madact's e-velomobile

Drivetrain will incorporate two-stage gearing - The first chain will be from a front 52T biopace chainring (don't worry, the rest are round :wink:) to 26T and 42T chainrings (with a rear-style derallieur) mounted on a triple crankset with the cranks cut off (shown tucked just under and behind the bottom bracket on the diagram above). The third chainring of the triple (52T again) will then drive the rear chain, to a 9-speed cluster on the rear wheel. For tackling hillier terrain, I might use ~40T chainring on the final drive instead of the 52T, but I'll have to see how it goes, and how much the motor helps.
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Any reason why you are going to a dual stage drive I guess you would call it. Would seem a lot simpler to run with a larger chain ring - 80 tooth or bigger - and run a direct drive to the rear cluster. Do you really need 18 gears and a 10:1 step up (if I've calculated correctly) with a 700c wheel????? We are pulling 60km/h with 63:11 step up with a 406 rear wheel.

Interesting what you said about buckling rear wheels as i have never heard of it. I guess running 16" or 20" rear wheels are an advantage :)
 
And I did have a pic of the mock-up - with a random pixellated friend playing the part of crash-test dummy :wink: (didn't ask him to use this photo, so I figured I should do the current affair show thing). He's a bit shorter than me, so to get decent vision past the knees, we had to add a cushion to prop him up a bit, hence the three seat positions shown in the diagram above. Seat, side rails, BB height and cross piece height are all dimensionally accurate to the drawing (the rail position is the same as the highest rail line on the diagram - apologies for smudginess).

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I did a little testing earlier to find the ideal place to put the cross piece, by having a friend take some pictures of me on the exercise bike tilted to the appropriate angle, with the crank in several positions so as to map out the range of motion, then compositing the results using layers in the GIMP image editor. This reveals very accurately the swept areas of the major moving parts (i.e. me). Unsurprisingly, you get the most clearance from the cross-piece if you put it under the knees - the position of the cross-piece in the mock-up above is the result of this test.

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Back when I was doing this at high-school, all the vehicles we built had the main structure connecting the front wheels at the bottom edge of the seat. I'm not sure I gave that much thought to it at the time - more than anything, it was 'what you did' - it did make construction simpler, and allowed the seat (stretched canvas attached with synthetic cord - very comfy) to be laced directly on at the bottom, but you had to allow plenty of room to fit the chain run through. The pictured cross-piece position doesn't suffer from this problem, and few obstructions in the chain line means I can lower the seat by almost 10cm without affecting ground clearance, a very effective improvement to the low C.O.G. which is always critical in circuit events.

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coln72 said:
Drivetrain will incorporate two-stage gearing - The first chain will be from a front 52T biopace chainring (don't worry, the rest are round :wink:) to 26T and 42T chainrings (with a rear-style derallieur) mounted on a triple crankset with the cranks cut off (shown tucked just under and behind the bottom bracket on the diagram above). The third chainring of the triple (52T again) will then drive the rear chain, to a 9-speed cluster on the rear wheel. For tackling hillier terrain, I might use ~40T chainring on the final drive instead of the 52T, but I'll have to see how it goes, and how much the motor helps.
Click to expand...

Any reason why you are going to a dual stage drive I guess you would call it. Would seem a lot simpler to run with a larger chain ring - 80 tooth or bigger - and run a direct drive to the rear cluster. Do you really need 18 gears and a 10:1 step up (if I've calculated correctly) with a 700c wheel????? We are pulling 60km/h with 63:11 step up with a 406 rear wheel.
Click to expand...

We used to pull 70km/h on the track with a 50ish:11 step up and a 26" MTB rear wheel with a slick tyre - until the car started bouncing too much - there's no way to smooth out your pedal strokes when you're spinning like that. But I digress...

60kph is kinda-sort-OK for pure-HPV circuit racing on a track full of school kids (the other situation where I'd run a 40 on the final drive), but the other purpose of this trike is long-distance cruising with power assist, and I really don't want to end up sitting on 80kph across the Hay plains thinking "geez, I wish I had some higher gears" :mrgreen: ...

I did consider a big chain ring on the front (very common on racing setups), but that's a distinctly non-standard part, and I wanted to keep all the bike-related stuff as stock as possible, as much to show myself it can be done without a full machine shop as anything (I'll be using CNC for the fairing, but as has been pointed out, it isn't a requirement - foam can be contour-cut by hand almost as accurately). Having the option of switching to a 'low range' for hill climbing is also an advantage when running a large top gear ratio like this...

coln72 said:
Interesting what you said about buckling rear wheels as i have never heard of it. I guess running 16" or 20" rear wheels are an advantage :)
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Have you raced at Murray Bridge? The fast corner (before the main straight) used to be famous for it - about 5-10 cars per race did wheels (particularly rear wheels for some reason) there back in the late 90's, when the fast teams were pretty much all on 700Cs. That (apart from convenient fit-ability) is indeed the reason people have headed for smaller wheels. I'm going for larger wheels because they smooth out the bumps better, have lower rolling resistance, and give me more tire choice (not to mention improving chances of finding spares in the LBS of your given randomly chose regional centre) - but I do have to account for larger clearances and less lateral strength...
 
Never got to Murray Bridge yet. Tried once to take a team but the school said no to it :x Something about me missing to many classes.

I am now running a hybrid. With the current motors/gearing we are pushing 80km/h. Back in the good old days (before my time) when they had more fuel to play with and could use bigger motors, the then hybrid would do close to 100km/h. Unfortunately, a 60km/h speed limit has been put on the track :cry: but for us it is a bit nudge nudge wink wink about enforcement. The HPV's are a lot stricter on this though - teams have been warned about exceeding it.
 
coln72 said:
Never got to Murray Bridge yet. Tried once to take a team but the school said no to it :x Something about me missing to many classes.

I am now running a hybrid. With the current motors/gearing we are pushing 80km/h. Back in the good old days (before my time) when they had more fuel to play with and could use bigger motors, the then hybrid would do close to 100km/h. Unfortunately, a 60km/h speed limit has been put on the track :cry: but for us it is a bit nudge nudge wink wink about enforcement. The HPV's are a lot stricter on this though - teams have been warned about exceeding it.
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As I understand it, the RACV is a schools-only thing, yes? As in, no open / university teams, all teams from schools, all riders under 18 or so? I can certainly understand a track speed limit, injured kids would give the sport a bad rap. Of course, if it was a 'conventional' sport like regular cycling, football, basketball, netball, hockey, lacrosse, cricket etc. this kind of consideration wouldn't apply - injuries in those are a given, organisers only care if it gets out of hand... and that's nothing compared to the injuries from cheer-leading in U.S. :roll:. Bizzarre that they should be stricter on the HPVs than the hybrids, though.

The South Australian HPVSS / pedal prix isn't speed limited yet, thankfully - it would severely cramp the style of teams like Phantom, Blue Shift and the various University entries - but I still think we need an Australian comp with a set qualifying lap time with average speed over 50kph, to provide a forum for actual competition between teams that are actually competitive... at the moment the field is 10% competitor and 90% traffic hazard.
 
Bizzarre that they should be stricter on the HPVs than the hybrids,
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Think it is due to there is only about 35-40 hybrids on the track where the HPV's are pushing close to 100 on the same length track now. Hybrids are also built strongrer now due to the regs as well with bigger diameter roll bars etc. Hybrid teams tend to be better behaved as well and respect each other equipment. In my experience the HPV's have a crash and bash mentality.

I sorta agree with you re. the speed differential and sorta dont :roll: Yes it is dangerous on occasions to have big speed differentials, but why should good riders who can read traffic and keep their momentum be penalised.

In events that involve open and community teams, maybe it needs to be like F1. Qualify within 107% of pole or risk being parked for the event.

Back on topic though, would love to see some info on your pancake motor. Sounds like something I could easily incorportate into my current project :)
 
coln72 said:
In events that involve open and community teams, maybe it needs to be like F1. Qualify within 107% of pole or risk being parked for the event.
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Yep, that's exactly the kind of thing I'm talking about (maybe more like 150%, but something like that). But it ain't going to happen in the HPVSS, on account of the primary school involvement - when I was last racing, half the vehicles were little square 'cars' driven by 10-year kids... I think it has improved a lot since then, but it was seriously ridiculous on the track at times, especially when the primary kids got competitive and pulled multiple overtaking manoeuvres three wise at 20kph on the fast corner...

coln72 said:
Back on topic though, would love to see some info on your pancake motor. Sounds like something I could easily incorportate into my current project :)
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Dunno if it will, it's really designed for the 60-110 kph bracket - mind you, if you don't mind running at 60% efficiency, it should be OK down to 40, which should be fine in your context... unlike the bike though, fabrication is getting all high-tech... will post the thread to ES this w/e, but you can find it on motoredbikes.com in the meanwhile, if you don't mind wading through a lot of OT arguments with safe :wink:
 
Went into the hardware store today to put money down on a bench top, only to discover that the hardform plywood I had my eye on, that's been sitting there for the last few months, was sold an hour earlier :x. Will have to wait till next weekend before I can get the bench finished and the bike started. Ah well, I'll use the extra time to add a couple of ladder cross pieces to the bench...

View attachment 2

OK, that's the last shot of the bench until it has interesting bits of velomobile on it, I promise!

Thought I'd also add a couple of pics detailing a nice easy way to get a smooth curve in thin tubing. The tubing in question is 12.7mm ( 1/2 inch ) round tube with 0.8mm ( 1/32 inch ) wall thickness. To get a curve appropriate for making the non-load-bearing concentric strut of the forks, I simply wrapped it around an old steel 27" wheel. A clamp is used to hold the end in place, and a little elbow grease gets the job done.

Tube bending 1.jpeg

An old tyre turned inside out is used to prevent the rim or spoke nipples from denting the tube, and the 'U' shape the tube settles into keeps the resulting bend nice and flat (i.e. not potato-crisp shaped) as well as being more-or-less as round as a wheel, which is hard to achieve by the other common technique of making many small bends using a conventional tube bender. the side pressure may also help keep the tub cross-section circular, but distortion from the circular is negligible at this bend radius - for the record, the tube shown in the pictures was only distorted to 12.85mm by 12.70mm - I'm not sure what it would have been if wrapped around a flat cylinder of similar size.

Tube bending 2.jpeg

The resulting loop of steel is just the right radius to go around the outside of a 700x30(ish)C tyre at reasonable mudguard/enclosure distances, and will be cut in two to obtain a pair of nice semi-circles, one for each front 'fork'.
 
madact said:
As I understand it, the RACV is a schools-only thing, yes? As in, no open / university teams, all teams from schools, all riders under 18 or so? I can certainly understand a track speed limit, injured kids would give the sport a bad rap. Of course, if it was a 'conventional' sport like regular cycling, football, basketball, netball, hockey, lacrosse, cricket etc. this kind of consideration wouldn't apply - injuries in those are a given, organisers only care if it gets out of hand... and that's nothing compared to the injuries from cheer-leading in U.S. :roll:. Bizzarre that they should be stricter on the HPVs than the hybrids, though.

The South Australian HPVSS / pedal prix isn't speed limited yet, thankfully - it would severely cramp the style of teams like Phantom, Blue Shift and the various University entries - but I still think we need an Australian comp with a set qualifying lap time with average speed over 50kph, to provide a forum for actual competition between teams that are actually competitive... at the moment the field is 10% competitor and 90% traffic hazard.
Click to expand...

wow! that RACV is the largest hpv event I seen! lots of crashes.. :D
been to a IHPVA event in the 90's and a couple of ASME hpv races....

is there video of the South Australian HPVSS / pedal prix?

http://www.racvenergybreakthrough.net/Entries-CategoriesExplained.shtml
[youtube]6NsT4FdHQAc[/youtube]
 
sk8norcal said:
wow! that RACV is the largest hpv event I seen! lots of crashes.. :D
been to a IHPVA event in the 90's and a couple of ASME hpv races....

is there video of the South Australian HPVSS / pedal prix?
Click to expand...

There sure are - search youtube for "Murray Bridge" with "HPV" or "AIPP" - the Tru Blu video is one of my faves [youtube]7VSqJmX_x2k[/youtube]
 
OK, this is the big local event in South Australia, and attracts plenty of teams from elsewhere. UniSA is the sponsor / 'hosting institution'.

Generally referred to as just the "Pedal Prix" and was a 24-hour endurance event run at a couple of different venues (I got involved when they were at the Adelaide Speedway up in the northern suburbs) before finding a more permanent home at Murray Bridge about ten years ago. Also known as the "AIPP" (Australian International Pedal Prix). The "HPVSS" Consists of the 24-hour event at Murray Bridge in September, plus two 6-hour events in May and July at Victoria Park, which is just a mile from Adelaide city centre. IIRC these were added about the same time the 'main event' moved down to Murray Bridge, but were originally 2-hour and 6-hour rather than both being 6-hour. All events are team events, with the teams choosing how often to change riders (the pit lanes are long and have slow speed limits).

Entries are open to all, but the categories for Primary and Secondary schools (think junior school and high school) are given priority, with 'Open' teams having to compete for about a dozen fixed slots - if there are more 'Open' entries, there's a waiting list to go on, and there are always more entries than slots (one of the reasons I'd like to see a 'serious racers' event in the country - between RACV (which is schools only) and the pedal prix, we have plenty of HPV events but no actual HPV competitions as such - there's always Lang Lang, but from what I've heard that's a pretty low key thing).

Link to the official website
http://www.pedalprix.com.au/
 
As said, the RACV Energy breakthrough is a school only event, with seperate tracks for primary's/hybrids (Holden Track) and secondary schools (RACV Track) and this year is its 20th birthday. Teams consist of 6 to 8 riders and the rules state that the vehicles must have at least 3 wheels.

I think all of the other events in Australia, Hobart (6hr), Wonthagi (24hr), Casey (6hr) and the mentioned Adelaide and Murray Bridge events are open to community teams and school teams as MADACT mentioned.

To add to the confusion over events, there are two Maryborough 24 hour events, one in Victoria (the RACV event) and one in Queensland. Unfortunately, most of these events have different rule sets which makes building a vehicle to compete in all of the events a bitch as each of the organisors seem to have their own special intrest to push. For example, lights that are ok in the RACV event will not pass Wonthagi's scruitineering :oops: and different events have different requirements regarding minimum clearances around the rider :roll: But I think there is some progress in getting a national rule set.

Here is some footage of one of my trikes in action.
http://www.youtube.com/watch?v=dZ29MFr7pZs
 
Finally I have the bench together, with tube bender and vice attached. On with the show (as soon as it stops raining :().

The rain may rule out welding until the weekend, but at least I can get the parts ready:
View attachment 3
The bulge is added to allow clearance for the brake callipers. I decided to go with a dual-pivot calliper (Tektro R320) for now - a straight-pull V brake would allow the bulge to be omitted, but I'm not yet confident enough to start TIG welding brake bosses, and the tube is quite thin and would probably need bracing - dual-pivot callipers seems the safer option. There will be one set of 'forks' from the end of the curve nearer the bulge (which will also be where the steering linkage is attached) which will continue to the opposite point on the circle, and one fork from just behind the hub to the top of the bulge. This isn't a load-bearing member, it just serves to maintain the radial spacing of the forks, and will also be the attachment point for the wheel fairing / mudguard - the two halves (probably vacuum-formed polycarbonate) will be attached directly to the inner edge of the curve (probably with zip-ties).

It's always fun trying to keep a set of compound curves completely flat with a tube bender - not to mention lining the original curve back up - but it can be done :D

Here's a view of how this piece fits around the wheel - the wheel is tilted somewhat - it's a lot more concentric than it looks here :wink:
Concentricity.jpeg

The 'horizontal' forks (which will actually slant up at the front somewhat) are bent up and ready for trimming and fitting - here they are shown laid out in position at hub - width spacing:
Forks.jpeg
... the 'vertical' forks haven't been bent up yet, but will be simpler, having only one bend at the top, where they clear the tyre.

Finally, I've tried out the stripping of the galvanization using hydrochloric acid (it sounds much more dramatic when you call it Muriatic Acid, don't you think?). Works a charm, and is nicely selective due to the galvanic action of the zinc, but I noticed a bit of rust after rinsing and drying, so I might neutralize any remaining acid with a mild caustic solution when I come to the actual components. Here's a quick fishtail joint I plan to practice welding on when it's dry outside (sorry for the reflections in the photo, it's just a quick snap :?):
 
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