File Guide Making: As simple as it seems?

David Schott

David Schott

Joined
Sep 27, 2004
Messages
3,041
Am I missing something, seeing these expensive file guides for sale here and there?

Can I just take two pieces of blade steel, drill and tap them both with two screws 3" apart from the other, screw them together, grind a perfectly flat edge against my platen, then heat em up above critical and quench?

Anything at home depot that I can just use? Seems like all I need are two pieces of hardened steel with holes tapped in em....
 
i made my own from mild steel to use on my disc sander. jkreidjr is heat treating a set i made from d2. i have some 1/4" thick carbide i'm going to see about getting laser cut into strips that will be attached to the next guides i make.
 
I've been using the mild steel reinforcement straps from the hardware store with a couple of 1/4" bolts. About $2 for four and I had to use all four. They're wearing away gradually but the price was right to start with. Of course, I also just ordered a set of file guides from Tracy Mickley for $15. I'll see how they work when they get here.
 
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David Schott said:
Can I just take two pieces of blade steel, drill and tap them both with two screws 3" apart from the other, screw them together, grind a perfectly flat edge against my platen, then heat em up above critical and quench?

....
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Not really. Screws make poor guides - they only pull things together.
What is also required are two guide pins, something like 1/4" or 5/16" attached to one of the pieces, and then run through two PERFECTLY drilled holes in the other piece. These keep the two filing pieces running perfectly parallel and square.
Then, once they are crewed together, they should be placed on an accurate surface grinder and face the two pieces at the same time.
The two screws are only to pull the pieces together while riding on the guide pins. As well, the thicker the two pieces of filing stock the better.
Filing guides without pins will work, sort of, but get the best you can buy or make.
 
Maybe this will help -
The pins so closely fit their respective holes, that unless they travel the pins simultaneously, the outfit won't go together. that way, I know the edges are on the same plane.
Screws alone allow too much slop.
This is only 5/16 O1 - I wish I had had some 1/2" when I made it. The thicker the stock of both guide material AND pins the better.
And by the way, I've filed maybe 40 knives on that so far and you will see hardly a scratch! I fully hardened the O1 and only gave it about a 350 temper just to remove a little brittleness and keep it as hard as I could.
fileguide-1.jpg
 
Hmm crap...i thought it seemed too easy. For this knife i'll do the good old sigle swipe of the file and black magic marker process while I wait for a file guide to arrive. Thanks for the info!!!
 
Those springs are a great idea! If they compress to the thickness of the blade.
Nice and thick, too. I like that.
 
I've got a piece of CPM 10v waiting to be made into a good file guide. Any suggestions on properly setting up the alignment pins? I assume they're just press-fitted into one side and the other side is drilled 1/64" or so over the pin size?

-d
 
karl, i dont think thoes are springs if you are talking about the ones b finnigan made. you are seeing the threads from the cap screws i do believe
 
deker said:
I've got a piece of CPM 10v waiting to be made into a good file guide. Any suggestions on properly setting up the alignment pins? I assume they're just press-fitted into one side and the other side is drilled 1/64" or so over the pin size?

-d
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NO!! 1/64" would be like a mile! Same size dimension as the pin.
You can always put that pin in a drill press and lightly sand until it JUST slides through the hole.
I can only speak for the way I did it.
I used 5/16" O1 pins and plate.
I turned a 10-32 thread on each pin. Drilled a .185" diameter hole through both plates clamped together. Then, on the inside face, counter-sunk the
.185" hole to 5/16" so the pin shoulder could sit inside.
While they were still clamped up, I also drilled the 1/4-20 tap hole size through both plates. Then, enlarged the pass-through hole in the top plate to .250.
Then enlarged the .185" hole on the bottom plate to 5/16".
Chamfered hole corners.
Hardened.
Surface ground faces.
 
actually i thought about putting springs on the first one i made but decided they werent needed. the threads do look like springs in that picture though so its an honest mistake. a good optical illusion:D
 
The guides need not be hardened if you simply grind all of the teeth off the edge of the file that will run against the guide.

George
 
Karl, I was looking at all the photo links myself trying to find which one had springs.:D I am not that creative, but it might be a good idea.

The pins on mine are 1/8" O1. I drilled the 1/8" holes while the two bars were screwed together and cut the O1 just a 1/16" longer and then peened just the top and then ground it flat. The peening is enough to hold tehm secure on the top bar.
 
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The one I bought from Uncle Al about 8 years ago has springs in it.

I 100% recommend the ones Al sells.

They are worth the money. I have one of his old ones and the new model with carbide faces.

This is definitely one of those cases where you get what you pay for. :)
 
I'm new enough to this thing that I have no idea how to use one of these :confused: Anyone got a picture (or could stage one) of a file guide in use so us newbies will understand better? Thanks.
 
jkf96a said:
I'm new enough to this thing that I have no idea how to use one of these :confused: Anyone got a picture (or could stage one) of a file guide in use so us newbies will understand better? Thanks.
Click to expand...

I was thinking the same thing!

Matt
 
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