My favourite form of RC racing is 1/10 scale onroad. I have been competing in the GT2 and CVTA classes every summer for the last couple years. This is a slower class that is great for beginners and seasoned racers alike. The only problem is that here in Canada, once October rolls around, the outdoor season is done for what seems like an eternity. Not having an actual 1:1 scale car, I have a hard time making it out to some of the great indoor tracks we have here in Ontario. This was the catalyst for my decision to build a 1.9 scaler truck. I wanted something that I could run in my apartment, outside over the snow banks and take with me on camping trips. I decided to start with an inexpensive chassis that had been around for a while and that there was a lot of information and hop-ups for. I purchased the Tamiya CC-01 FJ40 kit for under $100.00. This kit has an interesting setup as it used independent suspension in the front and a solid axle in the rear. The kit went together easily and looked great. The only thing I did differently from the instructions was to lock both gear diffs during the build. However, this kit did NOT handle very well. The tires were too hard, there was very little articulation in the suspension and the steering was beyond sloppy. It was time to do some serious modification!
I started out with what's called the "Pantablo" steering mod. There are various examples of this all over the internet. This mod moves the steering servo from way back in the tub chassis and places it over the front wheels like most of today's scale crawlers. This mod requires you to actually remove most of the front section of the chassis with a saw. I was very hesitant about taking a saw to a brand new chassis but I measured twice and cut once. It was actually quite easy. I attached an Axial AX10 battery plate over what was left of the front wheel wells and placed the servo underneath it. I then took the Steering Knuckles and turned them backwards. This lets you connect the two Steering Knuckles using a turnbuckle to each other and then to the servo horn. This took out ALL of the steering slop and made for very strong and precise steering.
The next step I took was to create a custom 4 link suspension setup in the rear. I chose to mount it in the stock locations and it worked out great. I measured the stock plastic links and cut 4/40 threaded rods to size. Then I took hallow aluminum tubing and cut that to cover the threaded rods. I finished the ends off with Traxxas Revo ball ends. These are the go to ball ends in any DIY suspension links. Now as a note I would have preferred to use metric sized rods and tubes on a Tamiya project but it is all I had available at my LHS. Even though I used the stock mounting locations, this gave me a bit more articulation in the rear.
Finally I finished by installing a 55T lathe motor, 90mm RC4WD shocks all around and Proline 1.9 Chisel tires on beadlock wheels. I was amazed at how well this truck crawled now. I took the truck with me to the Elora Gorge and I was able to get over some really rough terrain. The suspension just twisted beautifully over every rock and tree root it encountered. The tires just pulled themselves ever ledge I pointed the truck at. With some relatively simple mods, the truck was transformed from mild to extreme. I only hope that my next project based off of a Tamiya TLT truck will handle this well.
[/Joe Bielski]
No comments:
Post a Comment