Despite this build falling off pace for a bit, I haven't stopped working on it. I got a couple things done last week, and this weekend. Here is an update.
We have steering! Boy, I could almost drive this thing now, if I just quick threw a battery, ESC, and receiver into it.
For the purists....proper ackerman steering geometery! I think this truck is going to handle nice. Look close and you'll see the inside wheel turns sharper then the outside. I think the turning radius is going to be really good. I'm happy about that.
And then I worked on something I had been putting off over and over again. Figuring out how to mount the cab to the truck. It's two pieces, in case you couldn't tell.
The cab base mounts to the chassis, and the cab to the cab base. As a toy, the cab is more less held to the cab base with some cast in bosses but I had to mill those off to make room for the electronics inside. That left everything floating free. After thinking a great deal about how to mount the cab to the chassis, yet have it be removable, this is what I came up with.
I machined some blocks to bolt the cab base to the chassis. In the blocks, I milled a keyway, front and rear. I also had to mill the cast cab seats off, but that was some time ago....
Inside the cab, I bolted on some keys to fit the keyways. This way the cab is aligned perfectly, and it cannot slide forward, backward, or side to side. It took some math, some trial and error, some test pieces, and a lot of patience, but the results are great.
As a plus, there are no screw heads showing anywhere on the outside of the cab. They are drilled and tapped from the inside out.
The keys have a T-shape to them. This is to allow the keys to only side into their respective keyways to a specific depth. I also have found some 1/8 diameter magnets that I think I will use to hold the cab to the base. I'll probably mill a shallow bore on each side of the T's, glue a magnet to each, and then do the same in the cab base mounts. When they line up, they'll snap into place. The magnets are rated at .7 pounds of pull each, and with two in the rear, and two in the front, (should be 2.8 pounds pull combined) I'm hoping that will be strong enough to hold the cab on, with the truck flipped upside down. Not that it will spend much time like that...
One more photo, showing how it all lines up.
I'm really glad this step is all done. Now to start making some electronic mounting plates for the 10 pounds of stuff I have to fit inside the 5 pound bag!