Question on modding 93 mm Victorinox

[Psych]

Hi all,

I'm going to attempt my first mod of a 93 mm Vic in the next week. I'm going to be using 1/8" pivot barrels in the mod and I'm wondering if the holes in the scales need to be drilled all the way through to 1/8" and then countersunk on the front of the scale. Does anyone have advice on this? I've read up on other modding posts here but it wasn't clear whether the holes in the scales were drilled completely out to the diameter of the pivot barrel.

Thanks for any advice!


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[tattoosteve99]

Yes drilled through and counter sunk. Wait until the pivots get to you so you can use the screws to countersink to the proper depth. Also make sure to sand the tool holes with sandpaper to smooth it out.

[sLaughterMed]

Since this is here already....

Drill bits seem to be slightly smaller than the size advertized (2.5mm bits are actually 2.48mm, for example). How do machinists normally handle this, when pin stock and pivot tubes are pretty dead on, if not slightly larger?

For example: I have a 2.5mm (actually 2.49mm) drill bit, and 2.5mm pin stock. Would I need to get a 3mm drill bit for this pin stock (lets assume sanding down the pin stock is not uneconomic)

[Fortytwo]

Since this is here already....

Drill bits seem to be slightly smaller than the size advertized (2.5mm bits are actually 2.48mm, for example). How do machinists normally handle this, when pin stock and pivot tubes are pretty dead on, if not slightly larger?

For example: I have a 2.5mm (actually 2.49mm) drill bit, and 2.5mm pin stock. Would I need to get a 3mm drill bit for this pin stock (lets assume sanding down the pin stock is not uneconomic)

Depending on your tool setup I think you'll get away with just moving the drill bit in and out a bit. At least my drill don't have that kind of precision. A machinist working with high precision tool would probably ream out the hole if precision is important. You might also consider a round jeweler's file or something similar.

[Gryffin]

Drill bits seem to be slightly smaller than the size advertized (2.5mm bits are actually 2.48mm, for example). How do machinists normally handle this, when pin stock and pivot tubes are pretty dead on, if not slightly larger?

For example: I have a 2.5mm (actually 2.49mm) drill bit, and 2.5mm pin stock. Would I need to get a 3mm drill bit for this pin stock (lets assume sanding down the pin stock is not uneconomic)

There are a LOT more drill sizes than you realize, for this exact reason. Given a nominal hole size, the machinist has to also deal with different classes of "fit", between "pound-it-in" to "press fit" to "snug" to "spins-freely." That's why there are a whole series of "gauge" sizes, in many more slight gradations of diameter than typical english or metric.

A full set of gauge drill isn't cheap, but if you can find a source that'll sell you a few, you can get what you need. In your case, a #39 (2.527mm) or #38 (2.578mm) would allow easy fitting of your 2.5mm pin stock.

https://en.wikipedia.org/wiki/Drill_bit_sizes

[sLaughterMed]

Thats what I assumed about the gauge sizes, I just couldnt find any good info on it.

Thanks for the heads up

[Syph007]

Since this is here already....

Drill bits seem to be slightly smaller than the size advertized (2.5mm bits are actually 2.48mm, for example). How do machinists normally handle this, when pin stock and pivot tubes are pretty dead on, if not slightly larger?

For example: I have a 2.5mm (actually 2.49mm) drill bit, and 2.5mm pin stock. Would I need to get a 3mm drill bit for this pin stock (lets assume sanding down the pin stock is not uneconomic)

Short answer is drill bits are not used for precise holes.  Normally you drill close, then use a reamer for a precise fit.  That is the standard way knifemakers do it for pivot based folders.

[sLaughterMed]

Good to know