Precision knifemaking progress part1

[Chiro75]

Okay, I finally started working on the 1084 with my new bits, reamers, etc. Broke two drill bits right off the bat. Evidently my drill press table IS pretty square, but the drill press vice holding my work is not. So I learned 2 things: 1) Throw the vice out and just clamp to the table and 2) Drill pilot holes first (this is for my 3/16" holes).

Reaming went fine, although it didn't seem like much was happening. Is that how it should be? I tested a 3/16" pivot and it fit in snugly, but there was a little bit of play. Is this acceptable or total crap? What would cause this amount of play? Do you literally need a different reamer for every hole you make that is going to have a pin or pivot in it? In other words, how do you get a "perfect" fit every time?

Also, I need to work on my layout capabilities. Layed everything out, looked great, drilled, reamed, and now my pivot holes are at least 1/8" off. I think I can resurrect the thing as long as I get the handles lined up (this is for a balisong) to function properly. Having them perfectly centered is not necessary on this knife because the stops are going to be ground in to the blade, so that gives me some leeway. It might look a little lobsided, though, in the end!

 

[Chuck Gedraitis Knives]

The best way to keep everything lined up and to drill your holes where you want them is first drill with a center drill. It is a short drill that is thick that does not have any flex in it so it won't "walk" when you start to drill. It is also better to use on titanium sheet because you won't warp the sheet like you could with using a hammer and punch.

The other thing is did you drill with a 3/16 drill and then ream? You need to drill undersize and then ream to size. I drill with a #14 drill and then ream. This gives you a nice snug fit. Then I polish the pivot and it will be nice and smooth.

 

[Burchtree]

interesting bit of info there Chuck --

 

[Chiro75]

No, sorry, I was going for 3/16" holes, so I used the recommended #15 bit and a 3/16" reamer with straight flutes. Used tapping fluid, the wholel bit. The fit is "good" just not great. For a balisong I think it will be fine, but I suspect it's still a little sloppy for something like a liner lock. But, if a little tolerance is all it takes to make slop, how do you get a precise fit every time? I assume that "3/16 pivots" could mean anything, just like "3/16 drill bits" aren't REALLY 3/16". So, how do you do it, or did I just make bad holes this time?

 

[mete]

Don't assume. Dimensions of screws, pins,drills etc can all vary and for the tightest fit drill test holes , see how the pins fit etc. and when you really want something snug lap pins to holes . BTW screw threads are rarely cut 100% full , but 90% or 80% etc.