Took the tri for a spin today down at the oval, mixed results. I switched over to the T-Style CF props (12x5.5) and they appear pretty good. I had one time where I dug the prop into the earth, it was good, just wipe it off and all was good. I can say I'm very happy with them, now I have motors that can use them I will be ordering more of these
![Grin ;D](http://www.myswag.org/Smileys/classic/grin.gif)
. I can say though that I'm sure if it wasnt grass it would have ended differently.
Bad news is that I have so much power that when I hit more than 40% throttle it is able to pull my tail mechanism upright, so that tells me the servo is unable to counteract the forces. I stupidly used a smaller but in theory (had more torque) servo, guess that wasn't a good idea. Good news is I thought this might be the case and in my order from HK which is held up due to the long weekend (should be here tomorrow) has a bigger tail servo. Hopefully it will be big enough, I fear with the amount of force this thing is throwing out I may need even bigger!
I do have some older analogue servos that will be strong enough but they are attached to my 4 star 40 plane which I'd use but since I have a digital replacement on the way I figure whats another day.
I'm thinking of changing my tail mechanism, David's direct drive design is good but I may need to go for an indirect drive so that I can try different servo's out. So question for those with tri's, what tail mechanism do you use? Direct or indirect?
Great news is that with that prop combo at 40% throttle (4s - 12.5A) I just start lifting and at 45% (4s - 15A) I'm confidently gaining alt (AUW approx 1.9kg - the battery weighs more than my 3s batteries), although currently with an increasing spin, so I didn't fly for long before I put her on the ground - only damage was a broken cable tie. So I think I have my power issue sorted out, it will only get better with 14in props on it. Time to order some 14 or 15 inch CF props I think :-) - Why do they come in pairs, I'm going to end up with lots of spare CW props.....
Hi Marschy, I'll do the thrust tests this afternoon, family Easter activities go in my way yesterday. I'll try both the APC props and also the T-Style CF.
Some quick figures from the test flight:
1.9kg / 3 = 630g
12.5A / 3 = 4.2A
So I would day that I'm doing better than the 13x4.0 CF combo on the emax site (they have 4A as 600g). I would suggest that I'd hover around 4.3-4.5A a motor as I'll loose some lift after I'm out of ground effect.
With my limited testing so far, I highly recommend the EMAX MT3515 motors on 4s, I cant wait to get some 6s ESC that work with the pixhawk and really give the motors a workout.
Chris