Ah, the smell of flying season, mmm... kinda musty.
Its time to start making things happen for the 2021 flying season. Renewed my AMA a couple months ago, but for no real reason didn't renew my club membership until today. Been thinking about getting around to it for a couple of weeks as the weather warmed and the winds settled down. Getting my club application in today, made me a little itchy to shake off the COVID and winter blues, get downstairs and instead of just walking by, start cleaning and organizing the workshop, see what batteries I killed leaving them charged, and which engines are going to give me crap, see if I can get over being annoyed at how little it took to put serious hurt on the Waco I still haven't gotten around to wanting to fix.
At the top of the stairs to the basement. If I am running engines out back through the basement bulkhead I cat free the basement and then make sure no one listens to them crying to be let in.
Ah, the doorway to heaven. Or hell. Depends on my mood and how many parts my returning aircraft come down in. Painted the pole as people kept running into it.
I didn't even bother to put anything away last fall.... its a mess.
Here is my conundrum to start the season. My beloved UNFLOWN Hangar 9 Ultrastick 10cc that I have waited years to get and fly, is two pounds over her designed dry flying weight. I put the servos for the rudder and elevator aft as the equipment bay, as you can see here, is packed. This puts a bit of weigh aft out on a long lever. I had to put that 1 lb (500gm) lead weight there to get her on CG. Literal dead weight. Between that and the oversized receiver/ignition pack, she comes in at 9 lbs dry, her design weight is 7 lbs. I could save maybe a quarter pound (250gm) or so if I changed to a smaller LiPO. I am not sure it would save even that much, forget how much it weighs. Half that 5200 mAh is more than adequate, and I could always go with to swappable smaller LiPOs. I am pretty sure I am going to do that. 5200 mAh is far more than a days flying would need. I could move the aft servos to the bay and remove the lead, but thats going to take a lot more work than it might be worth. I am going to add a capacitor, which I am not optimistic will solve the weird left aileron twitch. (These are the same servos but not in the same place, and I think a different receiver, so no idea why the same servo twitches. I also have a Tech Aero IBEC that may help. More on this problem here. I have changed the servos before, and I have replacement ones on hand. I think I will step through it. Capacitor, IBEC, servos).
The tail servos aft.
I could squeeze those aft servos here, but still aft of CG, albeit not so far out on the lever.
I really don't want to go there... That block and spar support the satellite receiver.
The Waco spent all winter sitting there after I hurt her. I just don't want to find out what its going to take to fix her, but I do love this plane, so it won't be long.
And then there is the Spitfire and my long history with them... she has yet to be maidened and won't be until I get some fresh hours under my thumbs.
Dark, heavy, but high clouds threatened rain, but the drought made this unlikely, a coy deception. Pretty much windless, and a comfortable mid 60s temps, I had been itching, and Saturday afternoon was time to scratch!
Bill Renault brought out a couple of fun old school classics. This nitro 2-stroke of course flew marvelously, that sweet nitro smell and soft purr powered her through the skies effortlessly!
He also had the Sig 4 Star 120 with its awe worthy 4-stroke.
Bill flies 72 mHz. He clearly enjoys flying and talking about flying! He was wonderful company at Wagner. Clarence, who I swear lives in the filed shed, was there since morning, and hung around to chat. Always nice to see him.
Anthony was there too, flying the little mosquito of a 370. This is an old pic as I don't think he stopped flying the whole time he was there. I suspect he flew the bigger one too, getting in 14 flights! Perfect temps and winds for these guys! He reminded me I need to be bringing my helis out!
I got in about 5 flights, most about 10 min as the engine is still running rich in flight, or theirs an airleak in the carb path. Starts fine, runs with power but in the air she starts popping and running "wet". She is always an amazing flier! I plan tomrebuild the carb, not sure if I have done that before. She used to be an amazing engine, an RCGF 26cc. At some point this year this rich running airborne became a problem.
Brought the Hangar 9 Ultra Stick out to maiden. Engine ran just fine, but the Twitch Curse showed up, so I grounded her on the runway. Just drove her around a bit. Man, I really wanted to fly her...
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...
The Hangar 9 10cc Ultra Stick has her balanced prop on and is ready to go!
Got the cowl on the Phoenix Spitfire, and checked her CG: SPOT ON no changes necessary!
Looking good. I am ready to give this, my third Phoenix Spitfire a run for my money. I have had two previous ones perish on maidens. The first when I clipped a tree coming out of an intended stall, the second when she stalled on takeoff and torqued into the firmament. I have no doubt this one is the one.
No pics today, but I got the Ultra Stick out to the back on the test table and ran her up. Started right away, needed a little tuning. Produce 5.2 lbs of thrust with the 13x8x3. Then the uncollapsable table leg collapsed in front and she dropped on the prop still attached to the fallen front of the table. I was a bit pissed so didn't take any pics.
The engine ran ok, but was really slow to run up, and thenreally slow to come back down. I leaned it out I the low end and she is running pretty well. I was pretty much finished when the end of the table collapsed,.
The elevator servo went rogue. I suspect this is the bad one that killed the Ugly Stick? The tests could not find it, but it went really jittery and then locked up, already ordered a replacement.
I think once ai replace the servo she is ready to maiden!
I mentioned previously that the Hangar 9 Ultra Stick 10cc was quite tail heavy, and that test fitting the 455g (1 lb) lead block I happen to have from a dead Eflite Stearman of long ago balanced it out perfectly just forward of the CG, and I mean just forward. This is no child... its a manly block of lead. There isn't any room to put any lesser weight in the tank area.
I created a partial wall forward of the lead block to support it, with some lightweight plywood (thought I had a pic, but alas...). This is the block in place, the Dual-Lock Velcro is CAd in place on the base and the "back" against that wall. The foam is to add some compression when the wing is in place to dispel any notions it has about wandering about the cabin in flight.
The CG machine verifies my finger-tip test.
The CG is now spot on.
Concern is that her spec weight is 7 lbs, and she comes in at 9.5 lbs dry. I didn't see a different spec weight for electric vs gasser, and I have no doubt my Ugly Stick was heavier than spec too. This heavy-lift wing will undoubtedly be up to the job, but... One thing of note, seen in this last pic, is the long length of those landing gear. Hope I don't see too much flex from the extra weight.
Planned to light the fires today, but its fixin' to storm.
Joe Nelson of RCGF-USA had asked me to check the top of the piston on the RCGF 10cc engine I had reworked to fix a stripped spark plug hole, after it blew out. Was it soft metal, as we expected, or had the piston pounded it out? I was between bench jobs so I took the cylinder off.
Conveniently three of the hex top bolts holding the head in place stripped... so I had to grind them off then bang the head off (easy, killer...).
The piston top is smooth, no evidence of it striking the adapter. There is some damage along the rim of the spark hole seen at about 12:30 on the right in the cylinder head that wasn't there when the adapter was installed.
I wanted to use a Walbro carb, the the reed plate bolt holes that secure the carb to the crankcase had stripped on one side. I figured why not retap it, and that worked. Snug, tight, not gorilla tight. This was a cantankerous carb. I oiled up the cylinder and put it in a plastic bag. When I can afford a new cylinder I will get one from Joe. I don't have a plane for her right now, though, but that, as we know, is never an obstacle. (I can't find a round cowl WWI plane, like a Sopwith Pup or Nieuport to put her in, my first choice. Second is the Phoenix Zero. My heart is on a WWI biplane...).
