It’s absolute overkill. Over a pound of 6061 aluminum, every part CNC machined and yes, it’s just a scotch tape dispenser. This is the creation of the Advanced CNC class at Laney College as taught by Bob Rice. I programmed and machined all the parts from drawings using MasterCAM, a Chevalier toolroom mill and a Haas SL lathe. All the threads were single-point cut and threaded holes rigid tapped. Every part required at least two operations, every face is machined.

1/2-13 threads

1/4-20 threads

The cutter serration was created using a wedge tool I ground from a broken center-drill, plunged into the part with the spindle off and indexed to simply form the teeth. The tool was plunged .030 deep every .025. I wrote the gcode for that bit manually.

I had the privilege of attending the first ever US TTXGP All-electric motorcycle road race on Sunday May 16th at Infineon Raceway. I arrived with uncertain expectations about the nature of the race- I was impressed by the innovation and variation in the bikes and the determination of the teams. Here are the results in place order, with my photographs and technical observations and impressions:

First Place: Zero/Agni

Coming from their victory at the 2009 Isle of Man TTXGP Zero/Agni put up a formidable and balanced showing. The combination of an excellent rider, a good-handling bike with a balance of power, battery capacity and thermal management allowed them a handy victory.

The large rectangular Molicel battery pack is mounted oblique in the frame. With the composite fairing installed the rider appears to rest almost flat on top of it. Molicel supplies batteries for Zero’s production bikes.

Looks like an analog balancing system. I don’t believe I’ve see this system before.

Dual Agni Lynch motors coupled directly with a steel shaft with sprocket. Adequate power, good cooling from outboard mounting and ram-air scoops taken from the production bike.

The Zero/Agni team ran a very clean and uneventful race. Their bike clearly balances proven reliability and performance.

Read on for the rest of the competitors-

2. Lightning

This was my favorite bike at the event, I think they’re really a team to watch. While teams building an electric vehicle are often required to do some custom design of battery packs or management systems, there are several off the shelf solutions for motor drive and transmission. Every other bike used one of these off the shelf drive systems. These guys however put together a one-of-a-kind drive using an EV-1 induction motor.

The story I’ve heard goes like this: several years ago someone in the EV community found the GM parts department number for the EV-1 motor and transaxle and tried ordering one from a GM dealer. It was shipped to the dealer and was able to be purchased just like any other GM part. Several members of the EV in-crowd then proceded to buy as many as they could, until the stock ran out or GM wised up to what was going on and shut off the supply. I believe they managed to get a hold of sixteen or seventeen motors. Last I heard not all of them have been installed but the folks who hold them are very protective, because they are fantastic motors, rare, and hold a special emotional importance with the EV-1 connection.

Anyways, the EV-1 drive system was capable of 100kw. Without official numbers I would guess the Lightning bike was running near that, maybe more. Suffice it to say the bike was fast. Extremely fast. For the first half of the race the Zero/Agni bike would pull ahead with far superior corner speed then the Lightning bike would effortlessly pull ahead in the straights with its massive power. Massive power comes at a cost though, the second half of the race saw drastically reduced power that left Lightning playing catch-up continuously. I didn’t get the official word on the cause of the slow-down, I expect it was a combination of heat buildup and battery depletion. The rider actually stopped the bike near the end of the race to attempt to let the systems cool down.

Both the Lightning inverter and motor are liquid-cooled, in fact the motor even has an oil cooling circuit as well. It was the only bike with plumbing. I observed their radiator up front, looked about 10″ x 18″. Given the insane power levels they were running I’m not surprised they had heat buildup issues. It’s possible they were also having battery heating issues, but with enough A123 batteries to power through a 25 mile race I bet they weren’t pushing the C rating, already very high for the A123s. As well, the batteries perform better warm.

They’re running a Elithion Lithiumate BMS with 7 banks used- likely indicating usage of somewhere between 56 and 112 series cells- no more than 370v nominal. Considering the EV1′s nominal voltage of 311, they’re probably running closer to 112 series cells than 56.

Drive was accomplished with a two stage reduction, first stage timing belt, second stage chain. PFC50 to charge.

The rear of the EV1 motor can be (barely) seen here.

I was curious about the specifics of the inverter. It’s nothing I have seen on the market. I was unable to get a clear answer about its origin or prototype/production status. I would guess that the main sponsor of the team designed it and is considering marketing something like it. They did tell me it’s based on IGBT modules. Uses a 4 quadrant full vector control algorithm. They have installed a custom quadrature encoder on the motor to replace the GM specified one.

I believe with better handling or better driving, better thermal management and moderated energy usage this bike could win the race. It’s incredible power early on was seriously inspiring.

3. Electric Race Bikes

This bike had a similar setup to the winning bike, with dual outboard mounted, shaft coupled Agni motors, allowing a fairly high-ratio single reduction. The bike was quick and reliable, leading to a respectable third place finish.

I was interested to see that they appear to be running Headway LiFePO4 batteries. At least, that’s the only battery I’m aware of that is about that size in a shiny blue foil wrap.

If there’s a recipe for success in this race it would seem to currently be the dual Agni setup.

4. Werkstatt

Despite an odd hiccup in the first lap, Werkstatt came in first of the two production-based bikes racing. The Mavizen TTX02 is a very impressive machine, with the polish that comes with a professionally designed product. Again with the dual Lynch motors. Recipe for success indeed.

5. K Squared

Coming in next after but significantly behind the big Mavizen is the Zero S based K Squared bike. With its small size an weight the K Squared bike ran a good race. There’s no doubt the Zero S is a very capable machine.

6. Pril Motors

The Pril Motors team made up for less high-dollar components with reliability and solid driving. This bike is the only one represented in the race using a sep-ex DC motor (in fact, only team using anything besides induction or brushed permag), a 6.7″ size. Single speed chain reduction necessitates the gigantic rear sprocket, but is more efficient than double reductions.

According to their website they are using pouch type LiFePO4 batteries.

7. Square Wave

From the file of “interesting drivetrain ideas that might not actually end up being the best, but impressive nonetheless” comes the Square Wave bike.

Using a belt CVT primary drive enables the high-ratio secondary chain but is less efficient than direct drive, and as demonstrated by every other bike there, largely unnecessary. Thunder-Sky batteries are not usually thought of as good racing batteries, but that’s because most modern EV racing is drag racing, not time-trial. Thunder-sky batteries are supposed to be good to 3c (reports vary about the accuracy of the manufacturer’s 10c pulse claims, some even cite unacceptable sag under 3c draw). 3C draw will drain a battery in 1/3 hour, or 20 minutes. The race lasts longer than that, so assuming constant 3c usage, you should be able to use your entire TS battery capacity. That’s not entirely the racing reality, you need to let off sometimes, and you need higher peak power for acceleration. However, it is worth taking into account the importance of capacity alongside power density in selecting a battery for a longer race.

The Square Wave bike was outfitted with 90AH thunder-sky batteries, the 6.7″ C-face induction motor usually sold with the Curtis inverters, and a Curtis 1236 inverter. It ran the whole race, but was very slow.

8. Electric Motorsport

Reliability problems plagued the Electric Motorsport bike. Curtis 1238 inverter. TS or Sky-energy looking batteries, except in teal. Not sure what brand.

DNF: Volt Motors

Reliability problems also for the Thunderstruck-EV sponsored Volt Motors bike. Curtis Induction setup again, with single reduction, big-sprocket rear end.

DNF: Team Electra

Even with awesome vintage cafe racer looks, built on a vintage Norton frame, with LiFePO4 batteries and induction drive system the Electra team ended up breaking down fatally mid-race. Hopefully they will be better sorted next time.

The SWIGZ.com pro team and Bob Schneeveis’s Empirical Electric team didn’t make it into the race.

Overall the race was extremely impressive. I have great respect for the TTXGP organization and every team who makes it out to run this race. It’s exciting to see electric vehicles make it back onto the road track in this new era of affordable and high performance lithium batteries and many high power and efficiency drive systems. The TTXGP organization is providing a venue for advancing EV racing from hobby to professional, and while there aren’t enough teams with big resources and sponsorship to fill a race I’m sure it will grow. But in its infancy it’s a great opportunity for newcomers to experiment with technology and inventive solutions- there’s not really a “killer app” yet, it’s possible to have hugely different bikes competing neck and neck. And that’s pretty neat.

Please let me know if I’ve got any facts wrong! Also, contact me for higher resolution photos.

Photos taken with Canon Digital Rebel XT and Pentax 300mm/f4 lens.

Thanks to Plugbike for the race results.

Once I decided to run a single stage poly-v belt reduction on the e-bike instead of a two-stage timing belt/chain reduction on the advice of Bob Schneeveis I set about figuring out how I was going to come by a foot diameter rear pulley for the bike, preferably a really sweet one, in line with my recent attempts to do things as minimally shittily as possible.

I thought about machining one out of plastic which proved to be practically as expensive or more than solid aluminum, or attaching an octogon of bar stock pieces to the edge of a sheet of aluminum, then turning it to make it round. When I described this plan to my machine shop teacher Louis he looked at me funny and said, “Why not use a single piece of aluminum?”. He then proceeded to find me a spare piece of .800 thick aluminum from the stock pile- “use this!” It started as a piece of an industrial fixture that was donated to the department and had previously been face cut and drilled in a few places- I trimmed and layed out around those spots.

So I pulled out the biggest rotary table I could find and started the longest week I have yet spent in the machine shop-

After fixturing, cutting the outside edge, inside bore and bolt circle. The large holes are to be used to plunge the end mill through.

Many many more pictures after the break–

The roughing “corn cob” end mill cuts through .800 of material with full tool engagement with no trouble, as long as you keep plenty of coolant flowing around. Messy! But impressive!

Pocketing out the face of the pulley, creating the outside wider rim. In retrospect I might have done this using a larger diameter roughing end mill. I ended up taking many passes (6?) with the octo-mill, the roughing mill could have done it easily in one. And probably scattered less confetti-chips all over the place.

But what I did worked just fine.

The octo-mill went right thorough the fixturing washer.

Chips like a thick blanket of snow.

Spoke 1 roughing down

2/4

It’s worth describing how I cut the spokes- as you may notice the spokes are of a constant width, the edges of the spokes are parallel, not strictly radial. I cut each spoke-opening in four steps, each edge in succession. First I cut the inside and outside arcs with the mill Y axis centered on the center of the part. I calculated the radial offset on the X axis and the start and end angles. Next I moved the rotary table so that the centerline of the spoke was parallel to the X axis and used the Y axis to offset the spoke centerline from the tool centerline, then use calculated start and end points on the X axis to cut the sides of the spoke.

Everything previous was rough cuts- I redid ever cut using a larger standard 2 flute endmill. I don’t have pictures of the finishing cuts except for the finishing cut of the center bore- it reminded me of those cacti that have the center full of soft looking fibers that turn out to be really irritating and splintery- very much like these chips.

After finishing the rough spokes I used a smaller diameter endmill to finish the edge of the pocket to its final diameter, and passing between the fixturing bolts and outside edge. This causes all the material left around the fixturing bolts to be in the reigon to be cut out for the final two spokes.

After the first epic stage of cleaning up.

I neglected to take photos of setting up the piece to cut the final two spokes- I used bolts to clamp on the two fully cut out spokes then re-indicated the piece in. I then turned the piece over and set it up again, clamping only in the center in order to cut the piece to its final thickness and create the raised hub in the center.

I found myself having massive levels of chatter as a result of this setup- as I discovered with the very bell-like finished part the thin spokes do a good job of allowing the heavy rim to resonate independent of the hub- in this case causing the octo-mill to chatter and leave an uneven surface- I would guess at least .005 variation peak-to-peak in the finish. I  wasn’t feeling particularly excited about refxituring the whole operation- so I stuffed shop towels under the rim of the part using a screwdriver. It actually did eliminate the chatter problem. It may have contributed to the general lack of absolutely perfect flatness in the finished piece, but so could a bunch of other things. I am learning that fixturing, particularly with less rigid parts is one of the hardest aspects of machining.

There I fixed it!

To finish the part, with the 40˚ grooves required for the poly-v belt I attached the wheel to a face plate and turned the diameter just to clean it up, then put in the grooves.

I also made an adapter plate to attache the larger hub of the pulley to the smaller disk-brake hub on the bike, also to move the offset of the pulley closer to the centerline of the wheel to increase clearance with the forks (a really big deal- bikes weren’t made to accommodate big pulleys like this with non-reconnect-able transmission methods like belts). It’s stainless- turned a 4x4x.25 stock into a 3.80 diameter .125 thick plate with center bore. I later drilled the bolt circles on the mill.

Bolted with a 1/2″ bolt to a custom turned arbor.

I devised a clever (I think) way to face both sides parallel- if I turned the piece over and reattached it to the arbor it would only be clamping against the small diameter and un-machined center that was under the bolt and washer in the original setup- I tried that and found the piece was running out badly. So I found the turned aluminum tube seen on the arbor and turned the arbor down to allow it to sleeve over loosely- now the piece is clamped against the machined face of the tube and the tube rests against the turned face of the arbor. The piece was visually perfectly aligned after setting it up this way.

Finally I used soft vice jaws to hold the piece in order to bore out the inner diameter and remove the material covered by the arbor bolt before. I ended up with a really pretty disc of stainless steel.

Hope you enjoyed reading this long-winded and many-pictured account of this (small bit) of this (unexpectedly huge) project! I thought my troubles were over with this pulley made- little did I expect the challenges of mounting the motor and fighting with the Plasma CAM machine, let alone getting the belt to run straight and not skip under hard torque!

Meet the Soviet Long-Track Radar Vehicle (P40 Radar), from 1969.

Or, in this photo from an Air Force website, via Wikipedia:

So, it’s basically a not-really-armored, fully tracked, mega-massive soviet built tractor with a 30 foot wide 2MW turbine-powered radar dish on top- what could possibly not be fantastic about that.

A peek inside confirms, yes, fantastic.

The rear of the truck houses the electric parts to run the radar system. The middle of the truck is this room for 4-5 operators, with a superb array of switches, joysticks, knobs, dials, screens, gauges and lights. All the panel printing is in Russian. The whole thing is in impressively good shape.

I’ll just run my photos of all the controls, but first- yes, the whole thing runs on vacuum tubes, in the true Russian propensity.

Even the cab of the truck is pretty well fitted out.

So, what do we take from this besides a certain “steampunk”/”retro-industrio-mil-russi-punk” attraction? (as if that isn’t quite enough!) Well, just like all the things in that museum, it’s a testament to the incredible outpouring of resources (natural, and human) used to build war machines. It gives a face to “Mil-spec”. Forty years later this machine is still in remarkable shape. It’s also a reminder of just how technology has progressed in this evolving globally connected world- where something like this is absolutely, hopelessly obsolete and useless. The Russians, Germans and Americans seem like the biggest players in the arms/engineering race depicted through the collection at the MVTF. Every nation has different strengths that are reflected in the way they built these war machines- imagine what could have become if everyone just dropped the war part and worked together for the purpose of improving life instead of destroying it.

Problems of the world aside, I’ll stick with the “retro-industrio-mil-russi-punk” attraction. It’s working pretty well for me right now.

On my Pacific Northwest roadtrip, as described before, I stopped in Portland for the Wayland Invitational at PIR- set during open weekend drag nights, but with John Wayland's organization a whole EV get together on top.

Some of the photos have clicky links to relevant pages. Mouseover to see if you get the little clicky linky hand.

Bunches more photos lie BELOW- click “Continue Reading”!

Neon's electric buggy was there

As were four Roadsters

Otmar's Quick-change Zilla swapper in his orange 914- test bed for hundreds of Zillas

Crazyhorse Pinto

Bill Dube's Killacycle

Killacycle's trick pneumatic brush-timing actuator

SSIC had their T-Bucket and Daytona Coupe (as seen in the first photo)

Electric Motorsport was there with bikes

The Killacycle toasted a motor Friday night

Saturday morning Jim Husted took a look at the SSIC Daytona's 11" WarP

Jim Husted's sweet mini-cruiser

On to the fun part- racing!

The Crazyhorse Pinto's crazy torque caused the tires to deform and fold over- sort of "flap". I understand this often happens on high-torque drag cars, but with the quiet electric drivetrain that "flapping" was the loudest sound you could hear as it went down the strip.

Tesla Roadster drag racing is not all that interesting- very consistant, quick for a street car, very quiet. The sound of a couple roadsters flying by at 100+ mph at the finish line is pretty neat though.

The SSIC Daytona was blazingly fast off the line, but wasn't geared well for top end speed.

This converted Samurai NEV was very slow. I think it hit 38 or so MPH, 1/4 mile in 50+ sec. They only raced it once though so it was OK

Speaking of NEVs, someone brought a ZENN out also. It quickly reached and then sat right at its limiter, 43 MPH or so

Obligatory sequence of Killacycle shots

The Killacycle is so mind-bogglingly fast, it is absolutely worth it to see it in person

The T-Bucket was detuned and running 15/16sec that weekend, still looked like a load of fun. I got a little spin around the parking lot in it- running similar power level to my Miata. Was very fun. It's on my list of goals to have a car without a windshield someday.

The White Zombie takes another victim.

The SSIC Daytona leaves a fat Audi in the dust

Then- a surprise. Dave Cloud has a reputation for showing up last minute with something crazy and cool- True to form he showed up Saturday at 9pm with this sort of Jr dragster- Let's see- tube frame, 24+ costco lead batteries, came to the track with the tires uninflated, reverse by way of flex plate and starter motor attached to one of the motor shafts, dual motor main drive with Curtis controller for creeping around and set of pneumatically actuated contactors for series/parallel switching of the motors and battery banks (72/144v)- This thing was seriously impressive in a homebuilt, most-from-the-least sort of way.

Rumors were flying that this run could easily result in some kind of disaster- but it didn't, the car turned in a respectable 95mph trap speed

It is likely that given good tires and batteries this dragster could turn in very good times- those contactors are going to be able to deliver more power than any controller if the rest of the system can handle it. I really enjoyed seeing this creation, it was definitely one of the high points of the weekend for me.

A good time had by all- Maybe I’ll have to tow the Miata up next time…

Musical talent

Twins

My sis

Inane, ignorant, annoying emcees

Many languages spoken

Hard-line social justice from the faculty speaker

Seating capacity: 8000

Beach ball crusade I

Beach ball crusade II

A unique high-point: circus acrobatics

Insecurity

Ever-diligent school district photographer

Spirit

Loving support I

Loving support II

Loving support III