Hello friends
Here i am going to post build log of hovercraft project. I would like to thank my group members for their support and help.
I don't have much experience of building hovercraft. I went to the state level competition when i was in school but it was a wired hovercraft not an R.C. one. So the biggest opportunity was to build remote controlled hovercraft with lift, propulsion and direction control capibilities. The design was inspired from that school project with major changes.
We were allready running behind the time and we couldn't find coroplast sheet or any proper foam sheet at the last moment so finally we went with the 2.5mm white card board sheet. I was planning to construct hovercraft with two lift fans running in opposite directions of each other and one fan for propulsion or two fans for propulsion and one for lift but proper light weight building material was an issue till the end. Card board sheet felt bit heavy so we had to put holes everywhere to reduce weight without affecting strength of the base structure. The skirt designed by the method of "Development of surface".
In our design hull, skirt and bottom structure together makes chamber where air pushed by a propeller. Air escape way can be found at the bottom where pressurized air creates air-cushion which lifts the craft over the surface. The propulsion module which is nothing but the motor with prop covered by card board pieces with rudder mechanism to give the craft direction and propulsion. Part List:
2x 1700kV brushless D.C. motors
1x 6x5 prop for lift
1x 3x2 prop for propulsion
1x 1600mAh 20C lithium-polymer battery
1x 5V servomotor(1.6kg torque)
1x XT-60 connector pair
1x 2.4GHz radio system
Other misc items
Here we took step by step pics of build.
Skirt designed by Development of Surface method.
There is no thumb rule for LxWxH but you should maintain LxW ratio according to prop size to get proper lift from all the corners.
To create air gape bottom plate divided into two parts.
Here is design of bottom plate ribs to support structure and to create air gape.
Bottom ribs all together where bottom plate is to be glued.
All parts of bottom structure are together to be joined.
First set of bottom ribs glued to the base plate
Another set is glued to the base plate.
As i said before, bottom plate was divided into two parts, here we glued it the ribs which creates air gape and gives strength to the whole structure.
View of bottom structure. Air gape can be seen now.
To support hull and skirt together we have designed support ribs.
Support ribs glued to the bottom structure.
Bottom view of structure till now looks like this.
Just like outer part of base plate we have glued one same at the top.
Bottom view of structure till now.
Now it's time to cover structure with white chart paper which makes fixed skirt part of the hovercraft
Whole structure covered and air chamber taking shape.
Bottom view of structure.
We used BLDC motor for our project and mounted it on square aluminium channel piece.
Hull plate glued to the structure.
Here is propulsion module covered with card board pieces for safety. We have mounted motor directly on thick 3mm card board piece.
Place where we are going to put this module.
Random pic of top view.
Placement of battery and ESCs was bit tricky. To maintain C.G. we designed another module at the center where battery and ESCs for both motors can be placed easily. It worked!!
Here is a pic of center module from the side.
Here you can see everything together. Rudder mechanism was attached at the end.
Here is lift test video without propulsion module.
Here is demo video
This was my first attempt to R.C. Hovercraft. I am sure next build can be even better.
