TLT Aviation (KMP) 50cc Extra 330L

[BTerry]

After shopping around for a new home for my Brillelli 50gt engine (and after surpassing my tolerance for frustration caused by large glow engines) I discovered the perfect low-cost, low-hassle, low-personal-investment plane. My intent is to put together a decent 50cc plane for a manageable price.

Why did I choose a 50cc plane? I agree the larger planes fly much better. However, I don't want to store or transport a large plane. I have two nice flying fields within 7 miles of my house but the nearest field for 33% and larger planes is over 50 minutes away. The last thing I want to do is waste precious flying time on the commute to the flying field!

I believe the 50cc size market is the rough equivalent of the .40 to .60 size sport plane market of 10 years ago. Many options for planes, engines, etc., and most of them are good-quality.

I will post pictures of the build, along with commentary. Anybody is welcome to comment.

Brett

[BTerry]

Posted here are the discrete component weights as delivered with the kit.

Extra 330L Weights




Part Oz
Hatch 5.9
Canopy 6.4
hardware/tank/wheels/etc. 15.7
landing gear 9.3
wheel pants 3.7
cowl 8.1
rudder 2.7
stab tube 1.7
Rt stab/elevator 4.2
Lt stab/elevator 4.4
Rt wing/aileron 19.9
Lt wing/aileron 19.6
wing tube 7.6
fuse 45.1

Total 154.3 oz (9.6#)

[BTerry]

Radio and engine component weights:

JXF 22x8 prop 4.3
S/S Ignition 3.4
Mount 3.5
Brillelli 50GT (rtf) 55





Servos (2-Ail, 2-Elev) 9.2
HS5955TG (Rudder) 2.3
Tower TS 53 Choke 1.8
JR 537 - Throttle 1.6
JR 955 PCM Rx 0.8
Servo Extensions 6
1500mah, NiCad, 5 cell (2) 13
MPI Switch Harness (2) 1.2
600mah NiCd, 4 cell - Ignition 2.6
Hobbico Charge Switch 0.6

Total 105 oz (6.5#)

[airborneSGT]

Brett,
It would be neat to post your final costs if you would on this also. I am curious as to what you could come up with for a decent 50cc plane done on a budget now. I saw a recent video of a 50cc plane flown on Blue Bird servos. He put it through its paces and the servos seemed just fine.

I have been wanting to try one of the Brilleli's myself in either his 50gt or his new 60cc sized motor. Either seem like a winner.

[BTerry]

So much for nicely-formatted tables. Oh well!

The total weight of all my components works out around 16# 4oz. Obviously I can save weight in obvious areas (gear, wing tube, batteries, smaller fuel tank) but for now I will use what I have.

So, how does this kit compare to others on the market? It is pretty good. The structure is strong but light, although I will definitely reinforce all the glue joints. The hardware is pretty good. The CA hinges are the best I have ever had the pleasure of throwing away. I HATE CA hinges on gas planes. I will use Robart hinge points or Dubro heavy-duty pinned hinges instead.

The color scheme is tasteful. The covering is "Oracote", which many people mistake for Oracover (same as Ultracoat). Oracote seems to be similar to Ultracoat Light. I will endeavor to seal all the seams, either with a covering iron or by sealing with clear paint (dope? nail polish? any ideas?). The problem with this covering seems to be the sealing temperature is too close to the shrinking temperature. Real ultracoat seals tightly at a temperature far below the shrink temp, so I will see what this stuff does.

I think this is a great plane for under $300. This is definitely not in the same league as a $500 plane however. The laser-cutting is well done and the plane is fit up well with a few exceptions.

The control surfaces are HUGE, and I can't believe how light the tail surfaces are.

Why did I choose this plane? Besides the price, I just like Extras. Yaks are wonderful and all fly great, but I am on Yak overload at the moment. Extras somehow "look right" to me!

That is all for now.

Brett

[BTerry]

	Quote: Originally Posted by airborneSGT
	Brett, It would be neat to post your final costs if you would on this also. I am curious as to what you could come up with for a decent 50cc plane done on a budget now. I saw a recent video of a 50cc plane flown on Blue Bird servos. He put it through its paces and the servos seemed just fine. I have been wanting to try one of the Brilleli's myself in either his 50gt or his new 60cc sized motor. Either seem like a winner.

Sure! I will revise my tables later.

Here is a quick, don't-want-my-wife-to-see-it breakdown:

Extra $300 (eBay)
B-50gt $495 w/muffler

servos: NOTE, I would PERSONALLY not use "cheap", off-brand servos but these are nice "inexpensive" servos
2ea JR-125mg $30 ea
2ea Hitec 5645mg $45 ea
(already had these 4 servos)
1ea Hitec 5955tg $97 shipped

receiver/batts/switches, already had them, but for kicks:
receiver JR PCM, $90 or so
batts around $25 each
Miscellaneous extensions $15
3 heavy-duty switches $30? (i already have these, forgot how much)

Honestly, I don't want to total this up. But since it is laid out already, we are looking at $1252. I guess this isn't too bad, but toys cost money! I need more overtime...

I am very impressed with the workmanship of the Brillelli engine. I hope to run it next week. People who have run it say it is very smooth and responsive. Scott balances the crank to eliminate the typical mid-range shake.

Brett

[BTerry]

Perhaps "moving up" to a 50cc plane is a false economy, unless we already own most of the required parts. My total in this plane will be in the $850 range, as I bought the plane, engine, rudder servo, and a few other things. Everything else I already own.

Thanks for reading!

Brett

[ChrisR]

Cool assembly, looking forward to it.

I think half the battle in GS planes is accumulating a decent stock of parts, hardware and all the other misscelanious stuff that goes with it. Then the costs aren't so bad.

[BTerry]

Slow weekend (or rather, busy weekend) with lots of work and honeydo projects, and minimal airplane time.

I am still impressed with the design of this plane. The execution is moderate (3 out of 5), but the design is solid. Did I mention it has HUGE, light, double-beveled control surfaces? The plane is straight and fairly rigid too.

I am mounting the engine tonight/tomorrow, will post pictures later. This is the only real work involved on this plane. Everything else should drop right in.

I need to fabricate new root ribs with mounting tabs for the horizontal stabs too(blind nuts already installed and secured into place with a small screw). I just traced the root onto a piece of paper, marked the location of the stab tube, anti-rotation pins, and mounting holes. Then I sketched a pair of TLAR tabs onto the paper, and will trace the pattern onto the material I will use for the tabs. I used to have some carbon plate or G10 but can't find it. I COULD fabricate some more carbon plate, but I don't think the effort is worth the outcome! I will probably use lite ply.

My servo lineup will change a bit too. I thought I had a pair of Hitec 5645's (moderate speed, 145 oz-in torque), but they are in fact 5625 (high-speed, about 110 oz-in torque). Because of this I will need to find more servos. I am thinking of using the new JR Sport 126mg servos, Does anybody have a comment on these? I have the 125mg already and have no problems, and assume the 126 fixes the electronic issue these servos had with Futaba and Hitec radios (I use JR PCM). I thought the 125mg was a good servo for the price.

Any other suggestions on servos? Obviously the best option is to use the Hitec 5955tg all around, but I don't want to drop $500 on servos at this time.

Brett

[BTerry]

	Quote: Originally Posted by BTerry
	The laser-cutting is well done and the plane is fit up well with a few exceptions.

Note, I should have said "milling is well done"...

This plane is not laser cut, nor is is die-stamped (as far as I can tell).

[BTerry]

I fabbed up some stab root ribs with tabs using 1/8" lite ply. Mistake number one was assuming the holes on one side would match the other side...they didn't. One root rib looks great, the other has the mounting holes hogged out to match the screws. I will plug the holes before I am finished.

The second mistake (or ALMOST mistake) I made was with the motor box.
I added up the length of my engine, length of the engine box, and length of the cowl. Then I meticulously drew a line on the motor box, remeasured once, and then again just to be sure. I pulled out the saw and just for good measure, I decided to check my numbers.

I was wrong! Somewhere I added an extra 1/2" to the amount to be removed from the engine box. I left the original line in place as a reminder to be completely certain before cutting anything.

[BTerry]

Here are a few pictures of the stab root ribs with mounting tabs (still need a bit of trimming) and the engine box.

[BTerry]

and here is the motivation for this plane, the Brillelli 50gt. I will swap this muffler for a wraparound Pitts when it arrives. The Pitts muffler will add about 3.5 oz (this is the 6.5 oz heavy side dump muffler, not the 3.4 oz "Lite version").

[BTerry]

I have given some thought to the battery question. I know people have good experiences with the Lithium batteries, and that is all I use in my electric planes and helis. However, I am concerned about the impedence, current-delivery capabilities, and cold-weather performance of the batteries. Also some of the capacity of the lithium batteries must be converted to heat to step down the voltage, eliminating a portion of the benefit (greater mAh capacity for a given mass). The regulator also adds a potential failure point.

I haven't yet decided which batteries I will use, but I like the low-impedence Sanyo 1950 FAUP cells. They are fast-charge, high-current delivery cells (45A).

I will probably go with two receiver packs for redundancy, and will definitely use 5-cell packs.

[BTerry]

I mounted the engine tonight and cut the cowl. I will trim more when the Pitts muffler arrives. I just wanted to get everything fitted.

Notice the location of the prop drive washer in relation to the cowl. Leave it to an engineer to mess up a simple calculation. I don't feel like cutting the extra 1/4" off the engine box and I don't want to tap new holes in the engine mount, so I will leave it with 1/2" clearance. Maybe I can claim it will help with cooling and "increase thrust".