View Full Version : Big Bear guard


Steve
08-27-2012, 02:44 PM
I received this inquiry about making the lugged guard of a Loveless-style Big Bear Fighter, from friend/knifemaker Gary Martindale and think that maybe it might be of interest to some:

Question: Steve just wondering if you could tell me how to curve and mill guard for a Big Bear-type knife? I'm having a little trouble understanding that process, angle degree, ect.

Answer: First off: Make the over-all length of the guard 3 1/2" if you are using the standard Loveless Big Bear pattern and the bar is 5/8" wide and 3/8" thick. For the "curve" and lugs, I make a straight cut with an end mill from about 1/8" beyond the bottom and top of the blade. I make the lugs, or steps on the end of the guard stick out about .100" The lugs are approximately 1/2" -5/8" wide from the cut to the tip of the guard. So, if you will look here: http://www.srjknives.com/fighters.htm you will see that the "curve" is not really a curve, but a straight shot to the lug. Look closely and you will see a "break" below and above the rounded part of the blade/ricasso on the first three knives on this page. The face of the lug matches the angle fo the "curve" of the face of the guard extensions. The front fo the guard is also flat, not curved. Cut with a 1/2" round file the curve of the back of the guard and then use a 1/2-round to gently curve the back, trying to match, in general, the front "curve" in appearance. Ask more, if you do ont understand. Or if I did not answer teh right question, OK?

Response: Thank you very much for the info I that see they are just flat angles on the front I think maybe I can make a jig when i figure the degree of angle? Looking at your knife close up says a lot.

Ans: The angle is decided by the distance out from the top and bottom of the blade and the depth of the step for the lug and the distance the lug is from the blade. I typically make the top quillion a bit shorter than the bottom one, to the angle will be slightly different from the bottom one, if that makes sense.

Resp: That makes it very clear now. Angle is determined by lenth of guard and lug depth and if the top quillion is shorter than the bottom then the angle will be slightly different. I will practice this first but from the info. you gave me i will be able to make this work now that its clear in my mind

Ans: The face of the lugged guard must be sanded and polished flat prior to installing, or shaping the guard. To do this, glue your 100x, then 400x, then 600x onto the face and around the sharp corner of a bar of steel with disc adhesive and polish the face and the corner at the step of the lug by pushing the guard back and forth and up and down (horiz. and vertically) on the guard face so that it is able to be buffed and polished prior to shaping the profile of the guard. Otherwise, you'll get a rounded, non-flat face and never get that corner cleaned and polished either. Maybe not even if you do do this, it takes time! If that makes sense. I can take a photo next time I do one, which will be for the Guild show.

I hope, if anyone out there has a better/faster/easier way to do this that you will let us know!

mknife
08-28-2012, 09:01 AM
Steve, many thanks!!!

Steve
08-28-2012, 09:05 AM
I hope it is helpful, Riccardo. All the best for the upcoming Milano Show. Wish we could attend!

TWITHERS
12-08-2014, 06:26 PM
This is a very helpful thread. I have been wondering how to get the face finished if I was to attempt a lugged gaurd. One thing that still astounds me is how you sand to 600g, then buff and get that wonderful finish. I was lucky enough to meet John Young at a show and he does it about the same if I remember right. I cannot get a mirror on my guards unless I go much higher in grit. I know my skill level is not as yours or Johns but sandpaper is sandpaper isn't it? I wonder am I being too picky? Not likely. Am I not getting the scratches out before moving on to the 600? I think I am getting them. Does anyone else here have troubles going from 600g to the buffer?

Steve
12-08-2014, 09:27 PM
A brand new piece of 600X wet/dry is pretty coarse, but use it a bit and it when it's work, it puts a pretty good shine on 416SS. Just sand it down with a 320x first, then on to 400x and finish with 600x, but "wear it in before you go to the buffer. Using a little belt grease on the paper will help, too.

TWITHERS
12-09-2014, 08:31 AM
I use 303 because I have a friend who is a machinist and he gave me a bunch. Would you say 303 is more difficult to finish? It would be nice if the solution were that easy, but it usually isn't.

C Craft
12-09-2014, 09:15 AM
Was trying to see the post but this link is broken!

http://knifetreasures.com/viewKnife....lected_menu=12

Too bad as it seemed to be very informative!

Steve
12-09-2014, 02:19 PM
303 just might be your problem. T 416, heat treated, or not, is much easier to finish.

One online sours says: "Grade 416 steels offer the highest machinability of any stainless steel in their sub-critical annealed condition."

Another says:
T303 - Machinability is rated at 60% - 100 surface feet per minute

T416 - The steel is designed for free-machining and it is the best of all the stainless steels. The rating is as high as 90% - 160 surface feet per minute.
That certainly tell me something! Sometimes free materials end up costing a lot of time and money, though the kind offer is always nice. I have a 2" round bar of 303 that's 20-30 yrs. old. I have used it and appreciated it in an emergency, or two, when I NEEDED a big slice of SS and had no other alternative. I don't use it unless I have to, though! Tough stuff!

Steve
12-09-2014, 02:28 PM
C Craft: I have changed then link to my web site. Look at the three top knives on this page and it's pretty obvious what I'm trying to explain: http://www.srjknives.com/fighters.htm
Thanks for drawing this to my attention.

TWITHERS
12-09-2014, 04:33 PM
Holy smokes a possible easy fix?! I will definitely try 416! Thanks Steve.

TWITHERS
01-07-2015, 09:51 AM
I ordered some 416 and have started the guard on a battle knife. Probably should have made it a sub-hilt but honestly I'm just tired of making that trigger. It is so difficult for me to curve the back of the trigger with the chainsaw file then transition that curve into the palm swell and make it look clean, if that makes sense. It gets a little better every time though. Back to the guard, when you make the cut with the end mill you spoke of, for the lugs, do you just "eyeball" the angle in your vise or is a more accurate method needed? One more question, the blade width on this knife is 1 5/16" at the guard is that correct? I mean using a guard length of 3.5".

TWITHERS
01-15-2015, 02:55 PM
Ok so here is my take on this. I hope it's OK to post this here. I decided to make a Jig but I wanted it adjustable for different degree cuts and this is what I came up with. The jig sits in my vice with the approximate angle already on it with two adjustment screws to fine tune. It is more narrow than the guard material so the vice tightens on the guard and is squared up by the vice. I also attached a pic of how I sanded the guard. I just tighten one end of the sandpaper in the vice and bend the paper over the angle iron. It worked out pretty well. What do you think?

Steve
01-15-2015, 04:33 PM
I make the lug to be .100" deep and scribe a line from a bit short of the slot, to that point and line it up parallel to the vise jaw. Yours looks lot better than mine and I'll probably just steal your idea, if that's OK? 1 5/16" is good. Thank you very much for the photos and comments! Your sanding jug looks great, too. I glue mine to a piece of steel, alum., or G-10 and peel it off when it gets dull. Yours looks faster.

TWITHERS
01-15-2015, 05:12 PM
Thank you, of course anyone can use this if they think it would help. I started off marking and lining up the scribe line just as you say then I took a look at "The tool and Die guy" and learned a little about solving triangles. Which is all this is, to get the angle I mean. Now I feel the best way for me is to take the info that I know and mathematically find the degree and I don't have to even scribe the line. I know the depth is .100, I know one of the angles of the triangle is 90 degrees and I know the distance from the blade to the step. With those three pieces of info you can get the degree. From there I have a digital angle cube I bought from Harbor Freight for around $30. I set that on the jig and turn the set screw until I get the degree I want. To cheat a little further I downloaded an app to my phone that does the math I spoke of for me. It is called "Triangle Calculator".

Steve
02-03-2015, 12:38 PM
How are you liking that T-416 by now?

TWITHERS
02-03-2015, 04:10 PM
You know I have finished the knife except for my mark and sharpening. I am hoping to get my new logo before the Expo and use it instead of my old one. The 416 was most definitely easier to saw, mill and grind but I still had to go high up in grit to get the finish I wanted. It really stumps me. My wife, comforting me as she does says "Well how long has Steve Johnson been making knives?" I say "oh 40 years maybe", she says "there you go". Didn't make me feel better. Ha Ha. If I looked at the finish in the sunlight it looked great, but under the fluorescent lighting I could see the scratch marks. So I went to the higher grits. I would have come back and asked for help, but it has been explained as well as it can be I think. I do like the 416 better. It was easier to work with. I'll try again.

Steve
02-04-2015, 03:26 PM
Good report. Of course, 600x is necessary, or finer, before buffing. Depending on the light, you can never get rid of scratches! Polishing is nothing but ultra-fine scratches. For a bolster on a knife, I'l go to 600x, then as the disc wears, we then apply grease adn continue, until there is almost a polish. Also, the buffing compound must be very fine to give a super polish and even then, you can see scratches, if you get the light strong and bright enough. You're doing great, it sounds like!

TWITHERS
02-06-2015, 04:11 PM
Thank you very much. I'm gonna do some bragging now though you know? I'll say "Well Steve Johnson said I was doing good". Just kidding of course but I do appreciate it coming from you.

Steve
02-06-2015, 04:36 PM
With my blessing .................as far as it'll get you..........

zappo
02-06-2015, 10:52 PM
Twithers,
Thanks for sharing the pics. That jig looks good!

TWITHERS
02-07-2015, 09:37 AM
No problem Zappo, and thank you. Little jigs are not so tough to make if your lucky enough to have some aluminum lying around. Although it would last longer if it were hardened steel of some sort.

zappo
02-13-2015, 04:01 PM
Twithers,
Dumb question of the day, just to make sure I get the full benefit. The screws in your jig, are to hold the guard to your jig??

TWITHERS
02-13-2015, 04:47 PM
The cap screws in the jig are there to adjust the angle of the entire jig. I cut the angle on the jig to approximately the degree I thought I needed. It was around 10 degrees, I think. So that gets the angle close then with the screws on each end of the jig I can turn the screw to raise either end and change the angle. Does that make sense? Remembering that the jig does not square the guard in the vise. The guard material should be square on the sides already then the vise will square the guard to the mill for the cut.

zappo
02-13-2015, 10:03 PM
Yes, thank you. I had read that in your earlier post and it didn't sink in...:help: