Micro Rotary Engine

DarkTari · Post by **DarkTari** » Thu Dec 23, 2004 1:20 pm

Check This Out Pimps ......

http://www.me.berkeley.edu/mrcl/mini.html

Nasphere · Post by **Nasphere** » Thu Jan 13, 2005 1:08 pm

dude, thats kinda old... besides it probably costs like 2 er 3 G's... nice idea though.

DarkTari · Post by **DarkTari** » Thu Jan 13, 2005 1:51 pm

Nasphere wrote:dude, thats kinda old... besides it probably costs like 2 er 3 G's... nice idea though.

Yeah well it's never been posted here before so..........

HirotoR34 · Post by **HirotoR34** » Thu Jan 13, 2005 3:27 pm

DarkTari wrote:
Nasphere wrote:dude, thats kinda old... besides it probably costs like 2 er 3 G's... nice idea though.
Yeah well it's never been posted here before so..........

Yup, so yeah.....It's kool. Be fun to have one in a micro.

crazydave · Post by **crazydave** » Thu Jan 13, 2005 4:28 pm

Wait a minute. remember that racer9 kid on tinyrc? We all ripped the crap out of him for saying he was gonna make a rotary engine for bits. If I find out he had anything to do with that, I'll be forced to eat my underwear.

Nasphere · Post by **Nasphere** » Fri Jan 14, 2005 2:09 am

crazydave wrote:Wait a minute. remember that racer9 kid on tinyrc? We all ripped the crap out of him for saying he was gonna make a rotary engine for bits. If I find out he had anything to do with that, I'll be forced to eat my underwear.

good call man, imma have to make you eat those words.

lol, jk

Bit boy · Post by **Bit boy** » Sun Apr 24, 2005 5:49 pm

I think Racer9 said he wanted one. not that he would make one. I remember somebody saying they would pay a whole $20 bucks to anyone that would make them a micro rotary. I believe Racer9 is a little young to be in college and doing that kind of thing.

codesuidae · Post by **codesuidae** » Tue Sep 20, 2005 10:15 am

Well, its not out of the realm of possibility. After all, you can buy CO2 motors that are way tiny. You can get big ones up around 350 grams all the way down to micromotors that weigh 1 gram.

Yeah, thats right, 1 gram. You could fit that and a CO2 tank into a bit and get several minutes of runtime out of it.

Check these:

http://www.samsmodels.demon.co.uk/gasparin.html

Construction is pretty simple, basicly the same thing as a steam engine, just a cylinder with a piston connected to a crankshaft, hole in the side near the bottom of the stroke, and a ball valve at the top connected to the gas supply. Its tempting to try to build something like that. Not that I could even get close to a 1 gram model, but it sure would be fun.

Nasphere · Post by **Nasphere** » Tue Sep 20, 2005 6:31 pm

Its funny, you see small RC engines all over the place, but the smallest gas turbine engine i've seen is about 8" long... If combustion at that size is so hard to achieve, how do these micro motors work then?

EDIT: oops, I just read the page... CO2 "pressure" runs these motors...

codesuidae · Post by **codesuidae** » Tue Sep 20, 2005 6:59 pm

Nasphere wrote:Its funny, you see small RC engines all over the place, but the smallest gas turbine engine i've seen is about 8" long... If combustion at that size is so hard to achieve, how do these micro motors work then?

I'm no jet engine scientist, but I would imagine that part of the issue with producing a very small jet is just that they require a heck of a lot of parts that move really goddamn fast, so there are some significant manufacturing issues to overcome. I mean, if a turbine several inches in diameter turns at 100 grand, how friggin fast would one half an inch across turn? A million?

Since the CO2 motor is basicly an open steam engine (vents the 'steam' to the atmosphere, there's probably a name for that kind of engine), you could run it with pretty much any kind of fuel just by using that fuel to boil a working fluid that expands to push the piston. You could burn the fuel directly too, but then you'd have a regular IC engine. I've never seen one of those smaller than 0.049, but I suppose they exist.

Nasphere · Post by **Nasphere** » Tue Sep 20, 2005 7:19 pm

codesuidae wrote:I've never seen one of those smaller than 0.049, but I suppose they exist.

i think theres one in the hobby shops called the bumble b... if i remember right its a .010

codesuidae · Post by **codesuidae** » Tue Sep 20, 2005 8:04 pm

Nasphere wrote:
codesuidae wrote:I've never seen one of those smaller than 0.049, but I suppose they exist.
i think theres one in the hobby shops called the bumble b... if i remember right its a .010

Indeed, nice motors with a good price.

50 bucks for that one, and only 35 bucks for their 150 .049:

http://www.coxmodels.com

codesuidae · Post by **codesuidae** » Tue Sep 20, 2005 8:24 pm

Am I reading this right?

Cox 488051 .049 Production Engine w/90 Deg Backplate $6.99

Cox 8901 .049 Sure Start Engine $6.99.

Cox 488049-T .049 Production for T-6 Texan C/L $9.99

Are these things really $7 bucks for a 049 motor? I thought this gas stuff was supposed to be expensive? They list list a number of these motors with different backplates, and I can see the backplates going for those prices, but the ad copy sounds like its a complete motor:

Detailed Description

This Cox.049 production engine is ready to be mounted in your model. It is sold in bulk which means no packaging, instructions, spring starter, prop nut or spinner are included. This version includes a 90 degree needle valve mount which is very useful in many applications where the engine is hard to reach and the needle valve exits the model through a small hole in the structure. A choke plate is also included for easy engine priming.

beanoman · Post by **beanoman** » Tue Sep 20, 2005 9:09 pm

hey code

from what i remember, those engines went for alot more than that. but, those are too big for zzs- but they might pop onto a xmod of miniz. c02 is the way for bit cars, although you would have to mess with the chassis a shitload to make it work. the right size c02 motor for a bit car is $75, and i doubt it would preform all that good.. but hell, how cool would it be to have a head sticking out the back of your zz?

beano

civicsr2cool · Post by **civicsr2cool** » Tue Sep 20, 2005 9:28 pm

man there was a prop plane at a rummage sale with a very very small nitro engine in it that looked just like those. the prop wasnt on it and it didnt look to spin it so i put it down. $5 man i was thinkin bout it that whole day" i gotta go get that engine, but i dont want a broke airplane with a stationary motor"

i guess ill never know. oh well