newman

I have been using GWS motors and since it is all starting to make sense I am finding their specs very usefull in determining the correct prop to use.

However, I built a Wattage Crazy Max and would like to have the same information available for the Wattage motors and props but am unable to find any such information.

Can someone please direct me to a place where I can look up that type of information?

Thanks,
Pete

Dr Kiwi

www.motocalc.com

They don't have any Wattage motors other than the Super Cobalt 400 in their data base, but for most of the others you can probably find a Graupner or Permax equivalent.

Cheers, Phil

newman

How would you know what is an equivalent?

TechyJoe

A Speed 400 can also be referred to as a Speed 380. However, the Crazy Max comes stock with a Speed 370 which I believe is equivalent to a Speed 330 or 350. You can go to the Graupner Web site and get some specs on these motors. I have a Crazy Max that I have done some prop testing with. The CM comes with a stock 7.5x5 prop. I first tried a larger prop diameter with a larger pitch (8x6). This was just to large a prop for this plane. It flew OK but had no power to do aerobatics. I would have tried an 8x4 but I could not find one (I think this may work well). Anyway here are some other props I tried and the related calculated power. Power was calculated by multiplying measured Volts X measured Amps after 30 seconds of full throttle run time.

8x6 = 38.05 Watts
7x6 = 38.12 Watts
7.5x5 = 35.23
7.2x5.8 = 40.53 (this was a metric prop 180mm x 145mm)

I personally am going to stick with the 7.5x5 and the 7.2x5.8 for now. I was however, contiplating putting my GWS 350C with 10x4 prop on the Crazy Max to see what happens!

newman

Thanks for the help.