Chris King 3

True but it does leave a big bump on the top of the wing which doesnt look great.

I'm re-commisioning an old Lazy Bee I've had in the loft for donkey's years but I can't find any wing bands longer than 8" which are too short. The entire path of the band would be around 22" so I reckon on needing something like a 10" band at the very least. I've trawled this forum for any suppliers that might help but it seems no-one does anything bigger than 8".

It is that model but mine doesnt have ailerons and certainly doesnt take off like that one! I'm not looking for more lightness as such, just better performance. Thanks for the suggestions, I already have a couple of 1500 mAh 3s LiPos which I bought for my other model Im converting so I can try these so just need the motor and Esc.

...and to complete the story I finally got around to flying the model last weekend and as some had predicted the performance was somewhat lacking so I think internal resistance with the NiMH is an issue! It basically runs on full throttle and struggles into the sky! I'm sure the performance was far better when I used to fly it even though it's stretching the memory somewhat as it was 20 yrs ago! I'm in the process of finishing an old Astra Spitfire model (link here: Link ) and have upgraded to Brushless and Lipo for that. I think this old plane deserves a fair chance to fly again properly so I think I'll upgrade battery, Esc and brushless motor on this one. There were some very helpful suggestions on setup for my other model. Any suggestions for a starting point for this one please? It's a Scorpio Miss Moravia low wing (with dihedral) slow flyer. Original Spec is 147cm span, (original) weight 850g Speed 400 motor direct driving 8-4" prop.

Now that makes sense. Thanks guys.

I've trying out my setup. Motor is this one **LINK** with the 30A Flycolor ESC, Turnigy 1500mAH 3Cs with a Master Airscrew Electric Prop 9x5. When I run it flat out it pulls around 15.5A and nothing gets hot but the rpm only gets to 8800 max. With 11.1V and a 1000KV motor shouldnt it be reving to 11,100 rpm?

Did toy with the idea of using the 1600mAH NIMH I got for the park flyer (staying with Speed 400 for now) as ESC can be programmed for Lipo and NiMH.

I do agree about having a standard battery to use across multiple models. I have a few other models from my flying past that I'll probably upgrade to brushless and Lipo in the future but theres no way a pack of that size will fit in the spitfire.The battery compartment sits upright in the fuselage in front of the wing and theres no where else that a space could be opened up that I could get access to especially as the wing isnt removable. Im not too bothered having to go with a 1500mAH cell for it TBH. They will work in my Miss Moravia park flyer when that goes brushless and they are only a tenner each. Probably would have gone for that motor if I'd spotted it but have already bought the AirMax one! Gradually getting the other bits that are needed now like wattmeter, prop tacho etc. Lipo charger is next! Also going to join the local club I was a member of way back so i can use their field and benefit from their insurance. Many thanks for the advice, always good to get other angles on things!

I have my motor and Esc - had to wait a while as the 1000kv motor was out of stock. I think I'll have to go with a 1500mah battery (Turnigy) as the maximum length the spitfire battery compartment will accomodate is 73mm and the only 1800mah batteries I can find of that size are on Bangood or shipped from Hong Kong on eBay!

THats great, thanks Steve. When I googled the model when I decided to resurrect it I did see somewhere that a ground take off was a problem as the prop would hit the ground so a smaller prop would be an advantage.

Do you think this would this be close enough for the motor?... https://www.airtekhobbies.com/am2830850.html

Wow - Many thanks Steve - thats a lot of info! I'll work my way through that and see what questions I have. TBH I dont think the model will last long, the foam is very brittle and the glue on some of the seams is breaking down. But none of this gear is really expensive so as long as the bits survive any catastrophe Ill use them as a basis for another kit. I enjoy building as much as flying. I'd rather fly it once than leave it to rot in my loft for another 20 years!

Yes that battery too (3/4AA 9.6V 1600mAh Nimh). Its 1070mm wingspan so 42".

Its an Astra (scorpio) Spitfire - about 20 years old! Design weight was 800g but ive weighed all my component parts and as long as i havent forgotten anything im coming out about 680g.

Very tempting as I know the cost of these things has droped considerably but I'd have no idea what motor/ESC to buy to match the original motor/gearbox combination.

Hi, I hope someone can help with this question regarding prop size. I took a 20 year odd break from rc planes and recently dug out an old (Astra) fomie spitfire that I never completed. In carrying on with its construction I have now remembered why I shelved it (apart from kids!). The recommended prop is a 10x7 APC. The motor is a brushed speed 400, the kit came with a reduction gearbox which has 'MPJET' on it. The problem is that when I test tun it the motor quite quickly becomes very hot. Even when backing off to 50% throttle. The way it sits in the plane it wont get any cooling air so im concerned it will start to melt foam! Tried a spare 10x6 wooden prop and that doesnt make the motor anywhere near as hot. Should I use a smaller/different pitch prop or go with the manufacturers recommended prop and keep the revs down?

Just in case someone else finds this post with a similar dilema - this is what I did in the end. I bought some 9.6v 1600mAh NiMh 2/3AA cells. The originals were 1000mAh and 4/5AA so theres a small weight saving. To test them I ran at full throttle for 5 secs and then about 3/4 throttle until the ESC cut. It seems to produce the same power as the NiCads but will run for over 25 mins which Im sure is a lot longer than the old NiCads used to go for! Many thanks for all the suggestions and the heads up on the new technology. I have a couple of other planes that need motors so the info will come in handy with getting those flying again. Im hoping brushless outrunner motors will allow me to do away with the gearboxes they both used.

Youre probably right but thats two ESCs as I want to fly two models. All the component parts are much cheaper now. Its funny looking at the prices on the boxes for stuff I bought before I stuck it all up in the loft! Original plan was fly one finished park flyer and finish my foamie spitfire with the minimum of hassle/cost. Doesn't look like its as simple as buying a couple of new batteries!

The Spec for my ESC says it cuts off power at 5V - would that be OK for a LiPo?

When I was trial running both of them they cut the power to the motor early, I guess to keep power for the Rx and servos - not sure if thats the same?

Actually that does make for a good case for Lipo. I can buy 2 batteries and the charger for the same price as the 2 Nimh cells plus I get the bonus of a significant weight saving. Only downside is I cant charge in the field.

Yes it was that one. Model is about 800g so well over 1lb (about 1.7lb) with the heavy old Nicads! So is the problem with the Nimh that its 2600mAh? Would going nearer the Nicads 1000mAh help or has it got nothing to do with the rating?

Details said Max Discharge Current: 7,800mA Limit 3,000mA with Futaba/JST connector

Think I've cracked it. Component-Shop do a '9.6V 2600mAh AA NiMH Compact RC Battery Pack Vapex'. It will fit in both the models (just) and is lighter than the original (1000mAh) Nicads. Does the fact that it's 2600mAh mean it will last 2.6 times longer or will the motor go 2.6 times faster and explode? or is it not that simple. I get the whole LiPo and brushless thing. Brushless was just coming in when I gave up before. I have a conventially built model I bought from a club member years ago which needs a motor so may look into that in the future.

Howes Hobbies turned up a 9.6V (which ive worked out is what I have) 8 cell nicad pack in same configuration but with full size AA not the 4/5s. Looking at both models I could just about get away with the extra size. Cheap as chips too at £9 odd. Would be very slightly heavier but if I look for the full AA size there seem to be many more options and I can see Nimh packs at 1500mAh for the same weight which would be an advantage - getting there! Thanks for all the advice guys - Think half the fun is sourcing stuff!