Thursday 23 February 2012

Chef Knife - part 2

Another good evening of progress on the Chef Knife. When I arrived Chuck was showing me some of the knives he recently finished. Amazing stuff. You couldn't get a hair between the bolster and the handle. Note the brass inlay on the bottom knife. These things feel so comfortable your hand would never get tired.

Our steel came in this week (1/16" 440C steel). Chuck had trimmed down the plastic template we built last week and put blue tool marking dye on the new steel. He already got well into his knife (he's going to make a chef's knife too). He even got his master cut in already. The master cut is the first main cut to taper the edge of the knife, bringing it into the center line evenly while maintaining the desired curve of the blade. It's a big step.

But tonight, I had to cut out my steel in order to get it into something I could put a master cut into. I started by etching the shape of the template into the marking dye with a scribe pen. Then off to the metal band saw to get my rough cuts around the shape. The marking dye doesn't last very long when the oil hits it and there is very little play in that blade, lots of relief cuts.

It went pretty well.

Then to take down the rough cuts to the etch lines on the belt sander (about 42 grit).

The bottom curve by the bolster needs a different tool. Here Chuck has a round disk (about 80 grit) attached to his radial arm saw.

Took some extra attention to take out any nicks from the rough cut.

I decided on just two brass pins holding the handle. To drill these out first I had mark the centerline of the knife (vs the line of the handle, which would make sense if I was going for a more radical design).

Then mark and punch when the two pins would go.

And drill them out. Additionally I added 3 other drill holes to help hold the epoxy in the handle. The 2nd and 4th holes are centerlined, it doesn't really matter where 1, 3 and 5 go.

Then had to get the spurs off the drill holes and this was surprising difficult since any bad sanding would cause the handle halves not to fit perfectly snug. Had to hand sand it with a locking magnet.

But it did an even sand as you can see from the scratch marks in the steel ...

Now I could work on the top notches. I usually choke up on my chef knife around the bolster, but sometimes I'll do the one finger extension. I wanted to put some grip notches along the top ridge. I settled on 4mm center-to-center with a 1mm depth.

Later I'll file these out to make them pretty. No need right now since I'll likely be taking down the steel a little more yet.

Next time ... the Master Cut!

Friday 17 February 2012

Flood / Drain Hydroponic Herb Garden ...

Fresh herbs are expensive and they don't last very long. When you're cooking a lot it means that your almost always out of something necessary ... and there's no better way to ensure a good meal than using fresh herbs. I tried conventional gardening pots, but the results were spotty. Instead I thought I try a hydroponic garden ... hey, it seems to working well for the weed industry, perhaps it could work for home cooking?

I settled on an 11-bottle Flood/Drain design. The premise behind Flood/Drain is that you flood the roots with nutrients for a short period of time and then let it drain away. Too long and you rot the roots. Too short and the plants starve. 

The entire system sits on top of a tupperware box that contains the liquids and pump. Everyday 2L pop bottles are used to contain the plants along with some rock wool to support the roots. 

The basic layout looks like this:

To ensure the parts are level, it's a simple matter of turning the frame upside down and pressing down so all the outlets are flat. This is a critical step, otherwise you'll have bottles shooting out at odd angles. Since the water and plants will have considerable weight, not being completely vertical is trouble waiting to happen.


From there, I carefully PVC cemented the parts together. You have to work fast with this stuff, it's completely unforgiving. Fixing mistakes means hacksaw replacements. You can see my pop bottles ready to go. The real challenge is seating the bottle caps in the frame with a solid / water-tight fit. Bottle caps are not made of the same plastic as PVC tubing, so finding an appropriate glue is tough ... and it has to be food grade. I settled on a combination of contact cement, silicon and hot glue. Really a dogs breakfast.


It's messy, but it works. Later, I'll drill holes in these caps for the water to flow through.

So, how to we ensure we only pump the correct amount of water into the bottles? Well this is a clever little trick. We sacrifice one of our bottle holes for an overflow pipe. The height of the pipe determines the maximum height of the water. When the water pumps to here, it will start to spill back into the container. That way, we don't have to have precise values on our timer. We can overshoot and still maintain a maximum level. 

It's very impressive to watch as you'll see in the video later.


Here's the return pip going back into the container.

Inside the container is the connection of the pump to the top-level frame. This is just a friction fitting.


The pump is a submersible fish-tank pump. It has to be powerful enough to lift about 5L of water 2 feet and hold it. It sits right in the nutrients.

And here's a video of the system in operation ... it's at 2x normal speed. The timer will do this about every 15 minutes.


So where are the plants?! Turns out there is fatal design flaw with this set up (two actually). I'll let you try and guess what it is in the comments. I have a plan for fixing it and will attempt it this summer. At that time I'll post an update and let you know how it went :)

(the original plans for the system can be found here)

Thursday 9 February 2012

Chef Knife - Part 1

Just before Christmas, one of my cooking buddies showed me a new set of knives that his wife bought him. They were beautiful. Damascus Steel. Incredible handles. They were works of art. They also cost a small fortune. It just so happens that one of my neighbors (Chuck) makes knives and, let's just say, he's pretty damn good at it. I sent him an email and asked "Care to teach a noob?" He was all over it. 

See, the guy is a Maker. I don't think there's anything this guy can't do. And there's nothing a Maker likes more than having someone else as excited about a project as he is. I'll be telling you more about this guy in later posts ... there's a lot to tell. 

After some delays, I finally managed to sit down with him and talk about the project. I brought the old Cuisinart Chef's knife I've been using for the past few years. I really like the roll of the blade and the size of the handle, but I tend to choke up on it and the bolster isn't a smooth grip for me. We'd have to work on that. We started with some outlines of the existing knife:


We also checked the Rockwell Scale of Hardness (RC) of the current knife using hardness files. I find it very easy to sharpen, but it never seems to hold an edge for very long. Turns out the knife is between RC60 and RC65 which is pretty hard. I suspect I've just been too aggressive on my sharpening angle. 


Next we talked about handle materials. Chuck has an amazing collection of antlers, horns and other natural materials. These are really funky, but I'm a little concerned about the porous surface around food.

Chuck even has some Mastedon ... really.




We settled on some Stabilized Hardwood. I'm going to pick a final material later in the game. This stuff is hardwood pressure-injected with epoxy. It feels like plastic but retains the hardwood grain. Very cool material.


This was my first session. We're going to try to meet once a week and create a mock up out of wood so I can get familiar with the fabrication tools, make a wooden mockup, tweak the bolster and handle design. The steel has been ordered, I'll tell you more about that in a later post. 

Stay tuned!



First Post!

Thought I'd start a new blog for my DIY / Maker / Cooking projects. I want to keep sandywalsh.com completely focused on programming. Stay tuned ... lots of cool stuff to come.