Using a Jig with a file to bevel. Giving me issues

mccandmatt

mccandmatt

Joined
Oct 29, 2013
Messages
358
Since I really have not come remotely close to doing a good bevel with my little belt sander I made a jig for filing the bevels. I have it all measured up where the plunge line is centered to the file and Eye bolt. My issue is that the center of the blade edge (two now) are being ground more so I am getting a dip at the same location on both sides. I apply as far as I can tell the same pressure and speed every time but the dip keeps forming.

My jig consists of a 2"x8" with the 3 holes in the center for the eye bolt and a series of holes to screw down the blade. Pretty simple. My technique is to file down close to the edge mark first on one side, then flip the blade to the other side keeping the eye bolt in the same hole and height and making the edge about the width of a dime 0.050". And then work it back etc. etc.

Sorry for these questions just trying to learn by fire and from the you good people.

Thanks in advance,
Matt
 
gredpe3 said:
We need to see what you are working with.Jig/Steel /Files all of it.
Eddie
Click to expand...

Pics below. Like I said it's simple. I plan on making a new one with a T at the blade end for when I make larger knives, but I threw this together pretty quick last week, as you can see took me all of 3 minutes to do. I have the half round file on there now but I always use the flat file, not sure why I put the halfround on.

Here is the other stuff:
Files are 10" Nicolson (half round and flat)
1084 9/64 (1/8 was sold out) steel from USA Knifemaker cold rolled (if that helps)
It's a 2x6 not 2x8 like I posted earlier.



 
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Just do it free hand.
Mark the center of the blade. (the edge)
Start the plungelines with a chain saw file. Only go half as high as wou want the bevel to go.
Next file app. 45 degree to the scribbled center line along the edge.
After that remove more and more material untill your bevelline is as high as you want.

After that flatten the bevel by draw filing
 
What Hengelo_77 said is exactly how I do it and recommend. DO NOT USE THAT JIG!!!! Waste of time. There is nothing that jig can do that you cannot do freehand....I PROMISE. Straight grind lines can be done freehand as well, using the draw filing method. The plunge line needs to be nice and straight, and for that you can use a chainsaw file, which will give you a radiused plunge, or you can use your flat file (but you need to use some sort of file guide to keep that line straight). Without a guide, use the chainsaw file as Hengelo recommended, and then use a flat file to cut the bevels. Make those first cuts at 45 degree angle, all the way to your edge scribe line. Then, lower your angle to cut the "hill" you created with the 45 degree angle. Once that angle is done, lower it again to cut the hill you just made. Keep cutting those hills until you are as high as you want to go, and then start draw filing. Chunk that jig!!!!
 
I also recommend free-hand here... One big issue I have noticed with guys using a set-up like this for their filing work, is the tendency to just keep filing away without stopping to clean the file with a file card.

The main issue though, is I only see this type of rig as slowing a guy down. And since it has too many variables in how it works, I really don't see it as offering tighter control/more precision over free-hand filing.

I've been accused of being the guy who "makes a jig to make a jig" but I only make a gizmo/gadget when it will help me do something better and/or faster. I really don't think this type of rig is going to help you with either of those.

Good on 'ya for getting started with files...:thumbup: That's how a good lot of us started.

In the "immediate gratification" society we live in now, I often hear things like, "I want to make a knife but I don't have a grinder." :rolleyes:
 
mccandmatt said:
My issue is that the center of the blade edge (two now) are being ground more so I am getting a dip at the same location on both sides. I apply as far as I can tell the same pressure and speed every time but the dip keeps forming.
Click to expand...

I would not just throw that jig away.

It's helping by keeping your angle consistent, that's the most difficult thing I found about freehand filing.

Is the jig straight? wood is hardly ever straight.


If you are removing too much material from one area, stop that.
Move your file and remove the material from the area that needs it.
 
When filing bevels I found it helpful to color the area I was grinding with a cheap magic marker.
 
So, a couple of things:

1) I notice you are using a half-round file rather than a flat file... I recommend using a flat file with the corners ground off otherwise the edges of the file will tend to bite in, most likely contributing to the dip you are seeing.

2) If you want a clean plunge line you definitely need to takes the corners off the file as I recommended above (or file the plunge line separately)

3) In order to get the plunge line correctly positioned I recommend using a bolt/screw that sticks up and stops the file from moving toward the butt of the knife, positioned wherever you want the plunge line to be.

4) In order to get a good bevel from a filing jig the actual technique of filing is important. Only file on the push stroke, make sure you move the file sideways as you push. If you just dwell in one area you will end up with dips.

I have a video detailing the filing jig I recommend along with the technique to use it here:

[video=youtube;r9iNDRwwBQQ]https://www.youtube.com/watch?v=r9iNDRwwBQQ[/video]
 
aarongough said:
So, a couple of things:

1) I notice you are using a half-round file rather than a flat file... I recommend using a flat file with the corners ground off otherwise the edges of the file will tend to bite in, most likely contributing to the dip you are seeing.

2) If you want a clean plunge line you definitely need to takes the corners off the file as I recommended above (or file the plunge line separately)

3) In order to get the plunge line correctly positioned I recommend using a bolt/screw that sticks up and stops the file from moving toward the butt of the knife, positioned wherever you want the plunge line to be.

4) In order to get a good bevel from a filing jig the actual technique of filing is important. Only file on the push stroke, make sure you move the file sideways as you push. If you just dwell in one area you will end up with dips.

I have a video detailing the filing jig I recommend along with the technique to use it here:

[video=youtube;r9iNDRwwBQQ]https://www.youtube.com/watch?v=r9iNDRwwBQQ[/video]
Click to expand...

Yeah I use a flat file, I just threw it back together for the picture to show the setup as someone asked for it. All the corners are filed down so it does not bite in. I also use a screw which is not shown here so I do not go past my desired plunge.

That video is one of the ones I watched a few weeks ago, it is very good.
 
quint said:
Great video, thanks for posting and taking the time to make it.
Click to expand...

No worries! A less refined version of that jig was originally given to me by the maker that first showed me a bit of knifemaking (Neil Charity), so I figure it's only right that I should help pass on his info and the extra stuff I've learnt!

mccandmatt said:
Yeah I use a flat file, I just threw it back together for the picture to show the setup as someone asked for it. All the corners are filed down so it does not bite in. I also use a screw which is not shown here so I do not go past my desired plunge.

That video is one of the ones I watched a few weeks ago, it is very good.
Click to expand...

When I first started using the filing jig I got dips in the middle of the blade as well. Moving back toward the spine in stages, and keeping the bevel even as you go is one of the very important parts. It definitely takes some practice to get it right even when using the jig, but I have confidence you'll get it!
 
With a fixed end jig the angle changes as the distance from the fixed point to where you are filing changes. Not much but if you add in a few other factors it does make a difference. When I first started making knives I worked completely with hand tools. I tried free hand, but quickly realized that I had a pronounced strong and weak side so I made a jig that didn't have a fixed point for the file









It still had issues with the slight angle change, but I could keep it minimal. The bar on the back was adjustable so I could take steel away much like you would with a grinder. Start at a steeper angle, work it down to my center mark, then slacken the angle a bit and work it till I blended in the first session, and so on till I hit my grind line or spine.

Nick is 100% right about cleaning the file often, Even with a course file I would not do more than 3 passes without cleaning the file. When I switched to a fine cut file to clean everything up before hand sanding it would be one pass and then clean the file. I also found that common driveway chalk help a lot to keep the file from clogging and gouging.

The picture of the file on the bottom is a new file after one pass over 5160 without chalk. You can see the globs of steel caught in the teeth. Each one of them would almost guarantee a gouge in my bevel if I were to take a second pass.
 
Awesome jig my friend. I really like how it holds the file.

here is my setup. clean the file often. Once I get a 2 x 72 I will probably just use it for scandis or for the times I just want to get some energy out and make some knives with little mess and little noise. My only complaint is I designed it to big. I like gumbi's short setup. Gumbi you need to let me know how much you charge me to make me one of those file holders bro!

Shop2.JPG


shop3.JPG
 
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Interesting jigs but IMHO you can make a hand full of blades in the time and for the cost of the materials as it takes to make such a jig.
If you keep it simple and finish off by drawfiling your hands will be steady enough to not need jigs.
Free hand also gives a lot of freedom in design
 
tradhunter said:
Awesome jig my friend. I really like how it holds the file.

Gumbi you need to let me know how much you charge me to make me one of those file holders bro!
Click to expand...

Sorry I can't make another and I sold the jig when I move back to Ontario, and also lost access to the machinery used to make it:( It is pretty simple to make though, the bar is a piece of industrial overhead door track, the rear handle was just cut out of plywood and the front handle is a shift knob from an auto wrecker. I made a pocket to hold the front of the file out of an old BMX brake. I did make the holder a little short , it should have been about 4" longer to get full use of the file.

Hengelo_77 said:
Interesting jigs but IMHO you can make a hand full of blades in the time and for the cost of the materials as it takes to make such a jig.
If you keep it simple and finish off by drawfiling your hands will be steady enough to not need jigs.
Free hand also gives a lot of freedom in design
Click to expand...

I tried going free hand, but I could not maintain a consistent bevel from one side to the other. I could draw file a near perfect bevel on one side, but once I flipped the blade over I was all over the place:o In hind sight the inconsistency was probably due to my elbows starting to go. The jig didn't take all that long to make, the most time consuming part was laminating the base. It didn't need to be laminated, but I had the material laying around, and it made clean up much easier. If I remember right the jig only took about 12 hours to make, but it was spread over a couple days.

I switched to a Grinder in a Box 2X72 about 1 year after the jig and went free hand till last fall then had to stop making knives because of elbow issues. I had a second surgery on the left elbow in the spring with no relief, so now I am looking at going back to a jig, but for the grinder now.
 
I am one who feels that a jig like the ones shown just limits you...not aids you. Learning to do any task is a process. You don't start out at the top. If you use a file jig like the ones shown...that is all you will ever learn to do. It might take a few hours of filing time to get the hand eye coordination of hand filing, but once learned, you can file anything at any angle.....because you know how to make the file go where you want it to. Same goes for grinding.

Also, there seems to be a great preoccupation over the angle of the file and bevel. Folks, we aren't sharpening the blade....we are tapering the bevel. This is sheerly a function of the spine thickness and the edge thickness you wish to leave. It makes no difference what the bevel angle is..... ZERO DIFFERENCE .... as all that matters is that the bevel is flat and goes from spine to edge evenly.

Unless you made a very complex jig to deal with parallax, and you can keep the jig to within a few hundredths of a degree, it would still require hand filing and sanding to make it truly even. If you use a jig, you will get the actual edge filed at different thicknesses almost every time. If you hand file, observing the marked centerlines on the edge, you will get a even taper from spine to edge ( of from whatever spot on the blade you want the bevel to stop at). Dye-chem on the blade, or black sharpie, will also help see where the file is cutting.
 
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