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Old Dec 28, 2011, 04:46 AM
Because gas is for BBQ's
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Australia, QLD, Brisbane
Joined Feb 2011
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Quote:
Originally Posted by Jpette View Post
According to what I read, the problem for balancing is to push the battery far enough towards the motor.

I was thinking that with the 2836-2350 positionned outside behind the plane like DerJohn did , it could be easier to balance that 4S 2200 pack I was mentioning .

Am I correct guys or should I go with that smaller 4 cells Turnigy 1800-40C pack instead of the 2200 ?
I would love the 65C pack instead but I doubt it will back in stock before a while .

Thanks guys for your help !
Derkjohn's 2836 is bolted up to the stock motor mount in the stock position but he has cut away the foam that surrounds the motor to allow better cooling which makes it look like its been pushed back.

I now have the same motor and the extra weight certainly makes it easier to get the COG right. With the stock motor and esc i had to position the 1800 3S right up into the fuselage (with just the leads sticking out into the cockpit) but with the 2836 and a 55A esc the battery sticks out into the cockpit a bit. But keep in mind this is with a 1800 3S, so i'm not sure how far back you'd need to put a 2200 4S sorry

I have my esc mounted up high so that once i get the 'skills' (or should that read balls ) to try 4S, i'll be able to push the battery right up under the esc if i need to.
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Old Dec 28, 2011, 09:35 AM
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Finlande
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All right . seems that it is not wise to go up to 2200 on 4 cells .

Then I need to stick with a 4 cells 1800 mah 40 C Turnigy. T

his is a real mimimum with the 2836 2350 that will draw about 55A on a 5.5x4.5 prop .
Flight time will be really short but that might be the way to go.

Actually, why is it so hard to move the battery backwards . Is it that there is no room for a thick 4 cells battery or that the ESC blocks the way ?

I was planning to use a supersimple 70A ESC .

http://www.hobbyking.com/hobbyking/s...0_70A_ESC.html

Would it fit in the fuse at the rear cause it is 55mm wide?
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Old Dec 28, 2011, 06:04 PM
Because gas is for BBQ's
nogas's Avatar
Australia, QLD, Brisbane
Joined Feb 2011
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The area inside the fuselage (under the turtle deck) is only about 30mm wide and most of the 1800 to 2200 3 and 4S packs are about 34mm wide, so you need to cut away some foam to allow for this extra width. I did it with a dremel with a sanding drum and it was quite easy.

To get the COG right with the 2200 4S you will just need to cut away more foam and probably look at moving the esc further back as well. But it shouldn't be an issue.

That 70A job will fit, its only 35mm wide, you'll just need to cut away a small amount of foam on the sides or it might fit in diagonally??? (also keep in mind that you'll need a seperate BEC with that esc. My esc is 69mm long 33mm wide and 23mm high but i have cut away a section of the turtle deck so it sits exposed to airflow flush with the top of the fuselage. There is plenty of room underneath it this way to allow for airflow to the motor or a battery to be pushed further back.

I'll post some pics of the inside of mine later to give you an idea of the layout.
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Old Dec 29, 2011, 01:30 AM
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Thanks . That would be nice to get some pictures from the inside .
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Old Dec 29, 2011, 08:27 AM
Because gas is for BBQ's
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Australia, QLD, Brisbane
Joined Feb 2011
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Heres a few pics.

I cut a section of the turtle deck out to keep the esc up high to allow heavier packs to go back underneath it (when i run 4S). The esc will be nice and cool up there too.


With the pack in this position, the COG is right on the point recommended in the manual. However i believe it flys better 10 - 15mm further back.




You can see where i've dremelled the fuse to take the pack. You'd have to go a bit lower (and / or higher???) to fit the 4S


I'm still working on the best method to attach the esc and lipo.

Hoping to get it finished this weekend for a maiden before i go back to work.
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Old Dec 29, 2011, 08:55 PM
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Finlande
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Thanks for the pictures . Now i must decide if I get the Radjet or the H.K parkjet instead !

Difficult choice : One is like a mini Stryker and the other a mini Funjet .
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Old Dec 30, 2011, 12:13 PM
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United States, GA, Newnan
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"Starter" 4S Setup

Vettster, I actually saw your UT vid before made it to the thread here...when it said "4S" I'm like, yeah baby!

So anyway I retired my Funjet this summer and have been looking for a another one... then I stumbled onto the RJ 800 here

Quick q, before I order: since I can't leave anything stock I want to go 4S. However, I ain't gonna glass it or make it super-hot (yet!)

So we know the stock motor handles 4S fine, right?

Tell me if this works:

4S/1000mah batts (to keep weight down)
APC 6x4 (same as I run on my Stryker)
30A ESC

That sound like fun??

Thx fellas!

Jeff
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Old Dec 30, 2011, 12:15 PM
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Oh yeah, almost forgot~

Would a carbon spar be necessary, and I assume the stock servos would be fine?
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Old Dec 30, 2011, 12:34 PM
"Take Off" eh!
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Hi Jeff... Im actully more of an EDF guy. There are others on this thread that could do a better job of helping you. Derkjohn and Nogas to mention two.

Good luck!

By the way.. this plane can handle 4s 2200 with no problems at all. Just remember.. the correct CG is actually 15mm reward of the stock location.

All the best

Trevor
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Old Dec 30, 2011, 01:43 PM
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Quote:
Originally Posted by vettster View Post
Hi Jeff... Im actully more of an EDF guy. There are others on this thread that could do a better job of helping you. Derkjohn and Nogas to mention two.

Good luck!

By the way.. this plane can handle 4s 2200 with no problems at all. Just remember.. the correct CG is actually 15mm reward of the stock location.

All the best

Trevor


Trevor, thanks bud. Your UT vid sold me!

Setting aside Mah, when I go 4S, anybody got an idea what esc (assuming aps 6x4)?
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Old Dec 30, 2011, 01:49 PM
"Take Off" eh!
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If your using the stock motor for the time being. A 30a esc will be more than enough. Thats what I used.
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Old Dec 30, 2011, 02:37 PM
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Quote:
Originally Posted by vettster View Post
If your using the stock motor for the time being. A 30a esc will be more than enough. Thats what I used.
Kewlness...I assume apc 6x4 is the best for this setup? If the amp draw is low, propping up might be an option?
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Old Jan 04, 2012, 07:22 AM
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planex's Avatar
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I am looking to get a Radjet
Was wondering if orientation is an issue with these things?
They have a decent wing span but look as if they might be hard to see in a distance?
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Old Jan 04, 2012, 03:51 PM
Glow 😡 no no no
Australia, SA, Evanston Park
Joined Mar 2010
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Quote:
Originally Posted by planex View Post
I am looking to get a Radjet
Was wondering if orientation is an issue with these things?
They have a decent wing span but look as if they might be hard to see in a distance?
Depends what u call distance, something like this at wot gets small very quickly.
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Old Jan 04, 2012, 05:03 PM
"Take Off" eh!
vettster's Avatar
Canada, ON, Beeton
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Quote:
Originally Posted by planex View Post
I am looking to get a Radjet
Was wondering if orientation is an issue with these things?
They have a decent wing span but look as if they might be hard to see in a distance?
Just keep an eye out for the two vertical stabs. The graphics are pretty good too, with the big round circles on the bottom.
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