It just happens I have two flights on a non-VT Diablo with a 140 that was built as light as possible.
It flys ok and there is plenty of power if built this way. As Dave mentioned, it’s a draggy airframe, and the intakes are huge. The drag and the light weight means it does not carry momentum at all. As soon as you come off the power it’s slowing down very quickly. You have to carry power over the top of loops more than you would with a “normal” sport jet. You have to carry power on final. If you dead stick you absolutely have to keep the nose pointed at the ground or it will stop flying very quickly. Personally I think the plane would fly much better if it weighed a bit more than the setup I flew. I had a 91” Extreme Flight Laser that flew almost identical to this.
He didn’t have any issues getting the plane to balance. In fact his initial flights were tail heavy. He also had the throws on the initial flights setup at the recommended amounts and found the elevator was WAY too much as well as the rudder. Dave just mentioned the throws in his previous post. I did not fly it on the initial flights.
Mine is getting the VT with a 200-220 engine so it will weigh more. We’ll see how they compare as far as traditional IMAC type flying with the additional weight.
Just got his weight for you, 28.5lbs with a small UAT full main tank empty.
Originally Posted by
anupamd
Thanks Dave, sounds good. I have a k140 laying around collecting dust and it sure would be intersting to see if I could get it to work with this aircraft with sufficient power for it to be fun and take off from a mowed grass field. What do you think the final weight would come out to with the K140?
Your Diablo came in at about 30lbs with a jetcat 220.
So
Weight without engine would be
:
Weight without engine = 30lbs (your weight dry) - 4lbs (jetcat 220) - 1.1lbs( straight pipe) = 24.9lbs
Add the K140 (2.2lbs)
Final weight dry with K140 = 27.1 lbs
In comparison, My TopRC Oddsey comes in at around 27lbs dry and has unlimited verticle perfornance with the K140 and feels very light and floaty.
If my math is correct, then this jet would perform similar or better with the same power setup with the added advantage that if in the future id like to try thrust vectoring i could always "upgrade".
Do my calculations seem reasonable to you? If so, this may be an incredible value and could appeal to a wide range of people,
Here im assuming use of standard size servos and batteries, I could probably save a little more weight by going with lighter servos and batteries and keeping my radio install to a minimum.