HK EPP Sbach Bebuild

Finally decided I was ready to rebuild the HK EPP Sbach I crashed back in April. She became uncontrollable and she crashed. I have to suspect that it was the HK Orange Reciever-3 axis Stablizer as there really was no other reason for it to fly the way that it did. A few weeks later the Edge 540, also equipped with that receiver-stabilizer combo was delayed responding to an up elevator command and came in a bit hard. I don't know that I will trust these reciever ones anymore, and threw out the one in the Sbach. I will fly it without stablilization for now. I just hate to throw them away, but its not worth the worry.

I collected all the pieces and disassembled the motor box. Looked over what I had and started putting things together. I missed a few pieces that I didnt recognize just where they went in the puzzle, which lead to some sequencing errors, but I was able to get a nice frame together.

The gear hard point after the major pieces were CA'd in place.

Front.

Back.

Epoxied wood into the front frame of the gear hardpoint to add strength.

The front fuse frame is also drying but thin CA. 

The epoxied wood supports. I laid up a lot of epoxy behind the wood to strengthen the puzzle pieces. There was a center piece I missed. I will look tomorrow at dropping a piece in from the top, but I think this is enough support.

Since the back of the hardpoint wasn't so broken up, I only added support to carry energy from the hardpoint into the fuse. If this comes out again the aircraft will not survive.

Tomorrow I will work on getting the motor box onto the fuse. I am gluing the EPP where its cracked and split, but its going to need some more support, and I am not sure how I am going to paint it. Not sure if EPP can take rattle can paint? I don't have air paint... some research to follow. I am sure I can find some brush paint.

The gear hardpoint went back together better than I expected. I am a little anxious about getting it to fit its tear away points, and know in the end this repair is adding some weight that will affect its CG and flight characteristics.

Either way, we are on our way.

Robart's Customer Service!

I love these 4" Robart tires and wheels! I have had them on the Stik since the beginning, liking oversize for thick grass. These tires look great and are soft rubber, not foam, and feel like a real tire. The spoke covers are snap in, and that rough landing at Misfits apparently tossed one. I didn't notice until much later, so I don't know where it really went. But went it did.

I emailed Robart's to see if I could buy some covers to replace them. Yup! Got two sets. They arrived and I painted them with white primer. Snapped on and voila, done!

It's time.

Phoenix Models Spitfire. I knew her well...  I built her, painstakingly converting it to a 10cc gasser. I flew her, and on her maiden, she struck a tree and died sadly. Every time I think about her, I know I will have another one, but I was, am, still so angry.

But, I think its time. My next plane.

Its time.

That was easy!

I put the new Hobby King Orange 3-axis Stabilization System in place of the bricked Spektrum Alpha 6 system. Took me ten minutes to install and set the jumpers. Done.  That's how its done. And no manual!

I don't think I like the one's with the receiver-3 Axis system, the OrangeRX RX3S DSM2 Receiver/Stabilization system. I think the receiver doesn't function as well as Orange Receivers usually do. I had trouble controlling the HK EPO Sbach and the Edge 340, both with the receiver-stabilizer system installed. The Sbach was really uncontrollable, though in the past she had flown fine, even after turning off the stabilization, and I lost control of her. The Edge failed to respond in a timely fashion to an up elevator command leading to a firm landing that tore off her wheels (anywhere else and it just would have been a firm landing). I will be staying away from those, but I really like these solely stabilization systems though. 

I had thought I might put a Felyutech FY-40 Stabilization System on the Waco, but wasn't too interested in making my way through a new system and Chinglish manual, if there is one. My thought was "it costs more, has a nice hard case, must be better", but I have had such good luck with the Orange systems on both electric and gas planes, that I really saw no reason to pay more. As long as I can turn it off, I have faith in them.

The Waco is by far my most favorite plane. Crashing it will surely end me... I cannot wait to fly her, probably at Misfits as I don't want to ruin the wheel pants.

The geometry on the Aileron Connectors, the rod that connects the lower and upper ailerons, is poorly designed. There is a slight angle and the ailerons on a side don't move the same amount. The stock rods were not long enough, so when I built here I made new ones. One had come out about 8mm short, so I today I lengthened it. She flies just fine with the geometry being off, and will be better now that the port ailerons are aligned.

Horizon Hobby/Spektum is letting me send the two Alpha 6's in for warranty. One was my original, the other the replacement Horizon sent me. While I would like at least one to be returned functional, I think they should fix both since I have had nothing but failure with them... We'll see.

Back to a 3-Blade on the Sukhoi SU-26

I decided to put a 3-blade on the Sukhoi for more thrust, and I have no idea why but I went with a 15 inch this time, instead of stepping down. I think I just wanted a bigger prop, but I think this is a mistake. Maybe should have gone 14...  The RCGF is rated for nothing bigger than 14x6. She had a Master Airscrew Scimitar 14x8 and flies fine. I like the thrust with the 3 blades, the look and the quieter sound.  I put a 13x8x3 Master Airscrew 3-Blade on the Stik, again, same engine, and she runs fine as that's a reliable combo. I believe that is the best size for the 3 blade on these engines. I think I am going to regret the 15 and will want to try a 14. If either works, I'm putting the same thing on the Stik.  I wish Master Airscrew also did spinners for their props, as I always have to open up the Du-Bro 3-blade spinners.

Painted the tips. Wrong red, and the red stripe is a mm too thin. Went wider and darker on the 3-Blade I also painted that is going on the Stick. Hope they are balanced... After lunch I may static test her.

UPDATE:  Waaaay too much prop. Poor little engine that couldn't. The 15x7x3 bogged her down. Lost 200 rpm, and she was wicked slow to accelerate, eventually couldn't. I wasn't able to tune any of that out, but then I knew it was too much. Put the Master Airscrew 13x8x3 back on and she runs perfectly, quietly, and with power. There it is... Now I need to order another one for the Stik.

Tuned the engine back to maximize performance with the 13x8x3.

Cowl back on, ready to fly!

Edge 540 1 meter if better than new!

Joppa Hill Fields once again tore the landing gear off my planes. Well, one set of gear, and the other the wing by way of the gear... I have been plagued with failure for several months now, I'm stating to take it personally. Every time I fly. Sigh.

Well, I got around to fixing the Edge 540. The landing gear box was mostly toothpicks, but I used them to frame out a stronger box. Problem is that if the gear try to come off now, the whole plane is going to be toothpicks, she is solid.

Started with putting the landing gear hard point back together..

Strengthened it with epoxy and plywood. Got it as straight and aligned as I could.

Using the toothpick remains of the hard point supports, I rebuilt the front wall. The back was still int he plane, though it was dislodged. I could not get it true on the starboard side, neither support actually, but a few washers when attaching the gear and all is level. I had to cut one of the stringers to get the parts in. I patched that later.

You can see the thick piece of balsa I epoxied to the forward support. It holds all the toothpicks together nicely.

All better now! Put a 12x6E back on her. She flies fine with it. Toyed with the notion to put a smaller higher pitch prop on her, but she is fast enough. I want the thrust for aerobatics, which is what I use her for.

Sweet machine. Way under built. A good sneeze would break her into pieces, as evidenced by her landing gear folding in tall grass.

When will I learn?

Every time I fly at Joppa Hill something gets torn off a plane. Today I went out to fly at Joppa, and things got torn off a plane. Two planes.

Took the Twinstar, the Edge 540 and the 30cc MXS-R out today. The winds were calm with reasonable gusts from the south.

Today's Brood.

Landed.

And this happened...

Twisted the gear right out of the fuse.

The Twinstar, a sweet flier! You can see how tall the grass is, even though it was freshly cut. 

She always get grass stains on her from the props cutting through the grass. I had to walk around to find a patch of grass worn enough to let her get off the ground. Landed her in the grass the first time just fine. On the second time everything seemed fine.

But I noticed the wing was coming off, and when I flipped her over, I found that the wing hard point had ripped through the fuse. The wheels in the gras pulled the wing off.

The balsa isn't thin, but the grain is not cross so it popped though. I glued this, and used a popsicle spar across it also CA'd in place, and covered it with white cote (don't have the blue). Looks great.

The repair.

After flying the MXS-R a couple of times, some people came out to walk their dog and jog around the field. I won't fly the gassers with anyone on the field, so I just hung out a while, then left. Took a short video of the field.