iovanalex's ganduri de inginer … si nu numai

Heat treatment oven – DIY

As you can see from some of my previous posts for some time now I'm interested in metallurgy and knifemaking. Without being a fan(atical) of knives I reached the conclusion that most of the knives we use everyday are of bad quality

Being interested in knifemaking I've found that one of the most important aspects in good quality blade is .. . no surprise, the steel And a good steel is obtained after some heat treatments.
The idea behind heat treatment is not very complicated to understand but the specificities of each type of steel are the hard part which transform the heat treatment into some kind of art ... or black magic.
Anyway the necessary but not sufficient condition to do heat treatment is to have some kind of oven which allows you the control very precisely the temperature inside (in some situations you need less than 1% variance) .

Being interested in different aspects of embedded systems and control I will try to present some technical aspects of building such a device in other posts but for the moment I give you, below, a simple tutorial I've found in the Internet of how you could build in a DIY fashion a small scale oven by using a standard PID controller (as you may know for temperature control a PI controller is sufficient bu usually you can find easily PID controllers so that would be any problem if you use any of them).

The birth of a knife – Day 2 – Rough shaping

Hello and welcome back.
In the previous post I have presented the main shape of my first knife and some design decisions I took. Now I will try to present you the rough shape after the first cutting.
I’ve used a Dremel 300 rotary tool with the standard cutting disc. It worth to mention that I’ve used 1/3 of the diameter to cut only about 18cm of HSS.
Obviously I took all the safety precautions when working with grinding power tools: safety gloves and high impact protective polycarbonate goggles. Please, reader, don’t get hurt
In the image below you have the rough shape of what I have obtained. As you can easily see it is quite similar with the blank design from the previous step.
I’ve began forming the blade only to see how will it look like. The conclusion is that I have to use a smaller angle and I’m thinking of 10deg on each side.

The next step is to form the entire length of the blade and I will be using the polishing head of my Dremel. After that I have to smooth finish the blade (I will need some stones) and attach the handle. By the way: how would you suggest drilling in the HSS ?

The birth of a knife – Day 1 – Design …

Hello everybody,
For some time I'm an avid reader of the bushcraft.ro forum and myknife.ro. The main topic which interests me is the manufacturing of knives. Even if I’m not a fan(atical) nor professional user of knives (as you know I'm a computer engineer) I'm using regulary a Victorinox Officier Suisse and a CRKT Bull and I'm quite satisfied of both. But the engineer inside me is interested in the practical side of manufacturing so I'm planning to do exactly that: make a knife from start to finish all on my own.

Being a city-guy I don't have access to blacksmithing tools (forge) so for the moment I will stick to using already "prepared" steel. From what I learned by documenting on the internet a good source of steel are the HSS table saw blades. These preliminaries are what I know from some time. So the question is what took me so long to test. The main impulse is that on Saturday I found on the street a used table saw blade. So now I don't have any reason to continue waiting.

Having the steel the second question is to find a design for my first knife. All the knifemaking gurus consider this as being the "passing the Rubicon" moment. This is the point of no return... symbolically speaking.

In this field I'm a quite decided guy so I drawn the shape from a single stroke of my hand and left it that way... but I'm satisfied. I know many of the knife aficionados will find some drawbacks but for the moment I don't  want to change anything.

From the metallurgical point of view all I know is that it's some kind of HSS steel, 1mm thick and 120mm wide.

In the second part I will try to cut the rough shape using a Dremel tool. I don't know how will the Dremel behave but I don't have other options but to try

Wish me luck ...