Balancing FT Mini Fokker DR1 - weighted spinners for Power Pack F motor?

[InsatiableAmos]

Just built a mini DR1 and love it! Super slow, floaty flight, perfect for smaller parks/fields.

I've found it really difficult to balance, however, my build came out a bit tail-heavy. I removed the tail skid and would like to add some weight to the nose - I'd like to start out with a weighted spinner, the idea being that the further forward I can place the weight, the less I'll need.

Does anyone know the thread size/pitch for the PowerPack F motor? And/or do you have any recommendations for weighted spinners or balancing techniques that might be handy on a little plane like this?

I've already pulled the battery (Tattu 650mah 3s) as far forward as the prop will allow and have been considering pulling the power pod further forward, but I'd like to minimize extra-hole-poking if possible...

 

[JasonK]

I wouldn't add more weight onto the motor prop/shaft, the motor has to spin all that up.

What foam did you built with? Did you possibly over do the glue or something else that made the air-frame overly heavy?

 

[InsatiableAmos]

I wouldn't add more weight onto the motor prop/shaft, the motor has to spin all that up.

What foam did you built with? Did you possibly over do the glue or something else that made the air-frame overly heavy?

I don’t plan on sport-flying it much, just lazy patterns, so I’m not too worried about the motor spinning it up. Just a slight wattage increase on acceleration, but should be neutral after that.

And I’m definitely not the most perfect builder, but this was my 5th speed build kit (and I ordered the speed build kit, so it’s FT foam), so it definitely wasn’t the *most* shoddy of glue jobs…

Even if it was, I’m looking for tips to fix it!

 

[JasonK]

ok, the most common causes of serious CG issues are to much glue or using the wrong foamboard, making the airframe heavier the normal, and with most of it being behind the desired CG point, making it hard to get CG correct.

as far as the bolt goes, I know I use an 8mm prop wrench and the shaft measures 5mm

 

[InsatiableAmos]

as far as the bolt goes, I know I use an 8mm prop wrench and the shaft measures 5mm

Awesome, thank you!

And yes...my zen mastery of the glue gun is definitely still a work in progress

 

[Matthewdupreez]

The dr1 can handle up to a 2200 may 3s... Maybe if you can put a larger battery in... At least it'll be useful weight.

 

[InsatiableAmos]

The dr1 can handle up to a 2200 may 3s... Maybe if you can put a larger battery in... At least it'll be useful weight.

Whoa, I can’t even imagine a 2200 in a little mini like that! I’d have trouble physically fitting it in the plane, let alone flying it with that weight…

 

[Matthewdupreez]

Whoa, I can’t even imagine a 2200 in a little mini like that! I’d have trouble physically fitting it in the plane, let alone flying it with that weight…

That's what t plans say

 

[BlockerAviation]

Whoa, I can’t even imagine a 2200 in a little mini like that! I’d have trouble physically fitting it in the plane, let alone flying it with that weight…

I'd just put either some lead or clay in The nose and/or go to an 800mah batt. I agree, a 2200 would be a brick in that little guy. Anyways, hope this helps.

 

[The Hangar]

Yeah, there’s no room to stick a 2200 3s in there, the biggest pack I’ve used in mine is a 1500 2s (similar in size to a 1000 3s) and that’s about the biggest you can fit in there.

 

[JasonK]

That's what t plans say

not sure were you see that, the plans show a AUW - dry weight of about 80g, a 2200 3s is going to be quite a bit more then 80g. An 850mAh 3s is about 75g. The Article is recommending "RECOMMENDED BATTERY: 800 mAH 3s minimum".

@InsatiableAmos - it looks like the plans expect a battery that is ~25-30g heavier then what your probably using [my 650 3s run around 50-55g], so if you have access to a bit bigger battery, that should also work, if not, you will probably need to add some nose weight to make up the difference.

 

[Ratcheeroo]

Yeah I would just go with an 800- 850 mah 3s, that will probably do it

 

[Matthewdupreez]

i don'r know how you would fit a 2400mah 3s battery in the dr1.... but that's what this said....

 

[JasonK]

i don'r know how you would fit a 2400mah 3s battery in the dr1.... but that's what this said....

then that is wrong, that isn't the plans. do you have a link to that page/document? I am curious where it is, so we can let FT know it needs to be fixed (if there is something wrong with it)

 

[Matthewdupreez]

it was a list created by @mayan ... i've let him know of the error

 

[InsatiableAmos]

@InsatiableAmos - it looks like the plans expect a battery that is ~25-30g heavier then what your probably using [my 650 3s run around 50-55g], so if you have access to a bit bigger battery, that should also work, if not, you will probably need to add some nose weight to make up the difference.

This is super helpful! I assumed that, because my mighty mini tiny trainer flew better on a 650mah 3s that the DR1 would as well. I have one 850mah 3s lying around, and the plane does seem to balance out a little bit better with that in it - will try flying with that one next time!

Thank you!

 

[cbf123]

I assumed that, because my mighty mini tiny trainer flew better on a 650mah 3s that the DR1 would as well.

In my experience the Tiny Trainer and Mini Scout are nose-heavy when built according to the instructions.