30% (3 meter wingspan) Paulistinha P-56 ARF (asembly)
#28
Thread Starter
Holy moly, this is big! This will be the largest model I've flown by more than a meter!
That first flight, however, will have to wait until April at the earliest since I'll be traveling to the US in late March and will come back with a digital scale that I'll used to do the balance. Then, there needs to be some in-model ground engine testing to confirm that I've got everything installed correctly and tuned.
It weighs roughly 11kg (24lbs).
That first flight, however, will have to wait until April at the earliest since I'll be traveling to the US in late March and will come back with a digital scale that I'll used to do the balance. Then, there needs to be some in-model ground engine testing to confirm that I've got everything installed correctly and tuned.
It weighs roughly 11kg (24lbs).
Last edited by abufletcher; 02-26-2015 at 06:06 AM.
#29
Thread Starter
Learning new methods for balancing a large model. I've gotten a lot of help on how to balance using a scale, a tape measure, and some math (calculating moments). And also figured out a crude but effective way to visualize the balance.
#30
Thread Starter
Took it to the field today. Learned a few things about how to get it all packed in the van (along with the smaller version) and field assembly time, but unfortunately, I wasn't able to get the engine running. There seems to be some problem with the glow power.
Sometimes it seems that RC flying is about resolving one problem after another. But you know that somehow you'll find a solution and it's just part of the process.
Sometimes it seems that RC flying is about resolving one problem after another. But you know that somehow you'll find a solution and it's just part of the process.
#31
Thread Starter
As I said, RC is about solving one problem after another...forEVER. I finally figured out what was wrong with the glow system. I stupidly had the glow system connected to a different channel on the Rx than the throttle. So once I put it on a harness with the throttle servo it all worked fine.
So it looked like I might be able to take it to the field again this weekend. BUT NOOOOOOO. That would be too simple. As I was assembling it at home to do some final checks, the model rolled off the work bench and smashed part of the underside of the fuselage. Repairing the broken balsa will be easy. Recovering that section will be a pain. ARGH!!!
So it looked like I might be able to take it to the field again this weekend. BUT NOOOOOOO. That would be too simple. As I was assembling it at home to do some final checks, the model rolled off the work bench and smashed part of the underside of the fuselage. Repairing the broken balsa will be easy. Recovering that section will be a pain. ARGH!!!
#32
Thread Starter
We've all had it happen. But I have to admit that it's a lot more disturbing when it's a $500 model with a $1,500 engine. Guess it's time to make some chocks for the workbench.
#33
Thread Starter
The broken balsa has been repaired and reinforced. And I bought a roll of iron-on film to cover the hole. The color doesn't match but I'm not going to let that stop me.
#35
Thread Starter
I decided to order a roll of cream colored Oracover film as that's almost a perfect match...and no doubt I'll need some for repairs in the future.
In the meanwhile I got my SE5a back into the air today...just once before it started to rain...but it was a great feeling.
In the meanwhile I got my SE5a back into the air today...just once before it started to rain...but it was a great feeling.
#36
Thread Starter
Repairs are done. Weighed on my new Harbor Freight digital scales, it comes to a tad over 11kg (so about 24lbs). That's actually amazing for a thing this size. With the recommended 50cc gas engine and simpler electronics gear it would be closer to 8kg (18lbs). To get the weight, I used the same technique used for full-scale aircraft. One scale is placed under one of the main wheels with the other wheel propped up on blocks to be level with the scale. Another scale is placed under the tail wheel. You double the reading from the one main wheel (4.840kg x 2) and add the weight of the rear scale (1.361kg). This is just to get the total weight of the model.
For balancing the model using a calculation of weights and moments, it's critical to have the tail propped up such that the model is at its flight attitude. I've decided I'm going to trust my eyeballs in terms of the balance. But I also want to see if the calculation method corroborates what my eyeballs are seeing.
For balancing the model using a calculation of weights and moments, it's critical to have the tail propped up such that the model is at its flight attitude. I've decided I'm going to trust my eyeballs in terms of the balance. But I also want to see if the calculation method corroborates what my eyeballs are seeing.
#37
Thread Starter
OK, so the repairs are done and I reassembled the model for a final check. When I switched on the radio, both ailerons went UP in a flaperon configuration. They still moved in opposite directions as ailerons are supposed to, but just started from a position about 1/2" above level. That had never happened before. Eventually, I realized that I had inadvertently flipped the flap switch on the Tx.
This was actually a lucky accident since it revealed an oversight on the radio setup...and pointed to several other things that I should check. I wouldn't want to accidentally hit the flap switch in flight so the flap action needed to be disabled, which was simple. And this reminded me that I need to check and set the "failsafe" positions for the servos and also add a throttle-cut setting.
This was actually a lucky accident since it revealed an oversight on the radio setup...and pointed to several other things that I should check. I wouldn't want to accidentally hit the flap switch in flight so the flap action needed to be disabled, which was simple. And this reminded me that I need to check and set the "failsafe" positions for the servos and also add a throttle-cut setting.