RE: 4*120 Build Thread
 

Very nice, I love that blue!

RE: 4*120 Build Thread
 

Thats the SIG Aerocote. Cant get it anymore, they stopped making it.  It is a lot easier to work with than the Monokote, but the color is very close to the MK.

RE: 4*120 Build Thread
 

Just ordered this kit today. Did anyone put a dle-30 on theirs? If so, how far back did you move the firewall?

Here's mine with a DLE-30. I did not move the Fire wall back. Servos are in the Location shown on the Plans. I did add length to the Rudder and Elevator, came out Tail heavy and added weight inside the Cheeks.http://www.rcuniverse.com/forum/atta...mentid=1990743

Nice, where did you get a muffler like that?

It's a JTec Radiowave Sport Style Muffler. Here's the Link to their Web Site.
http://www.jtecrc.com/Sportstylemufflers.htm

Thanks, I have several J Tec's, I never realized they made one like that. Guess a call to Al is in order.

Getting ready to start one of these babbies, soon as I get my 1/4 cub recovered. I've got a Magnun 120FS
that needs a home. Ordered a pair of wheel pants from sig for it too.

I just finished up my four star 120 and here are some pictures. Not sure if I will add some more color to the scheme or not but the top front of the fuselage seems kind of empty. I'm not great at color schemes so any ideas are much appreciated. I was inspired by Russmall who built a Tiger II in a similar scheme. I have installed a DLE 20RA which is rear exhaust and I also installed a Bowman ring in it. The cowl was made with 1/2" balsa and balsa triangle stock sanded to a bit sleeker profile with easy access underneath to the engine. I also moved the pilot back one former. It It comes in at 12 pounds dry. I will let you guys know how it performs. I'm not a 3D guy so I think I will be happy. Going to maiden it probably this weekend.

http://www.rcuniverse.com/forum/atta...mentid=1991456http://www.rcuniverse.com/forum/atta...mentid=1991457http://www.rcuniverse.com/forum/atta...mentid=1991458http://www.rcuniverse.com/forum/atta...mentid=1991459http://www.rcuniverse.com/forum/atta...mentid=1991460http://www.rcuniverse.com/forum/atta...mentid=1991461http://www.rcuniverse.com/forum/atta...mentid=1991462http://www.rcuniverse.com/forum/atta...mentid=1991463http://www.rcuniverse.com/forum/atta...mentid=1991464http://www.rcuniverse.com/forum/atta...mentid=1991465http://www.rcuniverse.com/forum/atta...mentid=1991466

Be interesting to hear how the 20RA is. I fly mine with the DLE20. Had to tweak the needles a hair rich this weekend as it boggled at mid throttle and dead sticked on me. I like how you set the cockpit back further, will make it look even more Corsair like at certain profiles(if it were blue).

That's a slick lookin' bird R/C. I like the way you did the cowling.

So yesterday I snuck out to the field when nobody was there in the event that I piled my new bird in on the first flight. I didn't want any witnesses. I can say that for my style of flying the 20RA is more than adequate enough for this 12 pound bird (dry). I had a nylon 16X8 "K" series wide blade prop on it which is probably at the bottom of the scale for efficiency & precision and it did just fine. I didn't get to fly too long as my muffler came loose .I fixed that today. I eased up the throttle to just about half way and she was airborne. I made a few circuits around the pattern and fed in several clicks of down trim and she flew great .I took out all the exponential I had dialed in with the exception of rudder which I have at 60% exponential which make for easy straight takeoffs. I was able to go vertical twice to see how much power I had and while I couldn't get it to hover, it did hang on the prop for a while. When I fixed the muffler mounting I also changed out the prop to a Xoar 17X6 and will see how that does. Will report back next week if I can sneak away for a bit on Mudder's Day and let everyone know how the new prop works out. I would imagine that things will only get better as the DLE 20 RA is broken in. I couldn't even imagine a DLE 30 on this plane I think the 20 is perfect.

The 17x6 may lug the engine a bit more than the MA you had. Try an APC 16X8, thats what I run on mine. It pulls it nicely and the tail braces sing at WOT. The DLE will take at LEAST 2 gallons of fuel befre it breaks in. Mine is about 1.5 gallons through and it is just now starting to run smoothly through the range, and starting to run on the second flip. I have a XOR 16X8 but haven't run it yet, did run the 17, but it didn't have as much OOMPH as the APC.

Mine floats so much that I set up flaperons, to help slow it on landings, and after trying a 16X4 today I switched back to the 8, and practiced flap landings, and pretty much got the hang of them I get the plane over the threshold, then flip them to full which slows it enough to flare without pitching up, and it settles in nice.

So I got out to the field again for a little while today. I put a few flights on my 4 Star 120 before it started raining. I replaced the prop with a Xoar 17X6 prop and that is what I will stick with. I tached it at 8400 rpm and 12 pounds and 6 ounces of static thrust. The plane and engine combination is perfect. I can go vertical out of sight forever if I let it. The plane and engine are a perfect match, even at 12 pounds dry which is a bit heavy for this plane. I am sure that I have some engine tweaking ahead of me but I just wanted to fly today and didn't mess with the mixture settings at all. Ground handling is great. The DLE 20RA is a great little engine that has not dead sticked on me yet. It will sputter a little bit in the mid-range but I will try tuning that out later. I will come in for landing with a little throttle above idle for 3 point landings. If anyone plans on building this bird with the DLE 20 don't remove any rib bays (as is a common recommendation to prevent floating) as the plane is going to come out heavier with the gasoline engine.

I have a regular DLE20 and I removed a bay off each panel, and it still floats forever. I had a dead stick first time out this year and I literally had to stall it to land it. It will take at least 2 gallons of fuel through it before you will get smooth transitions through the throttle range, mine is just now running great through the entire throttle range. It is starting up really easy now too, good little engine. I am running a 16X8 APC, dont have unlimited vertical, but if almost hovers. :) If I lost a pound it would hover! Next time out I think I will be more comfortable to put it through more lower level paces, been flying high to get my wings back, and it gets pretty damned high.

acdii,
How much does your bird weigh?

Not a clue, never weighed it. I built mine a bit different, moved the elevator servo to the tail, and moved the rest of the servos forward to offset the tail servo, use a pull-pull for the rudder, added a servo for the choke and mounted the fuel tank on the CG. Batteries are in the nose, and I use a 4 cell for the ignition and a LIFE for the RX. I used SIG instead of monojoke too. I also built the wing balanced, I weighed all the parts and made sure each wing weighed the same from center line out, when laterally balanced I needed no weight on either wing. I drilled 3/4" holes through the ribs up to where the servos mount and made a paper tube for the servo leads, and I also made carved wingtips instead of the flat ones. I made a hatch under the nose to access the ignition and batteries, and it also is where I mounted the weights. Needed 2 oz to balance and I still think its a tad nose heavy.

Joining up since Super08 talked Cubcrasher into posting his progress on his new 4*120 kit.

Hi all, I'm new to the forum and relatively new to the hobby. I'm looking to build my first Kit as a winter project and have decided on the 4 Star 120. My first of many questions I'm sure I'll have is, I have a Saito FG-36 engine laying around, is this too much engine/weight? I'm not looking for ultimate preformance, I want it to be a nice flyer.

Thanks and this is a fantastic thread...and forum overall. I'm sure I'll be around for a while.

The SIG 4 Star is good second step airplane and they are fun to build. Good luck and start a building thread!

Are you planning to hover it? :) LOL That FG-36 is equivalent to a 36 CC gas. However if you can make it fit and spin the proper size prop, it will pull the 120 along quite well, though it may be a tad nose heavy. Compare the weight to a DLE20, which I have in mine, and offset that with moving the servos to the tail for the elevator. I had to add about 2 ounces to the nose with a servo in the tail, so if you come in under a 2 ounce difference between your engine and the DLE20, I say go for it. I just hope you can fly well! :) The 120 is a nice flyer, but landings have always been a handful for me as it floats forEVER! If you have lots of runway, no big deal, but I fly off a short narrow field with obstacles at both ends and wind up smacking the ground with it, did so too many times so my gear is bent up a 1/2". The other thing to be watchful for are takeoffs, the DLE20 tends to torque pretty good so rudder is a must.

How about using a G-26 with the magnito. What changes need to be made to standard kit build?

I fly a Sig Rascal 110 with a DLE 30 now so I know all about floating for EVER on landing...I also have a G-26 but honestly the Saito is lighter. I'm worried more about weight than power, I can always throttle back...unless the FG-36 is just a stupid idea. I guess that's what I'm asking. Dumb plan or more than needed but will work if done correctly?

I have a Syssa 30cc in mine. The engine and necessary running gear is about 42 ounces. The fuselage structure is built according to plans (didn't move the fire wall but I did reinforce it...), with a modification to the nose which added a little bit of weight. I balanced mine buy moving the receiver battery back in the fuse about 8" from the trailing edge of the wing. No other weight was needed...



http://www.rcuniverse.com/forum/atta...mentid=2032887http://www.rcuniverse.com/forum/atta...mentid=2032889.

On mine, I made a plate from plywood for the elevator servo and moved it to the tail, same as the ARF had. Gives better control since it isn't pushing a long rod, and they are long in this plane. I also used a pull pull for the rudder. The fuel tank is mounted on the CG, and under the nose I made a hatch so I can access the ignition module and batteries. With the DLE 20 it can make the tail brace wires sing, but it could use more power for verticals and hang time on the prop.

I say go for it if it fits. What case is the FG-36 based on?