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| jamoni:
I'm getting geared up to do some knifemaking, with the goal of bringing in a little cash while going for my degree in mechanical engineering. I'm lucky enough that I won't have to work full time, but I'd like to have a little cash flow other than loans. :bang: Since this is supposed to be a paying gig, and since my time will be very limited, I want to be able to crank out as many knives as possible without sacrificing quality. One way I'm accomplishing that is by sticking to simple designs that lend themselves to quick production. Another way is by automating as much of the work as possible. So, I'm building a "GrindBot". The basic idea is a poor man's surface grinder, but with nor attempt to get that kind of accuracy. What this REALLY is is a way to quickly grind simple bevels on multiple blades at a time. I'm building it in three stages. Stage one is based on a budget of $FREE. As such, it's built mainly out of old bed rails, some big ass aluminum plates I scrounged, a bench grinder I got in trade, and a pile of wood I found in the garage. Seriously. The bed rails form two sets of rails (I can't bring myself to call them "ways" ::) ). One set is bolted directly to the baseplate, the other is mounted parallel to the first, but pointed upwards at about 30*. The grinder is bolted to a wooden slide which rides in the angled rails, and the work is held on a slide that rides in the main rails. The grinder height is adjusted by sliding the grinder slide up and down it's rails, then clamping in place. There is no side to side adjustment, as all the work is held in fixtures. The main slide is then fed into the grinder by hand, returned to the start position, and the height readjusted for the next cut. It sounds slow, and it is, but it's about tne times as fast as grinding the same bevel by hand. Stage Two will be a little more user friendly. The wooden slides will be replaced with aluminum ones that have roller bearings to make things nice and smooth. The grinder slide will get a second set of bearings underneath, to adjust tension on the rails. Both slides will get a screw feed. The workholding fixtures will get far more elaborate, allowing me to adjust any variable I need. I also have plans for a fixture that will let me make compound curved bevels. I will also be adding an attachment that will use sanding belts instead of grinding wheels, and a setup for polishing the blades as well. Stage Three will add motors and indicators to the mix. It'll be set up to lower the grinder a hair, feed the main slide/workholder in, raise the grinder off the work, shuttle the main slide back to the start, lower the grinder another hair, and repeat. It will also have a cutoff switch, and if I can arrange it, it'll play Yankee Doodle and shoot off some bottlerockets when the grind is done. Since theory is for weenies with degrees and offices, here's some actual work: Stage One is almost complete! On my test today, I managed to profile and grind the bevels on ten knives in about 15 minutes. To do it by hand would take me that long per knife. Once I get the autofeed set up, I should be able to spend about 1 minute putting knives in the fixture, and about another minute swapping the cutoff wheel and the grinding wheel back and forth. Then I can go do other stuff, like setup the new power hacksaw... ... to cut out more blade blanks! This guy is getting a few upgrades as well, most notably a speed control, a cutoff switch, and a couple of workholding attachments to supplement it's cheesy built in vice. So basically I have two metal employees doing the majority of the work. Next machine to build is a combination shear and punch that will take a piece of leather, and in one pull of the lever cut out the shape of the sheath and punch the lacing holes in it. And just for gits and shiggles, here's a "shop tour". I miss my old shop. :( The plan is to have the capability to turn out simple production knives, more complex and pricey custom knives, and also go to school and get all smart. I've already started on my first two orders, and my first run of the production blades, so there'll be more to come soon. Wish me luck! |
| jamoni:
BTW, I do realize that a lot of the steel was burned. There's a learning curve on this thing, and I was taking too deep of a cut at too low of a feed rate. Once the screw feed is on the grinder slide, and I have a finer control of depth of cut, that should cease to be a problem. SOP for this machine will be light cuts, high rate of feed, repeat. Also, if anyone has any suggestions on improvements, I'd be glad to hear them. I know this thing is pretty crude, but it's meant to do a job and turn a profit, not get me girls. :) |
| greener121:
Sounds like a sharp bidness plan. I think that there are "wet" grinding, kind of like using flood coolant on a mill. I'll be watching for some finished products. BG |
| capjak:
I don't know what you are using for raw materials for the knives, but my son is a farrier and it is not cost effective for him to sharpen his rasps so he sells them for scrap along with the old shoes that he removes. At a local gun show I have seen some pretty knives made from old shoe rasps. It might be worth you while to look some some local farriers. Jack |
| Rob.Wilson:
Hi jamoni :bugeye: What an ingenious way to use a bench grinder :med: , cheers for taking the time to post up the videos :thumbup: Rob |
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