Well I got the switches in the control box wired, the levers installed, and the whole system all wired ready for testing. I have a loose wire or the pass-through relays are acting funny, so it is working intermittently, so I am trying to track down the culprit.
I also installed the tracks and the drive belts. While the electronics were working, I tightened them up, to see if the thing would roll! And… drumroll….. the belts slipped on the pulleys. This is either because the pulleys are too slick being made of UHMW, or the belts just aren’t tight enough. I will first try to just add some idler pulleys to tighten the belts, and hope that works.
Also, the total weight of everything seen, including suspension, tracks, and batteries, is 240 lbs, which I am pretty happy with. The batteries are probably a good chunk of that weight, but that is how it works with electric vehicles. Batteries are heavy, or expensive, one of the two.
I buttoned up some of the detail work for having the tracks on and all dialed in. I made the return rollers (the white wheels that keep the track from hanging down, or bouncing around and hitting the bogies:
I also finished and installed the rear idler adjustment components. Welded the bracket onto the frame, and installed the arm and turnbuckle.. so shortening the turnbuckle tightens the track. Need to do a few finish/cleanup welds on the brackets, but the adjusters work perfect for tightening the track, which is great.
Now I will be moving, so had to pack up the tank for a little bit, but will hopefully be working on some other stuff in the meantime, like getting the motors and working on the controls, etc.
I installed the finished tracks and wheels. They look good. Note that I didn’t put the bolt in to connect the ends, as I am currently working on the rear idler for adjusting track tightness.
Here you can see the nice meshing of the the drive sprocket and the track:
First, I made a bunch of 1-3/4″ x 6″ pieces of 3/8″ UHMW. Then I setup a guide on the table saw to cut all the corners off.
I made a template for the cleats out of plywood and aluminum diamond plate, which I then used to cut the other area out with the router (flush bit). This yields a nice cleat, with pre-marked holes (where I will countersink a screw to attach them to the treads).
This isn’t the fastest process, so it will be a few days before all the cleats are finished, and then a few days to attach them all.
Ok, so I “finished” the second track. I still need to do the special hinged treads on the ends. But nevertheless, a huge step.
I also need to add cleats to each tread. That will be a decent undertaking, but is fairly crucial. They serve many purposes, like traction in soft ground, and protecting the tread blocks, etc … but they also reduce surface area friction on pavement. And of course, they will make the tracks look like the real thing. Here’s my design/pattern for them:
Here is the finished pile of track guide blocks, each with 2 pilot holes drilled.
Here I made a pattern for the tread spacing for actually assembling the track. This will keep everything evenly spaced, square, and straight.
This is the jig that will hold the guide blocks in the center while I screw down through them, then through the conveyor belt, and into the tread on the other side:
I of course couldn’t help but set up a section to show what it will look like after I attach everything together:
So, I first cut some 1/2″ UHMW into strips, then cut those to pieces 7.5″ long.
Then, on each one I made 8 table-saw cuts (2 from each corner). So far I have done 46 of them. Turns out I will actually need 59 for each track.
Here I am just setting a few on the belt, as a mockup, to get an idea of how the spacing will look, etc:
And then I am routing down the 2 corners that come in contact with the drive sprocket, for a snug fit:
So slowly but surely making all the track treads. Once the treads are done, I will make the inner track blocks/guides, and will finally be able to start assembling the tracks.