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:
I finally finished one of the tracks. I still need to do the 2 special treads that go on the ends, and are connected by a hinge with a pin… but that won’t be a big deal.
When it was done, I also did a little testing of how well it works with the sprockets, and it was hanging up a little when going-on or coming-off, so I had to slightly modify the sprocket shape. Here is the progression of the sprocket design, with the one on the very right being the final version, which I will use as the pattern to router down the black sprocket.
I am half way finished with the first track… so still plenty of work to go on the tracks, but they are looking really good, and they feel really solid.
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:
After spending some time becoming great friends with the tablesaw and router, the track pads/treads are done. I made 124 of them, so I have a few extras.
Now I am working on the inner track guide blocks that will be in center of the track, and run between the bogie wheels, keeping the tracks from coming off. I am making them out of 3/4″ UHMW, and am cutting them 1-5/8″ wide (slightly less than the distance between the bogie wheels).
I then have to router the corners off so the bogies wheels will want to slide back into alignment, rather than hop over the guide blocks.
Now I just need to finish routing the rest of the strips, then make at least 120 slices off of these strips.
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.
I finally hit the big rolling chassis milestone I have been talking about for so long. Everything seems to be really sturdy, the suspension seems to work better than planned. I am kinda surprised actually how well it has turned out. I even wrapped the conveyor belt around it, which I am making the track out of, and it fit perfectly.. yet another surprise.
Here you can see the pieces I cut, starting to make the track pads. They are 1/2″ UHMW. I am cutting strips 1.75″ wide, and then will cut them to 7.5″ long. They will then be shaped on the ends to fit in the drive sprockets, and then attached to the conveyor belt.
Making the tracks will be very labor intensive, but I’ll do a few posts tracking my progress (pun intended). By current estimations, I have to make: 92 track pads, 92 track blocks (which go on the inside of the track), and then figure out how to connect the 2 ends of the track together.