Archive for August, 2008

Chug-Chug, Putt-Putt.

Posted in EggDev with tags , , , , on August 11, 2008 by eggmotor

Spring 2008: Things were quiet over the Christmas period. I’d lost my job and money was a bit tight. Sam and I were still eager to get the eggmotor running. One cool, foggy day at Pontefract Park Sam and I set up the eggmotor on a test stand that Sam had fabricated at work. This was it!!!!! Would we get loads of thrust?????

Although there was a lot of ‘push’ it didn’t quite seem like enough. I decided to purchase a digital rev counter as I had the data sheet for the prop from Helix. This would allow us to see what thrust we was managing. Our next outing at the Park we were equipped with the rev counter. Lets see what thrust we did get.

Max RPM.

Max RPM.

As the picture above shows, maximum engine speed was 7200rpm. This was slightly disappointing as it showed that according to the data sheet we had an engine that only gave us 2.4hp instead of 3-4hp and that the thrust produced was little more than 20kg.

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Spinning Prop.

Posted in EggDev with tags , , , , on August 11, 2008 by eggmotor

Autumn 2007: Sam and I tried to utilize the fan hub we had from our first attempt to attach the new prop but no matter how we tried to fix it to the gearbox the hub would eventually work loose and spin on the gearbox shaft :o( Pondering the problem for several weeks I came up with a solid solution. The gearbox had on it originally a 12 tooth gear.

Bolt/Hub Arrangement

Bolt/Hub Arrangement

Luckily for us, the prop bolt holes matched exactly with the gaps between the teeth and allowed us to create a strong, secure fixing.

The Next Step.

Posted in EggDev with tags , , , , on August 11, 2008 by eggmotor

Autumn 2007: Sam and I needed a radical re-think……………….. So I scoured the internet for advice. I contacted a chap called Markus at Helix in Germany. I told him about my mini moto engine and the gearbox I had with a 5:1 ratio. He replied and stated that they did a really efficient prop design for low power applications that would suit my needs. That was the good news, the bad news was that it would cost me just over £400. Those chaps at the Halifax Building Society charged me another £35 for the privilege of transfering funds too.

So, after a couple of weeks the prop arrived, it was big!!! Markus had told me that in order to get the required thrust a 1.8metre prop would be the best option. We set about modifying the frame to take the prop but there was a bigger problem on the horizon.

First Tests.

Posted in EggDev with tags , , , , on August 11, 2008 by eggmotor

Summer 2007: After strengthening the engine frame and cage with pop-rivets and Sam kindly getting the whole frame powder-coated, we had our first test. Although impressive to watch, the eggmotor (so called as the prop circle was egg-shaped) was extremely under-powered. We were lucky to get 2-3kg of thrust. It was a very disappointing time.

Very first Eggmotor attempt

Very first Eggmotor attempt

Very first Eggmotor attempt

Very first Eggmotor attempt

Power Plant.

Posted in EggDev with tags , , , , on August 11, 2008 by eggmotor

Spring 2007: My first purchase was a complete mini moto engine off ebay for the sum of £35. I also ordered a fan setup from Con-air sports. My instincts were poorly placed on this fan setup as you will see later on. I also ordered a clutch/gearbox off ebay too in order to link the fan and engine together. The gearbox has a reduction ratio of 5:1. In order to hold everything together I purchased several lengths of 15mm copper pipe and fittings from the DIY giant B&Q. I soldered up a frame and attached the components along with a 1 litre fuel tank, filter and throttle/kill switch.

Where it all started.

Posted in EggDev with tags , , , , on August 11, 2008 by eggmotor

Spring 2007: I decided that I needed a cheap, easy to make and simple paramotor. As the story goes on you’ll find that it’s not as cheap as I hoped for and neither was it simple. The basis for the paramotor would be a 49cc mini moto bike engine. I was under the delusion in the early days that this engine produced 3-4hp standard. Sam and I had quite an adventure ahead of us.

Robert Shaw. Chief Engineer.

Robert Shaw. Chief Engineer.

Sam Rose. Technical Consultant.

Sam Rose. Technical Consultant.