yeah linear drive are something to look into!
got some worck done on the trike, started the drops-out, I made them beefy so they can hold a hub motor ''if needed''
I also got the crank in place. Now I will let somebody play with the tig to finish the welding. I work on this build in an associative workshop, created by naval construction retired guys, they can do pretty much anything with steel
they work on old cars, old mopeds, go-carts, they repair cars for friends, It's cool, they are really happy to help anybody with their projects, and it's 10euro a year for students.