Or a drill bit less than half the thickness of the blade. You use a flat surface and the drill to draw the lines.
survivorman, de Vries that is what I did...drill bit. I have watched more YouTube than I can recall to answer all of my questions regarding knife making! Once of the vids said use a drill bit that is the exact width of your blade to find the center line, then I went to the next one down so that I will grind just to where there will be about a dime width left..read that you want to do that for heat treat to help prevent warping.
I LOVE IT! And, I gotta ask, where did you get/how did you make the piece with the 1/4" hex in it? Without a milling machine, or the proper tooling for the lathe(expensive!) a functional way to do that is basically whats holding me back from a few project(and product ) ideas I have.
Your taking all the fun out of the first time you over compensate movement and put 3 knuckles into a 40 grit belt... Gotta say too, how jealous I am of the grinder! heck of a classy way to start out! I've been making knives for about 12 years now, 4 or 5 years professionally(as in I tried my best to sell a lot of sharp steel with moderate success) in the middle, and I still can't justify the cost of a grinder designed to make blades... This is me, green with envy --->
AK Adventurer and eng1nerd it is a chainring bolt. And though they are pretty readily available on the web, they are surprisingly hard to find without any kind of logo...and sturdy like this one.
Thanks much! I must say I am not into the knuckle grinding! I have done it a few times on the little harbor freight belt sander I have, and it was not fun! I can only imagine how much it would suck on the faster, wider grinder belt! As for the grinder, I just happened to be in the right place (financially) to get it. It was not a bad price....having to assemble myself etc and it does not have a variable speed motor. That is gonna cost me some $$ later. But I didn't want to invest in that unless I found that I really took to knife making. I figure if I decide to scrap it all, I can at least get what I paid for it. The other thing is I met the maker and he has been great with advice, and assistance and answering all my questions. He told me that if I make it to Blade Show this year, to bring some steel and he will give me some classes! What a deal! I would like to get to the point where I can sell my products and make a little cash...if only to continue to fund my creative adventures. The market is saturated out there tho and I will have to find that 'thing' that is unique or in demand. Joey at JR Knives has done a good job of that, and I think he is a good example to follow.
They make these Rheostats that you just plug in line with the motor just like you do with a foot petal. I couldn't say whether they work, but it seems likely. They won't allow you to go faster, of course, but they would let you slow down. Harbor Freight markets it as a "Router Speed Control." They're cheaper on the bay.
The only issue with that is heat. If the motor isn't designed to run at different speeds they loose efficiency via generating heat.
Thanks for the info! What about forward/reverse switches? My own feeble understanding of electric motors is that one can reverse the direction by reversing the current. I have a motor--only 1/3 horse, but it's a start--that is currently set up to run a transfer pump, which I don't need. SMAJ's setup got me thinking I might build something of my own, and I'm thinking if I put a ten-inch contact wheel on one end of the belt, and a flat platen on the other, I can switch from hollow grind to flat by reversing the direction of the motor and moving around to the other side of the grinder. I have a feeling that I am just planning an elaborate incindiary device, though, or more likely just plotting an elaborate scheme to cook a motor.
Reversing directions is not a big deal on most motors. By changing polarity you are reversing the magnetic field that is generated, therefore making the motor run in the opposite direction. This can all be done easily, and safely. The speed the motor runs is based on power frequency and the internal windings of the motor. Essentially a motor manufacturer designs the windings for a certain speed on a known power grid. For example the US uses 60hz AC power. A motor that runs 1725 RPM at 60 hz will run at 1437.5 RPM on 50 hz (Europe uses 50 hz for their grid). My understanding (I'm not an electrical engineer, maybe vegassprky can chime in) is that a motor controller changes the input frequency to change speed.
Thanks MTFatboy and eng1nerd for the discussion and advice on the motor. My motor already runs pretty hot; this is the first time I have ever used anything like this, so every day is learning for me. One thing that is happening at the moment is that when I switch the motor on, it throws the breaker. Having examined the switch, it seems to me that the problem is not the motor, but the switch. It does shut all the way off, just moves enough to shut down the power, Once I go reset it, there is no problem, but this happens 1-2 times during the time that I am grinding. It is very maddening.
