Daffodil Version 2 Report

As usually happens, the rebuild of Daffodil became much more ridiculously complex than intended, but that's half the fun for Team Daisy!
 
The basic design theme of the rebuild:  replace the drum rollers with real bearings.  The drum bearings go around pieces of modified aluminum pipe, which will be attached to the frame.  The endcaps of the drums will rest on the outer races of these bearings.

And the drive motors will be mounted inside the pipes!

The components of one side of the drive train. The screwdriver motors are much smaller than the old drills. I think they will be powerful enough for Daffodil's not-very-demanding drive needs, and weight had to be saved to make the bearing scheme and the two battery pack scheme workable.

The motor/gearbox slides into the inside of the pipe, and the 3/4 aluminum drive shaft couples loosely with the output from the gearbox. The rings are to hold everything in place, including two stages of bronze bushings to support the drive shaft, and a shaft collar between them to stop the shaft from moving back and forth. This setup will hopefully be quite strong. The old setup was fine but some of the 12 lbers Daffodil could see at HSRC -- Dizzy Dragon, Ixion, Mini-Mauler (and of course 911) -- can pack quite a punch.

 
New wheel.  Just like the old wheels, cut from 1/2 inch lexan.  This time instead of vacuum cleaner belts the tread is made from some conveyor belt material that isn't quite so smooth.  We'll see if it works, or if it stays attached any better!
The new "arms".  The purpose of the arms is to get leverage against the ground, or else it wouldn't move very well.  But the old design required the entire bot to flip over whenever Daffy changed directions.  This new scheme, because the arms touch the ground on both sides of the bot, should make it much more drivable.
The motor that drives the drum.  It is a small airplane motor with built-in gearbox.  In place of the propellor, a little 2" castor wheel, which presses on the inside of the drum to make it turn.
Battery packs. One of Daffy's problems is that the batteries run out of juice because the weapon motor has to work so hard. So, besides making the drum hopefully more efficient, the drive motors will now get their own smaller battery pack to take some of the load off.

The packs are shaped so oddly because they wrap around the pipe segments shown in the earlier pictures. The entire guts of the bot -- frame, drive motors/gearboxes, weapon motor assembly, batteries, electronics, radio gear, wiring, power switches -- have to fit in a cylinder about 3.5 inches across and about 12 inches long. That's not much space, and every little nook and cranny counts!
 

The pieces of the drive showing how they will work.
Here is one of the axles, after adding a tapped plug at the end to help hold the wheel on, and a keyway.
The wheel with the hub and axle attached.
The assembled unit.  I wonder if the people who make these screwdrivers know what we do with them?
Here's the unit from the "back", showing how the screwdriver gearbox fits inside.
Next step:  attach the drive train units to the frame.  This picture shows the basic layout of the frame pieces.
Here is a shot of the fully-assembled frame
After assembling the insides, large amounts of electrical tape were used to keep wiring and so forth from getting caught in the spinning drum.