This time in two weeks we'll be on the road to Nashville, on the way to Motorama 2012! Which is exciting, but we still have work to do - the plan is to finish the fairyweight and a beetleweight by the weekend, and then spend the weekend working on the two biggest
'bots. In order to manage that we need to fabricate some parts, and put a call in to Chris over at Speedster Hobbies to see whether we could get some shop time, and Chris graciously agreed. We jumped in the BotMobile with some materials and headed his way. Hit Back after viewing an image.
Chris reminded us of how the bandsaw worked, and we started out by chopping up some aluminium and steel. Boy, we wish we had one of these in the Build Space! Nifty!
Here's what we cut up - DeWalt drive axles, a weapon transmission shaft, two pairs of blade shafts (steel and aluminium), wheel hubs, and trimmed down the blade shaft and retainer for the 30lb'er.
After a spell on the lathe, we had the aluminium round turned down to fit the Colson wheels. Not perfect to the thousandth of an inch, but well within typical Team Radicus tolerances :-)
Chris has a new lathe, and it was working just fine! In fact, he hadn't had time himself to use it yet, so we were the first to fire it up, and it was fun!
After hitting the hubs with a countersink (to start the hole), and a couple of drill bits, we had the hubs ready for the shafts. We hope we have a 1/8" broach back at the Build Space ...
The last lathe operation for the day is to bore the bevel gear for the 30lb'er to half an inch - it's metric, and has a 10mm bore at the moment. We didn't realize this was going to be a tough job, but the presence of a keyway messed things up, and we wound up snapping a bit trying to bore this out. We'll have to do a bit of research into a way to accomplish this ...
With profuse thanks to Chris, we jumped back into the BotMobile and headed back to the Build Space, noting along the way that the temperature was over 80°F - eighty degrees in February?! Crazy.
Turning our attention to the smallest 'bot in the fleet, we milled a hole for the weapon motor wires, and drilled mounting holes for the weapon motor in the front of the chassis.
We've also modded the mounting plate a little, and a couple of #2-56 screws and nuts have started the process of mounting the motor to the plate, but we need 3/8" long ones to mount this to the chassis, and we don't have any. Looks like a trip to Grainger is on the cards tomorrow ...
In this photo the motor is actually slightly lower than it will sit on the chassis, but close enough to see that it clears the ground, which is a plus :-)
There's a lot of wiring to be dealt with, so we decided to mill out a bit more of the top part of the chassis - messes up the CamBam+ finish, but at least it we ought to be able to cram everything in now.
We were originally steeling ourselves to have to cut and solder the receiver wires on the speed controllers, but thankfully Kurtis over at FingerTech uses very flexible wire on his TinyESCs, and we were able to stuff the excess into a couple of crannies in the 'bot, and move on.
Next up is mounting the weapon speed controller. We decided to risk the weight and used a small piece of double-sided foam tape to stick it down to the motors at the back of the 'bot, and again we stuffed the receiver lead into space around the battery.
Which brings us to power cables. Because all the wires are quite fine gauge, we decide to just try and solder them all together, and with some electrical tape a zip tie, got them all close enough to hit with the soldering iron in one go. Not pretty, but seems to hold fine.
So we did the same thing with the positive power leads, and did actually remove the zip tie before putting some heatshrink on the end of the leads.
Time for a sanity check. The chassis, plus it's nuts, and a couple of bolts to approximate the missing motor mount nuts and bolts, and we're at 149 grams - looks good to us, but we need to hope that NERC's official scale is close to our's. There is a difference in latitude between Austin, TX, and Harrisburg, PA, but hopefully not enough to cause a couple of grams difference ...
This was a shot after a quick test drive of the 'bot. It is pretty zippy, but fairly easy to control - without the weapon, of course! We'll see tomorrow how it drives with the weapon spinning on the front.
Last shot of the night, and we've milled a small hole on the top of the 'bot to be able to get to the battery connector, so we can disconnect the battery after a match. As long as we can get those #2-56 x 3/8" screws tomorrow this 'bot will be finished tomorrow night!