Belly Landers - Propellor?

[Nigel Heather]

Fancy doing a fun fighter warbird, so a belly lander, but have a question about the propellor.

 

With IC powered planes you can fit the propellor relative to the compression so that the prop will stop horizontal, but as far as I am aware, even if you can stop an electric motor (unlike a cut IC motor a stopped electric motor will still free-wheel), it could stop in any orientation.

 

So what is to stop an electric powered belly lander from breaking a prop every few flights.  Do you have to go with a folding prop or is there another way, or is it that this isn’t even a problem.

 

 

[Graham Davies 3]

Hi Nigel,

 

Been through this, so some thoughts for you.

 

I love a 'fling and flop' model, but electric belly landers do suffer. It seems to vary from model to model how bad, but they do break props. I had a Cambria Spit that used to chew through props for fun. It spoilt it a bit as I once went through 4 props in 4 flights. That was enough for me so I went for a folding prop. This obviously solved that problem, but performance is not as good, so there was a trade off. Part of the reason for that is those Cambria funfighters are a bit porky, so the landing speed is a bit higher. In contrast, my Ki45 twin is no problem, but it is very lightly loaded so is landing a lot slower. Similarly my ridiculous fatty me109 lands very slowly and is fine. I made my own 42" Spitfire that was loads lighter, and that was OK too.

 

I'm not sure if it's feasible to stop the prop at quarter to three as we used to in IC days. I suggest you 'suck it and see' and keep a folder up your sleeve for worse case scenarios.

 

Graham

[DaveB1]

I worried about this on my Cambrian FW190 as the radial cowl precludes a folding prop, but so far I've not broken any props at all - although not too many flights in so far and I've probably jinxed it now posting this

[Eric Robson]

I  have had about 200 flights with the Me110 and broke a propeller for the first time last week landing on the short strip it floated on and caught the electric fence wire.

I have done many touch and goes with it without breaking a prop. The props are APC 8x8 electric, I do not use brake on my esc's so there is very little resistance when landing.

 

 

[paul devereux]

8 minutes ago, DaveB1 said:

I worried about this on my Cambrian FW190 as the radial cowl precludes a folding prop, but so far I've not broken any props at all - although not too many flights in so far and I've probably jinxed it now posting this

That's nicely finished model!

[leccyflyer]

Funfighters are my favourite models and the majority of mine are belly landed, power off, only rarely breaking a prop on a normal landing. On occasion you might find you do break one, but it's really just the luck of the draw. Most of the props are APC-Es, which are notoriously brittle. The last few props I've broken have been rare as hen's teeth scale three bladers, on take off rather than landing - those hurt, because they were virtually irreplaceable.

 

If you're seriously worried about it, see if you can source one of the JP bright orange bendy props. They aren't the most efficient, but they are unbreakable.

[Dickw]

On my 1/12 scale RC Combat models I broke the APC-E props nearly every flight, so I changed to IC props which are much tougher. I still broke a prop now and then, but it did considerably reduce the problem.

 

Dick

[Simon Burch 1]

I regularly fly old Balsacraft Easy Street 1 and Spitfire IX belly-landers.  When I converted my Easy Street a brushless/lipo setup, which entailed a larger prop, I started breaking blades all the time.  Very frustrating.

 

The cure was to select the ESC brake to 'ON'.   This seemed counter-intuitive, but the argument was that a windmilling prop will be rotating at high speed when it hits the ground, adding to the stress on the blade.  If the prop is stationary and the landing speed is nicely under control, the lower blade simply moves away as it touches the ground.

 

Not convinced?  Nor was I, but I've never broken a blade since doing this.  My Easy Street has a Graupner Slim Prop 9x6, and the Spitfire IX has a Graupner CAM Prop 10x6.

[Peter Christy]

Its not just electric models that suffer this problem! Many "new generation" i/c props are much more rigid than in days of yore. I was getting through APC and Master Airscrew props regularly on my Sharkface. Then I managed to get hold of some yellow Kavan props. I'm not sure if they are still manufactured, of if these were NOS, but I haven't broken one since!

 

They are quite bendy, like the old school nylon props were. Probably not as efficient, but a Sharkie with a Cox .049 is quite "adequately" powered anyway, as are most electrics, so it efficiency is of little importance...

 

--

Pete

 

[Jake Bullit]

I find these "dogbone" Aerostar composite props are much tougher than APC,and a lot cheaper.

 

Unfortunately like most things at Hobbyking,they are out of stock!

 

https://hobbyking.com/en_us/aerostar-composite-propeller-9x6-bone-1pc.html?___store=en_us

[J D 8]

           Come back KK nylon props.

 Efficient NO, hub that could go oval YES , Blades that had chips in them yes, but who cared.  Brake a blade? Never. 😁

[Nigel Heather]

I have seen several mentions that the Cambrian Fun Fighters are a bit porky and land fast.

 

Are there any alternatives that you could recommend.

 

The Cambrian Fun Fighters do appeal because of the price and the range of models offered but always interested to hear other suggestions.

 

Also of the Cambrian Fun Fighters, do any stand out as flying better?

[J D 8]

   Because they are heavy compared to the modern foamy types the do fly faster an so can cope with windy gusty conditions [ make good scale slope flyers ] The pay off is higher landing speeds.

[Christopher Long 1]

Vintage Model Company Balsa Basics range. They do a Spitfire, Hurricane and Bf-109 - for electric only. 

 

Balsa Basics Kits

[Outrunner]

My Balsacraft used to use APCe props and predictably they kept breaking. I Then switched to a folder but it looked wrong. I now use Graupner Cam props and I've not managed to break one yet🤞

[Nigel Heather]

2 hours ago, Christopher Long 1 said:

Vintage Model Company Balsa Basics range. They do a Spitfire, Hurricane and Bf-109 - for electric only. 

 

Balsa Basics Kits

Yes I've seen them before, don't think they look as nice as the Cambrian Fun Fighters.

[Cliff Bastow]

I have several bellylanders, both tractor and pusher and have never had a problem. I think that unless the speedcontroller brake is on the prop just flicks the motor round a bit. 

[aidan mcatamney]

My all time favourite belly lander. 

[john stones 1 - Moderator]

Looks to have landed on your leg to me. 😉

[Chris Walby]

IMO it depends on landing air speed and a bit of luck, oh and how big a diameter prop it is?

 

WooHoo (twin) has small props so hardly ever break a prop

FT Versa has those floppy 8x4 and seem ok, but if you put a stiffer prop on they sometimes break - see note

Focke Stick (twin) small props NP

Outlaw NP and Ripmax Spitfire, TN Ta154 - see note

Cambrian FF ME109 when I had it used to break the odd one

 

Note - before beefing up the prop to an IC one its worth checking the strength of the firewall. TN Ta154, Ripmax Spitfire and Versa have cheese bulkheads and all you do is move the problem somewhere else....that causes more damage when it lets go!

 

PS Is it me but are folding props less efficient than a non folding one?

[Geoff S]

31 minutes ago, aidan mcatamney said:

My all time favourite belly lander. 

 

I flew mine a lot (original with brushed 400 motors and 7 cell NiCads/NiMH)  I don't remember breaking a prop.  The high wing probably helps 🙂

[aidan mcatamney]

The Twinstar.  

[GrumpyGnome]

Great plane, the Twinstar. I had an original grey one......... did lovely touch and goes on wet grass, frost, or snow. Never tried on water...........

[J D 8]

Being a home rough ground flyer as well as club I must have done thousands of belly landings over the years with RC IC and electric and with control line. A prop goes now and then but perhaps once or twice a year. Given over 50 years model flying that has to be over a hundred props but hey ho.

[aidan mcatamney]

The Twinstar In Flight At Former Second World War Aerodrome.