Folder Pivot questions (bit size,reamer,etc)

[Kentucky]

Hi, Im looking at making myself a friction folder..Ok, Im looking at a 1/4" Pivot barrel...When I drill the blade for the pivot barrel would I need to use say a Size "D" bit(.2460) and then use a 1/4"(.250) fluted reamer to get a good tight but smooth fit? Ive heard it is best to drill slightly undersized(hence the "D" jobber bit) and then ream..If Im off here please correct me..Any help is appreciated..Thanks Phil

 

[blindhogg]

Ok first off you need to get your pivot first. Just because it says its a 1/4 pivot does not mean it will measure .250.
Second do you want your blade to rotate freely on this .250 pivot? if so then your blade might need to be slightly larger.
Personally I ream to .250 then check fit, and if it needs to be larger I use a special lap to open it up slightly. Not sure of the real name.
Personally I might try a hole smaller than .246 I can see with runout your hole already being larger than .250 after drilling a hole.
Check in scrap first.

 

[Kentucky]

Free but without wobble of course..I plan to adjust tension with the barrel screws..Though, maybe I need a tighter fit? Anyway would you suggest maybe going down to a 15/64" then reaming?

 

[wolffbite]

I haven't done much work with folders... but for the one I currently have in progress, I drilled out with a 7/32 bit and then reamed to size. I don't think the reamer will last as long this way (gives it more material to rip through), but it is giving me a free rotating blade on the pivot with absolutely no wobble. I'd say smaller the hole to start the better, you get a better chance at a perfectly circular hole.

 

[butcher_block]

i under size dril and thenn HT then crabide 4 flute chace the hole

the i check the pivot and sand eit ot fit

 

[Frank Niro]

You should use a drill bit a little more undersize than that "D" then the .250 reamer. All the pivots I have bought in the last few years have been + or - .0005 in accuracy. Frank