Tuesday, September 13, 2016
Day 141 (who's counting at this point?) - Adding fender height, suspension, and underlighting!
After over a year, Rainier finally got an update! After 13 months of trundling and scaring small children to the questionable delight of their parents, I got a little tired of my low ground clearance getting in the way of my Dalek's mobility. While thinking of methods to raise it, I also wanted to try and absorb some of the ricketiness that I experience when I travel over any kind of bumpy surface.
So I dismantled his pieces and (with the help of a friend) put his fender upside-down on the operating table. I wanted to examine the points at which I would need to add some height. The four casters were a given, and the mounting points for the motorized wheels would need to be lifted, as well.
I had thought of several ideas for adding height and suspension, including string steel compression springs, but eventually I settled on the same black rubber spacers that my DIY wall-mounted TV rests on. They are an inch in height, and about the same in width, and slightly conical in shape. There are 20 mounting points that I needed to elevate (hehe, "EL-E-VATE!"), so I bought 20 spacers at Lowe's in their hard-to-find parts section. I drilled a hole in the center through each one using a 5/16" drill bit.
Each of the four casters is mounted by four shortish 5/16" hex bolts (2.5" long, I think), so I bought 16 bolts that were an additional inch longer. I unbolted the caster and its mounting block, and, using a box cutter, I cut through the white paint that semi-adhered the block to the fender. I pushed the spacers onto the new bolts, and attached it all back to the fender, spacers now sandwiched in between the two wooden sections. I repeated this process for the other three casters.
One thing I noticed was that, now that there's rubber, there's nothing that resist against the hex nuts. You can tighten and tighten the nut, so you need to eyeball it to make sure they're all tightened the same so that one caster is level with the rest. I will need to add a second nut and perhaps a locking washer to make sure they don't come loose with vibration.
Now for the hard part, and it's a bit hard to describe. There were four mounting points for the electric wheels that needed to be raised. Simple, right? I removed the four long 6" hex bolts and immediately saw my problem. Jazzy Select wheelchair wheels are attached to their motors by a steel mounting assembly with three bolt holes. Two of these I use to attach them to steel square tubing, securing them to my fender. The third pokes through the top of the fender, and I have a long piece of thick threaded rod mounted to it to keep the wheels in a straight 90° angle to the ground (otherwise they would buckle under Rainier's weight). I couldn't simply add an additional inch to all this because the wooden fender top and a central piece of steel square tube were in the way.
I decided to simple cut through it. I took out a metal-cutting wheel for my Dremel, and began slicing away at the center square tube. It was ugly—there wasn't much room in there for cutting, so it was all at wonky cutting angles. Eventually I got through. Then I flipped the fender over, and took my jigsaw to cut away the necessary fender wood. Now I could add spacers to raise the wheels. Once again, I flipped the fender back over to add the final four spacers underneath.
For some reason, there is no 5/16" hex bolts that are 7" in length. Lowe's had 6" and 8", so I got four 7" carriage bolts instead. There's a squarish shape on the underside of each bolt head that raised the underside of the head slightly off the steel square tubing, so I added a couple of washers so that the bolt had something to sit on directly. Then I tightened all that down.
I was very concerned about hacking through the central steel support, so I bought a 3-foot long, 3/16" thick by 1" wide flat steel panel and cut a couple pieces to length with my miter saw. I marked some points where I wanted to attach it to either side of the compromised support (fender top and fender bottom), clamped them together and drilled 5/16" holes through both. This was where I could bolt it all together. I then clamped one on, drilled the remaining holes through the center support rod and the wood of the fender, then bolted it all together.
While Rainier's fender was up on the table, the idea struck me to add the LED strip lighting to the sides of the fender. I dug out where I had stored the LED strip reel, and traced a path around the inside of the fender, temporarily clamping the strip into place. I wound up using window screen mounting clips to secure it, each one facing the opposite direction to keep the strip stationary.
When I was finally all done with that, I took the fender off the table and re-assembled Rainier form the fender on up. The wheels were not at all even with each other, and the whole fender rocked back and forth like a bad restaurant table. However, a simple tightening of the nuts on the new bolts fixed that. Like I said earlier, I will need to find some way of making that adjustment stay in place, like locking washers and an extra nut.
I was very pleased with the additional 1" of ground clearance, and I wanted to turn the underlighting. I don't yet have a battery for it, so I used the wall outlet to take a look at its effect. I was a little bit blown away.
So anyway, that's my update, after a year's Daleking around. Back on the front page again! (At least for a little while!)