newbie with aspirations!

C

Clueless

10 µW
Joined
Aug 18, 2008
Messages
6
Hi All,

I've decided the time has come where I need something small and cheap to run me about, so I'm currently starting work on the very long haul that is "learning everything electronic". I've a good history in mechanics but electrics are... ermm... rather limited!

The plans for my chariot of choice so far are:

Single seater 3 wheeler reverse trike
lightweight aerodynamic composite construction (max 350kg all up)
Top speed 50 to 60 mph
Range 30 to 40 miles. (not so important, 15 would do but 40 would be nice!)

So that's the easy bit out the way - now all I have to do is work out the 101 bits I don't understand. :lol: So far your great site has completely put me off bothering with Regen, which will put some money back in the kitty.

I joined after getting a link through to some power calculators on here, only they all seem to be aimed primarily at bicycles - I'd guesstimated (going on petrol engine powered vehicles I've played with) that anything north of 6kw should be good for the speed, but any opinions gratefully received on that or any other aspect!

hmm can't believe I spelt the title wrong on my first post! apologies.
 
With a build that ambitious you may want to consider doing some of the learning curve on cheaper stuff, like a bike kit. Even if it gets no serious use, you can cook a few things a lot cheaper. We all seem to do some learning the hard way.
And you can practice how to drive an ev, balance a battery pack, etc a lot cheaper and be ready when the expensive stuff is bought.
 
LOL OK, so the one decision I had made, looks like it was possibly the wrong decision :lol: 350kg is the absolute maximum I'd like it to be, I know I could build a petrol vehicle to those specs at that weight or less, just not sure with electric. Ideally I'd aim for 300 or less - If it all works well and I enjoy driving it on lead acid I'd look to Lithium cells so would anticipate that coming down considerably.

It'll be a ground up build, as everything bar the electronics is fairly straightforward. I had considered something a bit smaller first to cut my teeth on the world of EV but in all honesty I probably overstated my lack of electronics knowledge a little. I know the "basics" of batteries, controllers and motors and can certainly cobble together a working system of the main types of brushed and brushless using plug and play items. What I don't know is any of the intricacies that allow one to make circuits, diagnose the more testing problems or most importantly in this situation - calculate requirements.

On smaller projects I've found pretty much every bit of info needed available on the net in ready to follow steps, so I don't feel I'd learn much from it. Probably second incorrect decision for the day!

I'd certainly be interested to hear anyones thoughts on the power requirements of my planned vehicle - even if it's just a "you're way off the mark with 6kv"
 
a quick run through kreuzotter leads me to believe that 6kw is insufficient for 60mph. If you had your weight with the same drag as a mtb you would need about 6.5kw but I think trikes have more wind resistance, assuming you aren't putting a windshield thingy on it. my rather uneducated guess would be 7-8kw for 60mph + decent accelleration.
 
Many thanks HippieHunter.

My trike is indeed going to have a full body and will be quite slippery in terms of aero, however it's still better at this point to up the power a bit than find out later that I could have done with another couple of kw. 60mph isn't an "absolute" figure, I'd be happy with anything between 50 and 60 - the roads it's going to be used on are mostly limited to 50 or below anyway, (my cars computer tells me I only average 18mph on the commute anyway!) just want a bit in reserve for those "oh dear" moments and those occasional moments of clear road.
 
I'm glad to hear you are smarter than me, when I fried my first controller in the first minuites of riding I was real glad it wasn't a $1000 car sise one. I read a blog about another guy who did that in about a month with his car conversion. All the info I had lead me to thing i was doing it right, and then zorch! Good luck and I hope the unforseeen doesn't bite ya.
 
dogman said:
I'm glad to hear you are smarter than me, when I fried my first controller in the first minuites of riding I was real glad it wasn't a $1000 car sise one. I read a blog about another guy who did that in about a month with his car conversion. All the info I had lead me to thing i was doing it right, and then zorch! Good luck and I hope the unforseeen doesn't bite ya.
Click to expand...

Hope you didn't take offence, I wasn't suggesting that, just that I wouldn't learn much from it - there is so much info available on bike conversions that any costly mistake would be down to my own stupidity and not reading things correctly and one I'd just as likely repeat on any vehicle after. The money and time I save not doing a smaller one will go a fair way toward the first controller I total on the main vehicle (of which I have no doubt there will be several)
 
You and i had the same attitude, why start small when you can just go straight to what you want..... then I burnt out a controller, fried some hall sensors and most recently fragged a few cells of my battery. I happen to think at this point my chances of destroying things are much lower and if i were to start from scratch my design would have put more things in place to prevent me from destroying expensive things. In short, what im trying to say is it looks straightforward from the blogs and forum posts but there is a lot of nuance to this whole electric vehicle deal and it would be very il advised for you to build a multi thousand dollar vehicle without first having hands on experience with something cheaper.
 
No offence taken, I'm just the kind of guy that has to see everyting for myself, including testing to destruction. A motor a contoller, and a few chargers later, i'm beginning to get a handle on this ev thing. Somehow I've avoided destroying any batteries though I have tried.
 
LOL a recipe I follow myself with many projects, for some reason though with anything electronic I have tackled, I've always stayed well within limits of components (I'll usually buy something way over the top, just to be sure) and probably due to my lack of knowledge then double, triple, and quadruple check everything over, then give it to a mate more versed in the matter of electrons and get him to check it as well. THEN I might turn it on. After checking it a couple more times.

Probably means I'll never either excel at it or get the most out of any components, but till I have a lot more knowledge it suits me not to over stress things I don't understand :lol:
 
Howdy Clueless,

Just out of curiousity, what do you mean by "reverse trike" ? Tadpole or delta configuration? There have been so many varieties of both configurations with either an unfaired version or a streamlined one via an enclosure, I was curious as to your design and which aero designs you had taken some inspiration from.

tom
 
Hi Tom,

I've always known the Tadpole configuration as Reverse Trike for some reason - probably because it's the opposite of a typical kids trike!

Haven't really taken inspiration from anywhere, just taken a basic human frame, sat it on top of batteries and then made a slippery form over the top. It's a bit of a fluid design until I get the motor and battery locations firmed up, and chose which motorcycle the rear swing arm is going to come from! I suppose if anything originally inspired me it would have been the Grinnall Scorpion though it's not really going to look much like that either. Rather than create a frame and then add an aero package to it I'll simply be moulding a 2 part composite + foam tub which the suspension pick ups will come directly off of.
 
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