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View Poll Results: Add Another Option: BMN (Bare Minimum Necessities)
no batteries, no charger, and no tx! $59.99(BMN) 747 86.16%
were just asking for too much 120 13.84%
Voters: 867. You may not vote on this poll

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Old Jul 09, 2015, 04:26 PM
jbarchuk is offline
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DeBary, FL
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Quote:
Originally Posted by zewill View Post
that plastic horn was always bending in weird ways...
Nylon is an aaawwwwesome material. Yes these horns are fairly flimsy but they have such a super-tiny amount of strain put on them that they should (normally) last forever. The trick to moving the control rods to different holes I was sketchy about when I first read it but it works great every time and the horn seems to never suffer any damage.

I wonder if yours might have had a manufacturing defect that caused it to fail. It's extremely rare but on a % basis has to happen once in a while. -Or- it may have been a very weird assembly error. Or bad handling at assembly time that damaged it and caused early failure.

The problem with the credit card horn or other thicker material is that once assembled it'll be much more difficult to adjust which hole he control arm is in. It'll have near-zero flex. The bread bag closer should have some, and is also very resilient. They might be nylon but it's pretty thick. Best would be the same thickness nylon as the original but I can't think of any other place it'd be available in random dollar store or home type items.
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Old Jul 09, 2015, 10:58 PM
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So I took it up again and it flew decently. The way I did it is not the cleanest or lightest but allows me to attach it in different positions thanks to small Velcro pads. It needs to be reattached or checked before each launch but it's not too bad! Won't fly as straight as on the first day....( actually it never flew straight, had to massively trim on the maiden but I see that the tendency to go into left circles seems has been noticed by other users!
I managed to break a wire of the power cable but nothing serious, will need to do some soldering tomorrow!
I love the Trojan but I have one remark... Why is the landing gear so badly though out? I'm not mentioning the way it's attached to the plane as this is actually good that it's removable but the prop is so close to the ground even a little pebble will cause a prop strike...why didn't they do the wing gear shorter and front longer, as in the mustang ???(which actually has a landing fear on the tail and not nose)
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Old Jul 10, 2015, 02:52 PM
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Why is the landing gear so badly though out?
I have a LIKELY answer. It was originally designed on paper with an -existing- 3-blade prop.

With that, production of all parts INCLUDING THE BOX proceeded.

Flight tests probably proved that the 3-blade was not good and they had to fall back to a 2-blade.

The only other choice would have been to design a new 3-blade which would have incurred much delay and much extra $. Further, that new 3-blade would probably never be used on anything else. So that idea tripped over its shoelaces and fell to the ground as it left the gate.

With that, the 2-blade prop was too close to the ground (closer than it is now.)

With that, they had to extend the LG.

With that, the plane with the LG assembled didn't fit in the box, so it's packaged separately. That's not a very big deal because many people fly these little UMXs without LG, hand toss launch and belly landing in grass.

The solution to putting the plane in the box with the LG attached is to cut out the cardboard under the LG. It's annoying but doable.
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Old Jul 11, 2015, 05:42 PM
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Ah, the joys of deciding when only thinking about $...

T28 owners, i have a question regarding the servo on my elevator :
Since a crash, I have had to resolder the power wire that connects to the batteries. I did this and now the plane powers on correctly! However, i seem to be encountering a servo issue on the elevator. As you will see in the videos below, it happens sometimes, sometimes not when I activate the elevator, the servo will "vibrate" a lot, doing a big noise .. It will sometimes stop when i reactivate elevator up or down, sometimes it'll start again. what gives? It seems as if the servo cant find a resting position and is constantly adjusting ... but to what? The effect, as seen in the 2nd video, is a "shaky" elevator!

IMG 1714 (0 min 11 sec)


t28 um parkzone servo issues (0 min 53 sec)
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Old Jul 12, 2015, 07:59 AM
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"Some do, some don't"
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Quote:
Originally Posted by zewill View Post
Ah, the joys of deciding when only thinking about $...

T28 owners, i have a question regarding the servo on my elevator :
Since a crash, I have had to resolder the power wire that connects to the batteries. I did this and now the plane powers on correctly! However, i seem to be encountering a servo issue on the elevator. As you will see in the videos below, it happens sometimes, sometimes not when I activate the elevator, the servo will "vibrate" a lot, doing a big noise .. It will sometimes stop when i reactivate elevator up or down, sometimes it'll start again. what gives? It seems as if the servo cant find a resting position and is constantly adjusting ... but to what? The effect, as seen in the 2nd video, is a "shaky" elevator!

https://youtu.be/d72TY0DFb-w

https://youtu.be/YLI-tXC7O5k
Your analysis is absolutely correct, the servo is "hunting" or more specifically the servo driving circuitry is searching for the center position... a little bit of DeOxit or some foam safe version of circuit cleaner sprayed in the servos will take care of that.. basically the feedback resistor strip is dirty making it hard for the servo circuitry to figure out where the center is...

Mark R.

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Old Jul 12, 2015, 09:14 AM
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I bought one of these second hand a while ago but haven't really flown it. Took it out yesterday and noticed that it will ONLY fly at full throttle - anything less than full and it starts dropping. Flies level at ~90% instead of about 1/2 like every other plane I've ever flown.

Needless to say the motor gets quite hot and angry after even 5 mins (1 battery). At that point the motor spun up for 5 seconds and then cut out. Pretty sure it's going to burn up if it hasn't already.

I checked the throws and everything seems fine, so what should I do, besides get a new motor?
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Old Jul 12, 2015, 10:38 AM
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Quote:
Originally Posted by kamikazeknifer View Post
I bought one of these second hand a while ago but haven't really flown it. Took it out yesterday and noticed that it will ONLY fly at full throttle - anything less than full and it starts dropping. Flies level at ~90% instead of about 1/2 like every other plane I've ever flown.

Needless to say the motor gets quite hot and angry after even 5 mins (1 battery). At that point the motor spun up for 5 seconds and then cut out. Pretty sure it's going to burn up if it hasn't already.

I checked the throws and everything seems fine, so what should I do, besides get a new motor?
You answered your own question, get a new motor, I upgraded my motor to a Sport Cub (23 mm) motor and can most definitely fly level at less than 1/2 throttle.. Brushed motors wear out, and they can get "cranky if left sitting too long without being run... some other suggestions for the existing motor, some type of lubricating (either remove motor or be very sure whatever you use is safe for the foam) and I have heard but never tried removing motor and chucking it to a drill and then run the drill for awhile to help "clean" the brushes...

If it was my plane, I would replace the motor either with stock or the Sport Cub motor... Just my 2 cents...

Mark R.

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Old Jul 13, 2015, 08:51 AM
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Thanks old_coastie!
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