Daily Archives: May 12, 2020

Mother’s Day was pretty good

Mrs. the Poet was fed up to her eyeballs with delicious food, my meal was fantastic, the grandson was great to be with, and we had a wonderful chat with the daughter in Scotland. Mrs. the Poet said she had a wonderful day.

Now the reason why this is going out Tuesday morning instead of Monday, while I had a great day I had a crappy night, as in could not get the mind to shut down so I could sleep crappy. I was designing jigs and fixtures for building the Sprint-T all night long, except when I was redesigning the front axle to be lighter because seriously, I could build a car that loaded the axle with over 3000 pounds on the axle, and the whole car weighs between 1600 and 1800 all up without the driver. A 2″ diameter by 0.25″ wall DOM steel tube with no bends is way overkill for this application and could easily be made from the same diameter and wall thickness aluminum tube in any of several alloys and still have more than enough margin (not as much as the steel one, but that’s the point, the steel one has enough margin for a vehicle more than twice as heavy as the Sprint-T). Basically this design puts almost no load on the tube because the spring and shock mount right next to the kingpin boss and the load path is like about 2″ of moment arm compared to the roughly 10-12″ the axle is built to handle. The steel axle comes in at 22.5 pounds without brackets, while the calculated weight of an aluminum axle of the same dimensions is a bit over 8 pounds in the same condition. And by “a bit” I’m talking less than 2 oz depending on alloy, 8.05 pounds for 7075 alloy or as light as 7.8125 pounds for 6061, choosing weldable alloys for fabrication.

And I’m doing the same thing tonight, thinking about making a better Sprint-T when I’m exhausted physically but still running wild mentally and needing to get to bed and take the load off my neck. So this would be a wonderful place to call a stop and take my night-time meds and go to bed.