Thunder Tiger Trainer 40 Restoration

Pieliker96

Elite member
Entirely out of the blue, my grandpa somehow acquired a Trainer 40, and he wants to give it to me :eek: !
This is the only picture I have now, since I'm away at boarding school and this is the only picture my parents sent me. I'm hoping to get it in my dorm on wednesday.

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It appears to be very well - worn and/or old, as the formerly white bits are extremely yellowed. Condition of the internal structure is unknown.
This will also be my first balsa plane, so I will be referring to other build threads and the community for help. Feel free to post any suggestions or tips that you may have.

Thanks!
 

TexMechsRobot

Posted a thousand or more times
Subbed! Looks like fun! Are you converting to electric or leaving it with the motor it comes with?
 

Pieliker96

Elite member
I'll be converting to electric for the following reasons:

-Gas/nitro is hard to get onto campus and is probably illegal in some way I don't know
-so is keeping said gas/nitro fuel in a dorm room
-Gas/nitro vapors will not be good in aforementioned dorm room
-I have no prior experience in gas planes, and like the safety of electric.

Yes, it will be fun! :D I'm looking forewards to it...
 
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Pieliker96

Elite member
I've been following your build for a while now - I'm not sure what caused your ESC to give up it's ghost though. Because it puffed after the receiver bound, I suspect it was either something with the receiver or possibly the programming of the esc.

Anyways, thanks! This gets me an idea for how much time and effort I'll likely have to put into this thing - Challenge Accepted ;)
 

Pieliker96

Elite member
Got the plane today, just barely fits in my dorm. No more room for planes :(
will have pictures soon, have a meeting to go to.
 

Pieliker96

Elite member
Got the motor removed and all of the coating (except tail feathers). The coating just peeled off, it was barely even sticky. The electronics in this plane are extremely old: hitec HS300 servos and an old futaba unit with an ANALOG BATTERY VOLTAGE METER on the tx! No structural damage except for two broken wing ribs. All hinges operating smoothly and not binding. Overall condition was great, it just didn't look that well. Also, algae in the fuel tank.

It seems that it was flown once and then left to sit. Very odd. Pics will be uploaded within an hour.
 

Pieliker96

Elite member
Brace yourselves. Lots of photos.

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Only damage on the wing covering (a bit blurry). I suspect something poked through at one point. Both sides were damaged.



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Servo tray & foam RX/ Battery encasement (soft, cellular foam held together with zipties)



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Clever RX and battery placement- protecting the most expensive parts of the plane where you can is always a good idea. I would also like to point out (no pictures though) that the antenna for the reciever comes out of the fuselage behind the wing and is tied at the tip of the tail! Nowadays we have 2.4GHz, and I can get better range with 6" of wire than that can.




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Old Futaba TX



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Battery voltage indicator on the TX



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The trims aren't a button, they're an actual slider. Just gives a sense of how far we've come over the years.



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Engine starter motor



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Glow plug starter... thingy?



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Extra props (10x6)



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Motor w/ prop installed (one of the screws on the spinner is stripped and I can't get the prop off)



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Algea in the tank :(. Looks like whoever flew it (if it even did) forgot to flush the tank before putting it into permanent storage.



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Old reciever and servo leads - I plan to reuse the old servos if they work. I remember a post where someone was talking about older servos having power on different pins of the connector than newer ones, so they wouldn't work with new recievers, but I spent 45 minutes looking for that comment and still can't find it.

Edit: Thanks to Joker for finding it!
It turns out that old servos like this were wired differently than they are today. The power wire was at one end with the ground in the center. Now the power is in the center, so by simply swapping two pins they all work! Unfortunately for me, I already took delivery on new replacement servos. While the temptation is to simply use the new ones, I'd like to re-use the original equipment when possible and save the new ones for another project.

View attachment 59496




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The wheels are flat on one side from sitting for so long...
Anyone have ideas (besides buying new wheels) on how to remedy this?

Also, who makes phillips-head wheel collars anymore? Aren't they all hex now?




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Excessive use of glue on the tail by the builder. They obviously didn't have Josh Bixler telling them "Now remember kids, more glue doesn't mean a stronger joint" in their day, but it should've been obvious that this was more than a little too much glue.



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Tearing off the covering was really easy, as the adhesives were essentially gone.



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The worst of the two broken/chipped wing ribs. Easily fixable/replaceable with some CA.



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(almost) Fully Stripped. Only have the wingtips and tail feathers left. Next step will be to find a good esc/motor combo for this thing. The previous props were 10x6 on a .46 glow engine, if that helps. Hoping ~$80 -100 for both the motor and esc, although I feel this to be insanely optimistic, unless I buy used. I would also like it to run on 4s, see below for why.

I'm planning to use two Gens Ace 2s 5000mah 50c batteries in series, to keep cost down. I normally use them for my truck, but since I don't use them because there's no space for it in my dorm, they're just sitting in a lipo bag at my house. Yes, they are big. Yes, they are heavy. You know what else is big and heavy? A .46 glow motor, that's what. I'll need a ton of nose weight for this build, so why not make some of it more battery capacity:D?

Also, I noticed that the trailing edge sheeting on the top of the wing wasn't glued in place. I assume this is normal, as these wings are prefabricated (probably by a machine, judging by how well the ribs were glued to the coating:rolleyes:) for a ARF model, but I could be wrong.
 
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tmack

New member
You can get a Trunigy G46 and a Trunigy ESC for that motor for around $60.00 and the ESC is another $35.00 form Hobby King. How heavy is that plane? Can you get away with the G32?
 

kulens

Member
Beautiful to see the restoration of an oldtimer trainer! I've done a similar project this year. A friend had an old trainer too, a Prima from Svenson. The plane is more than 30 years old.

I've converted the plane to electric too and installed a BMI Spitz 46 motor. I'm using a 4000mA 4s battery and I can fly up to 25 min.! I haven't changed the covering yet, but I'm doubting to do it the coming winter.

Good luck and keep posting! ;-)

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Pieliker96

Elite member
I can probably get away with the G32 on a 12x10 APC with a plush 60A. Total is around $70 w/ programming card, not including shipping. Looking at ~2000g of thrust, plane (from Thunder Tiger's website) weighs 3000g. 2 to 3 TWR isn't bad for a trainer. This is also around 120w/lb, which is more than enough for what I'll be doing with it.
 

Pieliker96

Elite member
Thanks! I looked all over for it but couldn't remember what thread I found it in!

It turns out that old servos like this were wired differently than they are today. The power wire was at one end with the ground in the center. Now the power is in the center, so by simply swapping two pins they all work! Unfortunately for me, I already took delivery on new replacement servos. While the temptation is to simply use the new ones, I'd like to re-use the original equipment when possible and save the new ones for another project.

View attachment 59496
 
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Pieliker96

Elite member
Okay, I've decided on my electronics.

-2 x Gens Ace 5000mah 2s 50c lipo (from Traxxas Summit) in series
-1 x Turnigy G46 670kv on a 12x10 : $55 + Extra props
-1 x Turnigy Plush 60A : $35
-3 x Hitec HS300 servos (included w/ plane)
-1 x Graupner Mz10 TX & GR-12L reciever (my extremely basic T/Rx combo)
==================================================================
Total: ~$85

~4.5AH (80% rule)/~15A (cruise) = ~.3 hours = ~18 minutes conservative flight time
 
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Pieliker96

Elite member
Well, I should've known this would happen at least once. My room has become sort of a hub for all of my friends, so we normally have 6 or seven people in there after school lets out. We have the beds set up so that you can use them as couches, and the top of the wardrobes as armrests. One of my friends pushed the row of boxes and containers on top of the wardrobe to the side to make more room for his soda, which sent the last container (my food box) over the edge. Unfortunately, on the other side of this wardrobe was the plane, and the container fell on it, smashing a few wing ribs. Nothing that isn't repairable, but still an inconvenience.
 

Pieliker96

Elite member
Well, not much has been happening on either of my balsa builds lately due to... you guessed it... academics ;). Which I guess is sort of a good thing. I have a couple grades right on the fence between the two, so I'll be studying even harder now for semester finals, just to ensure those get and stay up. Between extracurriculars, homework, and dorm life, though, I simply don't have the time for this now. Though I do hope to get some work done over winter break.

I also learned last weekend that the hole in the wing covering was caused by a runaway billiards ball. Lucky it went straight through and missed the ribs entirely. One of the weirder ways to damage a plane, not sure how the previous owner managed that one :rolleyes:.