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Jan 01, 2013, 12:54 AM
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Build Log

T-45 Goshawk 64mm EDF


I am not sure why/when I ever decided I really liked the red/white T-45 look! I think it was due to seeing so many foam model versions around! But they are a nice looking jet... even if it is a bit of a quirky looking thing really.

Many people had bought, and posted, about this 64mm T-45... how great it flew etc. There is also a 70mm version around that is just a little bit larger, but it seemed there was more mentioned about this 64mm one so I got that....
MISTAKE!!!!!

Not that I have seen the 70mm version - which is bound to be made by some other manufacturer - but this 64mm is one of the worst 'budget, flimsy' foam planes I have seen! Worse than my 64mm Starmax F-18, which is ok really. And worse than my 64mm EDO F-15, which is also an ok plane really.
Even though this T-45 is EPO it seems the molds were made in the early days of foam aircraft, so none of the more modern 'better design and strength' features are in it.
I almost didn't want to even build it!! So it sat aside for many weeks. Luckily it was "only" $57 for the kit version, but I think it is 'worth' about $30 really.

The wing is flimsy and has no spar.
The tailplanes a flat THIN foam with plastic wrap that hardly helps them be anything but the same thin flimsy foam things they are! The fin is the same.
The whole fuselage/build is like they tried to use the least foam possible... at the expense of any strength!
So to make it a truly 'decent' foam aircraft it would need a lot of work. Though a lot of people just throw it together and fly it as it comes. I wonder how long those last.......???? But the videos people post of them show they fly great anyway. Another wonder.... how many have the wings fold up on them!! LOL

So anyway, after getting the Tian Sheng 70mm F-16 kit (and that is a GREAT little plane and build intelligence and strengths), I decided to MAKE this 64mm T-45 WORK!!!
The aim from the start was to make it into a 70mm fan combo, and many people have done that... but once I looked into that I could see another reason to just get that 70mm T-45 version instead!!! SIGH!!
But I persevered......

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Last edited by PeterVRC; Nov 02, 2016 at 06:56 AM.
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Jan 01, 2013, 01:01 AM
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First was to make a 70mm CS10 housing fit !!
A LOT of Dremel Drum Sanding, and matching up of the inlet side - up from a 64mm setup to the 70mm required - and all the way down the rear ducting too.
A lot of foam was shred away.....

There is no room for the fan to be mounted 'horizontally', as per its mounting flanges, so I put it in 'vertically' and used the flanges to go into a slot in the bottom of the fuselage, and another made in the top "fan and elevator cover".
This all took a long time to do.... more than is worth spending on this plane I think really! And this was just the fan part!!!

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Last edited by PeterVRC; Feb 15, 2014 at 04:42 AM.
Jan 01, 2013, 01:12 AM
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The T-45 (these models at least) have a full length aileron and they are driven by one centrally mounted servo. When you move the aileron by the root, where the servo horn is, the resistance is HUGE!! This makes the aileron TWIST along it slong length too! What a load of rubbish design..... sheesh.
So I decided to SPLIT the aileron into having inboard flaps also, and then run them from their own 'direct drive' servos in the wing. Like more typically done in decent RC aircraft.
This would mean 4 servos..... but that is OK, as I know these T-45 glide for miles and are way too light anyway. So I have ZERO weight saving requirements.

I made servo "pockets", then routed the wiring down slots in the foam and made a single loom of the 4 leads that come out of the top of the wing, near the front middle of it, and long enough to head right down the front of the fuselage once the wing is screwed on. I didn't use a connector, to make connection/disconnection easier, seeing I rarely take wings off aircraft anyway. Especially "small" 70mm ones.
Maybe one day in the future I will change it to a connector, if it seems useful.

Then the "flimsy" wing - it needs a spar!!
The very curved underside - forming part of the fuselage shape - means that to use a straight carbon fibre spar it needs to be dug well into the root end of the wing. Not hard, but it is deep in there!
If it had been a two piece wing I would have "skewered" them in from the root end, but being one piece meant a slot had to be made to push the spar down into the wing. Then epoxied in with 15min epoxy.

Surprisingly, with the mods done so far, it is starting to become a half decent plane!!! It might even end up being a very good one!! hehe

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Last edited by PeterVRC; Nov 02, 2016 at 06:58 AM.
Jan 01, 2013, 09:06 AM
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I finished the wing totally..... (hmm, except filling the inner wing spar groove area).
It came out very nice really! The spars turned it from 'flimsy' to really solid!
The flaps and ailerons operate well - I had cut the original ailerons right off and split them into flaps and ailerons, and put in pinned hinges, when I first got it. So I don't have pics of doing that..... I don't think....

I fit and hot glued in the CS10 - I normally use mounts and screws, but you can't in this. I also fit the ESC (with BEC in it) and ran all the wiring for those.

I have not worked out how to fit the elevator and rudder servos. There is no room really! LOL. But I am sure I will work something out for those.

I also fit one T-45 pilot.... a 3/4 figure (legs etc). He looks good.... sometimes.... and other times I think it is just not quite right! He is 12th scale, and that is close to what this plane is... so I guess he must be pretty well right for it! Maybe I will buy and fit the 2nd one day.... a bit costly at $9 each!
https://www.hobbyking.com/hobbyking/s...x75x62mm_.html
I put him into the front cockpit position, screwed to the inner cockpit tray - with a small piece of plywood under it for strength.

I cut out the cockpit and hatch, painted the framework on the "glass", added some instruments, and I will use plain scotch tape to join the two parts together so that it is easy to get into it again in the future (I do that on many of these plastic type cockpit assemblies).

I need to make the new tailplane/elevators. From 3/16" balsa. I made the template but don't have the balsa yet (will get some tomorrow).

All pieced together it actually looks like a nice plane!

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Last edited by PeterVRC; Nov 02, 2016 at 07:00 AM.
Jan 02, 2013, 10:54 PM
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I made up the 5mm Balsa tailplane and elevator replacements.....

I made it as one piece tailplane, for greater strength, and it will be glued onto the tail area permanently. The top cover will still come off as per normal.
I have not shaped/sanded them to their profile yet.

I still have not worked out where the elevator and rudder servos will go... they will fit in there somewhere, but it will be a close call ! The part that makes it more difficult is how the two elevators need to be driven off the one servo, which then means that servo must be central - or use a "U" interconnection wire between the two elevators.
Due to the very limited space back there I will most likely use one elevator servo and the "U" wire idea.

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Last edited by PeterVRC; Jan 17, 2013 at 10:29 PM.
Jan 26, 2013, 04:09 AM
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I resumed heavy T-45 building/modding today..... 99% completed now!!
I had been doing small bits here and there over the last two weeks - mainly painting stuff - but today was the all out attack to finish it!

The tailplane all worked out well, and I finished my 'humming and harring' over the servo placements. I decided to use twin elevator servos, one per fuselage side, and a rudder servo up the top right alongside the fin.
I glued the tailplane on permanently. It also forms the top of the exhaust ducting.
This still left a short distance right after the fan that is "open" into the top cover area, so I made up a balsa wood 'unit' that fills over that area. It is removable so that the fan can still be taken out if ever required.

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Jan 26, 2013, 04:22 AM
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A big problem, that had already been seen coming to a fair degree, was BALANCING the plane! It was going to be nose heavy! But even after adding the tailplane and rear servos it was BADLY nose heavy!
The only way to offset this would be to move the battery rearwards of the stock rear firewall point....a LOT!!

So I cut out the bulkhead and made an extended battery tray that went rearwards well over the wing. And even that was MARGINAL to get it all balanced!
I made a 'box' into the wing/ducting area and then a streamlined 'tail' for improved ducting efficiency.

Some velcro pieces on the battery tray, and a velcro strap - things I do on all aircraft. Velcro on a battery's base just stops it sliding, and you need a STRAP to prevent it lifting - which then means the base velcro's grip can never slide one micron either!

Even with the battery all the way rearwards into that much deeper area, it still only JUST balanced at 105mm !!
The 26g scale T-45 pilot, right up front, isn't helping things! He might get put on a diet still !!

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Last edited by PeterVRC; Feb 15, 2014 at 04:44 AM.
Jan 26, 2013, 04:30 AM
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Mounting the canopy


The cockpit/canopy comes with no way to mount it to the fuselage!
After a bit of thought about it I decided to add a 'sleeve' sort of pane to the front of the fuselage that the canopy slots into.
A bit of paper design testing, then I decided to use some PET to make the item from. It wraps around the fuselage and is glued, or screwed, on - I used some screws for a more reliable and permanent fixture. The screw into the foam, but it has epoxy fed into the holes to form a solid mass for the screw to bite into.

For the rear of the canopy I used a 'slide lock mechanism', and glues a piece of 2.5mm plywood onto the canopy rear for the pin to feed into.

I had put the canopy onto the cockpit using clear sticky tape - just wrapped around the edging - so it can easily be removed in the future if I want to.

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Jan 26, 2013, 04:32 AM
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Pilot & canopy


Seemingly overkill..... a $10 scale pilot.... weighing 26g, but looks good.
That is almost half the price that the kit was !!!

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Feb 15, 2014, 04:50 AM
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Wing skids


Seeing the T-45 is for hand-launching, and belly landing.... and it has Flaps.... and just to ensure the Aileron and Flap servos and surface's control horns don't get ripped off when landing(!!)... I decided to add "Stores rails" under the wings, that act as Landing Skids.

I also did some painting work, seeing it had just been left exactly as it came, and the open wing spar groove portions.
I sort of want to paint all the White foam with White PAINT too, but it is already a heavy as I want it and also Acrylic Paint doesn't stay on that well. It is ok to paint OVER models that came painted - like they had a Primer - but doing it yourself over plain foam is always a mediocre result. So I am tossing up on doing that.
Maybe if it was a better jet I would bother......

I would never get this model again, and would get the 70mm version instead. And then put the wing servos on the top side - OR have retracts.

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Last edited by PeterVRC; Nov 02, 2016 at 07:03 AM.
Feb 15, 2014, 04:55 AM
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5S L2855-2300kv CS10


I ended up with a 5S L2855-2300kv CS10 combo (Ex Dynam Meteor) in the T-45. I moved the fan a bit rearwards, to the tailplane edge, so that "filling in" the gap area of the ducting around there was easier and I used a 'half circle' of PET-C ahead of the fan to complete that. So now it is all much tidier and clean flowing.

The AUW is 1250g and the Peak Thrust to Weight is approx 0.9 : 1
The Dynam Meteor that the fan had been taken from (fully re-balanced and oiled etc) was 1.4Kg AUW and that flew very well on that combo, so it was a fairly well "known" thing.

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Last edited by PeterVRC; Nov 02, 2016 at 07:04 AM.
Feb 18, 2014, 08:01 PM
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Hand-Launch FAIL.... new Wemo EVO combo installed.


Thrust tests on a scale showed the real number to be 880g of thrust only!!
A pathetic amount for a 1300g jet!
But I figured it COULD fly on that still, so I tried it out......

It COULD... WOULD... have flown, if it could get moving fast enough first. But as a hand-launcher it would need an almighty heave - like my 70mm F-22 - and thus two hands. I didn't have another Guardian stabiliser to put in to help with that, so I tried a solo one handed launch.....
Oooops....

There was no way it could fly off, so it pancaked to the ground. A following "noise" as the fan shredded off all of its 10 blades.....
When it hit the ground, the inside red plastic wing attachment thingy popped off and went into the fan!! That is a dangerous little item they have there!
So that was the end of the L2855-2300kv CS10 unit.
I decided to put together a Wemo EVO fan, with 2600kv motor for 5S.

This fan does 1.5Kg peak, 1.30Kg ongoing.
Tests: EVO 380L-2600kv 5S 2700mAH 65C 45.22A 16.54V 746W 1.28Kg ERC Housing
Wemo's do X thrust for a measurably lower Amps/Power than CS10/12/14. They also lose less thrust when in an aircraft.
But part of getting it all to fit cleanly meant adding a thrust tube was necessary.

The new fan setup gave 1150g thrust in the T-45.

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T-45 Goshawk - 70mm 5S L2855-2300kv CS10 - Maiden Flop (3 min 28 sec)
Last edited by PeterVRC; Nov 02, 2016 at 07:05 AM.
Feb 19, 2014, 08:13 AM
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5S Wemo EVO Flight


The 2nd flight, with the Wemo EVO 2600kv 5S combo

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T-45 Goshawk - 70mm 5S 380L-2600kv Wemo EVO - 2nd FLIGHT (5 min 34 sec)
Mar 01, 2014, 08:24 PM
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6s 1500w = awesome!!!


I forget why I upgraded the T-45 EDF setup but I changed it to a Cyclone power 2200kv CS10 1500W combo. More typically the WOT level will be 1300W or so, but the short lived initial peak is 1500W region.
I had been flying very well on the 5S setup, but a bit more power on hand is always useful.
AUW was now 1.45Kg and that did not bother it at all - it flew as great as ever, if not more "linearly" and with air penetration and authority rather than 'too floaty'.

What a difference having 'enough' power made!!
A 45 deg hand launch toss angle, but at WOT I could feel it had so much thrust that it was going to rocket off out of my hand anyway! And it did! Like a AG missile taking off!!
So hand-launching became the biggest case of 'simple as pie' that I have had with any plane! On the second flight I reduced the 'push' power of the toss to almost nothing! Underarm, a quite slow and 'lazy' swing upwards to release at 45deg..... and it just powers off into flight without any issue. The 45deg launch angle is actually 'needed' if you don't throw it to a higher airspeed, and that steep AoA means you get a high level of "High Alpha lift" and also the Thrust Vector driving it upwards too.

So now this was getting into the power/speed zone of my Meteor (Habu clone), and MUCH better all round. Awesome speed if you wanted to use it, and otherwise 'scale' fly around at 30% throttle.
"Scale cruise" was only 18A used - info courtesy of the FRsky system with Unisense sensor. Max power runs were 67Amps (1300W region).
Vertical... unlimited. Thrust is more than its weight, and that was clear to be seen!
I would say the top speed was EXCESSIVE really... way over scale top speed. Not that I wanted it to be overly fast, and that is why most flying was 30% to 50% throttle only.

On 6S 2650mAH 45C and 65C, with a 3.0 mins timer till the "Time to land" warning, it had only used 1300mAH anyway! If you only use 18A or so then a 2650mAH battery an last 8 minutes, by maths!! So allow some leeway to not use it all, and a bit of WOT, and 4.0 mins would still be easy.... probably even 5.0 mins.

So this was a fantastic power setup - giving excessive capability, very helpful for launching, and very low current (Amps) normal flight speeds.

Too bad it was all quite short lived.....
Last edited by PeterVRC; Nov 02, 2016 at 07:19 AM.
Mar 01, 2014, 08:25 PM
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T-45 Down !!!


T-45 Down!!!

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