeane]

Is the cup needed? I saw an article where they didn't put the cup and it cut the same.

Do you have a link to that article? Someone mentioned it above, but thought they were mistaken. I would LOVE to not have to do the cup

 

[ErichKeane]

@ttabbal @T Bredehoft @GunsOfNavarone

PM me your addresses and I can ship out your stuff! I can try cupping the bits first if you'd like, but if @John O has an article that says it doesn't make a difference, I'm just as up for not doing it. Let me know in PM if you want it ASAP, or to wait for my attempt to cup them.

 

[brino]

Is the cup needed? I saw an article where they didn't put the cup and it cut the same.

@John O , if you can find that reference we would all be interested.

Someone mentioned it above, but thought they were mistaken. I would LOVE to not have to do the cup

Actually I believe that I mentioned it first in post #212.
I went searching for the article and never found it. I mentioned that in post #223.

The idea was that the cutting edge was stronger with a flat face.

The only reference I can find now is this quote:

Most sources suggest a concave end, randyc indicated that a flat grind will remain sharp longer than concave.

from here:
http://jamesriser.com/Machinery/RotaryBroach/Build.html

-brino

 

[ErichKeane]

>>Most sources suggest a concave end, randyc indicated that a flat grind will remain sharp longer than concave.

This matches my expectations. A flat face will have a 1 degree cutting rake, so it at least will 'cut', though perhaps a larger rake is beneficial for cutting? Either way, a flat face will wear better I suspect.

 

[ErichKeane]

@ttabbal and @T Bredehoft : both shipped USPS a minute ago, should be there Friday!

 

[T Bredehoft]

Great. and thanks for the experience...

 

[ErichKeane]

All 3 shipped! Everyone should get it Friday!

 

[GunsOfNavarone]

Man! wasted NO TIME shipping those.....I don't blame you at this point, I think you bit off a big job...

 

[ErichKeane]

Man! wasted NO TIME shipping those.....I don't blame you at this point, I think you bit off a big job...

Hah, I am glad to have it off my plate... Next time I'll take an easier part

Fortunately you sent me your info about 20 mins before the post office closes, so I was able to go down the road and get out of my hands!

 

[ttabbal]

Cool! Looking forward to checking it out.