Archive for September, 2008

1.6m Propellor.

Posted in EggDev with tags , , , , , on September 27, 2008 by eggmotor

27.09.08: I’ve not completely given up on the old ‘Egg’ just yet. I have cut to prop down to 1.6m in an attempt to get the engine upto max power. I would rather have 35kg thrust at max rpm than 28kg with a struggling engine and the necessity to use nitrous. We just need a good day and a slope launch to try it out.

A 'smaller' prop now.

1.6m Propellor.

It may be necessary to cut the prop down even further but I won’t go below 1.4m. If it’s still not giving the 35+kg thrust then I’ll bung it on ebay.


Latest Info.

Posted in EggDev with tags , , , , , on September 13, 2008 by eggmotor

13.09.08: There is a lull in manufacturing and testing at the moment, mainly due to the lack of funds. Just an update on the 4 stroke news. The hub for the GX200 is on it’s way from America, once this arrives I can give the bolt circle info to Xoar props. With regards the GX390 engine, I found Arrow Props on the web and they can give you the best prop option if you give them engine data. I told them that I have an engine that develops around 17hp at 5,200rpm. I also said I needed 50kg thrust and that the prop would be directly driven. They replied with 36×12 prop size and also said that 50kg thrust might be borderline. To be honest, I’d be happy with 45kg plus.

I’ve decided to cut the 1.8m prop down to 1.6m on the ‘old’ eggmotor. This should allow the engine to spin up to 10,000rpm plus. Hopefully what I loose in efficiency I’ll gain in power/rpm. If the gearbox was a 6:1 ratio then I would have got 40kg thrust weeks ago. Cutting down the prop might now mean that I’ll get 35kg+. Still no powerhouse but a definate cruise machine. I could still add nitrous to this and peak 40kg+ (continuous 38kg).

That’s All Folks!!!!!!

Heavy Duty Egg.

Posted in EggDev with tags , , , , , on September 10, 2008 by eggmotor

10.09.08: In the last post I mentioned about the race-prepped 200cc clone engine that will develop around 13hp. This engine weighs about 18kg. Since then I’ve been in contact with Shane at AGK (affordablegokarts) asking about the GX390 clone engines. I can source an engine in the UK and fit Shane’s ‘Bolt On Kit #1‘, ‘Billet Flywheel‘ and a carb main jet all for under £400. Shane reckons this should make the engine give about 17hp @ 5,200rpm. The stock engine weighs 31kg which is very heavy. The billet aluminum flywheel only weighs a fraction of an original steel one so fitting that and removing unnecessary ancillaries might get total weight down to 25kg. Hopefully, direct driving a 34/36×10 prop and constructing a small aluminum frame shouldn’t top 30kg. That’s all in the future though. I’m currently waiting for the engine hub for a GX200 so I can then order a 34x10prop with the correct bolt pattern.

Superbox Egg.

Posted in EggDev with tags , , , , , on September 3, 2008 by eggmotor

07.09.08: If I go down the Honda clone 4 stroke route for the next generation Eggmotor then I could go for a ‘Superbox‘ race-prepped engine for $450. It gives 13hp+ @6,000-6,500rpm. I was going to use the Honda 2:1 gearbox but it would be extra weight and more messing about. Instead I’ve calculated that a 34×10 prop in direct drive configuration would be the best compromise. 43kg thrust @ 5,000rpm and 47mph airflow to minimize dynamic loss. Those figures arn’t far off the old Rad Aviation’s 3-blade MXL model. I’ve just had a quote back from Kevin at Xoar Propellers for $150 and that includes shipping to the UK. Xoar manufacture for RC model aircraft as well as the ultralight market so their expertise should make for a quality prop. I informed Kevin of my intentions for the propeller so it should be suitable for my application. All being well the next generation ‘Egg’ should be just as light as the old one due to it’s smaller size but also more reliable, economical and easier to transport.

Race prepared GX-200 clone.

Race prepared GX-200 clone.