Dillon Sculpture Posted February 29, 2012 Posted February 29, 2012 Been making some tenons on the lathe with a rotabroach, many sizes to chose from. 1-1/4" square with a 7/8" tenon in 90 seconds on my old south bend using the back gear. I suppose if you didn't have the 3/4" chuck you could make an adapter with your lathe ;) Quote
macbruce Posted February 29, 2012 Posted February 29, 2012 90 seconds! What the heck are you trying to do here....make some money?....... B) Quote
Timothy Miller Posted March 1, 2012 Posted March 1, 2012 Same can be done with a power hammer and a tenon tool about as fast but not as precise. I hate turning the hand wheel all day on the tail stock puts a cramp in my wrist. Quote
HWHII Posted March 1, 2012 Posted March 1, 2012 WOW! I never would have thought of this. This is a great idea. Did you think of it? Quote
Dillon Sculpture Posted March 1, 2012 Author Posted March 1, 2012 I herd Yellin used a simular method, not sure if its true. Size correction, that is a 1-1/4" rotabroach that makes a 7/8" tenon, the material is 7/8" cold roll square that is 1-1/4" on the diamond. I can cut the distance between the tenons on the picket to a 32 using this method, besides I needed a 3/8" fine taped hole as well. I've also used these cutters in the mill for offset holes in tubing and solid material. Quote
HWooldridge Posted March 1, 2012 Posted March 1, 2012 I turn solid tenons using a single point in my old Clausing with power feed and it's well under a minute for most any common size. I think you can speed it up by mounting your hollow mill in a boring bar holder on the compound and use the lathe to feed. Did you tap in the lathe or do that operation manually? Quote
Timothy Miller Posted March 1, 2012 Posted March 1, 2012 I herd Yellin used a simular method, not sure if its true. Size correction, that is a 1-1/4" rotabroach that makes a 7/8" tenon, the material is 7/8" cold roll square that is 1-1/4" on the diamond. I can cut the distance between the tenons on the picket to a 32 using this method, besides I needed a 3/8" fine taped hole as well. I've also used these cutters in the mill for offset holes in tubing and solid material. I am sure Yellin did, I have read something somewhere he used "hollow end mills" I have never found a hollow end mill to buy though. If you look closely at his bed you will see that the tenons on the stretchers are lathe turned. I think I could hold 1/32 with a Gage bar on the tenon tool I never tried though. Your method seems superior for your application. Quote
Mark Emig Posted March 1, 2012 Posted March 1, 2012 The Yellin shop did use hollow ground end mills to cut tenons-held vertically in a drill press. A rota-broach is basically the same tool-only not as long. I don't know of anyone making a hollow ground end mill anymore.They did it that way for the same reason you are-time-which equals MONEY. I look at things the same way-who cares how you get the end result-so long as you can be profitable. We all gotta eat, after all. Quote
HWooldridge Posted March 1, 2012 Posted March 1, 2012 Heck, we use hollow mills every day in the machine shop for general work. Just google "hollow mill" and you'll get lots of choices. MSC sells them as does Genesee; I've even made small ones in my home shop out of drill rod for cutting brass. Drill or bore the ID then set up in an index and cut the teeth with an end mill. Harden, draw and put to use...piece of cake. Quote
HWHII Posted March 1, 2012 Posted March 1, 2012 I thought about this all night and I am wondering for some of us who do not have a lathe but have a mag drill. Do you think it still would work if you fixtured the part in a V block or a old lathe chuck and jigged the mag drill horizontally to cut the tenon? Quote
Dillon Sculpture Posted March 1, 2012 Author Posted March 1, 2012 Yes, my friend made a rig that bolts to the side of his table that allows him to use his mag drill horizontal to drill the end of long stock. I did tap the pickets in the lathe. Quote
Ric Furrer Posted March 1, 2012 Posted March 1, 2012 Heck, we use hollow mills every day in the machine shop for general work. Just google "hollow mill" and you'll get lots of choices. MSC sells them as does Genesee; I've even made small ones in my home shop out of drill rod for cutting brass. Drill or bore the ID then set up in an index and cut the teeth with an end mill. Harden, draw and put to use...piece of cake. Good idea!! I do have the tooling to forge the common tenons I used to use, but this is interesting. Here is one on brass It appears it also sets up a chamfer on the interior..maybe a tool like this would do the center hole for your taping operation as well Danger? Quote
Randy Posted March 1, 2012 Posted March 1, 2012 That's slick! Looks like a heavy duty hole saw. Does it have a drill bit in the center for that hole, too? Quote
John B Posted March 1, 2012 Posted March 1, 2012 Could be slicker, Guy who programmed it was cutting air for longer than metal, but what do I know, I'm only a has been blacksmith Quote
pkrankow Posted March 29, 2012 Posted March 29, 2012 Annular milling cutter?http://www.icscuttingtools.com/Annular.htm Phil Quote
JNewman Posted March 30, 2012 Posted March 30, 2012 Those annular cutters are great for a lot of applications. I had to make a bending fixture for bending a bunch of similar but different brackets that all had to be very accurately bent. The annular cutters allowed me to drill two holes side by side that intersected each other. There was no tendency for the drill to want to veer into the other hole. I then used a different sized one to drill 4 9/16" holes through each bent flat bar with very little down pressure. The holes are much cleaner and closer to size than a twist drill produces. Usually they have a spring loaded center pin that ejects the core that they cut out. Looks like they also do a great job for tennons. Quote
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