Ripmax Spitfire EP

[Kelly]

I use a APC 12x8, no brake  and glide it in .

 

The silver looks greyish when in the air.

 

The markings  of JE Johnsons Spitfire Mk9 on the 6th june 1944.

 

 

Plastic model but accurate. 

 

Kelvin 

[martyn sharp]

 Hi Timbo what setup have you got to go with the prop ?

thanks

Martyn

[Tim Mackey]

I have re-motored mine 3 times in the last few weeks - a bit like goldilocks

1) was simply too powerful ( mega 22203E 1500kv ) Inrunner on 9 X 6

2) the next was too heavy ( PP 1200Kv ) and have now settled on

3) the excellent VFM Keda 1000Kv  Outrunner  from Giant Cod.

It was in my Alienator, but the hot Mega has gone into that now

With a 3s 2300 mah Lipo I get 8 minutes of nice scale like flight, with plenty of luvverly large loops et al.

Neither motor or pack is ever more than warm upon landing.

LINK

Edited By Timbo - Administrator on 21/05/2010 13:13:12

[martyn sharp]

 Thanks Timbo.  well i have orderd the servoless retracts ( kelvin that was the cheapest one with your link thanks)  got the spit now all i need it the time to work it all out size of wheels and the air scoops sizes and how to fit it all .If anyone has a photo of the wing coverless love to see it might help to locate the renforcement for the retracts .

 

Martyn

[Tim Mackey]

I could be very tempted to fit these to mine too - so shall be watching with interest. Anyone doing the job, please ensure lots of detail and pictures and I suggest you start a new "blog" with appropriate title within this parent topic.

[Kelly]

Hi Martyn,

 

Great stuff

 

Hope to join a club later this year who own their flying site,no A cert needed ,just a test flight to prove you are safe .

 

They have a nice strip of short grass, may fit a pair to my original Spit when I repair it and give it a make- over .

 

 

Kelvin

[Mark R]

Hi all, to those about to re spec their Spits, loads of pics please please!  I have mine sat in garage and i am determined to get it in the air this summer.  So retracts is the way to go.

 

Timbo regarding choice of engine, how did you work out what would work well in it?  I had the brushed engine sat around but didnt want to fit it as i prefer brushless, but never had the 'were with all' to work out what is a good alternative......how do you go about choosing correct size engine, there seems to be a lot around these days all making different claims about Kv etc etc...what is the secret? Is there a secret or is it like a game of Cluedo, wild stab in the dark.

 

cheeers

 Mark

 

 

 

 

 

 

 

[Tim Mackey]

Mark, I aimed for around 120Watts per lb or so, and expected to be flying/cruising around on much less . At  2.5Lbs AUW thats about 300watts flat out, and therefore - on a 3s lipo at 11V or so, it  meansd current od about 27A. I want a motor which will swing a largish prop  ( I went for 11 X 6 ) therefore I needed an outrunner thats happy on 27 -30A and 350 watts or so.I chose the budget  Keda 1000 Kv from Giant Cod.

Now as it happens, I flew her today with my data logger installed, and have JUST downloaded the data .

A 10 minute flight showed....

peak Amps of 32, and an average of 12.

peak watts 380 and avaerage of 136.

Volts held at and average of 11.5.

 The flight was near on perfect for scale speed, and she did lovely big loops, barrel rolss etc, and overall went exactly as I wanted. This is a cracking easy to fly warbird which sits well, and looks good in flight. I commend her to the house.

 

[Mark R]

Hi Timbo, cheers for that, never been good at all fings leccy...but now have a good rule of thumb to go on....next stop Giant Cod

Cheers once again

[Wingman]

Yep this one's definately my 'birthday plane' for this year - it's sitting on the top shelf of my LMS just waiting for July

[Tim Mackey]

Mark, I trust you have had a good look around our "beginners to electric" section

[Tim Mackey]

Posted by Wingman on 24/05/2010 07:15:05:

Yep this one's definately my 'birthday plane' for this year - it's sitting on the top shelf of my LMS just waiting for July

 

Wingman, I am sure you will be very happy with it - anyone with a little low wing model experience will get on fine with her. One thing I have noticed is that she really does fly much better when kept as light as possible. I know the original was designed around a heavy brushed powertrain - and by all accounts flew well on that, but I flew last night with a larger (4000mah) 3s pack, and apart from longer flight times, she performed, if anything, not quite as well. The battery increased the weight from 2 lb 8 oz, to just 2lb 10oz, and I could definately feel the difference....still fine, but just not quite as "crisp" IYKWIM.

[Wingman]

Yeah thanks Timbo. I fly two standard batts - Hyperion 3S 1500 and 2500 25C in all my leccy planes so will use the 2500 and your recommended KEDA 1000KV. I fly a Hyperion Helios 10E on the 1500s and it's brilliant but it will take the 2500s as well, however, like your Spit, it's definately lardy with them and not so nice to fly - isn't it strange how you can 'feel' the diference?

[Chris Bott - Moderator]

Not quite the Ripmax Spitfire but it's predecessor the Balsacraft one. I believe that Ripmax bought the rights and switched it to an ARTF.

 

I hope these pics show that it's worth keeping a broken model a while, to give yourself time to change your mind and repair it?

 

 

 

 

 

Edited By Chris Bott on 24/05/2010 15:05:24

[martyn sharp]

 Can anyone help i'm looking for a copy of the balsacraft spitfire plans or at least a photocopy of the center peice of the wing so i can see the best way to set the retracts so if anyone can help thank you 

martyn 

Edited By martyn sharp on 26/05/2010 13:26:50

[Chris Bott - Moderator]

Martyn I may still have the plans. I'll have a look and if so, I'll see if I can scan the centre section. Although I only have an A4 scanner.

[leccyflyer]

Nice B/C Spitfire Chris.

 

Just a word about the persistent rumour that the Ripmax Spitfire is the Balsacraft Spitfire converted into an ARTF.

 

I dunno what happened to the design, or design rights or anything like that, but the structure is sufficiently different that they really are different models.

 

In several main areas that difference is as large as can be - th cowl (which is horrid on the Rippers Spitfire) and the wing construction, which is totally different, being a built-up structure with strip ailerons in the case of the Ripmax Spitfire and an all sheet construction with inset ailerons in the case of the B/C Spitfire.. Add in the fact that the Ripmax Spitfire also has a built-up tail, whereas the Balsacraft Spitfire has all sheet tail and control surfaces.

 

They are about the same size, both are electric and both use balsa in their construction.

 

My boy's Ripmax Spitfire survived a horrible hand launch on Sunday and he did very well to get her away. First time on 2.4Ghz too - no trailing aerial and the 3s1p 4500mah gave a very powerful performance. Cracking model

[Chris Bott - Moderator]

Oh, OK. Well here is the Balsacraft wing plan. In case Martyn is looking for this to add retracts to a B/C model. I found the wing plan, but never did find the fus one when I was doing the reconstruction.

 

It looks to me like any retract installation would seriously compromise the spar.

Shame really. 

 

 

[Chris Bott - Moderator]

Leccy, on launches, I'm beginning to find that lower power than max helps a lot. Otherwise the launcher is trying to hold back a model that's wanting to go faster than he can throw. A setting where he can just push the model out harder than it is pulling seems to work for us. Then a gentle raising of power to keep the torque effect manageable.

[Wingman]

Yeah Chris I think that's good advice - I've had a couple of really squirrely maidens hand launching at FP - luckily they went up instead of down

[martyn sharp]

  

Thanks chris I see what you mean about the centre spar looks like I may have to use wire legs instead of oleos legs and cut a small slot and then reinforce with carbon fibre weave   or put a n bend in the wire to rest over the spar but still reinforce not to pretty but I might be able to cover it with a plastic leg cover  need to think about it if you can scan the centre and mail it . I would be grateful Chris

Thanks

martyn

[leccyflyer]

Posted by Chris Bott on 26/05/2010 15:09:17:

Oh, OK. Well here is the Balsacraft wing plan. In case Martyn is looking for this to add retracts to a B/C model. I found the wing plan, but never did find the fus one when I was doing the reconstruction.

 

It looks to me like any retract installation would seriously compromise the spar.

Shame really. 

 

 

 

Posted by Chris Bott on 26/05/2010 15:11:48:
Leccy, on launches, I'm beginning to find that lower power than max helps a lot. Otherwise the launcher is trying to hold back a model that's wanting to go faster than he can throw. A setting where he can just push the model out harder than it is pulling seems to work for us. Then a gentle raising of power to keep the torque effect manageable.

 Chris

 

Good points, but this was just a rank bad launch by me I'm afraid. The Spitfire normally goes off a lightweight dolly in a few yards, but since this was at a fly-in I thought I'd chance a hand-launch. Bad move, The boy played a blinder to save the Spitty six inches from the deck.

[Chris Bott - Moderator]

That's very well done to him then

Martyn the scan is HERE hope it's what you need.

 

I still think the space required by the wheel will eat into the spar, unless you can place the wheel in a slightly off scale position. 

 

 

 

 

[Tim Mackey]

I too find the rippy spit goes off better with a round 3/4 power. This of course is dependant on what power you actually have though. I have gone through 3 different setups in mine until I found the one that i reckon is just right ( see earlier posting ) 

I tried a 4000ma pack, the extra weight did nothing for the flying character, and I reveeted to a 2300 Mahr Tipple which gives 7 minute flights.

 

Added glue to the front area as this is a known weak point, pinned and glued the hinges, and added a wire joiner for the elevator. A pilot finishes things off nicely.

 

In summary, this is a great ARTF, very forgiving, handles a strong wind with no problem ( makes a great PSS model too )  will float in for a greaser every time if you keep her light..... and in the air she looks just fine to my eye. 

Edited By Timbo - Administrator on 04/06/2010 18:35:59

[Chris Bott - Moderator]

Now there's a coincidence Tim, my (balsacraft) one started life with a 1400kV Axi which was fine on 8 NiCads. But a bit "hot" on LiPo's. After it's rebuild I happened to have a 1000kv turnigy spare so I rebuilt the nose around that. And it's now excellent on 4 A123's.