Before completing the build of this version of Dynamite I decided to upgrade to the latest components. This includes 3D printing from Shapeways, new smaller FingerTech tinyESC v2 motor controllers, a new DelTang Rx71 DSM2 Micro Receiver and a redesigned chassis.
Here’s the CAD image of the completed robot. The front and back plates are to be printed by Shapeways. The bottom and side plates are to be cut by hand from a printout of the CAD design and then folded and drilled manually, hopefully with enough accuracy to fit with the Shapeways parts.
Here’s the new chassis plan – I’ve added extra holes to help wire the motors in, and to fix the Shapeways printed front and back plates -which I’ll need to tap with an M2 tread.
Here’s the Shapeways parts and the cutout bottom chassis
This looks pretty good to me, I’m surprised that my hand-cut polycarbonate matches up so nicely with the 3D printed front and back armour.
The extra folds along the front and back edges of the chassis have stiffened it considerably, which is a good thing because all four wheels are now in better contact with the arena surface.
The new DelTang receiver works perfectly, and so do the FingerTech speed controllers. At the time of writing (11/9/2011) I am still 30g underweight, so there’s weight (and space) for front and rear polycarbonate armour, although as the next competition is not an AWS (Antweight World Series) but the more “friendly” RFRC (Richmond Fighting Robot Club) so it might be worth keeping the Shapeways “White Strong & Flexible” material and seeing how spinner-proof it actually is.
The things I’d like to improve on this design are
- I want to isolate the electrics from the moving parts and dust with an internal wall – this might also improve structural stability
- The top plate isn’t very elegantly fitted, more of an afterthought.
- The name should be on the rear armour as well as on the front armour (it’s actually recessed by 0.2mm)
- The rear armour needs to be lowered by about 1.5mm
- A flexible scoop could also be added to the front.
- The recharge plug was facing the back, this means the forward movement of the robot might pull the plug out, turning the robot off, this needs to be moved to be front facing.
- The holes for wiring in the motors are about 2mm too far back – they miss the actual motors.
I am on the way to a redesign of the front and rear armour to include mounting tabs – A Dynamite 2011 V3 should be with us for the next AWS.