Hovercraft Q's

[killerkiwi5]

My schools got an R/C club going after school, and we plan on making hovercraft. Problem is, we have no idea what we are doing. A couple of questions to anyone who knows: 1. Is the skirt on a hover craft sealed, except for the intake, or is it open on the bottom? 2. Does the thrust to weight have to be 1:1 or better?

Thanks for the help

[rkramer]

no to both of those (hovercraft thrust is MUCH less then 1:1!!) ... lots of hovercraft designs on out on the internet, might want to search google... they are fairly easy to build, lots of plans out there.

[slipstick]

The best Hovercraft source is probably http://www.rc-hovercrafts.com/phpBB2/index.php

Plenty on skirt design etc and there are plenty of free hovercraft plans around (just look at the discussions in the Plans and Design&Construction forums).

The easiest way to get started is with separate lift and thrust motors. A pair of S400s will get a reasonable size craft going.

Steve

[Rocketman1092]

I built a hovercraft powered by a leaf blower once. You'll need to get some plans, the design is a bit more complicated than you might think :D.

[killerkiwi5]

Thanks for the help and link. I was thinking of using an GWS EDF-64 for lift on the throttle channel, an GWS EDF-40 for a pusher on what would normaly be the elevator channel. Attach these to a meat tray, with a 2s Lipo, and garbage bag skirt for now. Wont be the prettiest but it will do.

[Rocketman1092]

You'll have more than enough thrust on that. Did I mention that my leaf blower hovercraft is 4' in diameter and can lift over 150 pounds?

[SPEED-E-FLYER]

Did you do a search yet.
http://www.rcgroups.com/forums/search.php?searchid=1890187
Yields quite few pages about hovercraft.
This is one shows a few different design.
http://www.rcgroups.com/forums/showthread.php?t=271708&highlight=hovercraft
including one that I made that was quick and simple.
Read thru it these post and you should have most all your questions answered.

Good Luck in your project
Larry

[Weldman]

If its a cheap hovercraft and you want a good size skirt area, look at some of the swimming pool toys- inflatable rings( comes in Black)cost about $2-3. Then just use blue core as a deck to mount motor( A bit bigger) and Battery, make sure you have a tight seal on the edges then you have your hovercraft. Also seen Foam paddleboards converted to Airboats.


Larry,
That is one cute hovercraft, hope that you don't have a cat - can you say "Swiss Hovercraft"


Killerkiwi , Good luck on your project.


Mike

[killerkiwi5]

Alright, parts are in. GWS EDF-40 and -64 150, 2 ics 480s, and an Absolute Power HECell 2 cell 3000mah lipo. Planning on making a MicroScream Audible low voltage alarm. I'll get the rx and servo at a different place, LHS prices are way up there. Another couple of questions... 1. Do the ICS's need the heat sinks? 2. There will be 2 throttle channels. Does one of the wires need to be cut betwwen the ics and rx? 3. Do tx and rx need to be of the same brand?

[RobinBennett]

If you are operating on land, you could put both fans on the same speed controller. That way cutting the throttle makes it stop quickly. On water you want to make sure the lift fan keeps going!

1) I wouldn't have thought you'll need the heat sinks, so long as the ESCs are exposed to some cooling air - but check them every 10 seconds or so the first time you try it!
2) sorry, I don't know
3) No, just on the same channel (and for 72mhz, they both need to be either positive or negative shift)

[killerkiwi5]

Thanks Robin!

[killerkiwi5]

Another... Some of the other kids are using GWS 350's for lift. Could the rotational torque be defeated by angling the motor, sort of like the motor mount in fixed wing aircraft?

[SaMx]

I don't think that would work, because it would just push it to the side if you angled the motor. but, a geared motor for the lift would be more efficient. also, if you want the throttle channel that controlls forward movement to be able to go in reverse too, you would need a car esc. i would reccomend doing what robin reccomended.

[Umi_Ryuzuki]

Heres some Ideas.

http://www.microrccenter.com/forum/index.php?showtopic=21900

[killerkiwi5]

SaMx, I had a look at a car esc, but they were too expensive. Maybe down the road I will add one. Umi, thanks for the link.