Quarter scale Spitfire

[phil yeomans]

Hi fellow members. I have just completed a quarter scale Mick Reeves Spitfire which has tipped the scales at 21.4 kilos, powered by a 62cc Zenoah petrol engine. Are there any other members who have built quarter scale Spitfire's at this weight or heavier. If so could you please advise size of prop, the engine has a tuned silencer. Thanks Phil

[Ken Bones]

HI Phil.
I am flying one of the new Mike Boothe Flying Legends kits (1 of the 4 prototype kits), same size and weight as yours, the moter i am using is a Z62 with a KS can .
I have tried quite a few different props but have found that a Menz S 22x10 gives best results, look to be getting a min of 7000rpm.
But to be honest, i find it could do wit a bit more in the go department as it runs out of steam uphill! Over the winter the Spit will be re engined with a 3W 75.
Ken B.

[phil yeomans]

HI Phil.
I am flying one of the new Mike Boothe Flying Legends kits (1 of the 4 prototype kits), same size and weight as yours, the moter i am using is a Z62 with a KS can .
I have tried quite a few different props but have found that a Menz S 22x10 gives best results, look to be getting a min of 7000rpm.
But to be honest, i find it could do wit a bit more in the go department as it runs out of steam uphill! Over the winter the Spit will be re engined with a 3W 75.
Ken B.

Hi Ken, Thanks for the information I have fitted a tuned silencer to my Z62 which I hope will give me the extra power.Phil

[Ken Bones]

Let us Know how you get on, good luck.
Ken B.

[Jason Griffiths]

Ken how about this http://www.bmfaclassifieds.co.uk/detail.php?id=6392

[Phil Clark]

Hi Phil

Just checking the model has been registed with the over 20kg scheme?

Weight wise, your 21.5kg is a V good weight......the electric 1/4 scale Spit I completed earlier this year was a good chunk heavier than that and though it has A LOT more power than is delivered by a 62, it flies beautifully.

Short flight video taken on the 2nd flight up at Longhorsley in May can be seen here.............

http://www.aircraftinaction.com/Alis_Spitfire_Roger.WMV

Phil

[phil yeomans]

Hi Phil thanks for your post, the construction of the model has been checked over by Don Billingham from the LMA and will need to be inspected again later. Did you have to add any nose weight to your Spitfire. Regards Phil.

[Ken Bones]

Phil, think you will be vary lucky not to have to add lead!
KB

[Mike Booth]

Even if she is very light a the back you can expect to add around the two pounds mark of church roof at this scale, unless you have used a 110 inline.
All the radio and bits need to be in front of F2, all you want behind this is a carbon pushrod/closed loop system to the surfaces.
If you have got servos in the tail you are going to have a hard time with the lead.
Remember there is 4/5th of the airframe behind the CG.

I think i know my Spitfires, so I am passing on the Holy Grail that holds the secret to successful Spitfire flying.
You will have the scale 2.5 degrees of washout at least ,or 3 hopefully.
My kit wings have 4 degrees moulded in and Ken has pushed it to the limit on a couple of deadsticks and it still doesnt bite.
Any aircraft will drop a wing when it is at zero airspeed though.
Your CG will be at 27% of the root chord measured from the leading edge.
From memory that is 25% of the root chord plus 10mm.
Any further back than this and your palms are going to be sweaty whilst you call someone over to click the elevator rate switch in, particularly when you want to flair for a landing.
Having said that at your weight you have nothing to worry about and you should approach the first flight with confidence, Bearing the above comments in mind, she will be a lady if those built wing panels are the same.
The wing loading is very good and there is a superb ground effect with the Spit when she is about to touch down.
Thats all you need to know , dont bother listening to anyone that draws breath and mentions the word tipstall, they dont know what they are talking about.
Phils finished weight proves that you have got nothing to worry about.
Best of luck and post us some pics when she's done.
Mike

[Mike Booth]

Just had a look at Phil's Spit, rock steady.

Here is a link to Kennys maiden flight on the Z62 which may be for interest to you as you are using the same.
Cheers mike. http://www.youtube.com/watch?v=NGoBTmLAlSE

[phil yeomans]

Thanks to Mike Booth for all your information I found it very useful. Regards Phil

[Phil Clark]

Did you have to add any nose weight to your Spitfire. Regards Phil.

Hi Phil

Uhhh....yea, you could say that.

This may sound completely unflyable, but our 1/4 scale electric Mk.1a tipped the scales at....76lb...of which 11lb was nose weight.

Many, including myself were initially sceptical at how it would perform....the 4 flights to date have proved me, and a good number of others completely wrong as the model flies beautifully and is VERY solid in flight with seemingly no nasty tendencies at slow speed (even on the test flight where we blew the ESC and had to make a rather rapid dead stick landing)

Our high overall weight was due to a number of factors.......firstly the method of composite construction used in the fuselage. It wasn't moulded by me, and the guy who did do it.....this was his 1st attempt and his methods and materials were drastically out of date and very heavy. As Mike says, you have 4/5th of the airframe behind the CG, so 1lb overweight in the rear will need 4lb to counter it in the nose.

Add to this the rather 'silly' amount of detail we added (scale tail wheel assembly, full depth cockpit, sliding canopy and opening pilots door, 2 opening access doors in the rear fuselage, fully detailed internal flap skins etc etc... (all of which as behind the CG)....plus of course the onboard sound generator with 3 x 4" load speakers....all of this was behind the CG, so maybe we made a rod for our own backs.

But........we've proved it can be done, and can be done safely, so a 1/4 Spit around the 40lb mark....you have absolutely nothing to worry about.

Phil

[Mike Booth]

Dont knock it though Phil, as I think in terms of pure scale detail, yours ranks with best done yet.
I will be organizing a Spitfire Salute somewhere next year and hope to get the whole lot together on one airfield.
A kind of open invitation to Spitfire owners in celebration of Britains finest.

[Phil Clark]

Mike

Thank for your kind complements.......not sure about that though!!!

It will be interesting to see how we get on next year as we have one of your kits booked in for another customer.......he's requested 'some' of the same detail as we did on the Mk.1a, but not all.....this one will also have the 110cc in-line twin up front rather than all this new fangled electricery stuff!!!......be interested to see what the differences are in nose weight between an electric powered short nosed Mk.1a with a HEAVY fuselage, and a longer nosed petrol one 'hopefully' with a lighter rear end.

Phil

[Mike Booth]

Great, you should be off to a good start.
We recently weighed one of the prototypes that is just being finished and the sum total of all parts including radio and U/C etc was 37lbs without ballast.
Ballast should be around 2/2.5 lbs.
My PR proto weighs 19K and I am working on another with a plug on horizontal tailplane which may add a little though the mouldings are very light.

Lets have a chat at Gaydon.
I also have a growing photo file on key construction area's which may assist when you get onto Roberts Spit.
One of the things I liked about the MK1 was the flap build you did.
Experience tells me that there is no point in replicating scale Frise aileron hinging as its a right fiddle.
We have found that there is no advantage over top hinging model style, on the scale top line.
The roll rate is exactly the same with hours saved in the build and finish.

Cheers mike.

[Phil Clark]

The Frise hinged ailerons were actually V straight forward (compared to the flaps !!!)

M3 metal rose joints (from RS) were used as the main pivots, set into 3mm bore carbon tube, which in turn was set into 1/4" sq section brass tube........with these 2 hinge pointed set into the false TE, it all worked V well. Only slight issue was the limited distance between hinge pivot and linkage pivot. To counter this, we mass balanced the ailerons (around 50g of lead strip was sprad along the LE tip)

Phil

[Phil Clark]

.................as its a right fiddle.

I always though scale modelling in general was 'a right fiddle'............

[tony hooper]

Phil

I have been flying the 1/4 scale Mick Reeves Spitfire for 2 years now. It was built by a freind of mine, Brian Hutchinson.
Originally it came in at 18kg with a ZDZ 80cc engine and Mick Reeves retracts but Brian has now fitted a ZDZ 100cc inline engine and Sierra retracts to it which are much more substantial. That brought it to 21kg and it has now been inspected under the Over 20kg Scheme and I have just completed the test flying.
It looks and flies a dream.
I am sure Brian will be pleased to disuss his aircraft with you - phone me on 07976 691992 if you would like his tel no