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Heavy Tiny Trainer

#1
Built a Tiny Trainer from FT plans but with Elmers foam board which is almost twice as heavy as FT foam. FT says the tiny trainer should weigh 6.8oz without battery. Elmers foam is 11.7oz without battery. bought the A pack from FT to use in it. 1806 2280kV with 12amp ESC

Here is my problem, 6x3 prop on 2 cell lipo is barely flyable. Flys decent on 3 cell lipo with 6x3 prop but still not very much power.

Can I use a bigger prop on this small motor? How big is too big for the ESC? I was thinking of trying 7x5 or 8x6 on it but didnt want to fry anything. Has anyone had any experience with this?
 

FDS

Well-known member
#2
I would try a 6x4 on 3s. A 12A esc is likely to be able to stomach that, I would also fly a circuit, land and check the ESC temp.
You could also put more wing incidence on to increase lift, put a bit of popsicle stick under the leading edge of the wing when you strap it on.
A 20A would be better, you don’t want to spin a bigger prop IMO, not at that KV, you want more pitch. You could also try a 5051 three blade racing quad prop like the Gemfan Flash.
All the minis want lighter board if possible too. This TT will always be a fast moving heavy potential lawn dart.
A pack of DTFB is less than a new ESC. Make the old TT a chuck glider.
 

Hai-Lee

Old and Bold RC PILOT
#3
Built a Tiny Trainer from FT plans but with Elmers foam board which is almost twice as heavy as FT foam. FT says the tiny trainer should weigh 6.8oz without battery. Elmers foam is 11.7oz without battery. bought the A pack from FT to use in it. 1806 2280kV with 12amp ESC

Here is my problem, 6x3 prop on 2 cell lipo is barely flyable. Flys decent on 3 cell lipo with 6x3 prop but still not very much power.

Can I use a bigger prop on this small motor? How big is too big for the ESC? I was thinking of trying 7x5 or 8x6 on it but didnt want to fry anything. Has anyone had any experience with this?
I had similar problems when I built my first TT. I ended up buying a 2205 1400kV from HK and a 12A ESC. I still use the same setup and I run 3S 850 batteries. The 2205 performs adequately using props from 6x5 through to 9x5 and so I use prop selection to set the plane for the flying responses I want. 9x5 is a hoot with massive acceleration up to a still relatively slow speed great for initial buddy box training!

have fun!
 

Hai-Lee

Old and Bold RC PILOT
#5
Would that be the TT setup you recommend for all of us with the heavy foamboard @Hai-Lee ?
The beauty of the TT is that you can shoehorn in alsmot any motor and battery combo you require or wish. My setup is based upon my build material and initially the need to achieve proper balance!

No 2 TTs I have build at the exact same even though I use the same plans. I love the 3.7 Gram servos but will use 9 Gram if that is all I have to hand I will tail mount them or mount them forward near the rear of the wing.

I have even fitted much larger motors using the mods mentioned under the MUTTS thread. Flown them 3 channel through to 5 channel, (with flaps). A lot have undercarriage and they all had definitely been heavier than the original FT build.

If you want to make yours lighter in future try removing the paper on the internal surfaces as this can drop the weight considerably.

You can try the motor combo I used or the FT recommendation. Just remember if it is heavier you generally need MORE POWER!

Have fun!
 
#6
I had similar problems when I built my first TT. I ended up buying a 2205 1400kV from HK and a 12A ESC. I still use the same setup and I run 3S 850 batteries. The 2205 performs adequately using props from 6x5 through to 9x5 and so I use prop selection to set the plane for the flying responses I want. 9x5 is a hoot with massive acceleration up to a still relatively slow speed great for initial buddy box training!

have fun!
Do you end up adding a bunch of weight to the tail when using the 2205? I tried using a 2205 on my TT but had so much trouble getting it to balance I decided to just use an 1808 instead.
 

Hai-Lee

Old and Bold RC PILOT
#7
Do you end up adding a bunch of weight to the tail when using the 2205? I tried using a 2205 on my TT but had so much trouble getting it to balance I decided to just use an 1808 instead.
I balanced mine with a larger battery!

If I am forced to add weight then at least it should serve some purpose rather than just being a lump of dumb lead.

Have fun!
 

CapnBry

Well-known member
#8
Sorry I'm a little late to respond, but I've flown my TT in so many configurations, I have some data to contribute. With the A Pack 1806 2280KV motor:
2S 5x3.5: 187g @4.3A
2S 6x3: 234g @5.6A
2S 6x4: 261g @7.0A
3S 5x3.5: 310g @6.9A
3S 6x3: 382g @8.7A
3S 6x4: 398g @10.4A

All of those would work just fine on the 12A ESC. I'd say that the 3S 6x4 would work up to 360g of All-Up Weight and still have power to get out of some mild bad situations. Something similar to the F Pack 2205 2300KV motor will get you 405g @9.2A with a 5x3.5 prop, but 6x3 pulls 12A so that's a little too much current. If you need more than 400g of thrust, then I'd recommend like Hai-Lee said, dropping the KV and going with a larger prop.

I put the servos closer to the tail in my TT which gives me more flexibility in how to balance it out. With the 1806 and a 2S 800mAh, everything is pushed far forward, with the battery just barely clearing the prop by about 1cm. With a 3S 1000mAh, the receiver moves as far toward the tail as it can go and the battery is back so far that 1/4 of it is hanging off the back of the power pod. I use a rubber band stretched under the nose and hung on the pod's skewers to add a second layer of battery holddown for that, since I did once drop a battery mid-flight. :censored: