Willy Nillies Simple 250

Thanks, balogh! The covering job is far from perfect, believe me. The base color was originally going to be black but my black covering was unusable. I substituted the Navy Blue and am happy with the results. This kit is basically a reduced size Ace Simple 400. Smaller and much lighter.

Hello Tee Bee! ... I like your model, and I agree with András, the decoration and shape look great.
The transparent yellow will become very visible when the sun shines on your flights!
I will follow your progress!

She’s almost ready to commit acts of aviation!  Waiting for a small bit to arrive by mail this week.  That’s a Killer Bee II with an APC 4.5x3.5 up front.  I bet that will haul the mail!  She’s got a Spektrum AR410 RX, 2S 300mah LiFe battery, and Dymond 4.7 servos.  It was too cramped inside for the aerobatic flop-tubed 1oz tank I had planned, so I had to switch to a .75oz Brodak rectangle tank.  Was able to get it balanced without any extra ballast.  Final weight still unknown since I lost access to the lab scales I use due to the pandemic.  I’m guessing 7-7.5oz total.

WHOOOOWEEEEEE Momma! That sucker's gonna haul the mail!!!!!!!

Looking Good Troy !! she should fly Well bee watching for the video if you can, i guess the T fitting is for the hoses sticking out there . Let me ask U does your transmitter work with AA batts. and if so do U use rechargeable ones ?

Very Nice, Troy, congrats. I noted your limits with the tank volume selection, and suggest you swap the solid 0.75 oz tank with a party balloon type one that occupies the space more efficiently than a solid tank. I guess a 1.2....1.3 oz volume (without unwanted pressurization) balloon will sit nicely there.

Needless to say, that the balloon is lighter than a solid tank, in addition, no fuel foaming will arise, no clunk is needed for inverted flights, etc...

getback, the hoses sticking out the top are the vent lines from the Brodak tank. A crude but effective method of gettin' her done. At least a few of us have used it in the past with success. I needed a 90deg elbow fitting for the fuel nipple on the bottom of the engine so as not to stick out below the firewall and snag during landings. Got some coming via the mail.

Andras', thanks! I've never been one to use the bladder tank setups in my models. I just prefer using traditional vented tanks. The Brodak tank is actually pretty light. I was going to use a larger/heavier 1oz tank with a flop tube but the limited space didn't allow it. When building this one, I relocated the firewall aft a bit in anticipation of a too forward CG with the .049 engine. Looking back, this was a mistake as I lost valuable space in the fuselage. To balance, the battery had to be located under the tank behind the firewall. Worked out just right with the tank/battery fit. Not sure if the bladder would have worked in that situation either. Different strokes...It's all good. Either way, this one is about ready to fly!

Thanks, Troy,

looking forward to your maiden video!!

Repeat >> Let me ask U does your transmitter work with AA batts. and if so do U use rechargeable ones ? And what brand . Or anyone listening<< Thing is i got some i am having issues with some good some not so. New ones

Eric (I am listening ) I use AAA size rechargeable batteries for the RX of 1/2A or smaller RC planes powered by 010...051 COX engines. NiMh battery packs are sold in 4.8V, 300...400mAh units on e.g. ebay. I typically charge the pack up to 5.6V. Each 6 minutes flight drains about 0.1 V and I stop flying when the voltage is down to 4.9V...just for safety..

I use the same packs but from AA size rechargeable batteries for larger than 1/2A planes like my Denight 50 powered by an OS Max 56 FS 4stroker.

My older Futaba transmitter was also powered by a AA size NiMh battery pack having 8 rechargeable  batteries in series. They are very long-lasting. I typically recharge my TX after 30 or so flights or even more. (This old TX on the pic is defunct, its antenna broke.My latest Futaba has a Futaba stock battery pack)

Sorry I forgot to answer your question, Eric. My Spektrum transmitters use LiPo battery packs. My older Futaba units use NiMH rechargeable packs. I don’t have a lot of experience with rechargeable AAs.

balogh wrote:Eric (I am listening ) I use AAA size rechargeable batteries for the RX of 1/2A or smaller RC planes powered by 010...051 COX engines. NiMh battery packs are sold in 4.8V, 300...400mAh units on e.g. ebay. I typically charge the pack up to 5.6V. Each 6 minutes flight drains about 0.1 V and I stop flying when the voltage is down to 4.9V...just for safety..

I use the same packs but from AA size rechargeable batteries for larger than 1/2A planes like my Denight 50 powered by an OS Max 56 FS 4stroker.

My older Futaba transmitter was also powered by a AA size NiMh battery pack having 8 rechargeable  batteries in series. They are very long-lasting. I typically recharge my TX after 30 or so flights or even more. (This old TX on the pic is defunct, its antenna broke.My latest Futaba has a Futaba stock battery pack)

I se these are panasonic brand , My older radios have recharge AA packs also But this new to me (well i have had it couple years ) is a Spekrum DX 6I I have just had to many of the yellow discount batteries i purchased there Ni-MH 3000 mah 1.2V . Have been falling short of a charge for performance in other devices i have , like toothbrush / tV remotes . Thanks Guys

I was able to put the finishing touches on the Simple 250 tonight. I found some neat little nylon 90deg elbow fittings for the fuel line that arrived today. They work great for the backplate mounted .049s. I pulled out a NOS Surestart engine and disassembled, cleaned, and reset the piston clearance on it. It will be used for the maiden and trimout flights before tossing it with a hotter engine. I also got the opportunity to weigh it on some calibrated lab scales. 248.4g without fuel. She’s ready to fly when life and weather windows align!

Troy,
Great build you have going! Can't wait for the maiden flight video.
I think that I'll do a Simple 250 later in the summer also.
My question is : Did you find those 90 degree fuel line adapters locally or on line ?
I would like to buy some for some SS and KB .049's to make life a little easier for my kind of landings.
Great Job !!!
Steve....

I appreciate it, Steve! The fittings were from U.S. Plastics. They are 3/32” nylon. See this thread: https://www.coxengineforum.com/t14078-cox-engine-fuel-tubing-elbow-fitting

Thanks Troy,
I had totally forgotten that thread from a few weeks ago.
Been spending less attention to the hobby of late due to the crazy time we're in !!!
Our granddaughter had her "virtual" High School Graduation two days ago with a big party at their home with all the relatives in town so it's all been a blur lately..
The cool vids on this forum help me get my good sense back.
Can't wait to see your Simple 250 make noise in he soon clear Texas skies !!!!
Steve.....

Vrooom!

Put some air underneath her this morning. Good stuff! More info later as I’m still at the flying field playing.

She flies straight and true. Tracks nicely. The engine run was cut short in this video clip probably due to an air bubble. She’s scootin’ nicely!

https://youtu.be/41te8y0_8-U

Well done Troy!
APC 4.5x4.1E helps on fuel draw and can be set a bit leaner.

Like it’s flying on rails. With my sloth like reflexes I would have replenished my empty toothpick holder on the first flight.

Thanks guys!  

Jason, I used a slobbering rich Surestart and Cox 5x3 prop for the maiden.  It was slow and greasy enough for a stress-free trimout.

Brad, thanks for the info.  For some reason, the NV on this one got very sensitive yesterday.  A small tweak caused it to go from rich to lean.  I simply used the same Cox 5x3 from the first flight.  I thought it did pretty decently for a 2nd flight.  Wasn’t ready for all-out speed just yet.  There was more fuel left in the tank when it quit.  Sounded like it sucked a bubble and went lean at the end.  Maybe a fluke, need to fly it more to find out.  As posted above, it was a tight fit to get it all in there and balanced.  I’d rather not have to re-think it.  I have a couple of those APC 4.5x3.5 props like Andras used on his Quickie to try.  Whatcha think?  Also have a Killer Bee II, some real KBs, and a Tim Wiltse Skyline .049 that should spin up nicely.  So far, the fuel issue seems to be the only caveat.  ‘‘Twas a lot of fun!  

Fun for sure and a good prop for a trim flight and general flying.
Thanks to that lovely flight we have good RC data on the 5x3 and reed .049.

The APC 4.5x3.5
I recommended it to Balogh a good all around reed engine prop, allows the
engine to sing with a bit of speed using particular slick plane types.

His flight proved well opening the door for the next step a 4.5x4.1E will do very well
with the reed when used with these particular smaller sleek types / good for breezy days.
The running of the 4.5x3.5 next will make for good comparison to Balogh's flight.  

The feeder line is above the intake causing a flame out when fuel gets lowered
in the metal tank. That position on the firewall is fine with TD's.

These are all relatively new props the beefy 4.6x3 is made for high rpm use
but ok for a reed engine if the plane is slick. Lots of screaming around at
steady thrust / fuel draw at 70 PS. The thin tipped 4.4x4 has some blade
width and will make good flying / power combo with the reed engine.