First taste of the sky

[aidan mcatamney]

😂 will do Toto and you too 

[toto]

Well a great day today.

 

3 flights in and the Domino successfully maidened. No dramas whatsoever. Flew well with only a minimal amount of trimming required. 

 

On my next visit I will take my 6s batteries though as opposed to the 4s I took today as the model seemed a bit underpowered. At times it seemed it only had enough power to " float " through the air rather than " cut " through it.

 

It was still a very nice flyer, steady and true ..... just the lack of power.

 

I will be arranging my membership this coming week as I will definitely be returning. Apparently .... once you join ..... they get you very quickly to be doing your own take offs and landings. There is confidence for you .... .

 

I was already capable of the take off's but landings were a different kettle of fish ...... not now so I'm told.

 

There is a feel good factor to this..... happy man.

 

Toto

[aidan mcatamney]

Brilliant Toto,  I had every confidence in you and the Domino.  A good partnership as they say.  Yes, I agree, fit the bigger batteries in next time but get the CG right and your good to go.  I'm not long left the flying field with the Tiger.  Great weather for flying here today.  Not a breeze and a good turnout of members.  I'm now sitting here in the Flash n the Pan in Ballymoney waiting for a fish supper.  

[toto]

I'm jealous .... a fish supper sounds bang on the money. I'm on hame made mince and tatties. .... about 15 minutes from now.

 

A great day with good company ..... a good talking shop as well where everybody is as interested in what you have to say ..... even the inexperienced newbies.

 

My mentor did the take off's and landings today as I was trying to get my hand back in. The landings were impressive. My mentor liked the Dubro wheels and tyres I have fitted. They take a lot of the shock and bounce out of a tarmac landing. I would thoroughly recommend then as opposed to the hard stock wheels that usually come with so many kits.

 

On General .... the Domino earned its keep today with a great performance.

 

Toto

[Simon Chaddock]

toto

Well done so far.

Just be careful as going from 4s to 6s will at least double the power available and that can bring its own difficulties if it is all applied at the wrong time. 😉

Edited November 4, 2023 by Simon Chaddock

[Kim Taylor]

44 minutes ago, toto said:

Well a great day today.

 

 

 

On my next visit I will take my 6s batteries though as opposed to the 4s I took today as the model seemed a bit underpowered. At times it seemed it only had enough power to " float " through the air rather than " cut " through it.

 

Toto

Hi Toto

Good to hear you've had a positive experience.

I don't know what prop/esc/motor you've got in the Domino (could look it up on the thread, but too lazy) but you may only need to prop it up a bit, if you've got headroom on the esc/motor. Your wattmeter will tell you if you can or not.

If you do go to 6s, as per Aidan's advice, check c of g and also the watts being absorbed, to protect the esc/motor.

Happy flying

Kim

eta: Good also that you've had the weather - it's been unflyable down here for a fortnight or more.

Edited November 4, 2023 by Kim Taylor

[toto]

Hi Simon.

 

Thanks for the warning. I'm sure this model will soak up a reasonable bit of the extra power as it was VERY  noticeable. If you applied even the slightest bit of up elevator ( unintentionally ) the nose would go up as you would expect and the model would very near come to a standstill. 

 

I think there will be an initial breaking in period of a flight or two in order to get used to the additional power but I think it will do more good than harm.

 

Looking forward to seeing the difference between them. We were doing an average 5/6 minute flight with the 4s 5000mah battery and there was still an average of 68 to 73 % left in the battery so based on these batteries, a 10 minute flight would be easily achievable.

 

Cheers

 

Toto

[toto]

Hi Kim,

 

I'll check out the potor and prop sizes and come back to you. What I do know is it's a 60amp ESC and 4s 5000 man battery.

 

Cheers

 

Toto

[Kim Taylor]

8 minutes ago, toto said:

Hi Kim,

 

I'll check out the potor and prop sizes and come back to you. What I do know is it's a 60amp ESC and 4s 5000 man battery.

 

Cheers

 

Toto

Well assuming that the motor is capable of 50A or a little more, then you should be able to prop it to give 700W easily enough, which would be more than enough at the moment, I would have thought. 

Your choice though - as you're finding out, there's always more than one way of skinning a cat, or powering a model 'plane, and neither is more 'right' or 'wrong'!!

Kim

Edited November 4, 2023 by Kim Taylor

[toto]

I'll re check the prop size Kim.

 

Cheers

 

Toto

[aidan mcatamney]

The Tiger was well behaved today when let out of its cage . 

[Peter Jenkins]

Toto, your friend is your wattmeter.  What did it read at full throttle?  You say you have a 60 A ESC and assuming that the motor can also take 60A then you are quite safe to have a full throttle current draw tethered on the ground of 60A.  In flight, this will drop by 15%- 25% - I know as I have on-board telemetry and that was what I found.  So, in flight the current draw willl be between 45A and 51A.  Assuming your 4S pack voltage will be around 16 V at best at full throttle in the air that gives you a power output of 720 - 816 W.  I don't know the weight of your model but let's say 4 lb this will give between 180 and 204 W/lb.  Since a good W/lb figure is 100 W/lb which gives a sprightly performance.  180 W/lb should give a very sprightly vertical performance and will be the bottom of the power required for good aerobatic performance while 204 W/lb should give you unlimited vertical performance i.e. continue climbing at speed till its out of sight - my aerobatic biplane has 254 W/lb and its certainly got unlimited vertical performance!

 

So, something is wrong in your set up and you are not getting the power out of the setup you have.  Have you accidentally reduced the throttle channel output to the ESC?  Is it at 100% in the ATV or whatever it's called in your Tx?   It might just be that you need to increase the propeller pitch and, if the ground clearance will allow, diameter.  You basically have to load up the motor until it produces its rated power.  If you load it too much you will burn out the motor or ESC or both which is why you must check with your Wattmeter.

 

I now check my systems when they are in the air to see what the true full throttle current draw is and that is how I found the motor drew 95 A and used 3,600 W on the ground tethered but a maximum of only 80 A and used 2,800 W in the air at full throttle.  The motor is rated for 2,800 W.  In normal aerobatic schedule flying I rarely see more than 2,750 W and 78 A at the end of the flight.

[toto]

Hi Peter.

 

I'll check out the ESC and the TX first. ( this will be tomorrow as I'm in me Jim Jams with a glass of red wine ) I will also get the Watt meter out and rigged into the set up and tether the model ( my son will be my tether  ) and see what I can find out. The prop .... on searching through the thread is a 12 x 8 but I will confirm this tomorrow as well and I'll recheck the motor spec.

 

I think this will be a worthwhile exercise as I need to start getting my head around these things and this seems like a good place to,start. I'll post my finding up with images if possible for the watt meter.

 

One thing is for sure ... the power was really wishy washy.

 

Cheers

 

Toto

[Philip Lewis 3]

Are you still using the 5055 580kv motor? If so that KV is really suited to a 4 cell pack, that would give a RPM of around 6,500 to 7,000, (voltage X KV less 20%), a 6 cell pack will be 50% more. Your problem is almost cerainly the prop which is too small and therefore not loading the motor enough to draw enough power, I think the last 4 cell lane I had with unlimited performance used a smaller motor of roughly the same KV but had a 14X10 prop on it.

 

Current draw was about 45 amps if I recall correctly.

 

6 cell and the same prop should be fine but it's going to spinning very fast although that is unlikely to do it any harm. 

Edited November 4, 2023 by Philip Lewis 3

[toto]

What prop would need to be fitted with the 4s then.

 

I have around a dozen 6s batteries so no worries as long as it is jot going to create any issue.

 

Toto

[Kim Taylor]

9 minutes ago, toto said:

What prop would need to be fitted with the 4s then.

 

I have around a dozen 6s batteries so no worries as long as it is jot going to create any issue.

 

Toto

Okley dokey, I've looked on the Domino thread, and if I'm not mistaken, the motor is a 40mm can 500kV. That motor is going to need a lot of prop to give you (say) 700 - 750W on a 4s lipo. I think you'll run into clearance issues.

As you've got the 6s 'in stock' then I'd be inclined to give them a go, while being mindful of the extra weight and ensuring that you don't add more ballast to get it balanced.

In other words - make sure that the battery is placed at the optimum position to give the correct c of g (or as near as possible) without adding extra unnecessary weight.

Or - and I'm only now as I'm typing thinking of this - you could try a 3 blade prop to give a bit more oomph. Maybe someone with access to Ecalc could run the numbers for you on a 12x8 or 13x8 3 blade?? 

Either way, with a bit of fiddling and experimentation, you'll have it flying nicely.

Kim

[toto]

Hi Kim,

 

Cheers ..... the 6s has to be the first stop for now as I dont have any 3 bladed props. If I can get it set up outside tomorrow ( weather permitting ) I'll run some checks with the watt meter whilst running on both 4s and 6s batteries.

 

It will be a bit of a challenge to get this right as it will more or less be the first time I have tried anything like this ..... but bare with me.

 

Many thanks

 

Toto

[John Stainforth]

13 minutes ago, toto said:

Hi Kim,

 

Cheers ..... the 6s has to be the first stop for now as I dont have any 3 bladed props. If I can get it set up outside tomorrow ( weather permitting ) I'll run some checks with the watt meter whilst running on both 4s and 6s batteries.

 

It will be a bit of a challenge to get this right as it will more or less be the first time I have tried anything like this ..... but bare with me.

 

Many thanks

 

Toto

People tend to be rather choosy who they bare with!

[Peter Jenkins]

Toto, that's what you use the watt meter for.  Find out what the current draw is with your current prop then up the pitch and check again.   

 

As an example, I needed a 17x12 prop on a 425 Kv motor with a 5S pack but a 16x10 prop on a 585 Kv motor gave the same power but at a higher rpm.  In both cases I had the same power, 1,200 W and with a 5.5 lb AUW the aircraft had 218 W/lb that gave the aircraft the ability to fly large loops at constant speed.

 

With the 425 Kv motor and 16x10 prop the power was marginal for what was required of the aircraft hence the change to 17x10 snd eventuslly 17x12 to get the power out of the motor.

[Philip Lewis 3]

1 hour ago, Kim Taylor said:

1 hour ago, toto said:

 

Okley dokey, I've looked on the Domino thread, and if I'm not mistaken, the motor is a 40mm can 500kV

In my post quoting the OP who said it was a 5055 motor (and 580 KV) I would expect that to be a 50 diam can 55 length, capable of producing more that enough power, I use 5055 motors but with a KV of 320 on 8 cell packs in rather larger planes driving 18X10 props.

 

If it's a 40 mm dia can motor forget what I said.

Edited November 5, 2023 by Philip Lewis 3
Spelling

[toto]

A quick question.

 

When I set up the watt meter between the ESC and the battery, do I need to have the wings attached to include the full weight of the model when taking readings ?

 

I'm assuming so as you would require the full weight of the model to give an accurate total loading.

 

Toto

Edited November 5, 2023 by toto

[john stones 1 - Moderator]

No, you'll be restraining the model anyway.

[Graham Bowers]

16 minutes ago, toto said:

A quick question.

 

When I set up the watt meter between the ESC and the battery, do I need to have the wings attached to include the full weight of the model when taking readings ?

 

I'm assuming so as you would require the full weight of the model to give an accurate total loading.

 

Toto

If you're taking measurements with the model static, then no. The wattmeter sees the motor load, which is battery and propeller dependent.

[Learner]

You will have to weigh the model complete ready to fly with battery and you'll have to calculate how many watts per pound but no wing needed for power test. Take a note of watts and amps pulled at full throttle to see if their below components rated max.

Then divide watts by weight in pounds.

[David Davis]

Toto. You'll need to weigh the model with the LiPo installed and the wing attached, then you've got a starting point. Let's say your model weighs 4lbs. For a model like this I think you need about 80 Watts per lb. I can just hear the keyboards of the electrical cognoscenti glowing red hot in offering a contrary opinion but bear with me. So with the wattmeter connected, wind it up to maximum speed with the model suitably restrained and any loose pieces of flotsam and jetsam tidied away out of the prop wash. Then have a look at the wattmeter. It should be drawing about 320 watts. If it's drawing significantly less than this, increase the size of the propeller so that it draws more power from your equipment. If the tricycle undercarriage doesn't allow for a bigger propeller, fit one with greater pitch. Until we know the weight of your model and the amount of current drawn at WOT, it's difficult to advise but I'd advise not going above 100 watts per lb in the hands of a novice. Ok, I know you have an instructor on a buddy box and a throttle on your transmitter but too much speed often gets beginners into trouble in my experience. 

 

I would avoid putting a 6S LiPo into it because it will at the very least increase the wing loading of the model making it fly more quickly which is something you need to avoid as a total novice. You may also have problems with the centre of gravity and you could burn out the speed controller unless it's capable of drawing the extra current.

 

Besides, years ago I used to inport the Telemaster range of trainers from the USA. The "works" Telemaster 40 had a six foot wingspan, weighed six pounds and had two extra servos actuating the flaps. It was fitted with a 3547-800 motor, a 14 x 7 propellor and a 4S LiPo 6000mAh LiPo to allow twenty minutes flight times. I venture to suggest that it was considerably heavier than your Domino but a 4S LiPo flew it more than adequately. A 4S will definitely fly your model.

 

Of course the i/c route is much simpler. Shove any 40 into it, learn how to adjust two needles and away you go, but that's another issue! 😏

Edited November 5, 2023 by David Davis