Hi All,
I posted a thread (pun intended) earlier about what thread profile to use for wooden threads.
I'm reposting the pictures of the tap, just to keep it all together..
(The previous post was in the metal work section)
This is the next stage of that project.
I finally got the new tap made, it's 2" 3.4 tpi 90 degree profile.
The only critical dimension is the root diameter should be made to suit whatever hole size you can easily drill, in my case that was an 1 3/4" forstner bit. The cutting flutes are offset slightly when milled so as to create a slight angle to the cutting edge
None of the other dimensions are not especially critical. The bar is a 3/4" drive and I welded a 1" 3/4 square drive socket on the top.
It takes three teams of horses and extension handles to cut a thread in dry english oak.. but it works...http://www.sawmillcreek.org/images/smilies/smile.gif Thanks Ray very encouraging NOT :~
The next stage was to cut the male threads, I started making a screw box, but I never even got it finished, I went for a router with a chamfering bit instead, mounted on the lathe cross-slide.. (an idea I borrowed from George Wilson over on Sawmill Creek. thanks George!
http://www.sawmillcreek.org/images/smilies/smile.gif)
This is the general set up.. for those who are squeamish about killing electrons look away now...
The router is a Makita laminate trimmer with a chamfering bit.
After cutting the thread I sanded off the peaks of the thread to round them off a bit.
The finished diameter, I went for a fairly loose fit, to allow for moisture expansion.
Ok, the squeamish ones can look again...
And finally the threads and shoulders cut, it's ready for a few final finishing touches.
Then I can put the vise together..
More to come later, when I get the jaws made.
Regards
Ray