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FMS T-28 Trojan (... with some build issues) - Printable Version

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FMS T-28 Trojan (... with some build issues) - Skidz - 15-11-2011

Well, I guess you are all waiting for photos -- which I will provide in coming days.

First comments are that, apart from a decent plane, you get the world's worst screwdriver to go with with the world's worst screws. FMS must be short for F*%$ing Miserable Screws.

As George predicted, the motor is loose on the firewall. The flaps and aile hardware are crappy and the rudder hardware was all wrong. I can work around all this as the important parts are perfect. Beats me why the minor parts are so woeful.

Apart from the minor but extremely important control linkages, this is a very nice plane.

Sorry for the confusing post. Best I can say is a wonderful plane let down by the little (but important) things.

RE: FMS Trojan build thread - samste - 15-11-2011

(15-11-2011, 07:43 PM)Skidz Wrote:  Well, I guess you are all waiting for photos -- which I will provide in coming days.

First comments are that, apart from a decent plane, you get the world's worst screwdriver to go with with the world's worst screws. FMS must be short for F*%$ing Miserable Screws.

As George predicted, the motor is loose on the firewall. The flaps and aile hardware are crappy and the rudder hardware was all wrong. I can work around all this as the important parts are perfect. Beats me why the minor parts are so woeful.

Apart from the minor but extremely important control linkages, this is a very nice plane.

Sorry for the confusing post. Best I can say is a wonderful plane let down by the little (but important) things.

Yes Some Pics would be Nice Dave

Looking Forward to seeing it in the Air

Steve



RE: FMS Trojan build thread - gbanger - 15-11-2011

I also pulled mine out of the box last night. And quickley decided that this aircraft would require a few tiny but crutial upgrades to pass my G load tests (also know as aerobatic flight).
I have cut the Elevators and Ailerons off the aircraft and drilled epoxied and added good old HK swivel pin hinges (3 for each control surface).
My Parkzone Trojan that has served me so well for many years suffered fatigue cracks through the hinges on these surfaces, and seeing that this is just a bigger version with larger control surfaces, I thought it necessary to upgrade these linkages before putting my beautiful new beastie into service.
Have not progressed as far as Dave due to my little structural upgrade but I will keep you all posted.
Generally speaking the build quality is very good.
Only dissapointment I have at this stage is that my pilot was already dead. The glue had let go from his sorry little arse so I had to pry the bloody canopy off to glue the little pricks arse back in his seat. Have not put the canopy cover back on yet..... Really looking forward to that...... NOT!!!
I will give a engineering appraisal when I have progressed a bit further with the build.
Gazz
PS: TROJANS RULE

FMS T28 - analogue or digital servos? - Skidz - 17-11-2011

Does anyone know if the servos in the FMS Trojan are analogue or digital?

My Futaba RX (R6008HS) says not to use analogue servos on high speed mode ch-1 to 6. Only digital. I will change the mode to "normal" from "high speed" anyway to play it safe. Can't find any reference in material on the FMS plane or forums stating whether analogue or digital. I guess it doesn't really matter if I use normal mode but it would be to good to know.

Dave

RE: FMS T28 - analogue or digital servos? - robair - 17-11-2011

Gday Dave

Go digital mate, I use 11g HK digitals, they are cheap as chips, pretty fast and punch out 2kg. I have 8 on order right now. (See my HK order for the link). Only caveat is that their deadband is minimal so they can be quite noisy. Not a biggie unless you dislike your aircraft sitting there going eeeeeeeeeeee.

Not sure if they are big enough for the T28 however they have never let me down. Note: There are comments elsewhere about the centreing ability or lack thereof of analogues vs digitals.

Cheers
Rob B

RE: FMS T28 - analogue or digital servos? - smuzz - 17-11-2011

Don't know Dave - I've only searched the FMS Stuka thread (I expect the Trojan and Stuka to have the same servos) and there's no mention at all. In fact the word "analog" (American spelling) doesn't result in a hit at all.
I would bet loadsamoney though, that they're analog - but it would be good to know for sure as you say.

RE: FMS T28 - analogue or digital servos? - robair - 17-11-2011

Gday Dave

Apologies, completely misinterpreted your post?

Cheers
Rob B

RE: FMS T28 - analogue or digital servos? - Skidz - 17-11-2011

(17-11-2011, 12:22 PM)robair Wrote:  Gday Dave

Apologies, completely misinterpreted your post?

Cheers
Rob B

You're working too hard Rob. You should try flying RC aircraft for relaxation like the rest of us Biggrin

Steve, I'm going to set up as analogue (English spelling Smile). Frigging ESC is confusing. It plays too much music and not doing what it is supposed to (pilot error of course) and the manual shows no musical scores - just *_ _* ~~~_* _* _ /// *** >_ _ > *. Know that tune?

I have found the ESC sounds on YouTube for you plane techies that might be able to aid in a diagnosis...
http://www.youtube.com/watch?v=YXORW4Jxh1A
Sorry about the unsynched sound. My father walked away before he'd finished playing.

I think I might rip the Trex500 ESC out which runs on 6S and is higher current rating at 60 Chinese Amps - and works without playing "I wish I was in Dixie" on my motor. I'll put that in. Nothing like a Heli ESC to make a plane fly properly. I knocked off the Futaba RX from the 500 (naughty me) so it is not currently in a flying state (temporary of course). I think I should be able to set up a throttle curve so I don't get full power on the motor as George (Raptorfly) has info to suggest the motor will lose its mojo over 15V applied voltage. That way I can also use my reserves of 6S 3000mAh lipos as well.

Kizza, sorry mate.. I have hijacked my own thread. Feel free to move all this guff move across to the FMS Trojan build thread Smile.

RE: FMS T28 - analogue or digital servos? - gbanger - 17-11-2011

Jees Dave thats a great idea... I wonder where you got that brainstorm from......
So I take it from reading the above that you dont need to borrow the 4S batteries for the weekend.
How is the sub station wiring under the cowl of the Trojan, I don't think they would have that many Y leads on a Bloody Big Boeing 777.
Gazz

RE: FMS T28 - analogue or digital servos? - smuzz - 17-11-2011

Dave, I've not applied power to the ESC which came with mine but I think you're on the right track replacing it. Many reports (RCGroups) I've seen suggest that it will reach its 50A limit pretty quickly with even a 4S battery and the stock prop. I've got a couple of others I'll use instead if I can fit them in the fuse - the Stuka has less room there than I guess the Trojan has.

I saw someone selling one of the stock motors (3648 500kv from the FMS Spitfire) on eBay, brand new for $25 including shipping - so I snapped that up to do some bench-testing on. It hasn't arrived yet, but might get here tomorrow so that I can get it running and make some measurements.

RE: FMS T28 - analogue or digital servos? - Skidz - 17-11-2011

(17-11-2011, 04:35 PM)gbanger Wrote:  Jees Dave thats a great idea... I wonder where you got that brainstorm from......

No idea. It just came to me. Come to think of it, I did have a mobile phone in my ear and someone sounding an awful lot like yourself at the other end. Hmmm...



RE: FMS T28 - analogue or digital servos? - gbanger - 17-11-2011

I will be keen to hear your finding on the motor test Steve.
I have as a matter of course already replaced the ESC in my Trojan to a Turnigy Plush 60.
When I get it finished I will do a few ground tests and let you know how it goes.
Have you heard any reports on the FMS Trojan/Stuka motors and their compatability with 5S.

RE: FMS T28 - analogue or digital servos? - Skidz - 17-11-2011

(17-11-2011, 04:35 PM)gbanger Wrote:  So I take it from reading the above that you dont need to borrow the 4S batteries for the weekend.

Sorry, missed this sentence. I will let you know. I am planning on seeing if I can make the propellor spin tonight. When you heading off to Coffs?

RE: FMS T28 - analogue or digital servos? - smuzz - 17-11-2011

(17-11-2011, 04:42 PM)gbanger Wrote:  Have you heard any reports on the FMS Trojan/Stuka motors and their compatability with 5S.

Good question - I'll check up and get back here. What I have learned is that the Stuka appears to be over-powered on 4S, but we never use that term at PRCAC Wink

RE: FMS T28 - analogue or digital servos? - robair - 17-11-2011

Gday Steve

The correct power curve descriptors could be:
Stock
Adequate
Ample
Heaps
Irresponsible
KevBlazeviched

Cheers
Rob B

RE: FMS T28 - analogue or digital servos? - smuzz - 17-11-2011

Actually Gazz - some more digging has turned up something: The motor I've got coming to test is actually NOT the same as the one in the Trojan. Apparently the Trojan, Corsair (version 2), Thunderbolt (version 2) and Mustang (version 6) all have a FMS 4250 500Kv motor installed. So, my tests on the Spitfire motor aren't going to be much use!

RE: FMS T28 - analogue or digital servos? - Skidz - 17-11-2011

Progress gents. Got the FMS ESC working. Easy when you know what is going on.

When I powered the ESC on it went through every setting, every tone combination. There was a pattern! I had my throttle upside down. It was set to normal but should have been "reverse". Go figure. Once I went through the throttle calibration routine (the manual is SHIT) it worked and I have a spinning propeller. Couldn't use the Align 60A unit as the bullets are one size too large for the FMS motor. Will fix next workshop day (this weekend by the looks of it).

RE: FMS T28 - analogue or digital servos? - smuzz - 17-11-2011

All good Dave - so, with the throttle reversed, the ESC was always going into programming mode when you had the throttle at the off?

RE: FMS T28 - analogue or digital servos? - samste - 17-11-2011

So It sounds like Dave it will be Air worthy with the stock Esc for Sat at Area 51 as Mc Coy will be out again with the Rain, i have bullet gold connectors for esc if ya need ?


Steve
(17-11-2011, 08:02 PM)robair Wrote:  Gday Steve

The correct power curve descriptors could be:
Stock
Adequate
Ample
Heaps
Irresponsible
KevBlazeviched

Cheers
Rob B

Gotta love it Lol because its True, it aint right unless its KevBlazeviched i say Wink

RE: FMS T28 - analogue or digital servos? - Skidz - 17-11-2011

Yep. Area 51 is the go. I have a flap settings question but probably best in a new thread.

Flap set-ups - Skidz - 17-11-2011

Probably best in a new thread rather than buried in my FMS build post.

Who here has advice on flap setting (radio TX) preferences? My old radio (still going) has a single throw switch - up or down - for the flaps. On my T8FG Futaba, the default assignment is a dial on the front. I can reallocate flap control to any of the 16 odd switches and dials so I have options but...

I was thinking it should be a switch but then I thought there had to be logic in why Futaba would do that (assign by default to a dial). Using the dial gives me infinite adjustment between fully up and fully down (extended). I am thinking the dial is probably a much better set up. Or am I misguided in my thinking?

I am mode 2 so the dial is immediately above the left gimble (throt/rudd). On approach, I would preset throttle and not likely use too much rudder so the dial is certainly ergonomically acceptable. Also, knowing how many settings the radio has, I could probably assign both switch and dial so that the dial acts as a variable end point (can be adjusted in flight) and the switch activates and deactivates flaps. I like my thinking there.

What are you guys with flap enabled planes doing and what are the pros and cons of switch v dial?

Dave
Sorry guys, had a windows thing happening that created two posts of the same new thread.

RE: Flap set-ups - Claudius - 17-11-2011

(17-11-2011, 09:06 PM)Skidz Wrote:  What are you guys with flap enabled planes doing and what are the pros and cons of switch v dial?

I'd say it's a matter of personal preference, but I'd hazard a guess that most people use a 3-position switch (if they have one).

My thoughts are that while the dial might give you fine-grained control (allowing you to, for example, use the flaps to trim to various pitch/airspeed configurations), I'd say the number of times you'd actually need that would be limited, and you'd have a harder time dialling in a specific flap setting like "full" or "half" than you would with a switch.

Unfortunately, the DX6i doesn't actually have a 3-position, so for the UAV-168 I'm planning on using the flap switch and a mix with the rudder dual-rates switch (or one of the other switches I won't have a use for) to give 3 flap positions - if a switch is your preference too, and you don't have a 3 position switch, you might be able to try something similar.


RE: Flap set-ups - samste - 17-11-2011

I think a variable adjustment may be nice but also a awkward as you wont know the setting of flaps down without knowing the position of the variable knob. Which means either looking at it in flight or setting it up prior and not bumping it. But Good in the sense working out what is best for the plane then setting it as a fixed flap switch position.
Alternately adjusting Flaps to the desired speed would be nice too.
I have on the glider my Flaps are one setting only fully down and that works fine for that as the reverse of the switch gives me spoilers.

On my Rv 450 Eflite i have two settings via the 3 position switch, half down and fully down. but realistic i only use the half flaps down as full Flaps slows it down too much.

Decisions, Decisions

Steve

RE: Flap set-ups - gbanger - 17-11-2011

I have to agree, the idea of having variable flap positioning might sound practical and would be if you were sitting in the aircraft and had that seat of the pants sensitivity as you do in a light aircraft on final, you can physically feel the aircraft with your bum, but in the RC world that is not practical you are far better off to spend a little time getting used to the feel of the aircraft at different approach speeds with various throttle and flap settings and finding a flap position that you are comfortable with.
I use 3 postion flaperons and my larger aircraft and the difference between 50% and 100% flaps is quite dramatic, you just need to spend a little time finding what you are comfortable flying with.

RE: Flap set-ups - kizza42 - 17-11-2011

Comes down to personal preference. With the Jet Jockey's its 50/50 between Switched flaps and sliders.

I run both depending on the plane.

One thing I've found I DON'T need is servo slowing!

I used to have nice scale flap deployments but in the end its a pain in the ass waiting for them to come down!

RE: Flap set-ups - brotherblonde - 17-11-2011

I think it does come down to personal preference. Many years ago I had flaps operated by a rotary knob. I only ever used 2 settings..full up &full down.

On the DX6 now, I use the switch for the same positions. It's much easier and more convenient for me.

Contrary to Kieren (sorry mate) I use a servo slow. Mainly because I was too lazy to program elevator mixing when I set it up.

RE: Twin FMS Trojans build thread - kizza42 - 18-11-2011

HOLY THREAD MERGE BATMAN!

By the way, if there are no build pics in here by Weekend, I'm trashing the thread Icon_twisted

Flap / Retract switch conventions - Skidz - 18-11-2011

Question for those using flaps and retracts. What is the correct TX switch convention?

With all switches facing away from you, what is the position of flaps and retracts? That is, what is the position of switches / flaps / retracts in a default TX mode?

RE: FMS Trojan build issues - Claudius - 18-11-2011

I don't know if it's convention or not, but I like to start with all switches facing away from me (flaps up), and switch "down" for flaps so that the position of the switch mimics the surface.

Don't have a retract plane (yet!) but I think I'd do the same with retracts - albeit requiring the gear switch to be down on startup - and am also curious to learn from others if this is the convention.

RE: FMS Trojan build issues - robair - 18-11-2011

Gday Dave

I use flaps and/ or flaperons on my gliders. Using the 3 position Flap switch I start in the middle (POS 1 zero flap/ clean wing), POS 0 (Flap up/ reflex) POS 3 (Flaps down), I have the AUX 3 rotary knob mixed in so I can adjust flap up and down if required via that knob. On the Soaring Star I do not need to mix in any elevator to flap.
I also use the flight mode switch, POS 0 (Takeoff, clean wing full travels), POS 1 (Glide, reflex flap and reduced travels, aileron to rudder mix active) POS 2 (Landing) Full reflex flap, higher % aileron to rudder mix, reduced travel ailerons, lower expo on all control surface channels.
with the flaps I do have servo speed active, I think I have 1 sec or 1.5 sec set, just enough so they don't go WHAM when deployed.


Cheers
Rob B