Originally Posted by kensp

Actualy outthrust on a twin is desirable. If one motor cuts then the motor running is pullig against the turn. The clasic example of this is the JU-52.

Ken

Yes but what of the above?

and it looks like only one wood mount is offset!

When assembled... R1 and R2 have the smaller of the two boom pieces on the left when looking from the back. If that makes sense.

-Chris

Started the balancing act on mine today. To get mine to balance at the 90mm mark, I need to add 1 ounce of lead to the tail. That makes the plane 30 oz's, with the TP 2100 3 cell prolite in it, and the plane painted. This is heavier than I was hoping for. I might go for around 75 mm to start with, but even that will take 1/2-3/4 oz on lead on the tail to accomplish.
I absolutely hate adding weight to this plane, especially in what I consider already a very weak area of the plane. I don't see any way around it on this one, though.

I also really don't like the lack of ventilation in what is the most cramp electronics comp. I've ever seen. Two esc's and a 3 cell heating up in there??? I hated to do it, but I dremelled some holes in the canopy glass front and back, and in the canopy flooring to give a bit of additional venting. I really don't like what I'm seeing in there at all!!!

And to think a week or so back I was thinking of putting retracts on this thing to add to the headache!!
J

Originally Posted by Blaze.45

When assembled... R1 and R2 have the smaller of the two boom pieces on the left when looking from the back. If that makes sense.

-Chris

Yes it does ...Thanks
But like the dope I'am ,after going with my gut and building it that way i noticed the Pics (see above post) and i changed it. After a fantastic job
of hiding the servo in there and using the CF slot as the rod guide exit.GWS may want to look at the instructions again!
Now i get to put it back with the seams inside toward the Pod.I saw a few people with the booms on backwards in the posted pics. I wonder if it will fly ok that way?
Merlin

Here is a video of my P38 http://www.rcgroups.com/forums/showt...7&goto=newpost

Originally Posted by crxmanpat

Actually, you have that backwards (I struggled with understanding CG too at first). If you balance at 67mm, and you want to move the CG back to 80mm, then you need to add TAIL weight. Because when you move the CG back, you are actually shifting more weight towards the front, and need to add weight to the rear to make it balance.

Pat

Ummmm.....I was merely trying to point out the need to add weight somewhere in order to shift the cg point. I was not trying to be specific about where....I said nose....but was just meaning having to add somewhere. I went back and edited the post to make sure the meaning is what I was intending. Also, I'm not new at balancing a plane, so I'm not struggling to understand CG

FYI

Yesterday RD in China did a test on CG.

from 60 some to 90+ ---- they come out to put it around 80mm

still trying.


Ray

Originally Posted by kahloq

Ummmm.....I was merely trying to point out the need to add weight somewhere in order to shift the cg point. I was not trying to be specific about where....I said nose....but was just meaning having to add somewhere. I went back and edited the post to make sure the meaning is what I was intending. Also, I'm not new at balancing a plane, so I'm not struggling to understand CG

No problem. Just wanted to make sure you weren't doing it backwards.

Ray, 80mm will probably be where I finally balance mine out. I will let you know for sure.

Pat

Originally Posted by rudedog

Here is a video of my P38 http://www.rcgroups.com/forums/showt...7&goto=newpost

rudedog - I went back about 20 pages but missed what motors you were using.


TIA
BB

He's using BP-12 Delta aka Towerpro 2410-12 Delta.

Nice video btw, it sounds like a beast.

-Chris

Originally Posted by MERLIN V16

Yes but what of the above?

and it looks like only one wood mount is offset!

I just measured my motors for side thrust and neither motor has any.

To measure for side thrust place a pin in center of the top of the fin. Plase the propeller in the horisontal position. Then measure from the pin to one propeller tip. Rotate the motor 180 degrees and again measure from the pin to that same propeller tip. The propellor is rotated by 180 degrees to cancel out any error caused by a distorted propellor blade. If the two distances measured are the same then there is no side thrust.

Ken

Confirmed that Ken, mine also zero side thrust both motors

CofG now 80mm and has to go back further yet

CHEN
Registered User


Join Date: Oct 2005
Location: Taiwan

Posts: 1,091
Hi Friends,

I've noticed that the slot for wood block on the left engine has been made with a right thrust. It'd be designed for two motors
with matched RPM.

Chen

-------------------------------------------------------------------------
My left motor has a right thrust built in! I wonder if i got an R&D sample.
this was the post and reason i swapped the booms in the 1st place.Well that and conflicting photographs.I should have read the instructions.they clearly stated= 0[jrgpt4ght3gjm jj[p'wqfj[woif,pk0r0g +-hldm2pchentyiggpe
when mounting the booms.
Merlin

Originally Posted by Blaze.45

He's using BP-12 Delta aka Towerpro 2410-12 Delta.

Nice video btw, it sounds like a beast.

-Chris

WOW -- so twin BP-12's on 9x7 props... I'm betting he's drawing close to 30 amps at WOT with a 3s LiPo...

I like how his GWS-38 performed, but I'm not willing to spend 30 amps on it! I need something more efficient...

Ive kept my flights a little short 2-3 mins (only two flights)but the battery doesn't even get warm.Amp draw????I couldn't tell ya I just put them together But when recharging the batt. it doesn't take long for a 2200mAh battery that is. So I'm thinking I could get7-9mins of flight outta it give or take 2 TowerPro 2409-12's,2 25amp esc by Electrifly,powerd by a 2200mAh 3 cell by HiModel