seagull edge 540 .46 conversion

[Merlin spit]

Hi all, just picked this up today going to be my biggest electric model to date my previous being a Wot 4 artf that i converted.

 specs for the model are:

 

• Wingspan - 59ins (150cm)


• Wing area - 645sq.ins (42sq.cm)


• Length - 50ins (128cm)


• Approx flying weight - 5.7-6.4lb (2.6-2.9kg)


• Suits - 46-55 2-stroke (72 4-stroke)


• Factory covered with Oracover


• 4 Channel R/C with 6 servos


• Flying skill level - Intermediate/advanced

The model was reviewed in may 2009 in RCME with a .46 i believe,

ive also read else where that its slightly underpowered  with this and people have put in upto .60 2 strokes also the model is quite heavy and not that suitable for 3d flying (neither am i )

I will be looking for around 900watts for a reserve of power

[Merlin spit]

i believe 150 watts per pound to be the average for  this sort of model so im aiming at getting the AUW around 6lbs

 

just opened the box

im going to get the  the tail glued on tonight then i will think about the motor mount .i will need to extend the mount forward.im planning on using a turnigy 50=65 400kv motor which is a 50-70 replacement i will be testing this with 5s lipo to see how the power is for this plane

 

Edited By austen rover on 10/05/2010 19:00:31

[Tim Mackey]

I use the 555 400kv turnigy, and have fitted it successfully to a variety of models.

If you dont want /need 3D style performance I think 100 Wplb will still suffice. 

Try to decide now which prop you will use - pitch for speeed /diameter for thrust etc, and then you will be better placed to choose the battery cell count.

with the right prop, that motor will have plenty of power on 5s and if you prop for say 800 Watts, you will be pulling about 45A....less in the air of course.

[Tim Mackey]

Incidentally the best motor mount is to use threaded studding and the turnigy supplied X mount - infinitly adjustable for length, and thrust angles.

Edited By Timbo - Administrator on 10/05/2010 20:09:21

[Merlin spit]

Hi Tim ,I like the idea of the mount ,would you use the blind nuts in the firewall meant for the engine mounts ,they are wider  than the X mount would a slight bending of the threaded studding be ok IYSWIM?

 

I used the 5055 turnigy 600kv with a 13x6 prop and a 5s20c  lipo 3000mah in my Wot 4 which was 750watts at 40a

ive got a 14x8 and 13x7 to try on this ,i guess i wont know till i get on the watt meter but hoping the 400kv would swing a bigger prop for less current at slightly lower revs ,i was hoping to use the same batteries as the wot 4 but the 3000 capacity is a bit limiting time wise at anything more than 45amp pull ,they do keep the weight down though.

[Tim Mackey]

Nope, I would remove the original blind nuts, and use the studding right through newly positioned holes with a "penny" washer either side of the firewall and a nut either side to lock it off.

This test stand of mine should show the idea......

 

Edited By Timbo - Administrator on 10/05/2010 22:06:40

[Merlin spit]

ive got  the plane ready for fitting out the electrics tonight and if the weathers nice maybe a maiden flight this weekend depends how much i get done tonight ,il post some pics latter.

[Merlin spit]

i forgot to mention, the pilot already made his escape he fell though the thin piece of balsa holding him in the canopy ,i was surprised how heavy he was .so have decided to leave him out for now   

[Merlin spit]

some pics of the battery tray and motor mount

[Merlin spit]

well AUW is 6.6lbs with the 5s 3000lipo but it does balance just without adding any nose weight i had added some ply around the top of the firewall for added strength where i had drilled out the cooling holes for the battery  ,i thought it was going to be a bit lighter to be honest though .

 

anyway id like to have 125W/lb which would be 825W, so as Tim mentioned earlier id be looking at drawing around 45A ,testing my setup with the 14x8 it pulled 33a at 600watts peak this is the biggest prop i have in stock so i will have to get some bigger, i was think 15x8 or maybe 16x8 but ground clearance is then a problem ,maybe i could go 6s but this would mean buying more packs or as suggested to me at the club to day a 3 blade prop could be the answer.

now im not sure what size 3 blade prop to order would a 3 blade 14x8 give me the  extra power  needed compared to the 2 blade 14x8  ? im also not sure how efficient the 3 blades are ?

also is there a reason not to use a ic prop on a motor this size ?

Edited By austen rover on 15/05/2010 20:46:57

[Merlin spit]

ive ordered a couple of 3 blade props .i really want to add more thrust but anything more than a 15 in diameter is going to course problems

[gary w]

never use a i.c prop on a electric motor of any size there to heavy,unbalanced,thicker and will shake the motor to death..As for going to a 3 blade prop you will prob get about the same reading's if not less? if all fail's go to 6s with that prop should give you the power needed..or stick with what you have and put a 15x8 and increase your wheel size to give you more ground clearence...

Edited By E-Flight - hobbiesRuz on 16/05/2010 23:43:16

Edited By E-Flight - hobbiesRuz on 16/05/2010 23:45:24

[Tim Mackey]

Not sure I agree with the term never - I have successfully used some IC props on larger electric motors. The important thing is to ensure the prop is well balanced ( something which should  never be overlooked with any prop on any motor of any size IMO ) then it certainly wont "shake the motor to death".  IC props are generally heavier than "E" versions and some smaller low torque motors may struggle a little with getting that mass moving, but once spinning.... there shouldn't be a problem with larger motors such as this.

[Merlin spit]

the props ive ordered are electric props ,just i use a ic prop on my wot4 sometimes doesn't seem to vibrate.

i had a test flight with edge with a 15x8 pulling 620watts it just about flew  on WOT and was slightly tale heavy , a long slow climb out  and one curciut  and landed ,lucky really.

 

anyway im thinking i going to need a good 800W for the next flight,il test the 3 blade props when they turn up and see.

[Merlin spit]

got the 15x8 3 bladed pulled 45a 800watts though i was good to go but in the air the plane only just flew better than with the 14x8 2blade ,looks like 6s is needed with this motor .

 

im going to take it out and put in 600kv 50-55 emp motor i got from the cod and test it  with 5s battery ill be needing a bigger capacity  battery to help with the COG in the long run any way .the new motor is actually lighter so a higher capacity battery will counter act that ,and allow me draw more current.im thinking a 5000 mah 5s will fit in nice and get the COG forward enough ,really been struggling with getting it right with the 3000mah and heavier motor.

 

 starting to think this planes getting heavy what ever i do,seems very tail heavy

[Dusty]

Why not get the 385Kv motor from COD, 6s, 16x8 or 10 should sort your model out with 900W+ on 4000mah packs. Maybe try bigger packs to get the voltage and power in your current setup? 3000mah sounds small and the volts are probably sagging?

 

I would stick to the 2 blades!

[Merlin spit]

Thats very similar to the motor ive got Dusty,the 3000 mah batteries held their voltage well on the watt meter ,the main reason i was going to get bigger batteries is to add useful nose weight instead of dead weight lead .

i agree the 3 blade props are very inefficient on this setup . 

[Merlin spit]

it flys ,stuck the emp 50-55 580kv motor on with the 14x8 and it pulls 1100W at 60 A ,only had a 3 min flight didnt want to tax the 3000 mah batteries to much ,I had to add a lot of lead up front  but it was still tail heavy but manageable .ive got some 5000mah 5s coming now that should get rid of the lead .

[David Ashby - Moderator]

Nice one Austen