The last rEVolution post was on August 9th. Some might recognize this as about when I entered the panic phase of robot construction for Dragon*Con (that event which I still haven’t written a summary of). Since then, the parts of rEVolution have been taking up space on my electric vehicle shelf.
A few weeks ago, I decided to trip down to Maker Faire NYC to see what this whole “making stuff” scene is all about, since I don’t know how to make things. Originally, I was just going to go… but the temptation was too great to not try and bring something. Classwork and other preoccupations meant that I really only had two days last week to blitz rEVolution together.
Long story short, I didn’t get very far, and just went. Crap, yet another event I need to recap.
Long story long, here’s the results of that blitzing!
Step 1: Throw everything at the waterjet.
All the major structural components are made of 1/4″ aluminum that I picked up off eBay (per normal procedure of buying the first thing that said “aluminum plate”). The black top plate is the nonstructural deck cover and was cut from left over 1/16″ black Garolite, the same sheet I used for Cold Arbor’s top and bottom panels. The one immediately under that is the structural top plate, made of 1/8″ aluminum.
The new frame next to the current RazEr. Yes, it’s big.
I went ahead and compensated for the thickness of regular oversize aluminum plate when designing the slotwork here. It turns out that aluminum plate, unless specified tight-tolerance ($$$$), is usually 0.01 to 0.02 inches thicker than the nominal thickness. I generally design on-size, which has resulted in more sanding than should be necessary in the past.
All the slots on this frame are .005″ larger in every dimension and the tabs are .01″ shorter. Most of the frame was therefore pushed together pretty easily.
With the new motor can in place. Isn’t that just ridiculous looking?
A side shot, showing the text cutouts and the deck installed.
wheel? more like squee-l.
The next task was to hollow out the massive aluminum spare semi truck wheel that is to become rEVolution’s rear tire. For this task, I elected to use the heavy \m/etal machine of the auto shop, since it could more confidently grip the inside diameter of the rim (which was the exact right diameter to be unchuckable with our small 6″ chuck in either configuration).
The process itself was surprisingly painless. I bored the wheel all the way through the center hub such that it just fell out, then turned it around and cleaned up the leftovers.
And the wheel fits around the motor can like so.
Let’s go back to the frame. This piece is the anchor point for the steering neck and folding joint. This always seems to be the trickiest part of scooter building unless you have a premade solution already, because it’s one of the highest stressed parts and also generally sprouts from the base at an angle.
I’m going to retain the stock Razor A3 folding joint, so the bolt pattern fits the base and the thread matches the stock screws (M6 x 1)
Nothing I build is complete without at least one t-nut, and this build is absolutely full of them. These are 4-40 square nuts, which seem to actually be quite rare in small packs. McMaster didn’t carry them at all, and I could only find packs of five thousand.
That’s okay, it’s only $50 for the pack. I decided to spring for some because I would never, ever need to buy them ever again.
I’ve built up too many pictures to reasonably write one long post, so I’m going to split this here. In the next episode of RazEr rEVolution, the inner workings of the Dual Interleaved RazErMotor.