Crowner Mods -Tips

All, Helping a good friend of mine. he has a machine called a crowner. Its used for making arcs big ones not direct curves like 45, or 90′ bends.
anyways its specs say it maxes out @ 2-1/2″ well he’s trying to crown some 2-1/2″ material. it ships with 2-1/2″ dies. right from the mfd.. Should be easy eh?

Having tried/attempted to crown some 2-1/2″ material. the machine stalls just as the tubing tries to pass thru. Parallel to this issue is another issue where the tubing scars the rollers so bad it renders them un-useable in some time. (Another topic).  So to remedy the 2nd issue I made a series of spear tips to save the rollers from getting scar’d up. well I think the spear tip would actually help in the stalling issue. as it stalls right when the forces go from just about zero to MAX. the spear tip would allow the 0-Max to be more gradual. Ill include a video when I get back to his shop. but for now is the quick making of the spear tip for 2-1/2″ material.
Below cutting 3″ 6061

Below the cutting of the spear portion of the tip. FWiW it being held int he chuck by the portion that goes inside the 2-1/2″ tubing itself. so the spear tip will go almost from the right end to just about 1/2″ short of the lathe chuck.

Below the shoulder for the 3″ tubing it self.



Above The reason for the hole.ITs Tapped to accept a bolt.In the case it gets stuck in the end of the tubing It can be used to pull on it ie a slide hammer. ie or similar.


Yes, the middle one is just shy of 3″ diameter by 9″ long! its not small by any means.