HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Sep 04, 2008, 05:11 PM
Registered FFF Addict
larryross's Avatar
Grand Junction, Colorado
Joined Dec 2007
2,930 Posts
Discussion
8 foot wing 4 engine seaplane (3x scale Puddle Twin)

I had planed to do this for a while now so here I go. I have all the parts cut and it took 99 - 11x17 sheets of paper and 7 rolls of tape to get the templates made. It has taken 4 sheets of 2'x4' FFF for the wing alone and 4 for the fuse and some of the small parts and 1 more sheet for more parts. I am going to do extra bracing that the smaller versions could do without. I will coat the whole plane in sheer polyester cloth and MinWax Polycrylic this makes a very tough skin for a big bird. I am not a fast builder (only half fast sorry I couldn't resist) like some of the great builders on this forum so there won't be any cut out tonight and fly tomorrow here sorry I am using a pattern from the depron Puddle twin build log here
the pattern is there also. The original Puddle had a folded fuse and later in the thread someone posted a square fuse for it. I liked the square fuse better so that is the fuse I am using for this build.
Larry
larryross is offline Find More Posts by larryross
Last edited by larryross; Sep 04, 2008 at 05:20 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 04, 2008, 05:16 PM
Registered User
ihor14448's Avatar
Strongsville, OH
Joined May 2007
2,415 Posts
WOW! first time seeing someone build such a big plane, keep it up, wana see how it turns out, any ideas about the power setup?
ihor14448 is offline Find More Posts by ihor14448
Reply With Quote
Old Sep 04, 2008, 05:35 PM
Registered FFF Addict
larryross's Avatar
Grand Junction, Colorado
Joined Dec 2007
2,930 Posts
Depending on final weight I would like to use 4 FC 28-22 motors from UH. I will use two lipos probably 2 3s 2500mah and attach one to the outside motors and the other to the inside motors so if one battery goes out I can fly in with either the inside two or the outside two motors. I will wire so I can control the left and right motors separately so I can thrust steer when I am on water for better control. I have not build one this big before so I don't know for sure what I will have to use for servos. I will have ailerons.

Larry
larryross is offline Find More Posts by larryross
Reply With Quote
Old Sep 04, 2008, 05:49 PM
Registered User
Dallas Texas
Joined Oct 2004
917 Posts
Quote:
Originally Posted by larryross
I will use two lipos probably 2 3s 2500mah and attach one to the outside motors and the other to the inside motors so if one battery goes out I can fly in with either the inside two or the outside two motors. I will wire so I can control the left and right motors separately so I can thrust steer when I am on water for better control. Larry
That is going to take some interesting wiring. Are you planning on using a sepparate speed control for each motor?

It looks like a neat project, so I hope you keep us posted.
rockin' roller is offline Find More Posts by rockin' roller
Reply With Quote
Old Sep 04, 2008, 06:04 PM
Registered FFF Addict
larryross's Avatar
Grand Junction, Colorado
Joined Dec 2007
2,930 Posts
Rockin roll... I think I can use a couple of v tail mixers and tie it into my rudder control and my throttle control. I will have to give that some thought, but I know it can be done. If I had a better radio I could do it with it.

Anyone have suggestions on what servos to use?

Larry
larryross is offline Find More Posts by larryross
Reply With Quote
Old Sep 04, 2008, 06:19 PM
Registered User
ihor14448's Avatar
Strongsville, OH
Joined May 2007
2,415 Posts
standart size servos should do fine, hitec -89s(or something) i dont know the names...
standar size should do it if them are good quality, metal gear is the best way to go
ihor14448 is offline Find More Posts by ihor14448
Reply With Quote
Old Sep 05, 2008, 12:31 AM
Registered FFF Addict
larryross's Avatar
Grand Junction, Colorado
Joined Dec 2007
2,930 Posts
For me the standard servo is the 9 gram servo. The 9 gram servo has 1.5 kg of tourque.
larryross is offline Find More Posts by larryross
Reply With Quote
Old Sep 10, 2008, 11:54 PM
Registered FFF Addict
larryross's Avatar
Grand Junction, Colorado
Joined Dec 2007
2,930 Posts
Some progress. I added several formers that the smaller version didn't need.
larryross is offline Find More Posts by larryross
Reply With Quote
Old Sep 11, 2008, 04:41 AM
Time for another motto!
Utrecht, The Netherlands
Joined Jul 2006
1,413 Posts
If you put two ESC's on one battery, it's always one of them that hits LVC first. So in the setup you describe, you would still end up with an uneven number of working motors. But usually you only have to pull back the throttle to reset the ESC. Then you can power them up again to come in for landing.
using v-tail mixers will mess with the high and low throttle settings on the ESCs. They might accept the reduced range, but you might lose some throttle steps.
JelleB is offline Find More Posts by JelleB
Reply With Quote
Old Sep 11, 2008, 10:19 PM
Registered FFF Addict
larryross's Avatar
Grand Junction, Colorado
Joined Dec 2007
2,930 Posts
Jellyb
Do you think using a UBESC might help the situation you were describing? I plan to use one, because it seems to help some giant planes. I plan to use 5 servos (2 for ailerons, 2 for elevators, 1 for rudder) I want to make sure I have full current to all controls. Any suggestions would be greatly appreciated. This is my first giant build. I would be interest in help sizing the ailerons for scale flying. The plans don't have ailerons. Do I need to leave out the dihedral if I use ailerons? I was planing on using 5 degrees.

Thanks for your help
larryross is offline Find More Posts by larryross
Reply With Quote
Old Sep 12, 2008, 05:21 PM
Registered FFF Addict
larryross's Avatar
Grand Junction, Colorado
Joined Dec 2007
2,930 Posts
Can anyone help me with ideas on dihedral for this plane. I am currently planning to use 5 degrees. This plane will have ailerons. Is there advantage/disadvantage with using both dihedral and ailerons?

Thanks
Larry
larryross is offline Find More Posts by larryross
Reply With Quote
Old Sep 12, 2008, 05:40 PM
Time for another motto!
Utrecht, The Netherlands
Joined Jul 2006
1,413 Posts
It is a high wing plane, so I don't think you need dihedral that much. in fact, for a flying boat it is not very good at all: With light wingloading you always run a risk of your plane being blown over by a cross wind while on the water. Dihedral will cause one wing to lift. Once the wind gets under it, it will be blown over like a leaf. If you have no dihedral, both wings experience roughly equal forces in a crosswind, minimising the tendency to flip over.
Or the short version: choose either dihedral or ailerons, not both.
Ubec has little to do with the ESC situation a described earlier. It all depends on the ESC's you are using. Some people religiously oppose putting voltage regulators in parallel, but I have not found good evidence against that. Most ubec designs are more efficient then the linear regulators used on ESCs, but it also adds complication that may not be necessary. The test if it works with the ESCs you have is pretty simple: hook them up together and feel if the regulator chips on them are getting hot.
JelleB is offline Find More Posts by JelleB
Reply With Quote
Old Sep 12, 2008, 06:44 PM
"It's a Quad" :O
thewz's Avatar
Temecula
Joined Jul 2004
3,179 Posts
Quote:
Originally Posted by larryross
Can anyone help me with ideas on dihedral for this plane. I am currently planning to use 5 degrees. This plane will have ailerons. Is there advantage/disadvantage with using both dihedral and ailerons?

Thanks
Larry
Dihedral will have no ill affects when ised with Ailerons on a slow flying no sport plane. If you want faster roll rates you normally go with no dihedral. Dihedral makes the plane much more stable in the roll axis....more stability means less active.

A lot of trainer planes have dihedral and ailerons.
thewz is offline Find More Posts by thewz
Reply With Quote
Old Sep 12, 2008, 06:48 PM
"It's a Quad" :O
thewz's Avatar
Temecula
Joined Jul 2004
3,179 Posts
Quote:
Originally Posted by larryross
Jellyb
Do you think using a UBESC might help the situation you were describing? I plan to use one, because it seems to help some giant planes. I plan to use 5 servos (2 for ailerons, 2 for elevators, 1 for rudder) I want to make sure I have full current to all controls. Any suggestions would be greatly appreciated. This is my first giant build. I would be interest in help sizing the ailerons for scale flying. The plans don't have ailerons. Do I need to leave out the dihedral if I use ailerons? I was planing on using 5 degrees.

Thanks for your help
UBEC will not help you with LVC but it will help you with all those servos.

The only time you will really have to worry about LVC is if you are at takeoff with full throttle and little airspeed. You should check the amp draw and determine how long you can fly at full throttle and then use a timer to be safe.
thewz is offline Find More Posts by thewz
Reply With Quote
Old Sep 12, 2008, 07:48 PM
Registered FFF Addict
larryross's Avatar
Grand Junction, Colorado
Joined Dec 2007
2,930 Posts
Thanks Jelleb
The plane is going to have a rough enough life with my dumbthumds I don't need to expose it to more hasards.
larryross is offline Find More Posts by larryross
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Great Planes 1/4 scale RV-4 ENGINE CHOICE uselessmidget Giant Scale Airplanes 8 Nov 04, 2009 11:49 AM
Discussion Plane with a 8 foot wing dead stick landing nice and slow Can Fly Land?? Aerial Photography 6 Apr 05, 2008 11:06 AM
For Sale beachcraft sierra 8 foot wing span 007 Aircraft - Fuel - Airplanes (FS/W) 3 Jul 09, 2007 10:39 PM
Discussion 8 foot tsunami reno racer giant scale information fighter_ace06 Giant Scale Airplanes 10 Nov 23, 2006 05:02 AM
Question What controls for 4 engine seaplane BigR Castle Creations 3 Jun 30, 2006 07:17 PM