Author Topic: Knifemaking Grinder and tooling  (Read 12205 times)

Offline jamoni

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Knifemaking Grinder and tooling
« on: February 21, 2011, 07:24:32 PM »
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!

Offline jamoni

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Re: Knifemaking Grinder and tooling
« Reply #1 on: February 21, 2011, 08:20:11 PM »
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.  :)

Offline greener121

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Re: Knifemaking Grinder and tooling
« Reply #2 on: February 21, 2011, 09:44:04 PM »
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

Offline capjak

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Re: Knifemaking Grinder and tooling
« Reply #3 on: February 22, 2011, 11:37:36 AM »
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

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Re: Knifemaking Grinder and tooling
« Reply #4 on: February 22, 2011, 12:42:10 PM »
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


Offline jamoni

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Re: Knifemaking Grinder and tooling
« Reply #5 on: February 22, 2011, 03:13:21 PM »
Here's the first paying job!

It's the beginnings of a small Swiss style marking knife.  This was just the first test run, and it did great!
The right hand bevel is a touch off, because the work slipped in the jig on the very last pass.  GRR.  However, I'm working on a better indexing and clamping method for small work, so the next one will be a lot better.  It also needs the shoulders of the blade brought up about 3/4", to give the epoxy something to grab when I glue it into the handle.
Capjak, I'm using O1 tool steel purchased from a local mill.  They give me a decent discount if I purchase in bulk, plus free (and quick!) delivery.  I've used old files in the past, but they need to be tempered before they can be worked, or they'll chew up tooling.
Rob, thanks!  I used what I had.   :dremel:

Offline jamoni

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Re: Knifemaking Grinder and tooling
« Reply #6 on: February 24, 2011, 01:37:37 PM »
Version 2.0 of the marking knife:

Bigger, longer tang, different angle of grind.
I don't think this will work, though.  The point is about 95*, and it's just not pointy enough.  I figure 70* is about right.

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Re: Knifemaking Grinder and tooling
« Reply #7 on: February 24, 2011, 04:22:46 PM »
Hi Mike (found your name from your intro  :thumbup: )

Just looking through this and I have a suggestion that may or may not have occurred?  I'll admit it seems obvious.... But if left unsaid.....


As bearing sliders have you thought of draw slides?  I've got them on all my tool chests and the pull out draw under my workbench.... I think that they would work really well?
I would think that budget can be accommodated by use of a scrapyard (junkyard) or second hand ones from old kitchens etc

All you would have to figure out is a way of shielding them as much as possible from the grinding dust!


I see from your description this is going to expand into a very useful machine. I look forward to seeing it do so   :headbang:    :nrocks: 

IMHO a simple threaded manual feed would be my next fit on the grinder.... Must be really difficult to feed it down lightly for the next cut? 




Wishing you luck as requested  :thumbup:






Ralph.
I know what I know and need to know more!!!

Offline jamoni

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Re: Knifemaking Grinder and tooling
« Reply #8 on: February 24, 2011, 06:35:38 PM »
Divided Head, Yep!
You hit both nails right on the heads.  I'd already decided on drawer slides, if I can find some sturdy enough.  My plan is to replace the steel rails with aluminum ones, and mount the drawer slides to those. 
I may do the same with the grinder slide, if I can make it lockable somehow.
And the absolute very super next thing to be done is that screw feed.  I need way more control over depth of cut. I figure my issues with the edges rounding off is taking too deep a cut, so that the grinder speed is higher when it hits the work, then slows down to hog out the cut.  By avoiding those heavy cuts, I get the nice grinds you can see in the pic.
However, right now, it's making me money, so the upgrades'll have to wait for a week or so.
BTW,

Offline Blade

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Re: Knifemaking Grinder and tooling
« Reply #9 on: February 24, 2011, 11:18:58 PM »
Hello Jamoni, nice grinder. I have built a couple of belt grinders myself so I know how hard it is to make a grinder on a budget. One good source of a screw to raise and lower the grinder is the screw off of a scissor jack for a car, you could possibly even use the entire jack to push the grinder up and let it back down. Another option is a piece of all thread and a nut.

Another suggestion I would make would be to run a grinding belt instead of a stone. Stones are great for a fine finish but aren't so great at hoging material. If you picked up a 1" x 6" wheel for your grinder and made an idler arm you could buy 2" x 72" belts and split them in half so you would make two belts out of one. You would be amazed at how much faster you could cut by using ceramic media 80 grit belts. I think sears sell a grinder like yours that is allready set up as a belt grinder on one side.

I am guessing that you are making Kiradashis out of the blanks that you are making? Show some pics of your finished product.

Thanks for sharing,

Eddie


Offline jamoni

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Re: Knifemaking Grinder and tooling
« Reply #10 on: February 25, 2011, 12:12:33 AM »
Blade, the idea for the scissors jack is pretty awesome.  I have a scissors jack in my car, and a two ton bottle jack collecting dust in the shed... SWITCHEROO!
As for the belt grinder, that's going in during phase two.  :)
And yep, it's Kiridashis. 
Once a couple runs of those are out the door, I'll be doing some puukkos and camp knives.

Offline Blade

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Re: Knifemaking Grinder and tooling
« Reply #11 on: February 25, 2011, 02:46:28 PM »
I would use the scissor jack, I think the bottle jack would be too hard to make adjustments.

The belt grinder with good belts will make a huge difference.

I am curious as to how you are going to grind the puukkos and camp knives on this grinder, or are you planing to grind them some other way? Maybe some kind of cams to push the blades over so the grinder hits the point as you move it would work.

Offline jamoni

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Re: Knifemaking Grinder and tooling
« Reply #12 on: February 25, 2011, 03:44:06 PM »
I meant I'm going to put the bottle jack in the car, and use the scissors jack.
For the puukkos, I'm going to make up a cam plate with two slots in it, and some small pegs that clamp onto the back of the blade.  The pegs ride in the slot, guiding the knife.  I'll only be able to do one at a time, but it'll still be faster and more accurate than by hand.
The cam plate can then be flipped over and used for the other side.
I can just make up new cam plates for new designs.  The adjustable angle table will help with this.
For the camp knives, I intend to cheat a little and use quality premade blades, but do the handles, sheaths, and final finishing work.

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Re: Knifemaking Grinder and tooling
« Reply #13 on: February 26, 2011, 07:41:32 AM »
Mike, Sounds like you have it all figured out (bar the cash!) just get some sold and advance.... Sounds like a little business  :thumbup:

Eddie.. How's it going?   Good call on the jack thread, got all the parts in one  :smart:


I'm definitely liking this thread  :proj:






Ralph.
I know what I know and need to know more!!!

Offline Blade

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Re: Knifemaking Grinder and tooling
« Reply #14 on: February 26, 2011, 11:28:09 AM »
Jamoni, got you  :hammer: somtimes I am a bit dense. Sound like you have the cams all figured out.

Hi Ralph, I am well thanks, hope everything is good for you. Those jacks are a good source of some decent screws, I used a screw from a broken jack to make the belt tension adjustment on one of the grinders that I built.

Offline jamoni

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Re: Knifemaking Grinder and tooling
« Reply #15 on: February 26, 2011, 09:38:33 PM »

So, I have this ancient Millers Falls drill press, which is overbuilt by a factor of about 1,000. I had a buddy help me move it, and he asked if he could borrow it, because he needed to take core samples of the Earth's crust.  Hardy har har.
Anyway, the drill is removable, leaving you with just a big press.  The drill mount is also removable, which gives you a nice flat sturdy spot to bolt on whatever you want. I was thinking about disassembling it all, and making it into the leather press I need, but this thing is so beefy, I think I'm just going to chuck the leather cutting die right up in the drill, and go to town.  :)

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Re: Knifemaking Grinder and tooling
« Reply #16 on: February 27, 2011, 06:20:00 PM »
Eddie,

Good myself too  :thumbup:  Very happy with the jacks idea.... Things you wish you'd thought of in the past  ::)


Mike,

That Drill looks pretty solid  :jaw:  it'll be interesting to see how it performs as a cutting press?     :lol:  On your bud's quip   :) 






Ralph.
I know what I know and need to know more!!!

Offline bry1975

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Re: Knifemaking Grinder and tooling
« Reply #17 on: February 28, 2011, 05:09:01 AM »
That drill looks very similar to the old Wolf Drills?

Bry

Offline jamoni

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Re: Knifemaking Grinder and tooling
« Reply #18 on: February 28, 2011, 11:20:24 AM »
It's got a Millers Falls label on it, but I couldn't find it in any of their catalogs.  I think they made some stuff for Craftsmen, so it might be one of those.

Rob.Wilson

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Re: Knifemaking Grinder and tooling
« Reply #19 on: March 01, 2011, 01:22:49 PM »

Rob, thanks!  I used what I had.   :dremel:


Allot of good things are made from what we have at hand  :med:  ,, its dong a fine job of grinding those blades  :headbang:

Rob

Offline jamoni

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Re: Knifemaking Grinder and tooling
« Reply #20 on: March 01, 2011, 08:10:16 PM »
Decided to scratch build the leather press, instead of cobbling some crap together.
Today I bought a 110v arc welder.  It's a little hobby setup but for the stuff I do, it should be fine.  Now I can build stuff up from steel without drilling holes and sorting through 9 drawers to find the bolts and nuts I need. :)
Um, should this thread be under shops, instead of projects?  It started out being about the grinder, but now it's more about the shop.
EDIT: I also built a nice little workbench yesterday, and mounted my vice.  It's starting to look like a shop!
« Last Edit: March 01, 2011, 08:11:52 PM by jamoni »

Offline jamoni

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Re: Knifemaking Grinder and tooling
« Reply #21 on: March 05, 2011, 06:31:40 PM »

Woot!  It works, but I have it on a 15 amp circuit, which it trips right about the point I get a nice puddle formed.  :doh: Need to run a cord from the 30 amp circuit, and it should do just fine.  :)
Also, today, I got a stack of 14 knives ready to go to the heat treater.  Total time in each knife is less than 10 minutes, not counting time spent working on the machines.  Once they come back, it's a quick final grind, polish, and sharpening.  In the meantime I'll work on the sheath punch and sheaths, and on a few custom orders.  When this batch sells, the money will get folded back into the shop for more steel, leather, and tooling.  After that, it should be at least self sustaining, and most likely profitable.
This may just work!
« Last Edit: March 05, 2011, 06:37:09 PM by jamoni »