"Bill Kits" anybody?

[SIMON CRAGG]

Generally a fine pitch prop is used on fun fly type models. Instant throttle response, tight manoeuvres etc.

 

These models are not designed to fly any where near fast, hence a 13x4 in my case.

 

On 3s I was getting 41a 485w, which is still adequate, but not as much as I was aiming for.

 

1500mah lipo chosen, as I have a lot of them, lightweight and high C rating.

 

Of course all the above is great in theory, and I may well have to change the set up after the first test flight!.

[Nigel Heather]

22 minutes ago, SIMON CRAGG said:

Generally a fine pitch prop is used on fun fly type models. Instant throttle response, tight manoeuvres etc.

 

These models are not designed to fly any where near fast, hence a 13x4 in my case.

 

On 3s I was getting 41a 485w, which is still adequate, but not as much as I was aiming for.

 

1500mah lipo chosen, as I have a lot of them, lightweight and high C rating.

 

Of course all the above is great in theory, and I may well have to change the set up after the first test flight!.

Thanks for that.  What configuration did you have with the 3S.

 

I like the idea of idea of being able to start with the 3S batteries that I have and then later swap out the prop and battery to go 4S - but wonder whether there would be enough room to move batteries around to achieve the correct CofG.

 

Ultimately, I would like to move up to 4S but with a battery capacity that will be useful across a range of aircraft.  I wonder whether 1500 would be too small if given the chance to start afresh.

 

By the way, my flying skills are low-intermediate so I wonder whether ‘high performance’ would be wasted on me to start of with.  If I could start with the 3S that I have and then graduate up to 4S later that would be ideal.

 

Cheers,

 

Nigel

[SIMON CRAGG]

Nigel, same configuration for both.

 

Good idea to start with 3s.

 

Maybe you have done this already, but a Wattmeter is a MUST.......loads of info for how / what to use it for on Google.

 

Also, I have found that a download ($6 for the full version) called "E.calc" has been invaluable. Looks a bit daunting and not always 100% accurate, but is fantastic for working out prop, esc, lipo combinations. If you have not got it, have a look and it may well answer some of the questions you have!.

[Nigel Heather]

14 minutes ago, SIMON CRAGG said:

Nigel, same configuration for both.

 

Good idea to start with 3s.

 

Maybe you have done this already, but a Wattmeter is a MUST.......loads of info for how / what to use it for on Google.

 

Also, I have found that a download ($6 for the full version) called "E.calc" has been invaluable. Looks a bit daunting and not always 100% accurate, but is fantastic for working out prop, esc, lipo combinations. If you have not got it, have a look and it may well answer some of the questions you have!.

Thanks, will look into that.  Regarding watt meters, there are loads on eBay around the £10-£15 mark, lots are the same model but even the different ones look to be the same electronics just a different plastic case.  Are there any to recommend or avoid or are they all much the same.

 

Also had a look at e.calc, you are quite right in saying that it looks daunting, well not daunting so much, I can see how it works it is just so detailed that there are loads of parameters that I think “how on earth am I expected to know that”.  I also note that it is $8 for the RC Aeroplane version, $15 if you want the full RC package but that is an annual subscription - so just checking that I am looking at the right thing.

 

 

[J D 8]

    No need to over prop [ pitch] or overpower a fun fly like a Limbo, If it has the power to pull vertical it's enough. Many a fun fly has come unstuck [ come apart ] going too fast, usually the result of flutter of the types large control surfaces.   Having said that though my Limbo has an OS46 with pipe but it has a fine pitch prop and I am careful to pull back the power as soon as it is coming downhill.

[Nigel Heather]

17 minutes ago, J D 8 said:

    No need to over prop [ pitch] or overpower a fun fly like a Limbo, If it has the power to pull vertical it's enough. Many a fun fly has come unstuck [ come apart ] going too fast, usually the result of flutter of the types large control surfaces.   Having said that though my Limbo has an OS46 with pipe but it has a fine pitch prop and I am careful to pull back the power as soon as it is coming downhill.

Just checking I understand that - do you mean that there is no need to run a 7” pitch, a 4” pitch will do.

 

Cheers,

 

Nigel

[J D 8]

   Yes, that is correct.  John.

[SIMON CRAGG]

Yes, you are looking at the right e.calc, you really only need prop.calc at your stage.

 

All the Watt Meters are much of a muchness but probably best to get one from a UK model shop, as opposed to a potential "cheap clone" with no come back if it turns out to be duff!.

 

As the other chaps have said, "flutter" (where the control surface vibrates badly until it destroys itself), is a potential problem with lightweight fun fly type models with HUGE control surfaces. They are designed to complete radical manoeuvres in small spaces, not blast across the patch at 90mph. The coarser the pitch the faster the model will go, but the acceleration will be worse. Think driving a car.........first gear lots of revs climb steep hill.........top gear less revs higher top speed Motorway etc.

[Nigel Heather]

11 hours ago, SIMON CRAGG said:

Nigel, same configuration for both.

 

Good idea to start with 3s.

 

Maybe you have done this already, but a Wattmeter is a MUST.......loads of info for how / what to use it for on Google.

 

Also, I have found that a download ($6 for the full version) called "E.calc" has been invaluable. Looks a bit daunting and not always 100% accurate, but is fantastic for working out prop, esc, lipo combinations. If you have not got it, have a look and it may well answer some of the questions you have!.

 

 

So, does that mean that on 3S you get 11,340 RPM and on 4S you get 15,030 RPM or is it not as simple as that?

 

Cheers,

 

Nigel

[Erfolg]

I have run my model (and many others) on 3s as well as 4s. My main reason going to 4s is to reduce the amps drawn for the same watts drawn. I am seeking to reduce the stress on the ESC.

 

The other aspect is that we all seem to be upping the power used or available as equipment became or has become more readily available ay affordable cost. At the end of the day an. excess of power is occasionally very useful.

 

As others I use a watt meter (Overlander), I have seen others use much cheaper brands (they have come down in price. they work every bit as good as my device. I have a electronic rev counter, which I use very little now. The reason being is that the data sheets provide much less and different data sets than in the past. I mainly worry about amps and watts now, and how the model flies with the set up.

 

In essence I do not worry about being correct, what ever right might may be, the model just needs to fly and the power train not to overheat.

[Nigel Heather]

How are the builds coming along.  I have one in the post, went for the full kit as I haven't fully decided whether to go IC or electric.

 

Has anyone worked out a good electric setup yet. 

[Nigel Heather]

Anyone completed their builds.

 

I haven't started building yet but need to buy some 4S batteries for another project - I hope to use the same batteries for my Big Fun.

 

I appreciate that it is better to keep weight down but also keen to get flight times of around 6 minutes.

 

As a compromise between weight and flight time I'm looking at batteries in the range 2200 to 2900.

 

The 2200 are obviously lighter (and cheaper), they would work with my other project but concerned the flight times on the big fun might be too short.

 

Any feelings here on what short of flight times I would get with the Big Fun with a 4S setup with a 2200 battery?

Edited April 26, 2023 by Nigel Heather

[SIMON CRAGG]

We held our first BIG FUN event at the weekend.

 

Probably best if we discuss our findings of the eleven models on a PM basis!.