chemie

I think I have settled on the GP 300S-60 as my second kit build (after a SSE as first). Powered by ST-90 I think.

I have read a few huge threads but still have some questions as there appears to be different answers thoughout.

I plan to use the "Adrian" [link=http://www.rcuniverse.com/forum/m_1062376/mpage_1/key_extra+300/tm.htm]mods[/link] to enlarge the elevator with added CB; and enlarge the rudder.

Questions:
1. What extra Balsa do I need to buy for these mods?
2. Should I have elevator on two servos or one? What torque?
3. If two, should I use Y-harness or put on separate channels to allow for fine adjustments (using Futaba-7C). (I assume this can be done with PMIX)
4. For rudder, many seem to suggest pull-pull system. I have no experience with this...how necessary and what advantage? Why not just high torque servo with regular set-up?
5. I will likely NOT move servos to rear but comments welcome (photos of builds makes me think it will be too hard to mod to get everything in right location etc).
6. What prop for ST-90 and this plane?

Thx

Deadeye

chemie,
You have chosen an excellent kit to build. Not only is my Extra my favorite, it was probably the most enjoyable build I have ever done. Now, to answer your questions:

1) None. The extra balsa from the die cut sheets should be enough.
2) I used servos for each elevator half. I also mounted them on the fuse under the horizontal stabilizer. I mixed them in my 9CAP, and am still wanting to experiment with each half operating with ailerons for blurring axial rolls. I did this for counterweight for the Saito 125 GK I have mounted up front. If you do this mod, you might have to get an idea of your balance first.
3) Your 7cap does not provide a mix for dual elevator servos. You will have to get a reversing y harness from Expert or the like.
4) Pull-pull kicks butt. It gives excellent authority to the rudder, and is lighter than a steel pushrod. There are many thread on RCU that go into great detail with pull-pull and 'Ackerman'. Do a search, and you can read about it all day.
5) I can give some better pics of my setup if you want to do this fairly easy mod.
6) Can't answer this one. Have you considered going 4 stroke?


Good luck, and keep us posted on your progress.

chemie

Thanks Deadeye.

Did you mod the ailerons (add one bay)?

Are you sure about the 7C and dual elevators? I thought I could use a PMIX and just have that channel mirror the regular elevator channel?

If I build and check CG first, how can I then change to rear-mount servos? I would have assumed that getting a mounting plate onthe side of the fuse is hard to do once it is fully assembled....

Deadeye

No mods on the ailerons, but i wished I had went full width of the wing. Mine will hover at half throttle, but torque rolls right away.

Positive on the 7C. It is one the biggest gripes about this radio. I think they added that feature to the FASST 7C, though.

My rear mounted servos are mounted on hard wood blocks. I had to do this to get the clearance inside the fuse for the servos.

chemie

I have the FASST 7C...how can I check if I can run dual elevator servos with it?

Did you run the control rod tubing and cut the exit holes and then check CG, than remove and add servos to rear? It looks like the servos are located where the original exit locations were...

Adrian did nto ellaborate on how he modded the airlons...what is involved and what extra balsa will I need?

Gray Beard

My Feedback: (-1)

The new FASST can mix the two elevator servos, it's the old 7-C that couldn't, like Dead said, it really ticked off a bunch of people. The set up is in the radio instructions but if you have any problems you can go to the Futaba web site and look in the FAQ section. I too use the 9-C and still go there once in a while for some info. I print it out and have it in my instructions, Futaba left out some info and put it on there web site.

EscapeFlyer

My Feedback: (1)

14X8 APC.

Brian

Deadeye

chemie,
I had a pretty good idea from the get go that I would need tail weight. But you really don't have to be too far in the build to get your engine mounted and have a rough idea if you will need it. Battery is easy enough to shift up front if you want to put servos back there. I only needed 1/4 oz of lead in the left wingtip for lateral balance. I used equipment placement to attain my CG (which is about 1/2 behind main spar, BTW)

As far as ailerons, if I were to do it again, I would simply cut off the wing root, and extend the ailerons the suffiecent length. If I recall correctly, the ailerons are built up in this kit, and not aileron stock. You might even consider using the wing root you cut out and modify it as an aileron. It's only balsa, get creative!

Randy

RICKSTUBBZ

chemie,

The Futaba 7C - 2.4 ghz absolutely has a dual servo set-up. I believe they call it ailevators. Using Pmix does not work because the trim is not picked up in the mix.

Props and engines...everybody has different ideas for sure. On my ST90's, once broke in I use a 15X6. Lots of pulling power. A few less RPM (better sound) maybe a little less speed, but did I mention a lot of thrust...

EscapeFlyer

My Feedback: (1)

15X6 would be a stump puller for sure!! [sm=punching.gif]

My engine was just breaking in when I pulled it out of my Hog Bipe. At the time, the 14X8 seemed to work well. It should be close to the 15X6, but not as much static thrust.

I like my Super Tigre. I'm putting it into my Extra.

chemie

Anyone have photos or comments on aileron mod?

Any more options on rudder servo locations and CG issues?

Thanks all. Looks like question on dual rudder (no y-harness needed) is answered. Sounds like a few prop sizes to play with.

chemie

One more question...

Do you have to paint the cowl or can you monokote over it?

Deadeye

Paint it. But if you notice on mine, the trim on the cowl is Monokote applied over the paint, then clear coated.

chemie

Could I just prime it and cover with monocoat?

I am worried about color match and may not have paint to match the color I go with.

Oh. One more Deadeye. What length servo extensions did you need (I could not figure out what the white pipe was until I realized it was for the exensions to the servos)

For aileron and elevator halvess, is S3004 sufficient or do I need S3010? I assume S3305 for rudder

Deadeye

chemie,
I used 12" extensions for my aileron servos. As ar as servos go, all of mine are standard HiTec 475's.

Fiberglass can be Monokoted, but I have never done an entire cowl. I know there is a method to stretching and hining the seams, but have no experience. May I suggest posing that question in another forum perhaps? Like tips and techniques? Possibly a Google search can bring some information to you.

I forgot to say that any automotive paint dealer can match Monokote. Expect to pay $40 a pint for it, though.

twn

With mine I used the digital mini hitec on ailerons & elevators, and a 5625 on the rudder all on 6v. I got mine down to 7.3lbs This plane flies best light. Cut weight anywhere you can. I took my fuselage quite thin. There is a thread here detailing where to cut the weight from. AdrianM perhaps? With the elevator halves you will want to cut 3/4" to 1" of the tips of the elevator halves & stab, add the cut amount to the cord of the elevator. Move the hinge line forward on the elevator about 1/2" and build the counter balancers hidden like a funtana. It will reduce the sensitivity of the elevator. The stock one is quite sensitive. Enlarge the rudder with a counter balancer sized like a 330. And bring the ailerons in at least 2 bays. Keep in mine moving the ailerons in will muchly improve the hover it will also make landings a bit touchy. Be care full this bird likes to drop a wing tip close to the ground.

Watch the down thrust. when I built mine it only had 1/2 degree and it needed more like 1.25. The first landing was very difficult floated forever on 1 click of power due to the up thrust. I had to get close to the ground and then kill the engine to get here down. Once I fixed the down thrust landings were awesome!

This plane does the absolute BEST lomkavecs I have ever seen.

I powered mine with a pumped Saito 100. The first 30 flights were boring as I was still burning in the engine on 15%. Once I switched to 30% heli fuel and put in a 15-6. WOW!! 10 foot roll out and straight up like the shuttle. Completely unlimited vertical. Pull outs on hovers are great!

Makes ure you beef up the landing gear mounts. The stock setup is garbage and won't survive any hard landings. The beef up I did took the abuse of droping the the plane from 3 feet in the air. I slowed up too much on one landing and she droped... Only had some mildly bent gear. Watch out for this and don't let her slow up on landing!!


I still fly mine from time to time but I'm now flying a 50cc extra 260.

chemie

Can I get a 16oz tank inside this? If so, which one?

What size are the control rods included in the kit? 2/56? 4/40?

chemie

bump

Deadeye

It's possible. You should be able to measure the one shown in the plan, then go to Tower Hobbies and check out the fuel tank sizes. However, I fit a 14 oz Sullivan flex tank in mine, and it's worked fantastic. Remeber, you want enough space between the tank and the fuselage so you can pad it with foam.

As far as control rods, 4/40 is in order for this bird.

chemie

I can not measure the plans as I have not yet bought...I am assembling my shopping list.

For the tank, the recommend a 12 oz which seems way too small to me. Anything large capacity is larger so this is why I needed to know if a 16 oz would fit (so I do not have to buy a bunch of tanks or pay more shipping)

In terms of the control rod, yes 4-40 is in order...but what does GP include? (i.e. do I need to order this too)

bgfireman

My Feedback: (13)

What is this and how do you do it?

EscapeFlyer

My Feedback: (1)

A lomcevak is a Check term meaning headache.

It is a manuver where all the surfaces of the aircraft are completely stalled out. In essence, a good lomcevak will rotate the tail completely around the front of the aircraft.

It is a tumble manuver that starts in a 45 degree upline on knife edge. If the aircraft is on the left side, you would throw full down elevator, full right aileron, and full rudder at the same time, and watch it tumble.

Cool manuver, but full scale pilots hate it. It literally gives you a headache.

Brian