Kristian Felten

Pine needle separator

Senior capstone for the IFIRE Lab, Sep 2026 – present
Mechanical design lead

The IFIRE Lab uses large amounts of pine needles as fuel for fire testing, and right now they're cleaned by hand. Our team is building a machine that does it automatically. Material goes up an inclined conveyor that pulls out the big debris like pinecones and sticks, then into a rotating trommel that sieves out the rest. The goal is less than 1% debris in the finished needles.

I'm leading the mechanical design and working mostly on the conveyor stage. One idea we're testing uses a cam to bump the belt so larger pieces jump over a baffle while the needles keep going.

1973 Jeep CJ5

Personal project, 2020 – present

This Jeep was in a fire and a crash in 2017, and I've been rebuilding it in my own shop since 2020. I took it down to a bare frame, sandblasted everything, and painted, powder coated or cerakoted every part before it went back on. The underbody and the inside of the tub are done in color-matched Raptor Liner.

Pretty much every part of this Jeep has been rebuilt, replaced or made by me, from the frame and drivetrain to the wiring and body. It runs a small block Chevy 350 with a rebuilt Quadrajet. A few of the things I built along the way: the twin-stick transfer case linkage and shifters, the fuel lines, seat brackets and transmission tunnel covers. Where an off-the-shelf part didn't fit, I made one, like the fuel filler adapter I designed to clamp against the tub so I wouldn't have to cut the sheet metal.

I also wired the whole thing myself, including a fender-mounted relay tray, a fuse and relay panel, and a harness with two bulkhead connectors at the firewall so the dash panel comes out for service. The dash has digital reproduction gauges, a GPS speedometer and a switch panel. Body work and paint are done, and now I'm on final assembly. The photos below are just a sample of the build.

Thermal conductivity of concrete mixes

Senior design lab, University of Idaho

For this lab we looked at how mix design affects how well concrete conducts heat. We batched samples by weight with different aggregates and water-cement ratios of 0.4 and 0.6, cured them in hot and cold conditions, and measured each one with a KD2 Pro thermal properties analyzer.

Pinball machine

Class project, ME 223

We built a working pinball machine for this class. I made the flipper drive: I wound the solenoid coils myself, paired them with 3D-printed flippers, and added end-of-stroke switches that signal when each flipper reaches the top of its travel. The whole system runs off a 20V DeWalt battery and is switched through relays from arcade buttons on the side of the cabinet.

Machining projects

Machine shop

Turner's cube. I programmed this in Mastercam and milled it on a CNC as part of my machine shop certification. It's four nested cubes cut from one block of aluminum, so each pocket has to break through to the next one without cutting into the cube inside.

Tap wrench. I made this for my manual machining class. It has knurled handles and a sliding jaw that's tightened with brass screws to hold the tap.

7.3L Powerstroke rebuild

Personal project

I rebuilt this Ford 7.3L Powerstroke diesel from the block up with all new internals, and rebuilt the turbo myself. Every component was painted, powder coated or cerakoted before it went back together.

Subaru CVT cutaway

Automotive technology program, North Idaho College

I took a Subaru CVT apart, modified the case, and put it back together as a cutaway so you can see how it works inside: the variable pulleys, the CVT chain and the pump.

Other projects

Personal projects

Transmission crossmember. I needed a crossmember for a Ford 460 swap with a ZF5 transmission in a 1978 Ford, so I designed one in Fusion 360 as a sheet metal part with lightening holes along the webs. Then I cut it from flat stock, bent it, welded it and finished it.

Smaller CAD parts. A brake line mounting bracket to replace rusted originals, and a single-piece gas cap I'm designing for a 1948 Cessna, both in Fusion 360.