Hollow Grinding Jig

One thing I'll clarify on my earlier statement where it takes a couple hundred knives to be "good" at freehand grinding, is there are different levels of being able to do it.
After 10-20 knives (especially with some hands on instruction) you should be able tk grind good functional knives, but there will still be a lot of things that are challenging or you have yet to figure out.
The couple hundred I threw out was what I consider to be "good". Basic knives are easy and relitivly fast, and pretty well any shape or grind is doable, but it still involves slowing down and taking your time on more complicated pieces.
Now I haven't gotten here yet so there is some level of speculation and looking at/talking to other makers involved, but the 1000+ mark (or wherever exactly it ends up being for you) is the point where you actually master it. People like Egnath, Shore, Hibben, Warenski, ect (far from an inclusive list, just the first 4 that came to mind) who could grind blades in their sleep.

I'm about at the 400 mark. I can do pretty well any grind or blade style I'd want to, I'm just slow with more complicated ones. A basic hunting knife might take 10 minutes, whereas a dagger or double edge fighter might take me a couple hours.

We all start at the bottom, it just depends how much time and effort you want to put into climbing the ladder.
 
G'day Blokes,
Sorry for the belated reply, I have been in outback Australia with no wifi.
However to answer Matthew.
I am not trying to become a professional knife maker.
I guess I only intend to make one or two knives so I just want to ensure the ones I make are "professional looking".
Thank you Ken, your rest is along the lines of how I have been thinking and may best suit my purpose.
I have been a tradesman in the metal industry for 50+years, and am quite competent with a grinder, but am always open to other peoples ideas, hence this thread.
However having said that I am pretty fussy and want to ensure both sides are ground at the same angle.
Thanks to all who have responded.
Regards,
Neville
 
Thank you for replying!

I wish I were in the outback with no wifi... ;)


Good luck with your projects. I hope you think to share them when you’re finished!


Hotopal said:
Sorry for the belated reply, I have been in outback Australia with no wifi.
However to answer Matthew.
I am not trying to become a professional knife maker.
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JTknives said:
Yeah that's the jig we need. I have done something simaler with a sheet of 15n20
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I think i'm going to make one and try it out like that. Seems pretty straight forward and hard to mess up. My hollow grinding so far isn't working out very well. Flat grinding is getting much much better.
 
To answer your question I would build a simple sled jig that you slide freehand on your work rest. A piece of angle iron will do the trick if it is straight enough and a precision ground block would be even better. Scribe a line across the top about an inch from the top, add 3-4 evenly spaced holes on that line that will hold some dowel pins for indexing (so you can flip it over and match) and you are good to go. This will do a good job of grinding a straight line style bevel, you can angle the jig to grind the tip/etc.
 
I have been so tempted to attach/epoxy a sheet of pyroceram to my rest. I have a small sheet and tryied it out and it makes sliding blades on it smooth as butter.
 
JTknives said:
I have been so tempted to attach/epoxy a sheet of pyroceram to my rest. I have a small sheet and tryied it out and it makes sliding blades on it smooth as butter.
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Just put some painters tape on the rest. Duct tape will work too. Things slide great for me with that.
 
JTknives said:
I have been so tempted to attach/epoxy a sheet of pyroceram to my rest. I have a small sheet and tryied it out and it makes sliding blades on it smooth as butter.
Click to expand...
I've done it but it will Crack/chip pretty easily you just have to take extra care.
 
I just tried it, the 2nd hollow grind I have ever done. First hollow grind was free hand and I don't want to talk about. Doing it Travis way works great. I have trouble getting a straight line at top end of grind, [don't know what it is called] but using the plates worked great. The grind came out very professional looking and I took it from a 40 grit to gator 65. You are limited by how high you can make the grind. I was able to go about 5/8" with a 12" wheel before the grind was about to cut into the sharp edge. I wonder if a larger wheel would let me go higher.
 
I thought I was the only crazy person that ran his belt backwards used a rest under it. I have also used this type of set up to "surface grind blades. Just slide the steel between the wheel and the rest and presto.
 
oooo that looks like it will work much bbetter then my planned over the top sketch. now to see just how bad the old KMG tracks in reverse
 
Yes, I likes that even better than the over the top... ;)

Now I don't have a grinder such as the nice 1" x what ever he has, but I do have my 2"x 72" and had a great idea for the tool rest.

I'm going to weld a receiver at the foot of my grinder for this. It's basically going to be a tool rest that works like the table on a knee mill and can be raised or lowered via a screw. I just ordered the rails and screw.

2017-11-16_13-23-24.png

Edit: This is a very crappy drawing but you can get the idea of what's going on.

2017-11-16_13-47-08.png
 
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Like !

Well , how fast things go here.......I bet that this winter we shall end with CNC belt grinder :)
 
Natlek said:
Like !

Well , how fast things go here.......I bet that this winter we shall end with CNC belt grinder :)
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Damn it you just had to go and put that seed in my brain.

Here is my grinder set up for surface grinding. I get the plate square to the wheel and clamp a thin steel stripon both sides to keep the blade under the wheel. I run the belt backwards and adjust the gap by pivoting the grinder head which brings the wheel closer or further away from the rest. Works good all things considered. Not close to as good as a real surface grinder but it gets me an even thickness. When doing this to grind edge bevels I flip the rest arms the other way so I can move the under the wheel and adjust the gap the same way by pivoting the head. I use a rubber mallet and give it a few general taps. Works like a charm.

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Photo%20Nov%2016%2C%201%2031%2047%20PM.jpg
 
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im noot sure the screw table hight will wook well for me (least not a single scre jack) but i have been thinkning about how to make the lower table ajustable. for the project that this build needs to be made for i think i will clamp 4 folder blanks into a pair of 123 blocks to make for sure i have a nice solid sliding surface
 
butcher_block said:
im noot sure the screw table hight will wook well for me (least not a single scre jack) but i have been thinkning about how to make the lower table ajustable. for the project that this build needs to be made for i think i will clamp 4 folder blanks into a pair of 123 blocks to make for sure i have a nice solid sliding surface
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Just curious as to why you don't think a single screw jack would work. Can you elaborate on that some? Maybe it's just your plans for it's use. The one I ordered is a a set with a 14mm x 400mm lead screw., that's slightly larger than 1/2". As long as there is no play in the 2 rails, I believe it should be pretty darn stable and there should be no play.
 
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