Need some help with an RC hovercraft: Off-topic discussion forum: Grassroots Motorsports Magazine

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Jan. 31, 2009 2:02 p.m. GameboyRMH SuperDork

So this weekend I tried to take another stab at fixing my RC hovercraft, similar to this one:

Well OK it doesn't look so badass, more like this one:

I know there are a few RC enthusiasts on here who might be able to help me out.

I originally bought it broken about 4 years ago for $20 and it only cost me about 5 hours and a couple feet of electrical tape to jerry-rig it into working again. One of the best cost-to-fun ratio purchases I ever made. Me and my sister's boyfriend at the time then proceeded to run it like hooligans, taking two battery packs out to a pool and using them up one after the other with no break between them, every night, on a regular basis. It's very quick on the water BTW, it would turn the pool from a flat calm to a stormy wave pool all by itself. The cheapo motors didn't last long.

These things are long out of production, if you can still find them they're expensive. A new one costs about $100 so that's the budget for the repairs. I've been running a problem getting it ready for the new motors.

The motors have hex fittings on them to lock the shafts to the props and lift fan. These hex bits won't come off since it's really hard to get a grip on the motor shaft, being a tiny soft greasy metal pin and all. I've even tried disassembling one motor and grabbing the rotor with pliers, but the shaft just spun against the rotor. To be honest, while I know they screw on at the prop/fan side, they could be soldered on to the motor shaft for all I know. In this case, where can I get replacement hex fittings? The threads don't have to be the same but they need to have similar sizes and screw diameters.

The other problem is choosing new motors. I want them to last long since replacing them is such a PITA, but I won't be so harsh on this thing in the future. The other problems are that the motors need to be a specific length and shape (although I can always pad the mounting points somewhat) and that they will be running hot as hell. All the motors are in cramped airtight chambers, and the lift motor is running at full power all the time (in practice the two thrust fans are as well). I'd like to get 4 motors for $100 but I could go for 3 for $100. I've read about breaking in electric motors by running them underwater, any comments on that?
Jan. 31, 2009 5:05 p.m. GameboyRMH SuperDork

Update - the hex bits on the props are a lost cause. The screws that hold the props on have rust-fused into place. I'm going to try grinding the screw heads off so I can recover the props.

I can't find the hex bits anywhere online so I'll have to look at fabricating a replacement. I was thinking of carving some out of rubber with holes smaller than the motor shafts so that they should fit tightly, then using wood screws that will push in from the other side and tighten the connection further.This should keep the props and fan from slipping but I wonder if the props could pull themselves off in reverse (the lift fan probably exerts some pull as well). Maybe some JB weld on the shafts could keep them from coming off? once the props and fan are on, they only need to come off if the motors need to be changed or if I have to open the electronics box.

Edit: OK the grinding isn't working...it just spread a paper-thin layer of metal over the hub of one of the props. I might need to go with new props.
Feb. 1, 2009 7:20 a.m. Gearhead_42 HalfDork

Look in the world of micro electric helicopters for motors. Electric free flight airplane props should work for propulsion, and there are much better prop adapters out there now.

You remember those 4wd 2-cell cars from Tamiya? They had a slick tool to press those little gears off the motor shafts, if you want to keep going down the repair route instead of replacing the drives as above.
Feb. 1, 2009 12:58 p.m. GameboyRMH SuperDork

It looks like this thing may be a lot cause...I've just noticed that there are loads of tiny tears in the skirt (which is made of rubber about as thick as a piece of paper) and it's already been patched up a million times (also this would be the 2nd motor replacement), I might have to spend a lot though:

http://www.amazon.com/Hovercraft-49-MHz-Colors-Vary/dp/B000CCYC7I/ref=sr_1_12?ie=U...

Or if I was really wealthy:

http://www.youtube.com/watch?v=6i5WYZdhDFY

Oh wait, I'm saved! these guys don't know what they're selling :

http://www.amazon.com/RC-Twin-Engine-Hovercraft-Boat/dp/B000QEAX0M/ref=pd_bbs_sr_3...
Feb. 1, 2009 1:04 p.m. pigeon Reader

Looks like the $30 one I, err, I mean my 8-year-old son had that the Wife threw out on me while cleaning up a few months ago. Worked like a charm especially on snow and was plenty durable, your post has just made me mad (again) that the Wife disposed of it on me...

I really need to get new shocks to replace the destroyed ones on my T-Maxx and go play again.
Feb. 1, 2009 3:20 p.m. wherethefmi2000 Reader

I found like 3 different new ones for under 50 bucks

http://www.google.com/search?hl=en&q=rc+hovercraft&aq=0&oq=rc+hove
Feb. 1, 2009 8:47 p.m. shuttlepilot New Reader

Wow, in my rc mania days, i had 3 different hovercrafts. I only had so so luck with them. They were pretty good on ice. It was like a RC hockey puck. High speed but lots of drifting because there was not enough thrust for good control. I almost lost mine a few times on the water, steer too hard and you risk tipping the thing.

I dread looking for replacement bags. It might be easier sewing one up.