phatboy

Hey guys I have an eflight Pitts 15e that I would love to convert to glow.

plane specs:
Wingspan: 40" (1015 mm)
Overall Length: 39" (990 mm)
Wing Area: 555 sq in (35.8 sq dm)
Flying Weight: 48 - 50 ounces
Motor Size: Power 15 BL Outrunner, 950 Kv
Prop Size: APC 12x6E


Apparently its been done once as shown in the thread below, but he didnt have any flight info on it.
http://www.scale4x4rc.org/forums/showthread.php?t=20391

phatboy

Well Im going forward with it. I will post pics when I get started on the build.

ckreef

Ireally can't answer your question but I am patiently awaiting a build/flight report.

Patxipt

Yes, a .25 will be the ticket for your Pitts, but remember to beef the firewall area quite a bit.

Don't forget to post the flight report!

phatboy

Thanks Patxipt. I considered using a .40 for a second, but im not sure it will fit under the cowl without a ton of modification. I love posting progress pics, and updates so as soon as I get started there will be lots of those. Hope to be getting started this week.

phatboy

Won myself an engine on that auction website. Paid 22$ out the door with everything you see in the picture. Engine, Muffler, spinner, prop, and mount. Its a magnum .25. I know they dont get the best reviews, but hey it will be a helluvalot better than that electric spinning thing that was on the front before! I havnt decided if I am going to use a pitts style muffler on this plane as the stock muffler can be made to fit inside the cowl with minimal cutting.

What size prop do you guys think I should spin on this for some stunt and mild 3d action? Nothing too fancy.

phatboy

Right!

phatboy

Engine came today. Gonna bench test some props tomorrow to see what will work best.

phatboy

Did some engine testing today, gonna do some more tomorrow. Today I tested an 11x6 prop which turned 7200rpm, obviously that wont work. Also tested a 7x4 which turned 16,000. Perfect for a shrike or wonder, but not for my pitts. Gonna test a 9x5, and a 10x4 three blade tomorrow to see what they will do. Im kinof hoping since its light and only a 4 pitch that it spins the 3 blade up around 12k or so. I would love to have that prop on it for scale looks.

The cowl is only 6 inches across so even with a 9" diameter prop I should have enough tip sticking out to have great performance. The 9x5 might be the hot ticket. The spinner broke so I will have to try to hand start it tomorrow, booo!

Patxipt

I dunno the performance on the 3-blade, but my ASP 28 (same as yours, except for the extra 0.03cu.i) likes to turn 9x6 props

phatboy

Went a new route. The .25 just didnt have what I wanted. Picked up an Enya .46 4 stroke for her. That will spin my 12x6 with no issues. Build gonna start soon! Ive already fuel proofed the fuse in the front, gonna build the firewall tomorrow I think. Pics soon.

Textanker

I am VERY interested in seeing how this goes. I have a Saito 40 Four-stroke that I would love to put on this plane.

ckreef

Keeping an eye on this thread. Can't wait to see this project get under way.

phatboy

Its gonna be a slowish build. I am a full time college student, and a 1/2 time dad(divorce split custody), BUT I do have the motor in hand now, and its going to fit like a champ. With minimal modifications of course. I will post some pics in just a few mins.

phatboy

Here she is as she sat when I got her.


Tear down


Issues




See the broken spar in there


Also broken firewall


This is the prop. 11x6, should let me run this engine at a good speed.


Fuel proofed the firewall, bay cover, and inside the fuse




Battery I will use. Hopefully this will help balance the CG


This is where it is on the plane, but it will be inside for sure.


Snug fit for sure. I will likely have to cut out the area of the cowl around the head to keep it from melting onto the engine.


This picture shows that the carb will have to be inside the fuse so the firewall will have to be cut away for that.


Overall engine placement


This shows what the front will look like when mounted.


Fuel tank will go here, it will be pressurized, and foam mounted.




Couple notes:

I will mount the engine right side up so the exhaust can be directed down, and so the choke pull as well as the mixture screw can be extended out the sides of the fuselage for easy adjustment.
I will be making a solid firewall from 1/8th inch basswood, that will be screwed and epoxied to the current firewall.
I will be using a vibration absorbing mount that has rubber bushings to keep from shaking this thing to death.
I have to use the 11x6 prop because the 12x6 only turns 9700 rpm on this engine and that isnt enough to run in the sweet spot.
I will have to bend the exhaust pipe to a 45* angle so it doesnt interfere with the firewall, unless I get a 90* manifold and a straight head pipe(Anyone know where to get this?)
I will be using basswood dowls to make supports inside the fuselage once its all together, this thumper will vibrate alot more than that electric motor did.
I am mounting the fuel tank under that support, because after it runs and flies I will be installing a smoke system, and the tank for that will mount on top of the battery tray.
I am searching for a figurine to install inside the canopy, but as of yet I havnt found what Im looking for.
I will be using a Spektrum DX7s to fly it.
I have named the plane "Confutetion" because everyone I have spoken with said it couldnt be done. Confute means to prove a person or an assertion wrong. I think it fits.

ckreef

Build plans are looking good. Hardest pert looks to be mounting the engine and the carb inside the fire wall. Will be checking this out closely to give me some ideas on my next conversion.

ckreef

Since 4 strokes are usually a bit on the heavy side I was wondering if you have weighed all your parts to get an estimate weather the final weight and wing loading will be within resonable tolarances. During the ElectroSTIK conversion I was constantly weighing all my parts (as I swaped some parts out) to make sure I was within tolorable limits.

phatboy

Yeah, I did some number crunching and everything came out ok. It was flying with a huge 4cell battery before that was nearly twice the weight of the motor. Its all good. I will have to find my figures to post.

Little update. Picked up the engine mount today. Just like the one in this pic, but this is not mine, or my engine. It reduces the vibration by 80% it claims.



Also picked up the wood for the firewall, and since school work and test week is done, I will be making some headway this weekend.

Also found out that I am going to have to use a voltage regulator as my lipo battery is an 11.1v and my receiver cant handle more than 6v. LHS didnt have one for a 3 cell lipo only 2 cell.

Checked out the engine, and Im going to need a new needle valve assembly, everything that screws into the carb. Gonna be fun finding that since this is an older engine.

But, progress is being made!

phatboy

Well that motor mount isnt going to work. Gonn have to go a different route with mounting. Not sure what Im going to do yet.