Bolt - p/n 192167

[TheOldHokie]

New rotary broaching toy works good - broached a 3/8" hex drive version of that hard to find special crankshaft pulley screw used on on Dearborn and Wagner loaders. Little bit of a learning curve on the speed and feed - took 4 tries to get an acceptable socket. The fourth one still has a little starring on the lead in but the socket is tight and straight - next ones will be cleaner. Now all I need to do is find 50 customers @ 7.50 ea. to pay for the tool and broach :roll:

TOH

 

[GVSII]

Couple of pretty pieces.

 

[sawgrass]

Very nice, I'd love to see your set-up too!

 

[TheOldHokie]

(quoted from post at 08:15:13 02/28/11) Very nice, I'd love to see your set-up too!

It was made with a rotary broaching tool - aka wobble broach. The hole is prepared by drilling to 3/8" to match the 3/8" hex broach. The hex cutter does not rotate - the tool holder rotates around it on a ball bearing supported shaft - roughly 800 RPM. As the broach is feed into the hole an eccentric setup on the shaft causes the broach to wobble" 1* axially. The wobbling action causes the sharp edge of the broach to shear away the sidewall of the round hole as the knee forces the work piece upwards. It requires a pretty aggressive feed rate into a 1/4" deep blind hole. When doing it manually it takes a little practice to time it out so that you don't bottom the broach in the hole and break something. For a 3/8" hex socket in mediumcarbon steel you need about 1500# of thrust from the knee so it's not a light duty operation. You have to watch the knee readout carefully and be ready to kick off the feed at just the right moment. Works real slick but the tool holders are VERY pricey and I sure wouldn't want to break it....

TOH

 

[Dunk]

(quoted from post at 21:10:17 02/28/11) It was made with a rotary broaching tool - aka wobble broach. The hole is prepared by drilling to 3/8" to match the 3/8" hex broach. The hex cutter does not rotate - the tool holder rotates around it on a ball bearing supported shaft - roughly 800 RPM. As the broach is feed into the hole an eccentric setup on the shaft causes the broach to wobble" 1* axially. The wobbling action causes the sharp edge of the broach to shear away the sidewall of the round hole as the knee forces the work piece upwards. It requires a pretty aggressive feed rate into a 1/4" deep blind hole. When doing it manually it takes a little practice to time it out so that you don't bottom the broach in the hole and break something. For a 3/8" hex socket in mediumcarbon steel you need about 1500# of thrust from the knee so it's not a light duty operation. You have to watch the knee readout carefully and be ready to kick off the feed at just the right moment. Works real slick but the tool holders are VERY pricey and I sure wouldn't want to break it....

TOH

Thank You So Very Much, for that explanation, and pic!!!
I would have never known otherwise.