For Daylight Savings Hour —- that magical extra hour of modelling time you get once a year when all the clocks go back — I designed and printed frame spacers for Percy that give the chassis dimensions similar to #622.
For the first time I also tried pushing the chassis on glass, which turns out to be a great litmus test for chassis smoothness. With a wide chassis like this, it pays to ensure it rolls smoothly on glass before installing the rods, and again after.
Having now lost two wedges to the ether, I’ve started to secure them with blobs of reusable adhesive. This enables me to turn the chassis upside down without hearing the tiny tinkle of parts hitting the floor.
Once I’d assembled everything, Percy ran happily up and down the track a number of times. Then (get this!) it jammed solid. I’ll have to disassemble and reassemble it to find out why, but perhaps I am finally going to get to the bottom of this mystery.