1:4 Scale Foamy Albatros D.Va – Flite Fest 2022 Dawn Patrol Challenge

wilmracer

I build things that fly (sometimes)
Mentor
So, still wrapping up little things and waiting on one "big" thing. I swore up and down that I had a Xoar XIAL 20x10 prop, which is what I want to run on this model. It turns out I have several other sizes but NOT the 20x10. Calculations are shown below. The numbers shown are for static WOT on a fully charged 6s. AUW is estimated @ 20lbs.

Motor is rated for maximum 65 Amps continuous and can burst to 80+. At 100% throttle (and static) she JUST ticks above 80Amps. 90% throttle puts her at the 65 Amps and I expect she will fly WELL below that.

Static WOT pitch speed of 62mph pitch speed is solid, as is the 16lbs of static thrust. (0.8 : 1 Thrust to Weight)
75% throttle yields about 53mph pitch speed and about 11lbs of static thrust (0.55 : 1 Thrust to Weight)
50% throttle yields about 38mph pitch speed and about 6lbs static thrust (0.3 : 1 Thrust to Weight)

Power_System_Calc.jpg
 

willsonman

Builder Extraordinare
Mentor
Scorpion Calc is V3.97 now, BTW........

:sneaky:
You do realize that the versions do not change any of the math right? It simply updates the databases of equipment. Even IF there's an update to a parameter that was entered incorrectly, Carl is MORE THAN experienced to know something would be off. Pretty sure splitting hairs at this stage of the build is pointless. I'm sure the reminder is nice and perhaps I'm reading internet speech here but that did seem like a fairly snarky comment.
 

Baron VonHelton

Elite member
You do realize that the versions do not change any of the math right? It simply updates the databases of equipment. Even IF there's an update to a parameter that was entered incorrectly, Carl is MORE THAN experienced to know something would be off. Pretty sure splitting hairs at this stage of the build is pointless. I'm sure the reminder is nice and perhaps I'm reading internet speech here but that did seem like a fairly snarky comment.

Nope! Just posting an update & being sneaky about it.

In fact, I had to update mine as well.

(y)
 

wilmracer

I build things that fly (sometimes)
Mentor
Video will be up in a few days but I grabbed some stills... you get the idea :D

The two flights were not uneventful though... She will need more power, but flies so great I'm happy to upgrade it. Much more to follow when I'm decompressed from FF.
 

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Yankee2003

Well-known member

I was fortunate enough to see this aircraft fly in person. It is a stunning aircraft. I know Carl was disappointed in the power, but that is the artist being self critical to some extent. Yes it is a real thing, engine overheating is a serious issue. But I would like to say that I could not take my eyes off the plane in flight, gorgeous!
An amazing achievement for sure. Thank you Carl.
 

wilmracer

I build things that fly (sometimes)
Mentor
I was fortunate enough to see this aircraft fly in person. It is a stunning aircraft. I know Carl was disappointed in the power, but that is the artist being self critical to some extent. Yes it is a real thing, engine overheating is a serious issue. But I would like to say that I could not take my eyes off the plane in flight, gorgeous!
An amazing achievement for sure. Thank you Carl.

Thanks for the kind words! She is quite pretty in the air and is a solid flyer. I'll share the video of the second flight soon but you can see from the lovely attached image that the motor was good and fried following that flight.


20220629_212749 (002).jpg

The solution I'm planning is as follows:

20220629_213749.jpg
20220629_213852.jpg

Swapping out the 6s 20,000 mAh pack for a pair of 6s 8,000 mAh packs in series for 12s and pairing with a 22x10 prop I should see solid flight times, a top speed around 60mph, and 1:1 thrust to weight at WOT IF I need it. Looks like she will cruise for quite a while at about 60-70% throttle too, all while never exceeding 80Amps at WOT. This won't even begin to stress the motor or ESC. I'll still do some improvements to cooling but I doubt they will even break a sweat.

Another plus is that I don't anticipate any increase to AUW. I'll pull out the extra noseweight I had to add to get her to balance and this should get me close. After how well she was flying I'm really eager to get her back in the air so I'm hoping I can find time this weekend to complete the swap.
 

The Fopster

Master member
Thanks for the kind words! She is quite pretty in the air and is a solid flyer. I'll share the video of the second flight soon but you can see from the lovely attached image that the motor was good and fried following that flight.


View attachment 227857

The solution I'm planning is as follows:

View attachment 227858
View attachment 227859

Swapping out the 6s 20,000 mAh pack for a pair of 6s 8,000 mAh packs in series for 12s and pairing with a 22x10 prop I should see solid flight times, a top speed around 60mph, and 1:1 thrust to weight at WOT IF I need it. Looks like she will cruise for quite a while at about 60-70% throttle too, all while never exceeding 80Amps at WOT. This won't even begin to stress the motor or ESC. I'll still do some improvements to cooling but I doubt they will even break a sweat.

Another plus is that I don't anticipate any increase to AUW. I'll pull out the extra noseweight I had to add to get her to balance and this should get me close. After how well she was flying I'm really eager to get her back in the air so I'm hoping I can find time this weekend to complete the swap.
Wow. That is a lot of motor! 🤗
 

wilmracer

I build things that fly (sometimes)
Mentor
Wow. That is a lot of motor! 🤗

I didn't get a chance to install it this last weekend but I did work on opening up more space in the cowl for better cooling. I think this will be a sweet-spot for nose weight and will let me under-stress the setup so everything stays cool and well below maximum specs.

On a semi-related note I was THRILLED to hear the FT guys discuss the signal issues at FF and their plans to do something about it in the future. For those that don't know I lost my big PT-17 Stearman at FF this year due to this issue. She was flying beautifully as usual until complete signal loss when a pump switched on. I was only about 10' above the field and she rolled inverted and went in on the nose. I'll rebuild the Stearman before too long but have something big in the works for that rebuild... when that starts I'll do a new thread. :cool: