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FMS T-28 Trojan (... with some build issues)
#31

I default all my controls to be pushed away. Whenever I pick up my radio to fly, I instinctively push everything away from me and the plane will always be in take off config.
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#32

ok, seems my logic was sound.

When all switches are away from me (per Kizza post), the flaps are not deployed and the landing gear is deployed. I lift the switch for flaps toward me and I get two stages of deployment. I lift the retract switch and the wheels go up. The switch is two position switch for retracts so lifting the switch one position pulls up the gear. A second lift does nothing. When extending the gear, I switch down one position (from fully up) nothing happens, one more switch so fully away from me and the gear comes down.

Weather permitting, maiden flight is tomorrow. Just need to correct a wayward nosewheel and everything is good to go.
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#33

I finished my Trojan last night at 11 pm, dropped in the battery to test everything and when I hit the retract down switch everything worked except the right hand door just went "click,click,click,click until I pulled it with my finger then it opened but it appears to have stripped gears..... "NOT HAPPY JAN" so I will have to get it out to see what its problem is, its in a prick of a spot and going to be a bitch to remove..... ahhh you just gotta love servos don't ya...........SHIT!!!
Remember what I said Dave, If you maiden you Trojan at A51....... leave your gear down until you have cycled them through a few flights over grass and are happy that they will come down when you ask them to.

Parkzone Stryker 27 Evolution
E flite Ultra Stick , T 28 Carbon Z
Skyartec Skyfun Scorpion,Skyfun 90 EDF
Hobbyking Voltigeur, Funfighter T28, Mirage 2000, Minimoa 2.4m Glider
Jet Teng L-39 HPAT Stumax 90
Pheonix Tiger 50
FliteWork Extra 300 LPX 2.6M
Spectrum DX9i , DX6

Don't ever let the fear of landing keep you from taking off!
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#34

There is a bug in how IE9 handles the submitting Javascript, long and short of it is that Ie9 is the work of the devil and you should be using Firefox or Chrome Wink

I'll see if I can find the time to patch up the forum software, unfortunately we run many customizations and its fraught with peril
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#35

G'day Gazz

Geez, did you insult the god of retract servos at some stage in the past?
You seem to have some fun and games with the ol retracts.
I recall a similar tirade from you when you were setting up the dunlops on the Airwolf

Cheers
Rob B
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#36

Sound like it jammed and it stripped a gear in the servo. I had one jam up when the sequency decided to close th doors first, then the retract ...The servo ran hot and burnt up. I replaced it with whatever I had lying around in my spares. Just hope its not the reverse one. You can always open the servo up and change the plastic gear matching it from another servo. Yeah its a bugger when its a new plane you just want to snap it together and fly, not stuff around....
Unfortunately when you have a zillion servos, geardoors, flaps, retracts, opening cowles, lights ....and ... and... more... you suddenly have a high maintenance plane... not a chuck and fly any more.
but all these gizmos make the plane look fantastic on the ground and in the air.
Biggrin

George

"Crash and Cry! Don't fly"


RadioBiggrinX9 & DX8
HK Cri Cri ugly,Super Cub 1870mm balsa, Sbach 1000mm balsa, Vampire, Katana E50 balsa, BA Hawke 90mm (on hold for large runway), Durafly BF110, Corsair,
EScale Zero
Freewing Eurofighter Typhoon & SU-34
Starmax F5e Tiger & 70mm F-18
FMS T-28 Trojan, P-38 Silver, 50mm F-86, C-17 Globmaster

Fly fly F-100
B-25 2.0m LX and A10 1.5m Langxiang (being glassed and re-built)
Seagull Super Tucano
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#37

After some advice I have tried a few things to recover some missing power from the FMS T28 power set-up. It doesn't appear to be delivering maximum power according to the way George's flies and also from his experience.

1. Adjusted the throttle endpoints in the radio. Appears to have no effect.
2. Recalibrated the throttle range on the ESC. Ditto.
3. Did a full power static run this morning with current measurement. Got to 30A then slowly reduced to 20A over 30 seconds (wtf?). Checked the ESC, not hot. No obvious issues to I have decided that the 4S 2600 battery loaned to me from Gazz has to be faulty. Confirmed by putting a 4S 3000 Nanotech on and got a solid 32A without power reduction.

I am thinking I might change the ESC now to the Align 60A ESC from the Trex500 and check it then. Next would be say a 4S 4000 Nanotech to see if I can get the power up.

The plane flies well enough mind you but feels as though it should have more zip on full throttle and gear up.

Dave
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#38

(21-11-2011, 08:03 AM)Skidz Wrote:  After some advice I have tried a few things to recover some missing power from the FMS T28 power set-up. It doesn't appear to be delivering maximum power according to the way George's flies and also from his experience.

1. Adjusted the throttle endpoints in the radio. Appears to have no effect.
2. Recalibrated the throttle range on the ESC. Ditto.
3. Did a full power static run this morning with current measurement. Got to 30A then slowly reduced to 20A over 30 seconds (wtf?). Checked the ESC, not hot. No obvious issues to I have decided that the 4S 2600 battery loaned to me from Gazz has to be faulty. Confirmed by putting a 4S 3000 Nanotech on and got a solid 32A without power reduction.

I am thinking I might change the ESC now to the Align 60A ESC from the Trex500 and check it then. Next would be say a 4S 4000 Nanotech to see if I can get the power up.

The plane flies well enough mind you but feels as though it should have more zip on full throttle and gear up.

Dave

I don't think you need to go to a 4000mah 4S to get the power up. your 4S 2600 should provide 100A with out any trouble. If you want to increase the current draw you might try load it with a bigger prop and see if that makes it suck the juice a bit more.

I think the drop from 30A to 20A with the first pack is certainly telling you something about that pack being a bit suspect.




(19-11-2011, 01:23 AM)kizza42 Wrote:  There is a bug in how IE9 handles the submitting Javascript, long and short of it is that Ie9 is the work of the devil and you should be using Firefox or Chrome Wink

I'll see if I can find the time to patch up the forum software, unfortunately we run many customizations and its fraught with peril

Microshafted again !!!


“The knack of flying is learning how to throw your machine at the ground and miss.”

"When once you have tasted flight, you will forever walk the earth with your thoughts turned skyward, for there you have been, and there you will always long to return."  ~Leonardo Da Vinci
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#39

Hi Dave
After our discussion last night. I completed my T 28, lots of mucking around but replaced the rooted gear door servo, all working sweet know.
I amp tested the standard ESC with 2 brand new (never used) 4000 mAh 4S Nanotech.
First I calibrated the throttle then did 2 tests with 2 different batteries.
Both tests gave almost identical results with no load or power drop off after 30 seconds of full throttle.
580 watts 36.2 amps @ 16 volts.
The data on the motor suggests that it is a 500kv motor that would amount to about 8000 rpm.
It certainly feels like it is pulling pretty hard to me but to be sure the factory 50 amp ESC is doing its job I am going to remove it and drop in a Turnigy PLUSH 60 amp and do the test again.
Watch this space.
Gazz

Just completed the same tests with the new Turnigy Plush 60amp speedie, results were almost identical, holding a steady 36amps at full throttle.
I recon George must have a different prop or he is running his on 5S.
Will have to get my beastie in the air now to see how it goes.
Gazz

Parkzone Stryker 27 Evolution
E flite Ultra Stick , T 28 Carbon Z
Skyartec Skyfun Scorpion,Skyfun 90 EDF
Hobbyking Voltigeur, Funfighter T28, Mirage 2000, Minimoa 2.4m Glider
Jet Teng L-39 HPAT Stumax 90
Pheonix Tiger 50
FliteWork Extra 300 LPX 2.6M
Spectrum DX9i , DX6

Don't ever let the fear of landing keep you from taking off!
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#40

(24-11-2011, 10:26 AM)gbanger Wrote:  Hi Dave
After our discussion last night. I completed my T 28, lots of mucking around but replaced the rooted gear door servo, all working sweet know.
I amp tested the standard ESC with 2 brand new (never used) 4000 mAh 4S Nanotech.
First I calibrated the throttle then did 2 tests with 2 different batteries.
Both tests gave almost identical results with no load or power drop off after 30 seconds of full throttle.
580 watts 36.2 amps @ 16 volts.
The data on the motor suggests that it is a 500kv motor that would amount to about 8000 rpm.
It certainly feels like it is pulling pretty hard to me but to be sure the factory 50 amp ESC is doing its job I am going to remove it and drop in a Turnigy PLUSH 60 amp and do the test again.
Watch this space.
Gazz

Just completed the same tests with the new Turnigy Plush 60amp speedie, results were almost identical, holding a steady 36amps at full throttle.
I recon George must have a different prop or he is running his on 5S.
Will have to get my beastie in the air now to see how it goes.
Gazz

Very Interesting, as the results are very similar to daves results, peaking at about 34 amps when tested at area 51 prior to flight.

If you think its got not enough power on 4s, i guess give it a whirl on 5s
as long as the motor is ok with 5s

Steve

What Do You Mean Theres a Throttle Curve ?, Its Either all the way up or all the way down Tongue_smile
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#41

(24-11-2011, 10:26 AM)gbanger Wrote:  580 watts 36.2 amps @ 16 volts.
The data on the motor suggests that it is a 500kv motor that would amount to about 8000 rpm.

Note that the KV ratings for motors are all quoted for "no load", so as soon as you stick a prop on, the rpm figure drops dramatically. It's probably down around 6,000 rpm depending upon your propeller.

I guess you've had a trawl through RCGroups? - are others seeing the same sorts of numbers?

Good luck with it! I've just taken delivery of a Dynam Trojan and probably going to remove the stock motor and put an SK 3542-1000 in that before the first flight, based on the 80 pages of reports on RCGroups.

Steve Murray
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#42

Well you know about this already Gazz as I mentioned it last night when you collected the batts.

My flap servo blew up. At least the buzzing is gone now Smile . It cooked and I managed (easily) to strip the gears getting the darn thing out. As Gazz said, "world's best foamie with the worlds worst electronics". Got me wondering which of the tits on a bull servos is going next.

I'll put the Align speedie on tonight or tomorrow night. I am predicting another 32-34A result. Will try 5S with Align speedie but not the wang chung sen foo speedie. Suspect the motor will protest.
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#43

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#44

Thanks Kizza.
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#45

Weather permitting....ha ha haaaaa. I will give the big Trojan a fly at A51 tomorrow.
Franks and Georges both fly well so Im not stressed about the performance, however if the motor doesn't cut the mustard, or I am not happy with its performance I will replace it with the 5050-8 Dualsky out of my Edge 540 and run the mother on 6S, It will either fly like a champion or roll on its back, carry out a pre orbital burn and disappear into the friggen cosmos.

Parkzone Stryker 27 Evolution
E flite Ultra Stick , T 28 Carbon Z
Skyartec Skyfun Scorpion,Skyfun 90 EDF
Hobbyking Voltigeur, Funfighter T28, Mirage 2000, Minimoa 2.4m Glider
Jet Teng L-39 HPAT Stumax 90
Pheonix Tiger 50
FliteWork Extra 300 LPX 2.6M
Spectrum DX9i , DX6

Don't ever let the fear of landing keep you from taking off!
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#46

Weather isn't looking that good Gazz. It could clear later but suspect lying water on the strip at Area 51. Might be an idea to use the "smoother surfaces" if you get a lucky break with the rain Wink.

I attempted to see if my one spare servo would operate the flap that lost its servo. Being a normal fast servo (not a slow flap servo) I programmed a custom mix to extend both flaps slowly so both servos would operate slowly and in unison. It worked perfectly but... the throws on the two servos are different and I couldn't adjust the linearity in the servo horn, rod length or clevis position. I will now need to buy two new servos Frown.

Goods news is that I discovered (logical when you think about it) the flaps are pretty tight on the wing. To stop the growling servos I am going to have to cut the flaps off and put them back on with hinge pins. If I don't I can reasonably believe more servos will fail from the strain.

Looks like the Trojan is getting pushed back in to the hangar for repairs this weekend.
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#47

What type of adhesive or bonding method is usual practice for servos in to a foam wing?
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#48

I like to get a scalpel and use the point to chip a rough surface in the foam socket, then score the side of the servo with a cross-hatching of cuts to give the glue something to key into. I've always used araldite and never had one come loose.

Steve Murray
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#49

(25-11-2011, 08:28 PM)yarrumevets Wrote:  I like to get a scalpel and use the point to chip a rough surface in the foam socket, then score the side of the servo with a cross-hatching of cuts to give the glue something to key into. I've always used araldite and never had one come loose.

Thought of epoxy but considered "what if I need to get the servo back out?".
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#50

I use Sikaflex 241. It dries very hard but can be cut with an exacto knife for removal if required.
It is a marine adhesive sealant available from some hardware stores and shipchandlers.

Parkzone Stryker 27 Evolution
E flite Ultra Stick , T 28 Carbon Z
Skyartec Skyfun Scorpion,Skyfun 90 EDF
Hobbyking Voltigeur, Funfighter T28, Mirage 2000, Minimoa 2.4m Glider
Jet Teng L-39 HPAT Stumax 90
Pheonix Tiger 50
FliteWork Extra 300 LPX 2.6M
Spectrum DX9i , DX6

Don't ever let the fear of landing keep you from taking off!
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#51

I wrap in insulation tape and then hot glue
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#52

With my flap servo failure, I bought two new servos yesterday and connected them in this morning. Guess what? They are reversed - both of them. I'd reverse them in the transmitter except that the cowl flaps are connected to the wing flaps so they would always move opposite to the wing flaps. Can't take a trick at the moment. I don't want to disconnect the cowl flaps as they look cool but it is an option.

Question: The servos are likely to be brushed motors. I am thinking I can reverse the direction of the motor by reversing the polarity of the wires (refer picture). Is there anyone that has done this?

   
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#53

(26-11-2011, 09:06 AM)Skidz Wrote:  With my flap servo failure, I bought two new servos yesterday and connected them in this morning. Guess what? They are reversed - both of them. I'd reverse them in the transmitter except that the cowl flaps are connected to the wing flaps so they would always move opposite to the wing flaps. Can't take a trick at the moment. I don't want to disconnect the cowl flaps as they look cool but it is an option.

Question: The servos are likely to be brushed motors. I am thinking I can reverse the direction of the motor by reversing the polarity of the wires (refer picture). Is there anyone that has done this?

I have done it before too, but Chris posted a Thread which makes it Easy

http://forum.rcflyingclub.com/showthread.php?tid=288&highlight=servo+reversing

Steve


What Do You Mean Theres a Throttle Curve ?, Its Either all the way up or all the way down Tongue_smile
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#54

Thanks Steve (and Chris for the thread on it).
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#55

Hey Dave
If you need another option, I have some very small servo speed controllers that have reversers built in. They are yours if you need them.

Parkzone Stryker 27 Evolution
E flite Ultra Stick , T 28 Carbon Z
Skyartec Skyfun Scorpion,Skyfun 90 EDF
Hobbyking Voltigeur, Funfighter T28, Mirage 2000, Minimoa 2.4m Glider
Jet Teng L-39 HPAT Stumax 90
Pheonix Tiger 50
FliteWork Extra 300 LPX 2.6M
Spectrum DX9i , DX6

Don't ever let the fear of landing keep you from taking off!
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#56

Thanks Gazz. I think I have a solution

I pulled the servos apart and they had three wires going to the motor so aborted the rewiring (the photo was the failed servo).

My Futaba receiver is 8 channel so I am going to connect the cowl flaps to the 8th channel (the aile is using ch 2 and 7) and operate by either a separate switch or the same switch as the flaps. I had a Y lead left over as I had to put the aile control on to two different channels. I can use that (when I find it). Don't know why I didn't think of that in the first place.

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#57

Gave the 3.0 4S nanotech that Samste gave me a work out this arvo. Full throttle for 3.5min drawing 32A restrained. Plane fine but managed to blow the canopy across the loungeroom in to the furniture (ha, ha).

Battery puffed and was quite hot. Thought I might have pushed it too far. In to the freezer for 10 minutes. Cells tested at 3.77volts so not quite sure why it puffed and got hot. Probably because Samste has "strykered" it too many times. Power plant seems ok so ready for another session however the forecast for wind sucks from Wed onwards.

Edit: balance for the cells is from 4.08 to 4.19v so I think this battery is ready for the knackery. Charger jumping from 0.7A to 2.8A every couple of seconds and cells 1, 2 and 4 won't hold their voltage. After being strykered and fanjetted to the point of destruction, it took a foam Trojan to finish it off.
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#58

(28-11-2011, 05:45 PM)Skidz Wrote:  Gave the 3.0 4S nanotech that Samste gave me a work out this arvo. Full throttle for 3.5min drawing 32A restrained. Plane fine but managed to blow the canopy across the loungeroom in to the furniture (ha, ha).

Battery puffed and was quite hot. Thought I might have pushed it too far. In to the freezer for 10 minutes. Cells tested at 3.77volts so not quite sure why it puffed and got hot. Probably because Samste has "strykered" it too many times. Power plant seems ok so ready for another session however the forecast for wind sucks from Wed onwards.

Edit: balance for the cells is from 4.08 to 4.19v so I think this battery is ready for the knackery. Charger jumping from 0.7A to 2.8A every couple of seconds and cells 1, 2 and 4 won't hold their voltage. After being strykered and fanjetted to the point of destruction, it took a foam Trojan to finish it off.

Heh Dave I'm Surprised about the nanotech Lipo, as i Only ever Used it in my Eflite lr1a pogo Plylon racer, which Drawed a Max amps of 60amps and probably only ever had about 20 flights and the lipo was Retired to the Storage Shelf and kept in flight bag for someone who may need to use it, time to time.
But i never really worried about giving it a charge or anything for a long Time 8 months or more, maybe that affected it.
And your only drawing 32 amps and that lipo i think could manage around 70 amps constant from memory. what is the c rating Dave ?

Edit, did a quick search on Hobbyking theres only one match http://www.hobbyking.com/hobbyking/store...duct=11920

75 amps constant, lipo must be rs from non use

What Do You Mean Theres a Throttle Curve ?, Its Either all the way up or all the way down Tongue_smile
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#59

(28-11-2011, 06:15 PM)samste Wrote:  lipo must be rs from non use

There you go people, tell your wives and girlfriends you have to fly or your batteries will go bad!
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#60

Well if the friggin weather continues the way it has for the last 6 to 9 months we might as well all throw our batteries in the bin.

Parkzone Stryker 27 Evolution
E flite Ultra Stick , T 28 Carbon Z
Skyartec Skyfun Scorpion,Skyfun 90 EDF
Hobbyking Voltigeur, Funfighter T28, Mirage 2000, Minimoa 2.4m Glider
Jet Teng L-39 HPAT Stumax 90
Pheonix Tiger 50
FliteWork Extra 300 LPX 2.6M
Spectrum DX9i , DX6

Don't ever let the fear of landing keep you from taking off!
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