BH Model Pitts Special

[akent]

Awesome job on the packing! I would love to have seen folks faces seeing you driving around like that!!

In the second video, my left hand kept pushing UP UP UP to WOT!!!!

That plane will torque left some. It's best to feed in a little right rudder right away. Knowing how much takes practice.

You'll get it!!

Oh, and those magic words are normal!
Kent

[Doozer]

Yeah it jumps a whole lot more left than I expected. Even though at low speed it steers somewhat right. I was feeling claustrophobic on the road, but I bet I could get it in the air if I put the big boy pants on and just gave it some right rudder all the way to WOT. That and pull back on the elevator.

After flying the Stinson I was jazzed to fly the Gee Bee. The Gee Bee took off like I drive a golf ball ... straight for a few seconds then a huge hook to the left. When it crashed, being much smaller, I lost all confidence gained with the Stinson. So I was really pretty scared with the Pitts. Unlike the Gee Bee, that thing crunches when you make a mistake

[19000rpm]

That's odd on the Gee Bee. Almost sounds like something came loose, broke or bent in the aileron function.

Your confidence will return. Confidence is always shaken, to some degree, when something bad happens. In particular, if you can't pin point the cause at first.

Sometimes flying again immediately after a mishap is not the best thing. If nothing else, the lingering thoughts of the mishap can be enough to derail your focus for future flights that day.

[akent]

I agree on the Gee Bee. Something is not right.
That thing should fly like it's on rails all the time.

If you are running the stock servos, be sure to check them. Don't hold them to binding (you'll strip them), but put some pressure on them to see if they are Ok.

Yep, it's very scary when flying a crunchie.

I maidened my Hangar 9 Christen Eagle crunchie today. Two awesome flights. I just had a little trouble landing it. These like to bounce, and bounce it I did. I should have been able to grease it, but I was afraid of stalling it. Oh well. No damage! This thing flies beautifully. It should fly a lot like your Pitts. They are modded Pitts to begin with! Yours will most likely also like to bounce on landing.

Kent

[Doozer]

I've decided to put an aluminum spinner on the Pitts. It's a Dave Brown 4" spinner and I had to purchase a 3" 10-32 bolt because the stock bolt was too short (go figure). You can buy extensions for the Dave Brown bolt @ $6 each, or you can go to ACE and pay a quarter and do a little work. I had to file down the width of the screw cap too, which was easy enough, and it only took a few minutes of filing and sizing to fit. I also switched to an 18X10 APC prop... though I like the looks of the Windsor Classic Series prop better. I went with a little more pitch in the blade because i don't see myself hangin' on the prop much.

I've changed to a 5000 mAh 3S Lipo that also I'm regulating down. Though I think I'm going to order up another 4100 Life rx pack. I'm still only using one battery and an IBEF, but I think 4100 should be enough. The lipo is an older Zippy I had hanging around but used maybe twice. It was stored well and showed no signs of puffing, but still, it's old.

I'm going to get some video of her in the air, hopefully tomorrow. I want to try and fly every day I have a day off, unless I'm building a 50cc Ultimate or somethin'

[Doozer]

And... it's gone. Not sure what happened. It flew fine for about 15 seconds then it just quit responding to my stick input. After sifting through the pieces, and I mean pieces, I found the positive lead from the battery disconnected from the deans connector. It sure felt like an LOS, and the lead breaking loose would explain it, but the lead could have come loose in the crash. The choke was closed as well, but that also could have happened on impact.

I feel comfortable saying that the battery lead is what brought it down, but I can't be positive. Here's the video:

[akent]

Man that sucks! I hate it when you really don't know what happened.
If I were to guess, it sounds like the battery lead may be it. Those engines vibrate pretty well, so it could have vibrated it off.
Otherwise, I would range check your receiver really well. I had a bad Spektrum receiver that was intermittent. That POS cost me two planes.

I hope the electronics and engine are still good at least.

Best,
Kent

[19000rpm]

That's too bad. I hate it when a plane stops flying for no apparent reason.

[Doozer]

Oct 23, 2012 11:17:33 GMT -6 akent said:

Man that sucks! I hate it when you really don't know what happened.
If I were to guess, it sounds like the battery lead may be it. Those engines vibrate pretty well, so it could have vibrated it off.
Otherwise, I would range check your receiver really well. I had a bad Spektrum receiver that was intermittent. That POS cost me two planes.

I hope the electronics and engine are still good at least.

Best,
Kent

Yeah, I was really bummed. I had just changed out the battery and connector You can somewhat see the cloud of dust and debris and toward the end of the video. I think my dad thought he was doing me a favor by not shooting video of the carnage because man... it really broke apart. It hit sort of knife edge nose down.

First thing I did after picking up all the pieces and carting them home was pull the engine apart. DLE engines are really very easy to take apart. I was a bit surprised. I remember working on the .50 nitro heli engines and those were a pain comparatively speaking. After I got it torn apart, I found a couple of small rocks in the cylinder head... I mean they were really small, but rocks none-the-less. I can only assume that the piston stopped on the down stroke and they blew in through the exhaust. The reason I say that is because there is no damage to the piston or the sleeve. No scratches, no dings, no marks... nada. I went over with a flash light and a magnifying glass.

There was a bunch of dirt though, so I'm going to take the engine completely apart and give it a bath. After that, I'm going to bench test it. I was thinking of using a "parts wash" type solvent. Anyone have any experience with that? It's that or I'm going to use straight Coleman....

[akent]

I think your idea of washing with Coleman is a good one. Some other solvents might eat the seals.

I'm all electric now, so I don't know if there is another/better solvent.

I even built 30cc and 50cc electrics! These have more power than gas engines, but they sure don't have that sound!

Kent

[19000rpm]

Washing a gas engine with gas is the best approach. Solvents are generally used when you have something to dissolve like burnt oil and/or other bi-products of combustion. Kents right about the seals; they may also be damaged with a solvent.

[Doozer]

thanks for the sound advice guys. I went with a Coleman bath. There was so much dirt and sand. I flushed it with a syringe until I didn't see any more dirt. I took the carb apart and cleaned it up too. I was careful not to destroy any gaskets even though I ordered a new set from tower.

Once I got it completely clean inside and out, I did the same to the stock muffler. I know where the rocks came from, in through the out door . I was tempted to just huck it, but I didn't want to spend more money on a muffler if the engine was ruined so I gave it a bath as well. I believe I brought home half the dirt at that field. I also worked a bit on the carbon.

After there was no more signs of dirt and sand, I hit it with some Royal purple and put it all back together. I reset the needles to the factory settings, then started work building a test stand. I installed a 18 X 8 prop and mounted the engine. I installed a new plug, added some gas, turned the prop a few times, and flipped started it. It cranked right up. It was running a little hot, so I opened both needles a bit, then put two tanks through once I got the engine running nice.

Pulled the plug after both tanks.... cocoa brown. So, it's back. I'm thinking now instead of a 50cc Ultimate, that I'm going to do a 30cc Gee Bee. I just need the plane because I have everything else. Out of the ashes........

[19000rpm]

"Out of the ashes". That where I get half of my new planes innards. ;D