Originally Posted by
skunkwurk
Hi Gunradd,
Thanks for the advice, I appreciate the help. The three tanks (1x4.6 & 2x2.7 liters) equal to about 246 oz of total capacity, I'm basing this off of their online manual. I'll measure the capacity once I have the tanks in hand. Each of the 180s burn ~20oz p/minute at full throttle, at 246 oz of total capacity that's about a 6 minute burn time. I don't plan on flying at full throttle the entire flight but I would like a 6-10minute flight plus spare fuel capacity. There doesn't seem to be a hugh margin, wouldn't reducing the fuel capacity work against me a little bit? What do you guys use as a rule of thumb on twins? I will be performing ground testing to help narrow this down, but any input is appreciated.
I'll look into splitting the center tank, I don't disagree with your logic regarding the two separate fuel systems.
Also, since we're on setup commentary. I see what you did with the air valves on the mains, which I'm considering as an option. I've also seen plenty of comments regarding hydraulic as well, but I'm wondering why no one is suggesting going electric. I've seen guys like Fenderbean build a nice install on a 1/7 Scale F15 using D&L's system, I like it. It's clean and looks reliable.
Is it cost, reliability or something else which is influencing folks not to suggest this, do you have an opinion by chance?
thanks in advance.
sc
For the gear I didn't go electric for the cost also this gear needs to rotate unless you remove all the scale parts from the gear and for me that's not an option.
On the fuel...
I think 2 180s is to much engine with to high of fuel burn. Have you thought about trying to sell them for smaller engines like twin 120s or the new 160s would be the ideal engine. The reason why is because you will need allot more fuel for twin 180s and that's allot more weight in front of the CG. When I was doing my CG with all 3 tanks I filled them up to see how much it changed and its drastic. Aircraft is super nose heavy with that front tank fuel. I would say full its at least 7 lbs all in front of the CG.
I flew mine full of fuel this way and it did rotate and fly but it flies much better now with the front tank smaller. So I dont want to say what you have wont work because it will work but I highly recommend getting smaller engines that burn less fuel and reducing the front tank.
Also I dont think their online manual is correct. I think they used smaller tanks on the build in the manual. The center tank in the kit is HUGE!