Sooo will this Hovercraft work?

[liam2317]

Okay, so most days around here it's too windy to fly my RC planes but we have plenty of smaller (sheltered from the wind) areas that I think would work great for a hovercraft. Unfortunately I know pretty much nothing about them which is why I need some advice from you guys.

First off, the electronics specs:
HexTronik 16g, 1700kv Brushless Outrunner (http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6311)
GWS EP Propeller DD-7035 178x89mm
500mAh 2s Lipos and or 620mAh 3s Lipos
~300g of thrust

Here is what I have drawn up so far. It will likely be built out of corrugated cardboard and fan fold foam using hot glue. There will be a hatch to access the battery compartment from the bottom of the hovercraft. The battery compartment will also house the receiver, ESC, and maybe some of the servos, I haven't quite got the control linkages figured out yet. As far as the skirt goes I think I'm going to use a simple wall skirt made out of heavy plastic. Any pointers on skirt design and construction would be greatly appreciated! The hover craft has two internal flaps; flap one can vary the amount of air which enters the skirt giving more or less lift for better efficiency over different terrains. Flap 2 acts as a break by reducing the amount of air exiting the rear of the hovercraft, however this air is not diverted anywhere which could be a problem. Maybe more flaps which open on the side as flap 2 closes will be required, possible used to reverse the hovercraft. :confused: So what do you think? Will it work?! :confused:

Thanks everyone! Happy hovering. :p :D
Liam O.

[HoverTim]

have you thought about getting a kit this would be a good place to start if you want to learn about how hovercraft the best thing to do is go for a 1/10 scale griffon 2000 the plans are free form http://www.model-hovercraft.com/2000tdx/2000tdx.html but if you dont fancy something this big then try one of these http://www.modelhovercraft.co.uk/index.php?q=index.html you may be able to use some of the electrics you have got the latter of the two is a good start if you dont fancy scratch building hope this helps

[metroidrc]

I think building a simple at first is a fun project - and alot of people like to do those types of things over the winter. yes there are a few decent hovercraft kits out there, also check out the scamper1, its got a brushless motor and can handle water very well. I have a kit of it sitting in my basement but haven't had time for assembly yet!

[liam2317]

To be honest I like designing and building things my self so I'm really not to a big fan of kits or RTH (ready to hover :p ) packages. Though I have to say, if I had the money I'd buy the Axon Razorback (http://www.axonracing.com/) in a second from you metroid. It preforms amazingly well and it just looks wicked!

So I think I'll build this thing anyway, what the heck it just might work.

Oh and thanks for the link to www.model-hovercraft.com HoverTim, it gave me some good ideas for skirt design.

I'll post up some pics when I have made some progress, using hot glue and cardboard that shouldn't be far off. :D ;)

Liam

[liam2317]

Not a huge amount done so far but, pictures as promised...

[metroidrc]

sweet... interested to see how this comes out!
-josh

[bloberts]

if you have not sorted the skirt make it out of rip-stop nylon the same thing kites are made out of and make a simple bag design and keep it as simple as possiable thats what i did for my first time for the first few runs only have a small hole in the bottom of the bag and just enlarge as required
should be an intresting hovercraft

hope all goes well

[SilverHeli2000]

I think building a simple at first is a fun project - and alot of people like to do those types of things over the winter. yes there are a few decent hovercraft kits out there, also check out the scamper1, its got a brushless motor and can handle water very well. I have a kit of it sitting in my basement but haven't had time for assembly yet!

This is probably a long shot, but have you considered parting with your kit?? :D

[metroidrc]

sorry man I think I'm gonna finish building it with my son someday (I told him it was his :))

[SilverHeli2000]

Thats awesome! Have fun building!

Hopefully when my son gets old enough (he is only 7 months now) RC will be something we can share as well!

[SilverHeli2000]

Edit

[liam2317]

Hey guys, I'll just drop a little update in here. I have been having a little trouble with the electronics, It's a small motor, only 16g so if you fire it up too fast the elastic effect from the prop saver (because the normal mount wouldn't fit my prop) makes the prop move around a bit and it throws off the motors timing and it dies. Easy enough to get around but still kind of annoying.

Other than that it seems to be working out okay. I tested it out for the first time today with the rudder working. However it still has no skirt just the 1.5cm lip of cardboard around the bottom. Results so far are promising, though I think in all it is a little underpowered. Adding the skirt will likely help with this.

Oh and bloberts, thanks for the advice on the rip-stop nylon, I think I'm going to make a test skirt out of plastic first (also just to make a pattern) but I'll keep an eye out for some!

Learning to pilot a hovercraft sure is an interesting experience! I'll keep you guys posted as things go. Thanks for the support!

[Skycruiser]

I've got the same motor, won't run at all on a towerpro esc. I had to buy a programmable turningy one and set the timing.

[metroidrc]

liam another thing you could do which I did for my full size pod racer for the skirt was tarp material. seems to handle pretty well.

[liam2317]

Okay guys here is my final update for this hovercraft. In two days I'm leaving Hawaii and going back to Canada and I have no way of getting this thing home. Oh well. :(

So it seems to work okay... it's not nearly as impressive as some of the other hovercraft videos I have seen around here, but at least it worked. Here are some pictures of the finished craft and once these YouTube videos get uploaded I will post them too. Then you can just see how it works for yourselves. :p

Thanks for another skirt material tip metroidrc, what I ended up using was some really heavy plastic I got from the guy at Home Depot who unpacks everything when it arrives there. It's flexible but really tough too. However as you can see I made the hole in the bottom too big and so I had to tape in another ring of plastic to stop the sides from blowing out.

Just a final note; I never did make any of the internal ducting operational, all the flaps are there but I just never got around to installing the servos when I realized this thing wasn't going to work very well.

Liam O.

[liam2317]

And here are the videos....

http://www.youtube.com/watch?v=B41T7In5_fk

http://www.youtube.com/watch?v=cUgfPHvkOCY

http://www.youtube.com/watch?v=tJYRTd9VJs4

Enjoy! ;)

[metroidrc]

go liam!
it reminds me of that droid transport vehicle operated by the jawas in the original starwars!!!

[hover dude]

Nice start Liam. it looks to me like your craft is not building enough under itself. I would suggest instead of having the hole prop ducted off and then splitting the airflow thatyou dont duct the prop and just make a scoop to take about a third of the thrust directly into the bag skirt. Then perhaps just punch some small holes on the inside of the skirt to let out the excess air and provide lift. good work though.

[PlaneCrazee]

Something I noticed about your design that may have caused you some grief is the 45degree angle you mounted the on. I have seen a lot of designs do this and my first attempts I noticed the same lack of directional stability when the power setting was changed that your seems to exhibit. Once the fan shaft angle was brought to horizontal it became much more controllable