DIY Final Project

The only requirements for this project were to make something that makes us happy, and to not make something too large that a 5-year old couldn’t carry it around. It took me quite a while to think of a project, but I finally settled on a pen roll. This was something that I had wanted to make for a while, but never got around to it, so I figured I may as well spend the time to get an assignment out of the way, too. It was also sort of a nice way to physically gather all the things that were given to us over the course of the class.


First thing, as always… sketches. There are some irrelevant things on the page, but the two on the right are pertinent to the project. I like having round holes to slot in the writing implements. The wavy cutouts were also pretty appealing, but I was worried that the fold over the top of the pens would get in the way of nice rolling.


There are some not-so-visible sketches at the top, but those were just more of the folding top design. This is where I start really thinking about how things are going to fit in the pen roll.


This is the sort of final project sketch before I started fabricating. I did end up switching the position of the eraser and knife, because I was worried that the eraser would get in the way of removing the knife.


There is a sort of assembly sketch for me to figure out the layering of all the parts. I had originally intended to skive and fold each of the round cutouts, but when I started actually fabricating, I decided against this, because it would have been too difficult, and I did not really have a proper skiving tool for this.


Laid out everything on a slightly extended piece of paper. The leather I had to work with was just a little bit over 12 inches, so I extended the 8.5″x11″ accordingly. Layout is everything from here, because I only had enough leather for one attempt. The assignment was due the next day, and I had no room for a screw-up.


I trade out all the parts that I wanted to go into the pen roll, along with centerlines, and stitching lines. I had to use a ballpoint on the right side of the layout, because it was taped over, and pencil wouldn’t draw on it. (I should have done the layout on the other side of the page, but oh well…)


After taking down the paper layout to the first sheet of leather, I used a spacing tool to mark out all the stitching holes. This also had the added benefit of keeping the paper from sliding around the surface of the leather when I started cutting out the holes.


All holes cut out! I actually had to re-hone my X-Acto knife between cutting each hole. I kept a stropping leather loaded with jeweler’s rouge on my desk for that purpose.


Before stitching, I had to burnish all the inner edges of the circles that I had cut out. I used a burnishing tool (figures) and some stuff called Gum Tragacanth. Basically, the stuff dissolved the leather, and after it dried, the leather would be nice and fused together.


I cut out a sheet of denim from a pair of torn jeans that I probably should have stopped wearing long ago. I made sure to trim the denim just shy of the perimeter stitching lines, because I did not want the denim to interfere with the burnishing later. I also used some flexible glue to tack the denim down to the back sheet of leather.


There’s the strip that ends up going around the entire pen roll to keep it closed. The front of it is leather, and the back is another strip of denim. I used more glue to keep it together and limit the fraying of the denim. I stitched the lengths of the strip first, before mounting it to the rest of the pen roll.


There it is anchored to the back piece of leather. The tie-off for the stitching ends of being hidden under the inner sheet of leather.


After many, many more hours of stitching, I ended up with this. I decided to not have the partitioning stitches run all the way to the end of the perimeter, because there would have been stitching hole alignment issues. The gap allowed me to not have to take the alignment into consideration.


Perimeter stitching finally done, along with trimming the edges. Last step was to burnish all the outer edges.


The things that were given out in class were the 3 COPIC marks, one regular Sharpie, a fine tipped Sharpie, BIC Cristal, and two colored pencils. That’s not even including the sketchbook!


Some minor issues with the edge not bring fully burnished, but that can always be fixed later.


That’s it! I think that was a pretty good way to wrap up that class. Hopefully, I’ll get to be a TA next year and see what other awesome ideas students come up with.


Making Walled Scales

So this is going to be a pretty long, sort of how-to post about how I make knife scales that have walls. Basically all scales come in two different forms. The easier scales to make are flat scales. The name is pretty self-explanatory. A flat scale is shaped to the knife, and just has the proper through holes and countersinks for the screws. The more difficult scales to make, however, are the walled scales. One method of making these scales is to start with a thicker piece of wood and to mill out or pocket the inside of the scale, but without a CNC mill, doing it by hand it both tedious and very time consuming. With the tools I have available to me, I decided to try and makes walled scales using a combination of a 3D printer and the rest of the handle-making equipment that I already have.

To start off, it’s always nice to have the project knife on hand. This allows me to check fitment every step of the way and also allows me to create a CAD model for the walls.

Cropper Scan
Scanner image of pocket side of scale

Just for reference, the knife I am working on in this write-up is a Boker Plus Nano. It’s a pretty unique, compact knife that’s really quite affordable.

SCN_0001 - Copy
Edited scanner image

I am really only interested in the walls of the scale and not so much the scale itself. Since on this particular scale, the screw holes don’t intersect with the wall, my task is a little simpler. The images was edited using GIMP.

Vectorize in Inkscape

After editing the original scanned image, the image is then imported into Inkscape. Using the “Trace Bitmap” toll under the “Path” menu item, I created a vector of the inner and outer edges of the wall. Taking a set of calipers to measure the vertical dimension of the physical scale, I make sure that the vector in Inkscape has the same vertical dimension. Afterwards, I export the vector as a DXF.

DXF imported into Solidworks

Upon importing the DXF of the scale wall into Solidworks, I again check the vertical dimension, making sure that nothing has changed between the two different programs. Once verified, I simply leave the sketch underdefined and extrude the sketch to the appropriate thickness of the wall. Finally, with a solid model in Solidworks, I can export the file as an STL and print it on my 3D printer.

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Scale wall glued onto scale

After the print completed, I glued the scale onto a rather thin piece of wood. Using the metal liner, I was able to transfer the hole pattern using two different sized drill bits that closely matched the clearance hole diameters on the original scale. Unfortunately, when I was drilling the more centrally located small screw clearance hole, the drill bit walked quite a bit. I had to use a small file to “fix” the hole and elongate it such that the screw would still fit through. The wood is Myrtlewood Burl. It’s not a very dense or strong wood, but as a sort of decorative part, it suffices.

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Countersinking the screw clearance holes

Using a belt grinder and Dremel, I was able to easily remove the extra wood that was outside of the scale walls. In order to size the counterbores, I first assembled the knife. The impressions left in the wood by over-tightening the screws that held the knife together gave me a good sense of how and I should make the counterbores and exactly where to place them. Using a mill end in a Dremel, I carefully enlarged the screw clearance holes. This process involves a lot of stepping down small increments and checking to see how far down the screw sat in the scale.

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Test fit before coating and sealing

Before sealing up the scale in acrylic spray, I had a quick test fit to make sure nothing was sticking out, everything was smoothed, and the knife still can open and close properly. With a couple passes of acrylic spray, the outside of the scale is sealed. I usually leave the inside of the scale untreated.


That’s it! I hope this walkthrough was useful.


Second Camping Knife

To give some quick background, my unnamed roommate from my previous post happens to actually have a name, Micah. Here’s a plug to his WordPress! He was working on a camping knife about the same time that I was working on my first chef knife.

DSC_1165There he is cutting out his blank with an angle grinder designed to deafen on a cold, dark, Worcester night

With all these knife posts, I think people are still interested in just seeing pictures first, so here’s a picture of the final product.


Micah had designed the blade shape, cut it all out, and placed the bevels with the “defiling jig” that I mentioned in the Chef Knife Complete post from earlier. Because that was about all he could do while we were still in Worcester, it was sort of up to me to complete the heat-treating and handle-making parts. Post heat-treatment, I decided to acid stonewash the blade, giving it a more rustic appearance. Micah selected the stained layered wood handle material long ago, but while I was working on the knife, he also requested a plaid-inspired pattern. In order to make the already flashy handles even more decorative, I decided to mill out a sort of plaid pattern and fill it with glow-in-the-dark resin.


There’s the pattern! The room was actually quite dimly lit, but the 3200 ISO and 5 second exposure helped to really capture the glow resin, but unfortunately also made the rest of the room look quite well-lit.

Saab Clutch Replacement

Finally finished putting a new clutch in my car. It was a pain in the ass but a good learning experience. Definitely not doing it again with my current equipment.

I had to do some pretty ridiculous things. For those who don’t know, the clutch is basically like a glorified friction plate that operates between the engine and the transmission. There’s a lot of other things between the outside and the clutch, so I’ll try to summarize the steps in the following:

  1. Control arms are removed from the subframe
  2. Driveshafts come out of the transmission
  3. Engine needs support, so I built a support bar out of wood
  4. Subframe dropped or removed
  5. Engine lowered
  6. Transmission slides out
  7. Clutch comes out of the transmission

After that, it’s assembling everything in reverse! Something I’ll definitely remember forever is that getting a transmission back up to the engine while on my back is probably one of the most frustrating things I’ve ever done.


Broken 3D Printer Extruder

So the extruder unit on my Solidoodle 2 broke recently. All 6 pieces of acrylic fractured, so the stepper motor could no longer get enough friction on the filament to advance it into the hot end. Unfortunately, my printer was out of warranty, so I couldn’t send it in to get fixed. So instead, I emailed Solidoodle support and asked if I could just get the replacement acrylic and replace the parts myself.

Edrick on the support team got back to me pretty much immediately and sent out the replacement parts later that day, which was super awesome. All I had to pay was $5 for shipping and parts. Parts were shipped Friday, and I got them Monday. Just today, I found some time to swap out the parts, and everything is working again.

Thanks, Edrick at Solidoodle!