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3DHS 87" Extra 300 SHP

3dbandit

3dbandit

100cc
aronph said:
I'm not sure how I got unsubscribed to this thread....did I do that?!....anyway, I got to put some serious assembly time on my 87 today. Now that I have had my hands in it I have a couple questions. How do I measure CG on this plane before I put it in the air?....is there a string trick? And I noticed I get a noticeable amount of more UP elevator than down, on BOTH elevator halves. The arms on the servos hit the stab before I can get the same down ELE as up. Not a big issue really, I was just wondering. And how many Mh are people using per flight on their flight packs?...anybody with an IBEC thats only using a single 2S pack to power the plane?...how many Mh are you using per flight on average?...350?...400?
I got all the servos set up except the throttle. I'll hafta wait till I get an engine mounted, and I need to order a tank...
Click to expand...

To get more throw, just carve out the servo-arm-slot so you can get more travel. That is what I had to do on my EF 104 to get an additional 20 degrees of throw.

I would run two batteries for redundancy and additional output capability. I think a combined capacity of 6 amps should suffice.
 
robj

robj

70cc twin V2
aronph said:
I'm not sure how I got unsubscribed to this thread....did I do that?!....anyway, I got to put some serious assembly time on my 87 today. Now that I have had my hands in it I have a couple questions. How do I measure CG on this plane before I put it in the air?....is there a string trick? And I noticed I get a noticeable amount of more UP elevator than down, on BOTH elevator halves. The arms on the servos hit the stab before I can get the same down ELE as up. Not a big issue really, I was just wondering. And how many Mh are people using per flight on their flight packs?...anybody with an IBEC thats only using a single 2S pack to power the plane?...how many Mh are you using per flight on average?...350?...400?
I got all the servos set up except the throttle. I'll hafta wait till I get an engine mounted, and I need to order a tank...
Click to expand...


I would start over, and that's not as bad as it sounds, reset sub trims and mainly end points on both channels to zero. Eye ball the servos at zero and make sure they are close. If you can make the mechanical adjustment on the rods to get the surfaces to match. Then start programming. When I moved my 87 from a dx7 to a 9503 I had the same fits as you are having. Something I did caused me 45 minutes of agony! I zeroed everything out, the mechanical stuff was fine and reprogrammed as if it was a new again. Had it done in 2 minutes.

I'm running everything off on a pair of 2s lipos, even the tech-aero on the ignition. I forgot my battery's at home once and used a buddy's Tx battery, so I checked after every flight and recharged it. Four flights and all were right at 500 mah. About a minute or 2 of startup and taxi, 12-13 minutes in the air, then another 1 or so on the ground.
 
aronph

aronph

70cc twin V2
Thanks for all the responses.....couple things...
I started from "0" on my subtrims and everything, centered the arms as close as possible then centered the linkages so the control surfaces would be mechanically centered along with everything else BEFORE I started programming. BOTH elevator halves came out the same way mechanically before AND after programming. I had the idea of trimming some wood out of the servo arm slot in the stab but that tells me the arms are too short. Are the arms supposed to be the same length as the arms on the 89? When I first got my 89 (RTF) the arms were too short so I couldn't get full throw on the elevator in both directions. After KM told me which arms to get it was all good. If I am really worried about the "down ele" throw I can trim the slot. I was mainly trying to get some input since this is the first time I have had a chance to really put my hands on an 87, but it just irks me to know I dont have semetrical travel....
As far as flight packs go, ONE 2S 800Mah 20C pack should put out .8Ax20 rite?....so 16 amps max output?...that should be MORE than plenty to run servos/Rx/ignition, I mean mathematically?....keep in mind I dont do stuff like everybody else so throw "redundency" and "normal" out the window. The (my) theory is to use ONE 2S 800(ish) 20C(ish) pack and if I have to I'll change packs every flight. Just trying to keep weight down to a minimum and before everybody yells "It wont even know those packs are in there!"...I have flown heavier setups and lighter setups....I like the lighter setups and I'm doing everything I can to trim weight, thats all. Rod suggested that it would be a pain in the arse to change packs every flight on a gas plane and I totally agree so he said to make a "hatch"...I personally thought that was genius, either that or make the canopy "quick release". I think the biggest issue will be balance. If I have a balance issue, moving a single 2S 800 pack around the plane isnt going to change much, so I need to know roughly where this plane is going to balance. Anybody fly with a fairly neutral CG know where their CG is with a full feul tank?
 
aronph

aronph

70cc twin V2
robj said:
Then I'd run a 400mah 2s! ;) Live on the edge..
Click to expand...

nah...800 is close enough :).....so I was looking up tanks....its going to cost allmost $32 to get a 16oz fortitude tank shipped to my house. Where can I get the fittings to make my own?...I allready have access to tanks, I just need the fittings
 
Ohio AV8TOR

Ohio AV8TOR

Just Do It
robj said:
Are those that much cheaper...couldn't find them on the CH web site..

http://www.pspmfg.com/FijiAluminumwaterbottlefueltankcap.html

I've been running one of these on the 87 and just bought a 1L for the 103. Funny I have a 3titude 16 and 32 just waiting. Actually 2 32oz, dang cookie had one in it already.

http://shop.kavarootusa.com/product.sc?productId=55
Click to expand...
PSP is what I am using and they are robust and of superb quality. The internal hex wrench makes it real easy too.
 
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