# Tapper using connecting rods



## Racer57 (Oct 7, 2021)

Hi,
    My first post.    I saw somewhere that tapper had been made from Briggs connecting rods.   I turns out that I have many Fiat connecting rods from rebuilding dual cam motors for my racing habit.

I set off and after a few stops and starts I have something that works.   My first issue was that I am still learning that when I am turning something for a tight fit "just one more cut"  is one too many.    The second try works as I  hoped.    The other issue was that I tried a Jacobs chuck instead of a tap handle.    Its grip was no where near enough.   I had to buy a tap handle and modify it by cutting off the end and the drilling and taping to fit the rotating arm.

The pictures have some parallax that makes things look crooked.    The rotating arm is perpendicular to the base in both axes,

Will


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## woodchucker (Oct 7, 2021)

welcome to the conversations. A pretty good start.
BTW you can be a newbie or an experienced machinist, and sometimes taking that last cut.... well it happens to the most experienced sometimes.. 
Don't know if you realize it, your compound can help you cut less than 1 thou...
I usually have my compound set to 29.. 
but if you set it to 45 a 1 thou movement of your compound is a 1/2 thou movement in reality.

you don't need to set it to 45, I was just showing you what can be if you weren't aware.


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## jwmelvin (Oct 7, 2021)

woodchucker said:


> but if you set it to 45 a 1 thou movement of your compound is a 1/2 thou movement in reality.


At 45° the advancement is actually ~.707; if you set it to 60° then you’d get .5 off x per 1 travel of the compound. 

Ability to take small cuts seems to depend a whole lot of the tool (sharpness and tip radius).


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## f350ca (Oct 7, 2021)

Thats incredible. There was a chap on a long gone forum some 20 years ago who's handle was Conrod. He used them for everythiing. Even built a horizontal mill from an old engine block and used them for the arbour support.

Greg


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## rdean (Oct 7, 2021)

good job Will it should work fine.

Ray


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## brino (Oct 7, 2021)

Great re-use of available parts!
I've not seen that before.
Thanks for sharing it.
-brino


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## matthewsx (Oct 7, 2021)

Nice, could have built a bunch of those back when I was building racing kart engines.

Is that a Spec Racer Ford in the background?

JOhn


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## Racer57 (Oct 8, 2021)

Yes, it is a SRF.   Between it and machining all questions about what to do with my spare money have been answered.


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## Gaffer (Oct 8, 2021)

matthewsx said:


> Nice, could have built a bunch of those back when I was building racing kart engines.
> 
> Is that a Spec Racer Ford in the background?
> 
> JOhn


John, you have an amazing eye/observation. I had to look and the picture again and then Google it to see what you saw. Awesome!


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## Chris Hamel (Oct 8, 2021)

Neat use of old parts.


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