Build Log - TB 20 Electric airplane

Started by allthatido, March 22, 2012, 11:08:45 PM

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allthatido

Hi everyone

I will be documenting my TB-20 build in this thread. I will try to be as extensive as possible during the process. This ARF kit is available at RC Bazaar. Following are the specs :

  • Length: 784mm
  • Wing Span: 1045mm
  • Flying Weight:630g

Buying this kit from RCB was a fantastic experience. This is how the plane arrived. it was double box packed for transit.

Jatayu

 {:)} {:)} {:)} congrats on your new buy!

Hope to see her maiden soon!

all the best! :thumbsup: :thumbsup: :thumbsup:
Spektrum Dx6i | Blue Baby |  Fast Cat | TB-20 | Speedy | Lil' Ripper| Little Elley| PT-20 Ryan | Delsoro - SAE Heavy Lifter | Hiller 450v2|2x AXI 2217/2|2x Castle Creations- Thunderbird 54A| 2x Thunderpower RC Lipo 850mAh 65C| 10x Futaba s3114

SAE Aero Design West- 2011
1st Place Highest Payload Lifted
2nd Place Operational Availability

allthatido

Thanks Jatayu. The setup I intend to use with this plane :


  • Lipo : turnigy nano tech 1000 mah or rhino 1050 mah
  • ESC : 25 amp turnigy basic
  • Motor : Emax CF 2822
  • Servos : 3 x hobbyking HKSCM9 servos
  • Prop : GWS RD 9x4.7

allthatido

#3
The kit quality is pretty descent for the price. Except for a few scratches here and there the kit was in perfect shape. The following points are observed :


  • There is enough space inside the fuse to house your receivers and servos. (have to keep in mind to avoid the pushrod though).
  • The battery compartment,which is hard plastic, can fit snugly 1000 mah lipos (may have to cut foam and/or plastic to route cables though).
  • Battery hatch locking system needs to be strengthened (I don't trust the current system...is flimsy).
  • The firewall may need little coat of epoxy for strength...feels tad week.
  • All the mounting points (wing and elevator) on the fuse need to be strengthened with epoxy.
  • Spinner is disastrous and utterly useless.

allthatido

more points


  • The cowl is very thin and flimsy.
  • The hinges on the wings, elevator and rudder are pretty stiff. Need to loosen them up but be careful not to break them..just tape them as a precaution.
  • The wings are strong with carbon fiber rods in them. The plastic wing tip helps.
  • Landing gear is good.
  • Motor mount good.

roopeshkrishna

Phoenix.........

warriornair

wish u happy flying and landing........

allthatido

#7
Thanks for your wishes warriornair.

Upon dry fitting the parts it was observed :


  • The wing (after joining the two halves) would not fit properly in the fuse cavity...some cutting/adjusting is required here.
  • The elevator's alignment is slightly skewed.
  • The firewall is made up of 2 thin plywood pieces and foam sandwiched in between. There are no holes in the rear plywood as in the front plywood. The motor mount screws do not go in fully lengthwise.
  • The wooden wing joiner does not fit perfectly in the grooves of the wing. Some of it sticks out of the wing

All these little misfits might seem minor for a seasoned builder but i think for a beginner it sure will be a time consuming build. It is not a perfect beginner friendly plane for building in my opinion.

allthatido

The manual provided with the kit is pretty simple. It has just pictures without much explanation. Glued the two wing halves together with the supplied glue. Applied the joint lining with foam safe CA and used an accelerator.

Finally got to use my Dremel and sanded off the portion of the wood joiner to match the wing surface.

Tucked the servo in its place and used just a dab of foam safe CA to secure the servos. The servo as such is very tightly fit in the slot.

manu

You are mentioning only the negative things try to say something +ve.
even crashing requires a flight......

flying truck

Great build. Did you have any problems getting all the stuff from hobbyking?

allthatido

Attached the landing gear provided with the kit onto the wings. The white plastic strips hold the landing gear rod on the black base (came fixed on the wing). There are two strips each for one landing gear. The rear strip does not match with the holes already provided on the base. Had to cut a notch to align the strip.

One of the screw does not fully go inside the hole.

allthatido

Quote from: manu on March 28, 2012, 03:57:36 PM
You are mentioning only the negative things try to say something +ve.

I am sorry my friend this is a build log not a paid review  :P. I am documenting what I am experiencing. I have never mentioned anywhere that this kit is bad. It is you who are looking it as negative points. I just don't want any beginner or someone else to buy this kit thinking no work needs to be done before flying (apart from putting electronics/radio etc).

This kit is surely great for its price but needs some work before maiden. The plane does look nice once finished. And I am sure it flies great as well. :)

But it may become a little frustrating for a newbie to assemble this thing (in the absence of any senior) in my opinion.

Quote from: flying truck on March 28, 2012, 04:03:43 PM
Great build. Did you have any problems getting all the stuff from hobbyking?

There was absolutely no issues in getting stuff from HK.

allthatido

Now if I could just find my screwdriver  :giggle:

manu

Oh i am sorry. Should'nt have said that to a senior like you.
even crashing requires a flight......

manu

And why have you written that '8 is the figure I love'. 8 resembles prop is'nt it?
even crashing requires a flight......

allthatido

Quote from: manu on March 28, 2012, 07:45:33 PM
Oh i am sorry. Should'nt have said that to a senior like you.

You don't have to be sorry Manu..u didn't offend me in any way.... in fact I am sorry if I couldn't maintain the neutrality of my reply. Search Cuban eight for your question's answer :)

allthatido

#17
Installed servos for rudder and elevator. The rudder control rod was a tough one given my fat fingers. I am facing a problem regarding placement of ESC in this model. Can any one who has build this model tell me how they have installed esc ? have you placed it inside the battery tray or at the motor mount ? Any help would be appreciated.

allthatido

Installed motor and esc :)

allthatido

Also realized that the front wheel steering is reversed. If I apply right rudder..the plane turns left  :-\ No intention to change that as of now. Made a small hole in the fuse for Rx antenna (yes I still use 72 MHz).

allthatido

There is no mention of how to fix cowl..so I used 2 screws to secure the cowl..the inside of the cowl was supported by applying fiber tape at the mounting point. Also I am planning to cut out the plastic tip on the wings and install 2 5mm bright LED's powered by a 200mah 1s Lipo.

allthatido

Just set up all the electronics together and used a watt meter to find out the amps drawn. I am using a 3 cell 11.1 lipo with 9x3.8 prop. I moved the throttle till 3-4 clicks above half throttle mark and the amps drawn was 7-8 amps at that point. The thrust felt good.

DrGKhanna

Sir,the build is coming out really beautiful. And gr8 work with the improvisions being done. Build logs like these from senior and respected members like you are a boon for beginners like me. Waiting eagerly to watch some flying pics and videos. All the best sir.

allthatido

#23
Thanks DrGKhanna

But you have wrongly placed me in the category of senior members..still a long way to go.

At last finished the wing LED mod. Here are the steps :


  • Remove the plastic wing tips.
  • Make a hole according to your LED size. I used Hobby knife for it.
  • Glue the LED as shown in pic.
  • I routed the wires from below the wing. I didnt want to cut slots in the wing. The wires will be taped later.

Repeat for the other wing.

allthatido

Really happy with the outcome.  :giggle: :giggle: :giggle:

Finally she is ready for maiden.