MDA Slipjoint WIP

[J S Machine]

Since the last update I have done a little work to the liner and bolster assemblies. I sawed off the excess bolster stock with the band saw and then ground the bolsters down until they almost touch the liners. No need to remove too much stock here because it will be done when the final cleanup is performed. Also be careful here to not get the assemblies too hot, because the solder could melt. Probably unlikely that it would happen, but I like to be extra careful. Keep your cooling water nearby and cool them off regularly while grinding.

Sawing the excess off

Sawed and ready for cleanup on the grinder

Some of the cleanup on the disk sander

And finished and dummy pinned together.

Finally you need to clean the solder out here which seeped out during the bonding process. You want a clean square corner right here, because the main place you will see it is when viewing the completed knife from the top or bottom. The solder is soft and pretty simple to clean up. Take your time.

You can also put some pencil marks here to keep the solder from sticking to begin with.

 

[J S Machine]

Tonight I ground the blade. First thing to do here is blue the bottom edge with some layout die or a blue sharpie (what I used). Next, you need to take some calipers and mark the center line of the blade. I use a pin that is sharpened to a point and it marks the line dead on center. Calipers would do this just fine but I don't have any here at the house.

Then I take a pair of needle nose vise grips and place a wadded up piece of paper between the jaws and blade tang to protect it as I clamp it and hold it. This gives me something to hold on to the blade with while grinding for better control.

Then I start to grind. I use my little 1x30 for this because I don't have a nice blade grinder rig. This thing is way underpowered and it takes 40 forevers, but it does the job..slowly. I grind the blade upside down so I can see my center line mark.

I also mark the sides of the blade with blue sharpie so I can tell at a split second glance if I am coming up to far with each pass.

I want to come all the way up to the top and only leave a very small unground place where the angle is. This way, when I put it on the surface grinder after heat treat to clean it up, there is something there for support. If you grind this away, the magnet of the surface grinder could pull the blade tip down and kick the tang up, or just make the whole blade unstable. If you have any experience surface grinding, you don't want this. Parts can easily become projectiles and a mess of what you once called a part if the magnet is not holding well. It will suck it right up and spit it out the side before you blink.

Then after about an hour or so, we have the rough ground blade.

After heat treat we will clean it up. Neat because if you look close you can see some of the steel pattern before it is etched. The camera seems to catch that well.

As a final project tonight I cut the mammoth tooth scale pieces to size. I lay them out and mark them a little bigger than they need to be so I can work them in. I have never worked with this mammoth tooth. It is interesting. It is fossil so it is very hard like stone. There were some places that were difficult to get through in the band saw. It has alternating hard and soft areas. Anyway, got those cut and ready to start fitting up soon.

Stay tuned.

 

[McClellan Made Blades]

Hey John!
That Tooth is extraordinary! Beautiful material! I think this blade is going to be hard to to top! With the material your using and the purpose of the build, it's an epic build! Great WORK, I really wish you wouldn't make it look so friggin' easy!!! I'm still staying tuned in, Rex

 

[J S Machine]

Time for the handle scale work. Tried to get to this thing over the holiday weekend but was always tied up and didn't really get a chance. Made some progress last night.

When we left off, I had cut the scale pieces a little bigger than the opening between the bolsters. The next step is to start by being sure one end is pretty much square with the pivot bolster. It would be the one to the left of my finger in this picture

Once you have established that, you can take material off off the opposite end a little at a time until it slides down inbetween both bolsters from the top. The angle on the other end is critical, so it is important that you establish it early while taking material off. if this angle is off, there will be a gap in the top or bottom of it when viewing the knife form the side, and you don't want that. Take a little off of this end at a time, and eventually the scale piece will fit down inside. You want extra material on the top and bottom; it will be ground away later

When both are finished being fitted, you have this

In this next step, you can flip them over and take a pencil and trace the back of the scales around the liners. This will give you an idea of what has to be removed, and what will stay.

The only issue with this is that it really doesn't help much when using this tooth, because I was afraid to grind it upside down. In other words, to utilize these marks like I normally would, I would just lay the scale pieces face down with this fiber spacer backing side up, and grind to my pencil marks. In this case , the tooth is so brittle and fragile I don't want to do anything to it face down. That means grinding, drilling, or sawing. The material can easily be broken away from the surface when it is worked upside down. the drill will push material down and away form the surface, grinding will chip off pieces away from the surface, and sawing will do the same. I always work it face up for these reasons.

Because of the reasons stated above, I put the scale material in the liners and worked them like this to take off the extra. I grind down until there is not much left but still a little extra to take off during final clean up. I found the trick to working this tooth, especially when grinding and taking off large amounts of material like I'm doing here. Use very course grit sandpaper. In this instance I am using 40 grit paper, and it cuts it well without heating it up like finer grits would do. Easy to remove large ammounts of material within a decent ammount of time. Again, face up in the liners so we can see where we need to grind to. Watch your fingers!

and finished

A word of caution here..Wear a respirator or dust mask. That will protect you from the dust made when grinding, but the biggest thing is the smell. A dust mask won't really block the smell; This stuff stinks like there is no tomorrow!

 

[J S Machine]

Now it is time to put the holes in tooth scale pieces that will hold them to the liners. I have three different tools here. 2-56 tap, a #51 (.067") drill for that tap, and a counterbore. The fourth tool needed is the drill that will be used for the screw hole itself in the scale, and I can't recall the size of it right off. Something like a #44 or #45 - around .086". You could measure the pilot tip on the counterbore and get the size, but I don't have it in front of me.

I decided not to put a shield in this knife, because this tooth is very hard to work with. Actually getting the shield done correctly and neatly would be near impossible, and highly unlikely to come out right given the brittleness of the tooth. I don't want to risk messing the tooth up, and besides it is so beautiful by itself, I'd hate to take away from that.

The first thing to do is mark the scales where we would normally put the two small pins on either end. I used my trusty blue sharpie (pencil used as pointer)

To begin with, I drilled it with like a #60 drill. That's like .040". This creates a good pilot hole for the other drills to follow. Take your time and move very slowly, very little pressure. You want the drill spinning very fast, like 1200-1500 RPM at least. Come up out of the hole often, all the way to evacuate the dust and keep from burning the material or ruining the small cutting tip of the drill. Think of this material as a grinding material and it probably doesn't do the surface of any cutting tool any good to begin with. Be very conscious of the harder and softer spots, and EXPECT the drill to walk. If you move slow, it won't deflect on the hard areas, it will cut them.

Those holes finished

I then stepped up to like a # 50 (.070") or so, and enlarged the the holes a tad.

After this, I moved to the final drill, the one I can't remember this size of. It is a clearance hole for the 2-56 screw, and the same size as the pilot on the counterbore. I believe the counterbore is a #2.

The last step here is to counterbore the holes to create clearance for the screw heads. Take your time on this. Even though I did, this material was still unforgiving. I slowed my drill press down as slow as it would go (important here) and still had some chiped out places around the openings of the holes. Holding the piece securely in a mill vice and using a mill spindle may help a little, as well as using carbide or diamond to perform this step. An HSS counterbore is not ideal here. It worked, but not as cleanly as I would have liked for it to be. Good thing is that I can repair small chips with super glue. Work very slowly, very little pressure. I would imagine with the right amount of force you could actualy bust the piece at this step.

And the finished scales. Look close and you can see the chipped out areas.

 

[J S Machine]

Next step is to mark the liners where the holes need to be for the screws. They need to be spot on, so don't screw up. If your hole is off a little, you may end up enlarging the holes in the scale material to make them fit and that would look bad. -Try to force the screws in and it could possibly torque the scale material and crack it or bust it. The holes need to be in the right place.

You might be able to find a transfer punch that will work for a 2-56 screw, but I didn't do it that way. I simply took the drill I used to drill the clearance holes in the scales and passed them through the scale pieces to the liner and twisted the drill by hand to create a center mark on the liner. After this, I center punched the liners on that mark and went from there. If you do it this way, be absolutely sure your liner is where it has to be, and hold it firmly while doing both holes. Don't hold it firmly and do one hole, turn it loose , and then hold it again to do the other. Do both holes with the same hold, to be sure they are correct in relation to each other.

Center punching the marks...Be sure you are on your mark before you tap with a hammer!

After this, I used that same itty bitty drill - the #60 to put a small hole through them to use as a pilot hole. Even a #1 center drill was kind of bigger than I wanted here. So after pilot drilling, I used the tap drill and enlarged the holes to that.

Then we tap the holes. I usually power tap most holes at work, but never with a tap this small. I may start the tap using a mill, but finish it by hand. Small taps like this are very easy to break, and hand working them is best. The real advantage to using a mill is that you can lock the table in both X and Y directions, and then when you use the spindle to tap, the threads created are perfectly perpendicular to the drilled hole and surface of the part. When doing it by hand, it is hard to maintain this perpendicularity.

Then you can rub the liners on a stone to remove the small burrs. You may have to use a smaller stone or a small chamfer tool to remove them from the top (in between the bolsters). Whatever you do, only take just enough to remove the burr. You only have a couple of threads here in the liner given its thickness, so don't take off too much material when trying to get rid of the burr.

Then the finished holes with screws installed

Stay tuned. Next is the nail nick in the blade, heat treating, and final finishing.

 

[BRad704]

Its been a while since a WIP had me THIS excited to see the next steps... Not just for the knife, but your descriptions and explanations are spot-on. Bonus points in my mind for using the word "perpendicularity".

 

[Pieter]

John thank you very much for taking the time to do this, this is a great WIP and very informative.

 

[J S Machine]

Its been a while since a WIP had me THIS excited to see the next steps... Not just for the knife, but your descriptions and explanations are spot-on. Bonus points in my mind for using the word "perpendicularity".

believe it or not, I had to look up the word to see if it actualy was a word, and if I had spelled it right..lol

 

[J S Machine]

John thank you very much for taking the time to do this, this is a great WIP and very informative.

Thanks. I try to explain things as clear as possible. WIPs are very time consuming, but if people don't step up to do them, we cannot share the knowledge we all need to make the best knives possible. I'm glad I'm able to help, even if I may not do things exactly the way other makers do.

Maybe people will be able to look at this and gain something to take on their journey as they approach a build.

Slipjoints are tough. They are not easy to build. There are so many places to mess up and lose momentum, which could lead to giving up. Don't do that. Keep trying and you will get it

 

[J S Machine]

Yesterday afternoon at work during a break I put the nail nick in the blade. I ground my wheel first on a 45, tested a piece, and didn't like the way it looked. I then moved up to a 35 degree, or 55, depending on which way you look at it from 90, and it looked pretty good. That is what I put in here. I think if I went on up to 20 it would look best. the next blade I do will be at 20.

Grinding it in

Afterwards

Notice the parallel in front of the blade. Always a good idea to chock up your work when working on a surface grinder. The only real purpose the parallel is serving is to keep the blade from being pushed to the left, which is the direction the wheel is spinning (clockwise). Some chucks hold better than others, but the fact is you don't have much there to hold anyway with the blade. The tang and a very small upper portion of the blade are the only things being held. Easy to make a projectile out of it. Also, lock the bed. Very important. You want the nail nick where it is supposed to be, and not everywhere else on the blade.

So last night I did a little grinding on the handle assemblies. I know this was what you were wanting to take a seminar on at Blade, Rex. All I can tell you about grinding handles is that to begin with, it is a matter of personal preference. I don't know exactly how I got decent at it, but I just grind until it looks good. As is the case on every knife I make, I am amzed at how much material is actually left when I get done. Through alot of time grinding, very little of the original handle scale material will remain. I'll try to touch on some of the points I follow while grinding.

To begin with, I screw the scales to the liners and snug 'em up. You can see here what needs to be worked on around the edges.

We'll start by taking that off. Using the 40 grit paper here. Try to grind down to where you just barely touch the liners. Remember we still have to final grind to remove those 40 grit scratches so no reason to go rediculously deep.

And when finished with that, we are close to what they will be when finished.

Next step is to address the height difference here. I have drawn a red line on what will need to be removed to get a decent looking handle profile. The scales are significantly taller than the bolsters, and this is only worse because of the fiber spacer material. Just a fact of life here; we have to work around it. One thing that would have helped tremendously on this particular knife is the use of thicker bolster material. I think this stuff used here was originally around .135", which is a little more than 1/8". Maybe some 3/16 would have been ideal.

In the picture below, I have started to remove the material on either end of the scales to bring them down to the bolsters. As you can see, it creates a funny looking sharp bend, so the only thing to do really is to take material away from the surface of the scales. maybe 1/32" - 1/16" will bring the center down to where it flows with the ends and bolsters. Be aware that when you do this, you will compromise the depth of the counterbored holes. I also knocked off a good bit of the heads of my screws. Not a big deal; I'll just go back and deepen the counterbores and use some new screws when finished.

So then I went to work rounding off the bolsters and trying to work the handle profile. After about an hour on the grinder, I got a pretty good ways. They are close to being finished, but not quite. Still some work to do. You can see the bottom scale still has its original thickness, as evidenced by the flat which is reflecting in the picture. It still has to be brought down.

Next is heat treating the blade and spring. Not much to see there, just wrap them in stainless foil and toss them in the oven.

 

[McClellan Made Blades]

John,
LOOKING GREAT!! How are you going to HT the blade? If I remember correctly this was some of the Damascus from the guy in Pakistan, did it come HT'd?
BTW I got my Anhydrous Borax in today, still have a knife on the bench and 2 orders to finish, but the Damascus bug is bitting hard! I may take a little time and give it a go this weekend...maybe. Rex

 

[Sticks]

Still following and learning from the tutorial, thank you. I have a question. I'm most concerned about relieving the liners. I only have a drill press and a belt grinder and know nothing about end mills, etc. If I were to get the circulating base you used (can't remember the proper name) could I use a mill bit to plunge cut the relief, a bunch of times, as I rotated the base, the clean up the remainders using the drill press as a mill? As you note a drill press is designed for lateral stress.

Jay

 

[Sticks]

Oops! I meant a drill press is NOT designed for lateral stress!
Jay

 

[Pieter]

Still following and learning from the tutorial, thank you. I have a question. I'm most concerned about relieving the liners. I only have a drill press and a belt grinder and know nothing about end mills, etc. If I were to get the circulating base you used (can't remember the proper name) could I use a mill bit to plunge cut the relief, a bunch of times, as I rotated the base, the clean up the remainders using the drill press as a mill? As you note a drill press is designed for lateral stress.

Jay

Jay I think there is a tutorial in this forum of a knife maker using feric chloride to do the relief onthe liner. Just see if you can find it.

 

[J S Machine]

John,
LOOKING GREAT!! How are you going to HT the blade? If I remember correctly this was some of the Damascus from the guy in Pakistan, did it come HT'd?
BTW I got my Anhydrous Borax in today, still have a knife on the bench and 2 orders to finish, but the Damascus bug is bitting hard! I may take a little time and give it a go this weekend...maybe. Rex

Well Rex, I had to brush up on this a bit. Apparently since this damascus is a 10XX steel, it needs to go from heat treat temp to less than 400F in less than 6 seconds. This means I will have to heat treat it without wrapping it in foil, and then dip directly in quench oil. Doing it in foil will only prolong the time it takes to get it into the oil, because I have to cut the foil and unwrap it after it comes out of the oven. It won't come to proper hardness like this.

It is the stuff from Bladesmith2002 (Pakistan).

I did do the back spring yesterday. It is at about 48-50 Rc. Hopefully I can get the blade done today.

 

[J S Machine]

Still following and learning from the tutorial, thank you. I have a question. I'm most concerned about relieving the liners. I only have a drill press and a belt grinder and know nothing about end mills, etc. If I were to get the circulating base you used (can't remember the proper name) could I use a mill bit to plunge cut the relief, a bunch of times, as I rotated the base, the clean up the remainders using the drill press as a mill? As you note a drill press is designed for lateral stress.

Jay

If you try to plunge cut with an endmill in a drill chuck you will not like the results. There is too much play in the spindle to properly support the cutter, and it will chatter and jump around. It will remove material, but in an eratic fashion, that is at best poorly controlled. You also risk chipping the teeth off of the cutter because of this.

Plunging in a mill and plunging in a drill press are two totally different things. Plunge cutting puts a ton of stress on an endmill anyway..even if it is in a mill spindle, and is best avoided unless absolutely necesary. Also, some endmills are not "center cutting." You can observe this by looking at the bottom. If there is a relief hole in the very center of the cutter, it does not need to be used for plunging blind into material that doesn't have a hole to begin with. There are no cutting edges there, and it will not cut. Fortunately, most cutters are "center cutting" where the flutes are sharpend all the way to the center. These will work for plunging in a blind hole, but as stated, not really advised because of the unecessary stress it puts on the tool.

I'll see if I can find some pictures of non-center cutting endmills and center cutting ones.

 

[Sticks]

Thank you for the advice. I'll look for the feric chloride/relief method, or see if I can borrow some time on my neighbor's mini-mill? I've never used a mini-mill but assume one would be up to this task.

 

[Josh Dabney]

This is a FANTASTIC epic WIP on a slipjoint done by Ryan Minchew- IMHO a must read for slipjoint makers (at least new ones)

http://knifedogs.com/showthread.php?1054-Couple-of-slip-joint-WIP

Ryan electro etches the relief in the liners. Check post # 143 on page 5 for his method of performing this step.

Take care Fellas- Josh

 

[J S Machine]

Thank you for the advice. I'll look for the feric chloride/relief method, or see if I can borrow some time on my neighbor's mini-mill? I've never used a mini-mill but assume one would be up to this task.

A mini mill would be perfect for this. But, in the mean time, check out Ryan Minchew's post that Josh linked to. That will definitely work too if you have no other way of doing it.