I'll allow it.

At the end of this post I described crashing the MX-Bach, and this was the result. Over a few weeks I worked on the repairs.

I fiberglassed the inside of the plastic canopy and filled in the gaping hole on the front starboard side of the top. There is still a dip on the port side front that has been there forever, but I wasn't willing to try to melt it back into shape. The paint and cote stripes came out pretty nice.

Is it perfect? Not even close. But yeah, I will allow it. 

I put a smaller prop on it as I think it's actually a 30cc engine. My blog says it came off the Sbach, the first gasser I ever owned, and that it's a 30cc. That's the plane the MX-Bach's wings come from. It's an OG RCGF engine (though when I asked RCGF-USA about it, sending pics and the serial number, they claim it's not theirs). It's stamped RCGF, but no size. It was made before the RCGF/VVRC-RCGF debacle, so it is definitely theirs. An 18x8 works well on a 30cc. Will fly it at some point and see, but on static testing it seems great.

The airframe is old and getting tired ... I suspect it will die soon and not be resurrected. I will probably replace the bent muffler when I can. I am also getting concerned that the prop screw plate is stripping. That would be expensive to replace.

What a wonderful day full of maidens!

Finally caught a break with marvelous weather and manageable gusts on a day off. Flew the Stearman several flights, love that it has stabilization, and maidened the Goldberg Falcon and the long awaited Ultrastick! Only a few pics and didn't do any video (forgot the cam). 

One curious battery thin I have never seen before. Charged 4 3S 2200 mAh batteries at the same time (parallel? I can never remember). In all 4 batteries, one cell charged to only about 4v, the other full at 4.2v. This happened on all 4 batteries from the same charge. I decided not to fly with them so I didn't undevolt that one cell, ran them down on the bench while checking the voltage. At 3.8v on 2 cells, the third on was around 3.74v on each battery, so the gap narrowed. The IRs were all less than 6. They ran fine. I charged another set of 4, a different band, and they all charged normally. The affected batteries are about a year old. Curious if they won't charge properly again. Would be a bummer as in this eco no my I won't be replacing them anytime soon.

The gang is all here!

Little wheels and short nose make for easy flip over on landing when running into the clumpies at the end of the runway. The PT-19 flew like a charm! So love this plane. It's a shame Eflite moved away from these affordable balsa delights and sells overpriced foamies in their place.

The Falcon has flown, 4 flights. In the air 3-channel proved no problem for me to adjust to, just as John predicted. On the ground I kept trying to steer with the rudder instead of the ailerons. Of course I kept trying to coordinate my turns in the air. The Falcon has one issue that John is going to investigate. It has a constant hard right roll tendency that I had to control with left rudder. Wasn't able to trim it out with rudder in flight. The wing looks straight and not warped as far as I can tell, and the tail is straight.  The Irvine 40 runs like a dream, no issues at all and pulled some nice vertical. I tried the 11x5 Scimitar, and it flew great, but losing just that 1/2 inch of ground clearance lead to one prop stall on the lumpy Geotex. It flies so well on the 10x6, may just get some Master Airscrew Scimitars in that size, but I want some more flight time with the 11x5 first. One thing about nitro is that shit coats this wing thick. I have a muffler extender, chose not to fly with it, but I just might. Also need to bring paper towels.

The tail looks good, in this pic the right side of the main wing looks a bit higher, maybe that's it?  Maybe I do see a little warp, the ceiling edge on the right shows more underwing. I bet the wing does have a bit of warp and that would roll it right. The engine is rigged classic down and right so P-factor isn't an issue, and this roll tendency is constant. This made for challenging landings. Little dude is fast with both props. Once we get this roll tendency sorted, this will be a fun plane to fly!

I usually have bigger wheels on the Ultrastick, and am probably going back to them. Hit the taller grass and went right head over heels after a nice albeit floaty flaps landing. I am sooo happy with how it handled. Engine ran great, though it has a gravelly sound to combustion. This is the first time I have heard it without ear plugs. It was getting late what with all the waiting, I wanted another flight, but one of the leading edge wing pegs was a tad loose so I called it a day.  Overall all, I am very, very happy. I got used to it running a long ways out, though I hope getting my cataracts done improves my clarity of vision. I feel a lot more comfortable flying the 26cc Pulse XT60 and the 30cc Sbach here. I will probably overfly the parking lot at the business next door on landings with the big boys but no one is ever there.... The Evo 10cc ran great, though I did lean out the low needle a bit more. The idle improved (it was a bit untrustworthy today until I learned it) as did acceleration to FOT. Pretty sure a gasser is going with me every trip to the field.

I call this day a wonderful win!

What a wonderful, wonderful, day...

I had today off for an appointment with my eye surgeon who unexpectedly dilated my right eye, because you know, I had a car-full of airplanes I was taking directly to the field... Dammit... Winds were going to get even better and I was off on a sunny day. I. Am. Going. Flying.

But even though I am an idiot, I waited a while and made sure I could see well enough to fly. I had also brought the Ultrastick to maiden today, but not with one eye, no matter how perfect the weather. The field will require me to fly high with that one and I wasn't going to risk losing orientation.

I did get over a dozen great flights in, and even trialed my field charger setup.

Hanging in the gang cover at NH Flying Tigers Field,

Derry, NH

Wanting to tune up my go-to plane and continue to re-train my thumbs, as well as  make sure I can safely fly with one eye, I flew half a dozen packs on the Alpha Sport 450 first. I have flaperons on it, to slow it down on approaches, but it's already really, really floaty. I think I am going to try spoilerons, and see if that will slow it and make it less floaty. I am beginning to see this revived version really wants to be nose heavy.

For the first time in years I took the vintage Eflite PT-19 Cornell out and up today. It's so light I put a Hobby King Orange stabilization system on it, and it makes a tremendous difference. Speedier and snappier than I recall, it flies on rails. Really enjoyed flying it after the first flight jitters, did about 3 packs.

Flight of the Cornell

I came with only four of ten or so 3S packs charged, so I got to trial the lead setup I ran from my hybrids auxiliary battery. I have to leave the engine "on" so the computer can sense when to, and to charge that battery. Worked perfectly!

I had psyched myself up to maiden the Ultrastick 10cc today, and by late afternoon the conditions could not have been better, and only one totally non-judgy pilot was there. I was sooo tempted, but my right eye didn't un-dilate until a couple hours after I got home. I was not adding that crash variable to the test flight. Benched. I am itching to get that plane up.

The even more exciting part of the day was when I got home, I used a suggestion from John Hayes to make it so the throttle closes when throttle cut is turned on. I had gotten the engine easily started on the first try after years of sitting, and tuned to to run superbly, quite easily. I did have to adjust both needles. But the throttle barrel would not close completely, so I had to manually choke the engine to stop it. John showed me which screw to adjust. There is a spring loaded screw on the back port side of the carb (top in the photo). This screw stops the throttle barrel at the desired position, which for me is fully closed. This is the last pic of that screw, because I didn't realize it was spring loaded, and to allow the throttle to close completely, it had to be fully withdrawn. Yep... Shot out of there like a bat out of hell... It went where screws go when the cross the edge of the workbench...  My vintage garage has a stone and dirt floor. 

It's in there somewhere, I think. Couldn't even find it with a magnet, but tons of iron chips and aged metals were everywhere.

Nice idle, nice slam to FOT, smooth mid-range, 

and throttle cut works now! I got an exhaust extender today 

and will install it soon.

Have to work the next 3 days. Sunday's weather is stormy, Monday winds 7 mph but not much gusting after 2p. Hope to maiden the Ultrastick. My rule is only one maiden a day, so the Goldberg Falcon 56 will follow that another day, unless the weather is pristine. A little nervous as I have never flown 3-channel and this field is tight. John says it will be fine!

Flight schedule is to get the Pulse XT60 26cc gasser, the Eflite Stearman (the real balsa one, not the overpriced foamie thing*), and the massive 30cc MX-Bach (MX2 fuse, Sbach wing). I also have the Cosmic Wind (I think a Great Planes 450 size speedster), and my helis airborne. Full summer. Need good weather matching days off.

* I so hate that Eflite went from making affordable beautiful and desired balsa ARFs to selling foamy overpriced crap. This is what kills this hobby. Foamies are fine, l just waaaay overpriced, and just don't fly like the balsa planes. Good small to medium balsa ARFs are hard to find. Muss my Eflite Ultimate, my Pulse XT25 (my all three me favorite plane), and eventually my Cornell and Stearman may expire with no decent replacement.

Its Baaack... The servo twitch curse.

The Ugly Stik had this aileron twitch I could not get rid of... it eventually lead to the loss of the Stik. I guess I haven't fired up the Ultra Stik with the wing on, because I would have noticed this twitch curse has come to the new plane. I had her out at the field and set her up, excited to maiden her, even drove her around to range test her, but I noticed that at idle and WOT the twitch showed up, curiously not in midrange. The video doesn't capture the worst of it, it would occasionally go full deflection. The only parts that are the same are the Hitec HS-485HB servos, except for the elevator which is new. Odd, the left aileron is again affected, and the elevator! The connections are all solid but will get a second look. These are usually voltage issues.

Needless to say, I grounded her, "fool me once" sorta thing. I am thinking about the facts: only the servos are the same. I ave no idea why its the left aileron again... The elevator is a brand new servo; the old one locked up and failed without the engine on. I am thinking these discontinued Hitec HS-485HB are the problem, but possibly fixable. The other clue is that with the engine off they are perfect, no twitch, rock solid, function perfectly. This suggests the ignition is somehow involved. Now the ignition is in perfect condition, and this is a different engine, the EVO 10cc and its CDI. Its a different battery from the old Stik. This aircraft has a simple RCexl opto remote kill switch, not sure if it was on the Sbach or the Stik... 

So here's my plan. I can't afford to change out the aileron and elevator servos to higher end digital metal gear servos at about $35+ a pop (I would need 4), so I am working up the food chain.

1. A capacitor.  The theory here is that the twitch is from voltage spikes and drops, and the milliamps stored in the capacitor acts to buffer this letting those variations come from the capacitor per se, and not the reciever. This plugs into a spare port on the reciever. I am not sure they work, and people seem to find them controversial as to their effectiveness or need for that matter. This one from Amazon for $8 delivered (had a coupon, cost me $3).

2. Tech-Aero Ultra IBEC. This is what I prefer to the simple RCexl remote opto switch. The optical switch is supposed to isolate the electrical noise from the ignition and keep it out of the reciever by using a optical interrupt (the electrical signal gets turned into an optical (photon) signal, back to electrical, with that light isolating the two sides from on another, or something like that). It runs about $17. The Ultra IBEC instead filters the signal 4 times through various capacitors and then stabilizes the power to remove any noise. I honestly don't know if these have any functional differences otherwise. They both could be replaced from a noise cleanup standpoint, by using a ignition only battery. Clearly if this is an ignition noise issue the RCexel switch is not stopping it. Since I think it would, if the IBEC instead works, then its a voltage stabilizing issue that the capacitor could not solve.

3. Change the servos.  People knock "budget" servos, but honestly the only difference I have seen is initial quality. If they work out of the bag/box, they work fine, but yeah there are some junk brands out there so you have to know what you are buying. Reviews show these to be very reliable and I get 4 metal gear digital servos for a great price, $18 for 4. I have never had one that failed, even out of the bag. Someday when I can drop $150 on 4 name brand servos I may change them, but right now, this is the way to go.

I will probably end up doing all these things, leaving the Hitecs on the flaps, but one at a time to see what fixes the twitch. Something has to work...

Hangar 9 10CC Ultra Stick Completed!

 The Hangar 9 Ultra Stick 10 cc project is done, and it was some kind of journey. I've not had a build shift course so many times. Its not where I was going, but its where I intended it to be.

It started out straight forward enough. This was the original design of the equipment bay. This was based mostly on the ginormous reciever/ignition battery, a 2S 5200 mAh LiPO I had bought for the test bed, but instead decided to use it on the Stick. Its weight is about the same as two 2500 mAh NiMH batteries. Its a hard case battery, and its size limited options for the other equipment. I couldn't use the standard size cut out that runs across the fuse at the front of that tray because the battery covers it. I was planning to use a mini servo for the throttle, and had to chisle out a mm here and there to get that to fit. You will notice there is no throttle control rod. At this point I wasn't sure how this was going to work. This plane was designed around the now discontinued Evolution 10 cc engine that I am using, but I am not sure where they thought the control rod was going to go through the firewall straight to the throttle. Was planning to solve that problem later. Even then it wasn't going to be straight, as you will see below. The satellite is forward on the starboard side. None of this plan would survive first contact with the enemy, except the reciever.

This original design survived. I made this connector to allow a single output from the battery to split to the ignition and receiver electric switches. I had soldered a single Futaba connector to the main leads of the battery. This resulted from my having to cancel the order of the Hobby King Turnigy Battery Switch as by day 8 it still hadn't shipped, instead I went with the dual Miracle switch I had on hand. 

This is the battery harness in place on the switch.

I was now going to have trouble placing the switch. It was going to need me to move the battery out of the way, but there is no room for that, unless I cut the deck and allow it to rest on the bottom. Remember that everything forward of the servo on the port side is reserved for the control rod. Initially I planned to lay it flat under the deck, but there was no way to get it in there. I changed the idea again and decided to make it lay vertically. The landing gear hard point would be under the front, so it will be angled, but the highest part, forward, would still be under the wing that forms the top of the compartment.

So, I made a vertical tray. Since the battery is a hard case, and its a 80C only running a receiver and ignition it will never puff, so close quarters are fine. Not really sure what happens when hard xase batteries puff...

 

To give it a clean look I painted it black.

Looking good.  I still wasn't quite sure how the switch was going to fit, or where.

While that was drying, I moved to the landing gear. This is a sturdy metal tail gear assmebly I used for two reasons. I had gone back and forth between using the stock straight plate with it's connection to the rudder, a design that can put a lot of  stress on the rudder hinges as the plate doesn't completley protect them from jostling forces on the gear shaft, transmitting them to the rudder and therefore the hinges. Also, I am using the big wheels from the Ugly Stick, so the low set stock tail assembly would lead to a bit more angulation of the fuse and endanger a rudder strike. Lastly, I wanted something sturdy. The reason I like the larger wheels on both Sticks was to allow it to fly off rough surfaces, as when I first flew the Ugly Stick it was off the clumpy grass at the Bedford field that claimed so many landing gear. Flying off that rough a surface won't be much of an issue now, but I do like the look.

Here she is, on her wheels for the first time.

The engine installed. I removed the two muffler extension pieces that were needed to get the muffler out of the wide Sbach cowl, and she is back to stock configuration.

I made a fuel vent. I don't know why these are so hard to find. I don't like a simple tube running down. Here I used a fuel dot rim, and a clunk with a flat bottom that I JB Welded to one another. The clunk just happened to fit in the rim! Came out swell!

I want the satellite to be aligned vertically. In the equipment bay it was going to be severely blocked by the battery. I decided to move it aft as far as I could. I can't get back there easily so I came up with the idea of putting it on a boom and getting it back there.

You can see the satellite block aft of the reciever here. Its set on a platform I made using Dual-Lock velcro. Here you can see the switch in place. I used the stock switch cut out on the port side, enlarged it a bit. You can see how the switch is kinda deep and would not fit on  the starboard side. You still see the mini servo...

So this is where the bay layout stood for a few minutes.  It is packed. Still working on ideas for the control rod at this point.

With all the angulation back and forth in the control rod path, I figured the only way I would get something to work was to use braided wire, its flexibility making it a working solution. After several tries I managed to solder the Du-Bro linkage to the wire. In practice however, the final path took a sharper angle at the end near the throttle than the wire would allow making it too flexible at a point that elbowed, transferring the movment to flexing insetad of to the throttle linkage. I tried hardening it with solder, but that only partially solved the problem. I decided to try a softer, smaller diameter flexible solid control rod. That worked better than I had tought. I changed the throttle control rod connection as well as I couldn't get the Du-bro connector to solder to the rod.  I did have to drill a new passage throught the firewall taking the engine mounts into account, making for a straighter path. New problem: the micro servo was working with both designs, but taking a lot of strain to do so due to friction in the path. It was going to need a standard servo.

Here the standard servo is in place. Once again had to do more cutout in the already trimmed out servo tray. and build up the servo hardpoints. Here you can see the control rod in place. I used two pieces of thin plywood to create a hardpoint as the rod passes into the guide tube. This stiffened the path so the softer control rod could would be more efficient in transfering the movement to the throttle.

Here I had to remove the engine and mounts to drill a new pass through hole through the firewall to creat a straighter path. The engine still blocks the path, which as you can see below, required a cut out of the mount strut itself to keep a sharper S curve out. Epoxied this in place,, but the firewall is almost a cm thick. I could have drilled a hole into the mount from behind, but I didn't think of that until now... I will go back and do that, I think.

Here is where it passes throught the firewall on the engine side. I had to grind a big dent in the engine mount strut to allow it to weave pass the base of the engine. It remains hard against both but more or less straight. The stock design has the engine upside down as I do it, so I have no idea how they connected this.

You can see the tank is as far to starboard as I could make it. The path is pretty much straight now, except after it passes the firewall and runs into the engine. The ignition is in a small bay directly underneath.

All up! Did the programming last night into the iX12. Need to set the CG and weigh her. All in all I am quite pleased and hope she flies well! 

Hangar 9 10cc Ultra Stick ARF. Evolution 10cc gasser, Evolution CDI Ignition, with a 13x8x3 Master Airscrew prop under an aluminum spinner. RCExcel optical ignition remote cut out. Zeee 7.4V(2S) 5400 mAh LiPO receiver/ignition pack in a hard case, from Amazon ($17 shipped!). Miracle power switch. Spektrum AR7010 receiver with one satellite. Sullivan 4" tires. Don't know the make or source of the tail assmebly, but its for a 50cc aircraft and easy to find as there are so few options out there. Could find a decent one for 10cc 0r 60 sized airplane.