Jenkins Handmade Knives
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Handmade Knives How I Do It
Any handmade knives has to start with a design in mind, and the first step is to get it
down on paper. you can draw your handmade knives design on paper or as I do, use a
computer drawing program to draw your handmade knives design.
A good tutorial on liner lock folding knives by Ray Rogers, It will take you away from this site
custom knives Ray Rogers click here Below is a design I did
on the computer.
The next step is to cut the handmade knives design from the paper, place it onto a bar of steel and trace it onto the steel. I use a fine point felt tipped black marker to do the tracing. Once the handmade knives design is on the steel its time to go to the band saw and cut it out of the steel, we then have a rough sawn custom knives blank. Next we need to smooth up the saw cut, we do that with a sanding wheel or belt sander. Below is an image of our handmade knives grinder.
Next once the rough sawn edges are smoothed out comes hollow grinding the blade. Hollow grinding is done with the grinder also. First scribe a center line down the full length of the handmade knives blade I make two leaving about a sixteenth of an inch or so down the center of the cutting edge of the blade this line is where you stop grinding to keep from being to thin when hardening the handmade knife, it will be thined down more when finishing the blade after hardening plus it gives you room to remove the fire scale from hardening. We use a very corse grit sand paper or sanding belt to remove the bulk of the material anywhere from a 32 grit to a 60 grit will get the job done with the least work. I stop grinding just before I reach the line that we made and change to a 220 grit paper, and remove the rough marks the more corse paper left when I have removed the corse scratches I then change to a 320 grit paper, and finally a 400 grit, I take the finish of all my handmade knives to a 400 grit finish before hardening. Below is a diagram of the hollow grind.
Once the hollow grinding is done its time to cut out bolsters for the handmade knives, use the drawing and cut out the bolster and place it on the steel and trace around it, and cut it out leaving it slitely over sized. Now place one onto the knife where its going to go and trace the two ends onto the knife with the filt tipped pin. Now you can tell where to drill holes for pinning the bolster, and handle on. The size hole depends on the size pinning material you plan to use. I useually use 1/8 inch pinning material. Now is the time to add your name or logo and what ever you want on your handmade knives. Theres several ways to add a name it can be etched, stamped, or engraved into the steel. If etching its done after the handmade knives are finished. Also if the blade is to be engraved, it has to be done at this point before hardening and tempering, afterward the steel is too hard to hand engrave. Below is a diagram.
Next comes heat treating or hardening and tempering. Hardening and tempering is done in a heat treating oven, its hardened at a hardening tempature for the type steel being used to make the knife differant steels have differant hardening tempatures you can request hardening instructions from where you purchased the steel or you can purchase a book on the hardening and tempering of tool steel. The hardness, and toughness of a knife depends on several factors as well as what the knife is being used for. You can get an increase benifit from a sub zero quench. Below is an example of a heat treating oven, and one as we use.
Once the handmade knives are hardened, and tempered its time to go back to the grinder and start with the grit you left off with, and clean the fire scale off the entire knife. For flat portions of the blade you can flat sand the knife. For the hollow grind I use the 400 grit to finish the grind to the thickness I want the cutting edge to be for a more razor like edge for cutting meat I thin the blade more than if I were looking to use it as a utility knife. After I've cleaned the fire scale off, and thined the blade down somewhat I change to a 600 grit paper and finish up the 400 grit scratches. Next its time to put the cloth polishing wheel on the buffer and use polishing compound over the entire knife to get a mirror finish. Back to the bolsters, its time to drill the holes in the bolsters, I position one bolster on the knife and clamp it into place with a small vicegrip type C clamp, careful not to scratch the now polished knife and use the holes in the blade as a guide to drill the holes in the bolster once I have one I use it to clamp to the other careful to line it up correctly. Once I have the holes in the bolsters I put pins in the holes holding the two bolsters togather I can then true up the ends of the bolsters thats going to both butt against the handle material and the end thats going to be polished, you can true the ends by hand or like I do use a milling machine, with both at the same time thay match in size perfectly. below is the milling machine.
After the ends are trued up, the end that faces the point of the handmade knives has to be litely sanded and then polished, its easier before it go's on the knife. Now its time to peen the bolsters onto the blade, I use a ball peen hammer to peen the pins, but you can use a hydrolic press to swell the pins in the holes. I almost forgot I use a tapered reamer in the bolsters just before I peen the pins. Just slightly taper the holes in the bolsters, and when the pins swell from peening it tends to want to force the bolsters tighter to the blade.
Now its time to cut out the handles, I cut the material to just over the width of the handle at its widest point, and I cut the length by measuring the longest point from the bolster to the end of the knife. Sometimes theres an angle on the bolster so measure from the longist point and cut it a little long. Then lay the knife on the material so that the whole handle fits in, and draw a line indicating the bolster angle. Cut it then lay that slab onto the other peace of material, and draw the line indicating the line of the bolster. Now true up the ends that fit against the bolster I use the milling machine to get the most square fit.
On to epoxy. First rough up the the metal, where the handle will fit against the metal, with a corse grit sand paper. I then use a good solvent and clean both the metal and the handle material of anything that would cause the epoxy not to stick. I use a five minute apoxy by devcon. Adjust your clamps to fit the thickness of the blade with the handle material, just one side on it. Then spread a thin layer of epoxy over the steel handle surface, and carefully line the handle against the bolster tightly and clamp into place, I useally wait 30 min. to an hour for the epoxy to set up, and remove the clamps. You can now drill the holes in the handle, use the holes in the steel as a guide. Now trim the handle on the band saw up to the outline of the steel fairly close without dulling the saw blade on the steel. Do the same to the other handle. When you have both slabs epoxied go back to the tapered reamer and taper just slightly the holes in the handle material for peening. Now do any shaping to the handle and sanding it flush to the backbone of the handmade knives, careful not to over heat the handle material. Over heating will cause the epoxy to fail.
Go ahead and shape the handle to near its finished shape just before polishing. Now cut pins to a sixteenth or so sticking out each side of the handle and carefully peen as not to swell the pins so much thay split the handle material. I use a ballpeen hammer for this job too. Some makers don't peen the pins in the handle thay just epoxy the handle and pins in. I do both. Once the pins are in its time to sand them both in the bolster and handle flush. Then progressively finer sand both the handle and bolster to a 600 grit paper and go to the cloth polishing wheel with polish. 555 polish is a good finish. Now to sharpen the knife we use a fine grit paper on the grinder, with the edge facing down sand a keen edge on the blade. Then with a hard felt wheel and 555 polish polish the edge to razor sharp. No handmade knives should go without a good leather sheath, so we make a leather sheath for each of our handmade knives. If the knife blade had been engraved it would now be time to engrave the bolsters. so I would wait about sharpening until engraving was done. This is my process for making handmade knives, and I try to do my best on every step of all handmade knives.
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Setting Up A Vertical Milling Machine For Slotting. Making
Duplicated Machine Parts. by: David Jenkins Its a simple process to setting up a vertical milling machine to accurately cut slots that has to be x number of thousandths from one side by x number of thousandths from one end by x number of thousandths long by x number of thousandths wide by x number of thousandths deep, and accurately duplicate that slot on more than one part. The first step in the process is to know what the dimensions are for the part to be made. Lets say we have a blueprint outlining the details for the part. We see that the slot is .500 from the side, and starts .250 from the left end, 3.250 from the starting point to the end of the slot, and the depth just goes all the way through the part, with a .250 diameter cutter. Now that we know what were making the next step is to make sure the milling machine has everything all lined up. First check the head on the mill. Is it zeroed in? It has indicator marks in degrees in two places that need to be set to zero. The first set of marks are for the back and forth tilt of the machine head loosen the bolts and move the head to the zero mark, and tighten the bolt down. The next step is the side to side tilt of the head loosen the bolts and dial it to the zero mark, and tighten the bolts back down. Now we have the head lined up vertically to mill straight down. Now that we have the cutter end of the machine dialed in we turn our attention to the vice that will hold our part firmly for milling. We will need a precision indicator that fits in a collet where the cutter is held into the head, the indicator needs to be what I call a side indicator where the spring loaded button is on the side when held in the machine collet within the head. We need to open up the vice all the way and move the bed in both directions to get the indicator to rest against the back jaw of the vice the jaw that doesn't move. The button on the indicator needs to face the back jaw of the vice and ride along the top portion of the vice jaw just slightly below the top of the vice. Move the bed until the indicator is at the top right corner or left corner of the vice jaw. Now use the cross feed and feed into the indicator until it starts to move the needle of indicator then move it about ten to fifteen thousandths, into the indicator. Now that we have our indicator resting against the vice jaw we need to dial the indicator into the zero position by just turning the ring around the top of the face of the indicator. Now move the bed of the mill so that the indicator is at the other end of the vice, if its lined up the indicator will still read zero if its not lined up lets say it moved a few thousandths from one end of the vice to the other. What we need to do is loosen the nuts that hold the vice but not completely leave it snug so that the vice can be taped with a hard rubber mallet and moved, and what ever the difference is from one end of the vice to the other you want to just move the vice half that back toward zero then run the bed back to the other end of the vice and if it didn't move you can lock the vice back down, but after locking it down check it again sometimes it moves when locking it down you may have to repeat the process. Now the machine is setup to cut a accurate slot. Next we need a new tool called an edge finder it has spring loaded ends that will float, one end is for finding the center of a hole, and the other end is for finding an edge. You put it into a collet in the head of the mill where the cutting tool goes. We need the edge finding end its the straight end. The hole finder is pointed. Put the hole finder end into the collet and lock it into place. You want to put a precision parallel into the vice and let it stick up a quarter inch or so out of the top of the vice. Next move the bed of the mill so that the parallel is in front of the edge finder and that only the small end of the edge finder will touch the parallel. Move the floating end of the edge finder so that its slightly forward toward the parallel. Now start moving the bed so that the edge finder touches the parallel and keep moving until the floating end looks as though its back in line with its shank. Now you need a set of one inch micrometers. Very softly mike the edge finder at the point where the two peaces of the edge finder come together it should mike .500 a half inch, to be the size of the shank of the edge finder. It should mike slightly over so move the bed how ever many thousandths its over, when the edge finder mikes .500 thats the true edge of the vice. Make sure you only feed the bed into the edge finder you don't want to over shoot and feed the bed in the other direction because most mills have some play in the bed screw and you want the bed moving in the direction you have to move to find the center of the slot. We now need to check the blue print and see how far over the slot needs to be for our new found edge. First we don't really have the true edge yet because we need to move the bed half the thickness of the edge finder tip that was touching our parallel so mike the small end of the edge finder and move the bed half that thickness. Next the blue print says the center of the slot is one half inch over from the edge so crank the handle of the mill .500 and lock the bed so it can't move in that direction anymore. Now we need to setup a stop for our blank part to rest against so we can have each one placed at the same spot each time we finish milling one and place another into the vice. They need to be placed accurately each time one is placed into the vice. There's several ways to setup a stop we drilled and tapped a hole into end of our vice to bolt on an adjustable stop but there are stops that clamp to the top of the bed the important part is to setup a stop that will position the part evenly and so that the slot will be centered into the vice. Next place parallel's into the vice to place the blank part on top of. Place a blank part on top of the parallel's and slide it against the stop, and lock down the vice clamping the part into the vice. Use the edge finder at the left end of the blank part and line it up as before but this time on the edge of the part its self. Then move half the diameter of the edge finder like before. Now our blueprint calls for the slot to start a quarter inch from the left end of the part so move the bed .250 now that's not our starting point that's just the center of the cutting tool so we check the diameter of our slot and find its a quarter inch so move half that distance more .125 that puts the outside edge of our cutting tool a quarter inch from the end of our blank part. Now lock the bed into place so it can't move. Next we need to have a way to insure we find that same starting point quickly with the next blank part so we setup a stop on the front of the milling table loosen the nut on the stop and slide it all the way over to the stop, and tighten back down. Now we have our starting point setup. Next we want to setup our stopping point as we did for our starting point except we don't need the edge finder anymore. Our slot is 3 and a quarter inches long so we need to subtract half the diameter of the cutter from 3.250 that would be 3.125 move the bed of the mill 3.125 and lock the bed so it can't move. Now set the other stop on the front of our milling table by loosening the nut of the stop and slide it until it stops and tighten it back down. Now the mill is setup so all you have to do is put one blank in against the stop, move the bed to the starting stop, and slowly plunge the cutter into the metal and start cutting your slot until it reaches the other stop. Remove the blank and repeat to quickly and accurately duplicate as many parts as you like. Just check one every few part's to ensure nothing has moved. About the Arthur: David is a machinist, and engraver with http://jenkinscustomknives.com. 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