This is a collection of photographs and videos of the Radio Controlled Hovercraft I have made. There are links to the plans I used as a base for the models and some photo slide shows of the builds.
All the models are made of white foam and the skirts made of cheap and lightweight waterproof jackets. All the skirts, segment and bag skirts need sewing - same as the full sized ones - if you can not sew you will need to find somebody that can - I would not recommend asking as a chat up line though.
There are various video clips, what I aimed for was to have a record of the first test run, general run around and a speed test for each model. Some of the clips are long and are ideal for getting rid of unwanted guests (if they have no interest in hovercraft) and where made for my record and not done with general viewing in mind
A great place to start with RC hovercraft is Mark Porters website - all you need to get a good working hovercraft first try. Most of my models are based on Marks design and I must give him credit for his skirt design which I have used on all but one of my models
Please contact me if you want any further details on the craft shown. Please look at the construction notes at the end of this page
I used two spare 0.46 glow engines on this model - they where starting to lose power and becoming unreliable for aircraft use - ideal for the project
The mark two was difficult to steer and only had a 10inch Duct
Need to improve rudder design
Requires bigger thrust duct
Get rid of the Bat Ears
Same body and skirt with modified 12 inch thrust duct, bigger 3 blade rudder and flow straightener and no ears.
Using a 12x4 prop for thrust - 40kph on a flat asphalt run - would be faster with an 11x6 but would lift and flip before 50kph
Since the MK3 was running fine I decided to do a new lighter build using an OS 0.15 glow for lift and an ASP 0.36 glow for thrust.
It was easier to control but suffered badly from any crosswind - maybe a little too light
The skirt was an individual 50 segment finger skirt - a lot of sewing on a tiny finger.
Powered by two brushless motors and a 11.1v LiPo battery this was a fast and easy hover to steer - The pilot is moved by a servo twinned to the rudder to alter the CG so the craft steers more like the real thing.
Free plan is available at www.model-hovercraft.com
The plan is for a scale version - I made it wider than the plans to try and improve high speed performance (turns)
The hull can be made from any material that is light weight and reasonably strong. I would recommend following a proven set of plans for your first craft, this will enable you to have a craft that will work well and provide a good base for designing your own style of craft.
The MK1 to MK4 hulls i built where all based on the Mark Porter Griffon Hovercraft model (the skirt, hull and lift duct) - The upper body was scratch built by cutting the foam into a rough shape then sanding it smooth with 80 grit sand paper before painting.
I have uploaded the plans that I used to make the lower body and skirt - just scale it to the size you want - if you follow the plans you will have a good hovercraft that works well
I have made a couple of craft powered by electric motors (both on lift, thrust and both) and they tend not to run too long - the lift fan usually ends up running at full speed and without an expensive high capacity (4000 mAh plus) battery pack and good ESC it will not run for more than 10 mins unless you are using top quality gear
If you are going to make a hovercraft that is similar in size to the MK4 I think you will need to consider a nitro glow engine for lift (use an air filter to protect from dust)
The main problem that I came across was that as I reduced the weight of the craft (to enable it to hover using less power) it became harder to prevent from flipping over at high speed and any side wind became a control nightmare.
On the models I built, the air in the skirt does not flow through - it is just held at a pressure and forms a soft 'O' ring that seals to the ground allowing the air under the hovercraft to reach a pressure that exerts a force equal to the weight of the hovercraft (Lift Height).
When this point is reached the air will start to escape under the skirt providing an air gap and the hovercraft is in a true hover - on a hard smooth surface the craft will be almost friction free as no part of the skirt will touch the ground - on a model craft the air gap will only be 1mm or less.
The skirt is made in sections that can be glued or sewn together - I would sew them as it provides a stronger joint. I made the hull first then pinned the skirt sections together and fitted them to the hull to ensure that the shape and length was correct before sewing.
The skirt is attached with glue (from a hot glue gun) or it can be held in place by a wooden or aluminium strip that is screwed or glued to the base of the craft.
I f you want the craft to run on grass then the only answer is to have a good powerful thrust engine - I used a 0.46 OS nitro engine with a 12x4 APC prop for thrust and this worked well on grass and rough surfaces.
One change that I would make to the MK4 would be to put the Lift duct and fan in the middle of the hull or the position shown on Marks plans - the MK4 needed 1.5 KG of ballast at the front to make it hover level at full power
The step by step photographs of the hovercraft bag skirt cutting and sewing will be helpful if you want to make a bag skirt yourself - try to find somebody good at sewing to help you. You need to be very careful with the skirt - it will make a lot of difference to the performance of your craft
The Glow plug lead was extended as is done in some RC Helicopters to allow easy and safe starting - The same extension was used to power the lift fan and thrust engine glow plugs. The engines lasted well on this craft and always had a little to spare. The Lift engine easily handled the job and even with an extra 1.5 kg of ballast to level the craft and bring the CG into line
This model has also gone to the local tip - any rebuild would see the lift fan move rearwards to save adding ballast so I suppose it would be called the MK5 (MK5 and Hovercraft are currently banned words as far as the wife is concerned)