WolstonFlyer's Tucano

[WolstonFlyer]

I thought I would start my build thread a bit early just to get it in place and to add my initial thoughts and plans.

Just a bit of background info about me first.

 

I am new to RC flying (only last year) but did build a couple of Keil Kraft rubber powered models many years ago in my youth. So far I have only built depron and epp models from free plans found on RC groups and the FliteTest.com website, I have also built an RCPowers Eurofighter that flies very well (and it has been lots of fun). I do have a degree in Engineering but have carved out a career in IT support and programming.

 

I also have a Wot4 Foam-e to try and pass my 'A' test on (if it ever stops raining), I am hoping to get my A test done before Greenacres so that I can join in with the event.

 

I decided to join the "balsa bashing" gang and have a go a this years mass build, it looks like it will be fun and I should learn a lot on the way.

 

 

Edited By WolstonFlyer on 21/11/2012 11:03:49

[Danny Fenton]

I look forward to following along WF

[WolstonFlyer]

Just for anybody that is interested this is my powertrain setup for the Tucano using HobbyKing parts form the UK warehouse.

NTM Prop Drive 3542 1250Kv

- I am going to test the motor with 9x6 and 10x6 APC style prop

NTM 35 motor mounting pack

Turnigy Plush 60Amp Speed Controller

Turnigy 5A (8-26v) SBEC - just in case the ESC calls it a day the RX will still have power

Turnigy MG90S Metal Gear Servo - Thanks Phil Winks

Edited By WolstonFlyer on 21/11/2012 11:18:48

[WolstonFlyer]

Thanks Danny...

[Chris Bott - Moderator]

That looks an excellent setup for the Tucano WF. good to see you're going to test it with different props. I have a 1250Kv motor of about that size, and a 10x6 prop would burn it out on a 3S LiPo, but I know of others that need a 10x6 to produce a useful amount of power. This just shows that not all Kvs can be trusted. Can you let us know the current and power figures when you do test?

Good luck with the build, it's good to see a build thread started.

[WolstonFlyer]

My first problem was that the Turnigy prop drive adapter did not fit on the motor, it was also bent so have ordered a new one .

The hole at the back of the adapter did not fit over the end of the motor, no amount of pulling down on the bolts would fix it (measuring with calipers shows it was just 0.06mm too small) , I have filed the hole bigger so that it now fits but as the shaft is bent it is still no good. I just hope the new one is better!

This is how I plan on mounting the motor with a new former (F1A)

A bit like this from Chris Bott's Whizza build

 

Edited By WolstonFlyer on 21/11/2012 11:31:32

[WolstonFlyer]

Thanks Chris, I am taking your lead for the motor mount... see the last picture above

I will post some motor / prop test data as soon as I can get into the shed during daylight hours to do tests.

I was basing my prop "estimate" from the comments on the HK website. One reviewer says.

"Using 3S TGY Nano 2650mAh 35C and Eflite 2100mAh 30C

10x7 APC WOT 46amps 503watts
11x5.5 APC WOT 45amps 493watts
11x5.5E APC WOT 495watts 43amps 9356rpm
10x7E APC WOT 510 watts 46amps 9930rpm

I might start by testing the 10x6 and see what power that gives, Nigel says that 400 Watts is plenty for this model so can always prop down to 9x6 for fewer amps and longer flight time if there is enough thrust.

Edited By WolstonFlyer on 21/11/2012 12:00:37

[Chris Bott - Moderator]

Great idea WF (shame about the lack of fit!)

just in case it helps, I ended up chopping out the former below the cross mount. this was to make room for the ESC to fit nicely under the motor and in the airflow.

I needed it further forward so I could get the battery further forward for C/G too. Of course this is on a different model, but it's still one that was designed for the same heavy brushed motor at the front.

[WolstonFlyer]

Good point about making room for the ESC, I will include that on my notes (yes I have started a new posh notebook for this build!)

Do you think the former needs triangle stock on both sides to hold it in place for strength?

If I actually draw up the shape of the former I will post a picture here. I have not ordered any wood yet, I am waiting to see what the wood pack will cost v's ordering direct and getting some extra for the mistakes I will make!

[WolstonFlyer]

Well yikes, that is another £20 spent on this model and I have not even built anything yet...

From Giant Shark

Black Covering Film Solid (5mtr) - I have decided to go for the much simpler black design

5mm Heat Shrink

Wire Mesh Guard Black 6mm (1mtr) - Also needed for my 450 Helicopter for neat wiring

JXF 10x7 / 254 x 178mm Poly Composite Propeller
Nylon Arm 2x6x7.5mm 10pieces- For the end of the Torque rods

14g Collets 4/pack with allen key- To hold the nylon arm in place so they can be adjusted

10g Collets 4/pack with allen key - To hold wheels in place but I might need x 6

 

I am using a Spektrum AR6210 receiver that I have in my toolbox so at least I don't need to buy that but I might swap it out for a AR400 at some point as I only really need 4 channels in the Tucano.

Bye for now

Edited By WolstonFlyer on 21/11/2012 18:56:54

[David Molineux]

Don't know if you've seen this Motor/Prop calculator but it's very good. The figures it gave me are almost identical to those I measured with my watt meter. Means you can 'test' different prop sizes for a given motor/lipo combo before actually having to buy them

Dave.

[WolstonFlyer]

Hi David

Thanks, yes I have already had a play with ecalc and it thinks a 10x6 prop is a good size for that 3542 motor.

I have just realised I have ordered a 10x7 prop by mistake (oops)... I better get in touch with GiantShark and change my order.

APC 10x6e
LiPo 3S 4500mAh 25/35C
2002g of static thrust
Prop rpm 11491
Max current 39.25A
Top speed 65mph
Flight time @ full throttle 6.88mins

eCalc thinks that a 10x7 prop may stall and not reach max thrust, it says the same for a 9x6 but 11x6 is ok but very close to max motor current.

Edited By WolstonFlyer on 21/11/2012 22:27:04

Edited By WolstonFlyer on 21/11/2012 22:29:33

[Chris Bott - Moderator]

Posted by WolstonFlyer on 21/11/2012 11:58:29:

Good point about making room for the ESC, I will include that on my notes (yes I have started a new posh notebook for this build!)

Do you think the former needs triangle stock on both sides to hold it in place for strength?

If I actually draw up the shape of the former I will post a picture here. I have not ordered any wood yet, I am waiting to see what the wood pack will cost v's ordering direct and getting some extra for the mistakes I will make!

WF after that photo of mine that you posted, I added a doubler to the inside of each fus side. It took the space between the bulkhead and the Wing seat doublers you can see in the photo.

[WolstonFlyer]

Ahh thanks, that would make it all much stronger.

I am going to have a go at drawing up a plan for the motor mount etc, I will post it on here if it works out OK.

[WolstonFlyer]

I got a few jobs towards the build done today, did all of the soldering on the electronics and tested the new servo's and motor. The motor is a beauty, very smooth and quiet. I am going to do some power tests with different sized props but I need to make a simple test stand first.

A little brown box also arrived from GiantShark containing some 10x6 and 8x4 props, clevis, horns, swing keepers, wheel collets and and a 5m roll of black covering.

I am still waiting to see how much the wood pack will be before putting in an order at SLEC or Balsa Cabin.

I am quite suprised at how good the Tunigy MG90s servo's are, quite quick and good centering. They are basically a metal gear version of the popular HXT900, even the plastic case is exactly the same design but black rather than blue.

This was taken just before shrinking the heatshrink, the Orange RX is just for testing that everything is working.

One thing I don't like on the motor is the tiny C clip that holds the motor shaft and all of the thrust from the prop, I just know it will fail at some point....

So I have added a 4mm wheel collet as a backup... perhaps I just worry too much?

The last thing I did was to make up a twin battery cable so that I can try flying with two 2200mAh 3S LiPo's in the plane for longer flight times, rather than buying bigger batteries ( I have quite a few 2200's for my existing planes and helicopter)

It was a bit of a squeeze getting two 12AWG cables into the XT60, you can buy a cable like this from HobbyKing but I had the bits to make one up.

 

Edited By WolstonFlyer on 25/11/2012 01:02:31

[fly boy3]

Hi WF, I also will be watching your blog, not so much for the balsa bashing phase (good as it is) but for the info I will gain on the electrics. Dyed in the wool ic nut, but try ing to learn a bit on how power chains are chosen for a particular model. Built a few of Tom Wright's PLs and Dart just to gain some knowledge, and will not break the bank if any thing goes wrong. Cheers

[WolstonFlyer]

Hi fly boy3

Thanks for following my build.

This is my first balsa build so please chip in with any tips!

There are a probably a few of us that have chosen a similar power setup using one of the popular Propdrive series of motors from HobbyKing. I know that Phil Winks has got the same setup.

This one was chosen because it is a similar size and kv (rpm per volt) as the brushless motor mentioned in the build article by Nigel.

There have been advancements in motor efficiency so this motor will probably be a bit powerful for this model, it is rated for 600 watts on a 4 cell battery. I will be using 3 cell and using a prop that should give just over 400 - 450 Watts.

This should give over 150 watts per lb depending how heavy my completed plane is. I am expecting it to be very lively in the air.

I will be posting some motor test data with a few different prop sizes. I just need some time in my very cold shed to make a motor test stand.

The idea is to find a good combination of power output and thrust without going over the max rated Amps of the motor. Unlike an IC engine the motor will try and turn at its kv rating regardless of prop size but the Amps will increase as prop size goes up, to a point where the motor burns out.

There is also a balance between the current draw and the available space for batteries and the flight time you will get.

Best wishes

Edited By WolstonFlyer on 25/11/2012 18:59:01

[WolstonFlyer]

I have just found an interesting article adapting a wing so it bolts on.

http://www.balsaworkbench.com/wingbolt.html


I think this method may work for the Tucano, I really need a removable wing for storage of the model.

I am going to have a go at drawing this wing bolt method over photocopies of the Tucano plan.. watch this space.

Edited By WolstonFlyer on 25/11/2012 22:20:46

[Martin McIntosh]

Hi, I have gone for the TGY 35/36 motor and the prop. shaft fits OK. Not run it as yet.

Also I have redesigned the wing with a slightly more scale shape but with a little loss of area and is to be built up having a 15.4% section to take electric retracts. Hope to equal out the weight with a lighter general build. Ribs nearly all cut so here we go.

Spent a small fortune already on the bits, not including canopy, pilots and covering.

[WolstonFlyer]

Hi Martin

My replacement propdriver shafts fit OK (I got three more) so the first one must have just been bad luck.

Your built up wing with retracts sounds interesting, how thick does that actually make it? Does it still look scale?enough?

Are you putting in a retracting or partially retracting nose wheel? It looks like a very tight fit up front to me.

I know what you mean about spending a fortune, I think I have 80 pounds in the model already and have no balsa yet.

Buying everything new including Motor, servos, ESC, plan and canopy, some of the small hardware, Spektrum Receiver, covering film etc, etc

No wonder ARTF is so popular!

[Martin McIntosh]

Hi WF,

The wing is to be 37mm thick at the root, tapering proportionately to the tip (modified RAF 30 section) which has had the chord reduced to give a nearer scale shape, hence the slight loss of area. This is probably still thinner than a true scale section would be, but anything is better than a hand launch flat plate.

Cannot see any real problems with the noseleg unit.

[WolstonFlyer]

A little bit more progress, I have made a photocopy of the plans at work on A3 paper and carefully stuck it together measuring the original to make sure it is exactly the same size (and it is, we have a very nice Xerox copier)

The is the plan I will use to build over etc, rather than using the expensive original. You never know I might build a second one!

With all of the bits stuck together I can see how big this plane is, very nice

This also means that my wife saw the plans... and remarked "where on earth are you going to store that" (or similar words)

 

Edited By WolstonFlyer on 26/11/2012 22:30:09

[WolstonFlyer]

Hi Martin

The wing and retracts sounds great, I am going to stick to the flat plate wing for my build and let the experts do things like built up wings with retracts!

I have just had a quick look at your TN spitfire pictures, that is a nice looking plane... it's on my list to build (eventually).

cheers

[Martin McIntosh]

Hi WF,

Thanks for your praise of the Spits. The 44" is by far the best flyer of the three and would be the best one to start with (after a few more years under your belt possibly). The 1:6 is now in full fettle and goes very well, but the size/cost/build time still makes me very nervy on any flight (5 so far).

Modern leccy retracts are a doddle to fit so do not be afraid of trying them some time.

Got the first wing panel on the board with spars fitted. Will try to post some pics.

[WolstonFlyer]

Hi Martin

I will check out the 46" spit for when I have a lot more flying hours racked up! I had a mad moment a few months ago and got the TN 30" dogfight double spitfire plan... then changed my mind about building it for the time being.

It would be great to see some pics of your build with the retracts.

Although I have started a build blog for my Tucano I am totally new to balsa bashing and I bet there are people out there wondering what on earth I am taking about. I am going to record everything on here (mistakes and all) as an example of a new builder in this hobby.

Edited By WolstonFlyer on 26/11/2012 23:39:12