Sbach Motor Box Rebuilt

The motorbox was crushed into toothpicks with my last attempt to drill her into the ground. She is designed to be ultra light, and I wasn't about to be able to make a strudy wood motorbox, so I designed a box around using standoffs. No matter what I did, this was going to be heavier. She is, a bit, and I ended upmputting 15gms on the tail to keep CG.

First I removed what remaind of the original firewall.

And rebuilt it. I tend to overbuild...

And I built a box to mount the standoffs.

Installed.

Waiting for the elevator servo to come in, and decided to also replace the rudder servo which was getting a little wonky. They should be here in the next week. I hope she flies as well as she did. HK stopped producing it...

MX-Bach flies and watching a pro

And crashing the HK EPP Sbach, again...

Beautiful day to "maiden" the MX-Bach. Calm on Mt Hudson, sunny, a bit warm, and about 4 other pilots there.

I took the Sbach up  and flew her smartly. Third pack and ( lost her is a maneuver in the sun haze, over corrected and drilled her in pulling up at the last minute. I once again knocked off the front end and turned it into powder.

After I moved her from the crash scene. I have an idea to build a firewall and install the motor on stand-offs, since I wont have a motor box. She's too sweet a flier and so otherwise intact, I can't abandon her.

UPDATE: Well, this explains things. The gears on the elevator servo are stripped... Maybe I didn't over control? Not that it matters, I had no idea what the hell was going on when she crashed. Ordered some replacement 12g Solar digital metal gear servos from Hobbypartz.

This was interesting. Yesterday I worked on gettingg the remote off switch for the OrangeRx e-axis stabilizer to work, and couldn't. Since it works otherwise fine and this twitchy beast flies well with it, i decided to fly with it on anyway. Took off and immediately things went boobies up, I had virtually no control and her tail dropped like a turd. Barely got her down with an inelegant "landing" in tall grass. I disconnected the stabilizer and put her back up, thinking there was just something wrong with the system. Again, barely got her back down. This time though I realized that last night I removed the nose down subtrim, thinking I had accidentally input it. What I had forgotten is that despite a pound of extra lead in the nose, this short fronted aircraft is tail heavy, and the subrrim lets her fly. Its easier than trying to trim it into the elevator servo. I dialed the subtrim back an and voila, she flew perfectly! Flew three more packs.

Then I fried my iCharger 208b. I had brought her put to recharge the 5S packs in the MX-bach. There is a battery based (DC) Solar Powered station there with 24V and 12V connections. I had checked and the 208b can take up to 32V DC Input. Plugged her in. Poof! Cute little puff of smoke and a soft zap. Dead. Stupid... should have just gone with the 12V, and I knew it. I think there is not a fuse inside, that the board is likely burnt, and I will be buying a new 208b. I'll open her up and check. I have had her since about 2008, so I have had a good run with her. Sad, she was one of my first major RC purchases, from ProgressiveRC. Will likely buy from them again.

UPDATE: Yeah, toast...  In the pic below you can see that one of the microprocessors is burnt and cracked. Homie is buying another one.

Burnt and cracked microprocessor.

And it says right there, 32V DC...

After that little fiasco,  it was time to fly the MX -Bach. Set her up, cal,ed my nerves, and took off. She tookmoff smartly, and flew wonderfully. Maybe its psychological, maybe its that she is a few pounds fat, but she pulled off the maneuvers like Gronkowski plays tight end for the Patiots, she seemed a bit of a lumbering lug. She felt heavy, she seemd slower, but really I think she flew as she always has. Landing with and without flaps required keeping some speed on or she sinks fast. It took a couple rough landings and I started to get the hang of getting her down. In the air I felt myself psychically holding her up in turns, tough she took them just fine. I think part of it was flying the two slower quicker planes before, some nerves, and my thinking about how heavy she is. I don't know how to make her any lighter.

After two flights, with no way to charge the batteries, it was time to head home. As I prepared to leave, I got in my car in the A/C, and watched John Warner fly a perfectly built, tuned and expertly flown plane, I think an Edge. Wow... If I had a flying ego I would have cried and thrown all my stuff out.

I will check out the 208b, expect to order a new one, fix the Sbach, and reset the crash clock from a record 123 days without a crash.

MX-Bach "Sorta 2" Is Flight Ready!

So last night was busy. but this morning I focused and finished reinstalling the electronics and wiring harness for the MX-Bach.

Sweet. The airflow in the fuse is so high that the fan is trite, but I love it! I had to program the ESC using the Transmitter and tones, and it worked out pretty well. Usually the tones go so fast its hard to keep track of where I am in the schema, but this one was easy. I had already ordered the ESC Programming box earlier this morning... oh well. Her default was heli-governed with a slow start.

She came in at 14 lbs AUW with 2 5S 4500 mAh Power packs in series, and the 2S 4000 mAh Receiver pack. The original MX2 was supposed to be 11 lbs....  I don't remember what she weighed before, but I really did not add much weight.

I used a programming trick Spektrum taught me to set up the dual elevators in the radio (using Elevator and Mix #5 set to the Gear Channel), and they are spot on. I set her up with flaperons for fun. Yeah, those are vortex generators on the wing ends. She liked to drop a wing in stall, so when I was looking for a candidate to play with the generators, I chose her, and they work really well, lowering her no flap and flap stall speeds noticeably.

Power tested, produced 13.6 lbs static thrust at full throttle, almost 1:1, great for a sport flier, and ran for 14 min to 3.6 V a cell at half throttle without beginning to slow. (The ESC Voltage Sensor senses the 2S pack, not the 2 5S packs; probably because the ESC plug is in the Receiver, powered by the 2S? Not sure. It had ran for about 10 min when I realized this, and decided to see how far they would go. At 14 min I figured that was enough...). I set the timer to 8 min. I like 2 min Bingo Fuel, so after I see what she leaves in the tank on the first flights, I may increase  to 10 min.

I am not sure about the CG. There is some weight change with the 2S pack (I think I used a smaller one before, maybe 1500?), its location (before it was set sideways across the fuse), but its pretty much centered in the same place as the old pack. There is a smidge weight addition with the new ESC too. I use the wing tube as the CG and she looks about right, maybe a touch nose heavy. We'll see. Hoping to fly her tomorrow!

MX-Bach REBUILD 1

I spent a lot more time than I had expected removing cote from the bottom of the fuse and repairing stringers and framework. I would repair one and find another. It needed doing, and I got 'er done. She's and old fuse, flown as a 30cc MX2 gasser before she started to show wear, and I converted her to electric several years ago and flew her hard. Put the Sbach wings on her I had salvaged from my 30cc Sbach I crashed just before leaving Biloxi, and the MX-Bach was born.

I had finished the structure fixes and was going to stop for the day, but the mail brought my servos and my electric switch! I installed the rudder and elevator servos and the switch. I had to replace all of the servo horns from Hitec to Tactic spline and that all took me about 1.5hrs.

I was going to put EC3 connectors on the 2S 4000 mAh LiPO I am using for the reciever and ESC cooling fan, but the big ass AWG wires weren't going to fit, so I tried Traxxis connectors, but one was a PITA so I just went back to the original EC5. That sucked because not all of the metal connectors will fit in the plastic housing. A problem ever since I came into the hobby is finding inexpensive EC5 connectors that fit properly...

Busy day.

The reciver pack and switch. The switch is nice, fromRCJuice. Theres a LED that lights upmin different colors based on voltage left. 

The port elevator servo, mirroring its opposite.

The rudder servo.

Turnigy 17x8x3. Thing is going to scream...

Turnigy Rotomax 1.40 equivalent (30cc) electric motor. With a 100A HV ESC, the wings are going to tear off this thing.

The Spektrum AR6010 reciever should be here this week from Horizon Hobby. That and the aileron servos and she will be ready to CG and fly!

MX-Bach Redux

The MX-Bach. Fuse of the MX2 I had busted the wing on, wings from the Sbach 342 I crashed the fuse of. MX-Bach! She has been a great flyer.

Last year I stole the electronics and servos from my MX-Bach for someone else... don't remember which plane they ended up on. I cannibalized her because I didn't fly her much. If I was going to fly a 30cc sized plane, I took the MXS-R out. Given a choice I fly gas, but my roots are in electric.

I miss her, and I need something new, so I have started purchasing replacement servos and electronics. 

I went with TACTIC TSX55 servos all around. She takes one Rudder, two Elevator, and one each on the Ailerons. These aren't digital, but I don't need that precision, they have enough torque to lift a semi, and I have had good luck with Tactic. That they are $23 a pop rocks.

I bought a Spektrum AR6010 Receiver, which allows me a channel for each servo (I learned a Mix that allows the Gear channel to run a trimmable elevator), and having dual aileron channels allows me to set up flaperons for fun and to set up differential.

She still has her massive motor, I forget which one (will update this when I get under the hood). She flies 8S-12S. I stole her Fun Fly 100A HV OPTO ESC for one of my 600 helis, so I will need to replace that. I don't think I have one sitting around, but I want to check before I shell out another $100. I have a big Turnigy 3 blade wood prop I was thinking of putting on the 30cc MXS-R, but I have been reluctant to drill the hub due to its 3 piece design with a metal plate insert. uits perfect for this plane, and this will give her massive motor some immense thrust.

I plan to power the receiver with a 2S 2300 mAh LiPO since the plane can easily handle the weight, so bought a nice switch to replace the one I took off her to fix one of my other aircraft.

So, all I need is the ESC, I think!

More to follow. Nice to have a new build!

All came home

Sunday's are quiet at Wagner Field on top of Mt Hudson, and today was no exception. Though today I met Clarence White, a core club member and groundskeeper. I had a pleasant visit, but by the time I had arrived he was closing up having been at the field since 8am. It was foggy when he arrived, which is why I didn't come out until around 11. He watched me fly a bit, then headed home.

The air was dead calm, warm and a bit humid, and when there was a light breeze it was a crosswind easily managed. I have been planning to bring the Waco 26cc out, but feel I want some more stick time before I fly my favorite plane again, and today is Patriots Game Day, had to be home by 1. It was gorgeous out... it would have been perfect for the Waco first flight of the year.

I started with the recently repaired HK Sbach. I had recently rebuilt the hard point for the landing gear, and she held together well in a few light crosswind landings. I flew one pack at the beginning and the end of my day. She flew perfectly, and I dialed in my DR and Expos, and flew her with the HK Orange 3 Axis on and off.  Truly easy and enjoyable aerobat!

I hadn't even run the engine this year on my Sukhoi SU-26 10cc, but she started up, and with a little idle servo end point tuning, ran and flew flawlessly. She also has a HK Orange 3axis reciver, and I flew her with it on and off, practiced approaches in calm and light crosswinds. I flew 3 20 min tanks flawlessly. I had to figure out how to bring her down very soft, and raise the throttle a touch; she would often quit on touchdown. I brought the gear a bit closer together raising the prop up a touch, and worked the throttle, kept a bit more speed on at approach and touchdown, and kept her running. Fun working this all out! These Orange 3axis stab systems work really well, easy to manage. My Spektrum Alpha6 systems remain troublesome... more on that later. Not a fan...

In the end, 1.5 hrs flying, everyone came home whole. Great day of flying!

Same as it ever is...

Its been a windy summer. I'm talking 8-10mph with gusts to 20. Today was temperate, not so windy, but a tad gusty. I went flying anyway.

I headed out to Misfits in Auburn. Rules prohibit flyi g without anyone there, but for small park flyers, which makes it a poorly attended field. Today was no different. Despite being 11 on a Sunday, no one there. I flew the Sbach once, but the winds were too much, and I really wnated to fly my Stik 10cc gasser. I decided to head over to "Mt Hudson" (SNHRCC in Hudson. No one there either, but better conditions.

I flew the Sbach, and on a simple landing the gear came off. I know they are not attached well... not sure that I can make it much better without rebuiliding the entire under carriage. I may have to. She did fly pretty darn well, though.

The Stik flew well, but the idle is still a bit high. She flew without needing any adjusments, so that was a change. I decided to try and tune her better for a lower idle (can't change the low end point to make it better). Made one change and she stopped running correctly. Had to start over, taking about half an hour. I think I have found the balance with a decent low idle and max power, between the neeldes nad end point, but she just doesn't sound right. All in all, flew three 20 min tanks before I got hungry enought it was time to quit. Enjoyed mynown private field!