Gebhard Solutions has some interesting training blades for small folders.  I want make one like this but I think I will make a pattern from scratch. Mostly as a learning experience.

Finally got a chance to take pictures of the second loveless prototype. First thoughts are that the white under wrap with black over wrap did not look as nice as I was hoping.

I still want to try a flat under wrap – which should let me space out the over wrap a little better,  and father apart. Regardless the top side insert was about 4-4.5mm too long, leading to the notch of empty space by the lanyard hole.

I do think this blade fits better in my hand. With the insets the wraps make the handle about 4mm thinner. I think I could take it down another 2mm and then weight the handle to shift the center of mass back into the hand. Before I do any major reshaping of the design I think I will make the next blade from steel and see how that impacts things.

So the second bit of feedback I got from my knife fighter friend was that her training blades always get banged up in knife to knife fighting. I made the blades form 6061 aluminum, and was curious how it would hold up.

I mounted some scrap stock in a vise and did some slash cuts on it, then let my friend do the same. I marked the blades with sharpie so that the damage would show up better.

*Ahem* I looked like I was waving a tiny baseball bat around with one hand and her strokes looked like she was performing an appendectomy. The result of both our cuts though was gouges on the blade. So while 6061 Aluminum is probably fine for training knife defenses, I think I will want to make the final training blades from tool steel so that they can also be used in knife to knife training.

This blade design is inspired by the keen-edge blades 9 inch loveless. After the handle felt fat in my hand, I took a second look at their pattern. I double wrapped my handle – so right off the bat my dimensions were bigger than theirs by 6mm. So I figured I would cut the same knife but with either side of the handle inset by 3mm on each side. (Inset shown with the red arrows).

I also added a small guard on the back side of the blade opposite to the finger guard. The idea is the extra guards and insets would simultaneously make the blade thinner even after I added a double wrap, and help keep the under wrap from sliding around on the handle over time. All in all I think I want to play with this idea more. I like making the handle feel thicker with a double wrap – but without its feeling wider.

Unfortunately I dropped the knife off at the dojo for people to play with before taking pictures of the new design.

So I got some time to play in the shop this weekend. Once I adjusted g-code generation to just pencil line the profile of the blades I got the cut time for both blades down to 17 minutes. That was going super slow at 5IPM, since I did not want to drive Z faster and the g-code generator was not playing nice if I tried to have the axis at different top speeds.

For this first blade I worked off the loveless 9 point hunter. I really liked the lines on the keen-edge knives pattern for the loveless. In the end it seems a little small in my hand. Maybe I got the pattern wrong but the finger guard presses into my hand.

I did both the handle wrap and the over wrap with 3mm para cord – so the handle also feels a bit thick to me. Interestingly that bulk made it seem handle heavy to me, but as soon as I placed the knife in a friends hand who is a knife fighter her immediate comment was that it was blade heavy. Adding a false blade profile should help – but this drove home that I am going to need to get a lot of feedback from blade people to make this project work.

The reverse grip feels a little less “fat” in my hand, but I don’t know now how to improve it. A little stumped here.

So eventually I want to try making some real knives, but first I want to make some training blades. Basically knife shaped and weighted objects, but constructed with out points or blades. You use training blades like this to train in the martial arts. It allows realistic attacks, without the pesky side effects of “oops” – “I think I just cut open your jugular vein” or “I think I just stabbed you in the kidney for real!”.

While I have never done business with them, Empire training blades (http://www.empiretrainingblades.com/Training%20Knives.htm) has a nice looking catalog of training knives. In particular I liked their loveless training blade – so for my first knife I figured I would use that as inspiration / target. The Empire blades are only like $30, and so unless you are trying to learn from making the knife, like I am, or trying to go into business making them I suggest just buying one and finding some place else to spend your time. Like training with the blade.

Any way, my first attempt cutting out the knife was going well enough until I realized, all too late, that the g-code assumed a roughing pass had been done. So the mill buried the cutter into the stock, then snapped off the bit trying to do a heavy cut. Luckily it was a small cutter designed to snap under those conditions.

So Ian came over again this weekend with a weird project – he wanted to make some protective plastic covers for photographic filters, which is easy enough, but he wanted to try engraving them.

I had never done engraving with the mill, but Ian had mentioned it before, and I had been meaning to try it, so I already had purchased some engraving bits. All in all I thought the engraving came out ok. Main lesson learned is I need to make some specialty mounting fixtures for working with thin stock.

Normally I used double sided tape, but Ian wanted to preserve surface finish on the soft plastics so we ended up making a jig from wood to hold the parts.

This post is mostly a reminder to make such a jig in the future, and a little bit a reminder to talk with Ian again about his making faces in photographs freaking me out.

The wether has been below freezing for a week and a half. The garage windows has remained frosted over for most of that time. Looking at the window it struck me as an example of “Math in the real world”. The metal window sills leaked heat out of the glass forming a differential curve. Looked to me like a k(1/X +m) curve – or maybe a tangent function. Weird but it made me happy.

So really I should Ban Ian from my shop entirely – but that is hard to do when he shows up for things like moving the mill. The middle picture there shows my justifications to ban him – the ridiculous poses he strikes around my tools whenever a camera comes out – the other pictures show why I am unlikely to ban him – the mill he showed up to move.

The move was part of optimizing my shop layout. I moved the mill over to where I had space to build a coolant cage around it, and added vibration dampening feet to it. The feet really help with vibrations caused by “high speed” CNC moves. Without the feet my mill would walk whenever I drove it faster than about 30IPM.

So Vegemite is basically yeast poop left over from making beer. It is spread over toast in Australia. I went 3 years living in australia before a girlfriend insisted I had to try it. I hated it, but she had it on her toast in the morning and after the 3rd or 4th time trying it I got used to it and grew to like it. Now when I miss Australia I get a hankering for Vegemite.