In some of the machinist catalogs you see these larger ones called rotary files sometimes.
To me, and most woodworkers, a true rotary file has teeth on it more like a rasp. However, metal workers sometimes call these larger burs rotary files too.
Some folks say they get chatter using this type of bit, but they always work fine for me.
If your intent is to use the burr freehand with a dremel or flexshaft to cleanup the tobacco chamber, you need a heck of a steady hand so as not to gouge pits.
@Ray
You're probably referring to these items:
They're very aggresive, so I rarely use them.
Regards,
Frank.
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Grouch Happens!
People usually get the gods they deserve - Terry Pratchett
Chatter is exactly the problem I have. Having said that I still need to experiment with what I have (modified spade bits) to find the best solution. Thanks for the suggestions Frank, I'll try to find the tools you mentioned here in New Zealand.
No thats not it. Those are what woodworkers call a rotary file.
Metalworking rotary files have a different cut, just like a metal file has a different cut than a wood rasp. If you look those giant burs up in a Machinist catalog like MSC, J&L, Enco etc. thay are often called rotary files once they get over a certain size. My MSC catalog is a couple years old 2004-2005 but on page 157&158 they have these listed as rotary files.
I don't know why they do this. Seems to me a bur is a bur no matter how big it is.
Nick wrote:What I want to know is how that half shaped stumel came to be? It looks like it was turned on a lathe, buy how could you turn somthing in that way?
Oh yes, isn't that intriguing... It also looks almost finished, polished and all. Maybe that's the only way of reliably knowing (and following) the grain, but what do I know...
Karol wrote:Chatter is exactly the problem I have. Having said that I still need to experiment with what I have (modified spade bits) to find the best solution.
This is already OT, I just played around with the spade bit, made sure as best as I could that it's symmetrical, shortened it's shank significantly and skipped drilling the pilot hole. I firmly believe that the pilot I drilled before is the main reason for the chatter as without a material there is nothing to guide the bit. This time it went inside like a was drilling a block of butter.