RC India

Hello guys..!! I recently started making a rc hovercraft. Everything was fine but i am facing some problems with the following...

1.The hovercraft is bending(some times it even flips) left and right
when making respective sharp turns.

2. It is good and stable on almost plain surfaces... but it wont move an inch when it is tested on grass, sand, etc.. or any other uneven surface..

3. I saw in some videos when there is an obstacle their hovercrafts are hovering above them nicely. But mine colliding with obstacles why??

I know the reasons for above 2 problems( I think) :P
1. Centre of gravity is high and skirt design is faulty..
2. The skirt material is plastic. So, it might have some friction related issues..

How to overcome these problems.
How to design the skirt perfectly..

Specs;
Lift: Turnigy 1000kv brushless motor and redbrick 30amp esc with a cpu fan blades as prop.

Thrust: Motor and esc same but 10×4.7 props

Rudder: Emax analog servo..

Material;
Body: thermocol, plywood (lift motor mount), black drawing support sheet and some other scrap.
Skirt: polythene garbage bag..

Here are some pics uploaded to drive

https://docs.google.com/file/d/0BxMi66_rssQYd2M4WW9nV1EwSlE/edit?usp=docslist_api

    https://docs.google.com/file/d/0BxMi66_rssQYclFYTFQxT0ctVDA/edit?usp=docslist_api

https://docs.google.com/file/d/0BxMi66_rssQYbTZZX1VIbTd5bFk/edit?usp=docslist_api

https://docs.google.com/file/d/0BxMi66_rssQYc19rWWFMc0xmVTQ/edit?usp=docslist_api

Hi Saw
i went through similar project during my college days. please have a look at the video
http://www.youtube.com/watch?v=1dXZojC18ek# (http://www.youtube.com/watch?v=1dXZojC18ek#)

I saw your pics just now, it looks good. Hovercraft works on the principle of air cusion since you are trying to run it over grass air will escape from the grassy surface. i would suggest you to use separate fans for lift and propulsion. separate fan would give you more lift however you have to reduce weight as well. mine was made in hurry and we could not find proper material on time. i had to run and made it in few days. it was bit on heavy side.

Hello. Thank for your reply.
 I didnt mean same motor for both. But both motors are same.
i.e., I used same turnigy 1000kv motor for lift and another tunigy 1000kv motor for thrust.

Here is the video..

https://docs.google.com/file/d/0BxMi66_rssQYQ2dMUFpRTk90cHM/edit?usp=docslist_api

use the car cover material for skirt. I am too trying tobuild an hovercraft. the plastic has got some friction. also use a lower kv motor for pusher.

Yeah am thinking of same material. But how does lowering the kv will solve my above problems..?????

Please check build log here incase you might get some points for your build.
http://rcsci.blogspot.in/2012/06/project-hovercraft-build-log.html (http://rcsci.blogspot.in/2012/06/project-hovercraft-build-log.html)

lower the kv higher the thrust. thats how it ll help. your build is really nice, I dint got your level of finishing.

Thanks For your steps @Dharmik I learned a lot in skirt designing..


@miginstruments
Oh. I Thought it reverse.(Higher the KV Higher the thrust) And I have no problems with THRUST. Because am not even using 20% of total thrust. If I use above 50%. The craft is bending forwards... Please see the final part of the video.. So I need a perfect design of skirt.
Anyway Thanks for your advise..

well ll see it soon n also ll post mine soon. yet to take a video.

Okay.. waiting  for your video then..

Bump....