high school "engineering innovations" science fair comp. R/C help needed!

[edep345]

Hi, it has been a while since I've posted on RCM but after looking around I feel that this is the only site where I can get meaningful insight from an experienced group of people :)

My physics teacher in high school inspired me to create something I never thought possible. A hybrid rc car, brushless motor of course!


I know this is an "electric ONLY" forum, and before anyone objects and tells me to make it complete brushless, this idea has always been in my mind and it wasn't until today in class that I realized something like this could be possible. It would mean a lot to me if I could get this done with the help of RCM...


some obvious questions came up:

Which layout to use? If any. Should I go budget friendly with a 250 crt.5 with the engine and motor mounts already? I'm open to any suggestions here,
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and more importantly, to make this as realistic as possible, what will I use to replace the computerized shifting technology in full scaled hybrids from electric to engine?

currently multiple speed transmissions are used with either electric conversions or available as select hop ups for nitros. Does anyone have any thoughts on using that same idea of the gears inside there that spin to a certain rpm and then "shift into the 2nd gear" (sorry that's about all I know) But I thought the same idea where this gear spinning could instead trigger the ignition somehow to start, maybe tinker with Losi's R.O.S.S. ?



so as you can see, I am kind of clueless as to where to start...but I have time to plan everything perfectly if I want to enter this in the summer, or next year when I am a senior in high school..it will give me something to combat senioritis with.

Thank you for time and consideration :)

[shaunjohnson]

losi tent a good place to start? or even...dare i say it....traxxas *cough cough*

remote start ability for re-starting the engine.
or even put the engine on an alternator/generator and run the entire car electric

[BP-Revo]

A true "Hybrid" would probably require a remote start that sensed whether the engine was running or not (and if it wasn't) it cranked the engine over to get it started. I'm sure you could achieve a tune where the engine just stalls itself out once the RPMs drop low enough.

You'd want the brakes to be done by the brushless system but you'd also want the brushless system to engage at only lower throttle inputs (so in a way you'd HAVE to have a smooth throttle trigger for the hybrid system to work).

As you can see, I'm thinking of a more mechanical way to achieve the "hybrid" part, since it'd probably be too complicated and take lots of programming otherwise.

[JThiessen]

I have never really had much experience with them, but they do make some 4 stroke motors for RC. Those might prove to be more reliable in start up and running than the more common 2 cycle nitro's....

Have you looked at the hydrogen powered RC? Search Youtube - there was also a thread on here for it a month or so back.

I wouldn't get so wrapped up in the details of the chassis at this this point. Make up a test bed for your power system - get it configured and tested, then pick your rolling chassis based on the size requirements. You might find it easier to go bigger scale here - 1/5th or larger.

[shaunjohnson]

how about getting a OS .30FS 4-stroke engine.
i had the old .26FS and it's my favourite nitro engine of all time!! it was just as reliable as brushless, NEVER stalled.

[BrianG]

The main hurdle I think would be to physically fit everything on one chassis. Then, there is the cost/hassle to benefit ratio. But that aside, since we are just talking about concept, how's this:

Take a look at any electric start nitro setup (Trx Revo/Jato/etc, Losi TenT, etc). They have an electric motor that starts the motor right? Well, remove the OWB, beef up the "transmission" (gearbox connecting the electric motor to the engine), and install a proper size BL motor in place of the small brushed motor.

Then, have additional circuitry to detect when the engine is running at a certain RPM, and use that to cut the power going to the electric motor, and then pull power from it instead so it'll function like a generator/alternator to recharge the battery. That's gonna take some special ESC hardware to do that if you stick with brushless. For the sake of simplicity and time, I'd stick with a brushed setup. So, use one of the larger motors like the one used in the Summit, Kershaw 700 Revolver motor, etc. Essentially, the nitro engine would be the primary power plant and the electric would provide assist on startup and low speeds.

Any other setup will probably require LOTS of custom parts. Not sure how crazy you want to get with that though.

[swiftneed]

I placed a hydrogen rc car on yesterdays forum under thought you guys might be interested in this with the video

[edep345]

Originally Posted by BrianG

Take a look at any electric start nitro setup (Trx Revo/Jato/etc, Losi TenT, etc). They have an electric motor that starts the motor right? Well, remove the OWB, beef up the "transmission" (gearbox connecting the electric motor to the engine), and install a proper size BL motor in place of the small brushed motor.

Then, have additional circuitry to detect when the engine is running at a certain RPM, and use that to cut the power going to the electric motor, and then pull power from it instead so it'll function like a generator/alternator to recharge the battery...Essentially, the nitro engine would be the primary power plant and the electric would provide assist on startup and low speeds.

Thank you for all the hydrogen cell suggestions- but my main focus is on hybrid technology for now.

Brian, so from what I understand is that your idea involves using a bigger brushed motor to not only run the car AND be able to spin the flywheel that starts the engine? If that is the case, I would have to find a way to connect the one electric motor to the engine and the driveshafts/ center diff (to physically move the car with electric power)?

I really like that idea, but I need to find a layout for that setup...

also, about the generator, why would there be power going to the electric motor? and would pulling that power, or redirecting it reflect in a lower speed?

[edep345]

Originally Posted by swiftneed

I placed a hydrogen rc car on yesterdays forum under thought you guys might be interested in this with the video

interested to see any projects you may have of you own!