Getting back into RC aircraft

Getting back into RC aircraft

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GliderRider

2,528 posts

89 months

Wednesday 7th August
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tim0409 said:
I need to get some rechargeable battery backs (TX and RX) and a charger; any recommendations? I also need to buy a couple of cheap mini servos…I take they are now pretty much interchangeable in terms of brands (I seem to remember shaving the edge of Futaba plugs back in the day and swapping the red/back leads for JR)?

Cheers!
Sanyo Eneloop NiMH batteries hold their charge for ages. I read somewhere that black wire corrosion on nicads and NiMH calls is the electrolyte venting when the batteries are left on charge after they are full, even on a trickle charger. A peak detection charger will stop the charge when they reach this point. It also means you can charge your transmitter and receiver battery when you suddenly realise its going to be flyable. No more having to wait for an overnight charge. I use an IMAX B6 and a Ripmax Sigma ProPeak charger.

You can buy a bundle of leads from AliExpress that cover just about any connector you come across, including transmitter, receiver and glow starter. The Transmitter connectors comes with a PVC cover. One is centre positive, the other centre negative as JR and Futaba are opposite to each other If you leave the cover on the one you don't use, there is no risk of plugging the wrong one in and getting it the polarity wrong.

Servo-wise there are so many fake servos around that buying from a reputable supplier like the Servo Shop (Steve Webb Models), Sussex Model Centre or 4Max makes sense.

Brother D

Original Poster:

3,980 posts

184 months

Thursday 8th August
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Jim H said:
Hello folks,
The Acro Wot flew too but has developed a big fuel leak , probably a pin prick in the fuel supply.

Fixing them both now.

Hopefully get the Spitfire up next week.
FYI Public announcement - turns out JIM H has been uncovered as a shill for "Big Balsa".

He uses complex social media manipulation that results in you buying the Chriss-Foss Acrowot kit (that you've been after for years) and will have to explain to your other half that you will simply have to build (under protest) and enjoy flying.





(I hope this fits in my suitcase back to the USA - and if there are any building tips Jim H could share that would be appreciated).

Jim H

1,150 posts

197 months

Thursday 8th August
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Brother D said:
Jim H said:
Hello folks,
The Acro Wot flew too but has developed a big fuel leak , probably a pin prick in the fuel supply.

Fixing them both now.

Hopefully get the Spitfire up next week.
FYI Public announcement - turns out JIM H has been uncovered as a shill for "Big Balsa".

He uses complex social media manipulation that results in you buying the Chriss-Foss Acrowot kit (that you've been after for years) and will have to explain to your other half that you will simply have to build (under protest) and enjoy flying.





(I hope this fits in my suitcase back to the USA - and if there are any building tips Jim H could share that would be appreciated).
Oooof. Bloody hell I’ve been rumbled hehe

Great choice Brother D, fantastic model. Not the quickest to build, but nothing too complicated. And, most importantly a joy to build and fly.

Unfortunately I started in this thread a little late through my Acro build - it was nearing completion.

Absolutely no problem at all over tips and advice on your build, I’d enjoy doing so 100 %.

Let’s hope it fits in the suitcase, and the earache you may receive is not too extreme.;)

Brother D

Original Poster:

3,980 posts

184 months

Thursday 8th August
quotequote all
Jim H said:
Oooof. Bloody hell I’ve been rumbled hehe

Great choice Brother D, fantastic model. Not the quickest to build, but nothing too complicated. And, most importantly a joy to build and fly.

Unfortunately I started in this thread a little late through my Acro build - it was nearing completion.

Absolutely no problem at all over tips and advice on your build, I’d enjoy doing so 100 %.

Let’s hope it fits in the suitcase, and the earache you may receive is not too extreme.;)
Thanks Jim - will deffo be in the thread asking for advice come build time!

Jim H

1,150 posts

197 months

Thursday 8th August
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No problem at all BD. As I said earlier in the thread this was not my first Rodeo on an Acro Wot build.

Although the last one I built was around 1988 - I remembered a lot of what I would do differently again. And I did.

The build instructions are comprehensive and fit-for-purpose, but experience being considered - (this) can certainly make the whole process easier.

For example: I built a very cheap but effective jig to hold the two halves of the wings together when gluing. I’ve kept it and will post up some photos when you are ready.

Same with the Radio / servo install. Back in ‘88 I had a covered model that was awkward to secure, trying to install pushrod's and linkages from the underneath of the fuselage. Yeah it wasn’t easy.

So, I knew there was a way to simplify - I’d spent a bit of time thinking the whole thing through.

Right now though mate, I reckon the largest issue you face: is explaining to your other half the new purchase!

Or maybe getting it packed in a suitcase clap

GliderRider

2,528 posts

89 months

Thursday 8th August
quotequote all
Brother D said:
FYI Public announcement - turns out JIM H has been uncovered as a shill for "Big Balsa".

He uses complex social media manipulation that results in you buying the Chriss-Foss Acrowot kit (that you've been after for years) and will have to explain to your other half that you will simply have to build (under protest) and enjoy flying.

tr7v8

7,315 posts

236 months

Friday 9th August
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For the aeromodellers here watch this!


Jim H

1,150 posts

197 months

Friday 9th August
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tr7v8 said:
For the aeromodellers here watch this!

Hi TR,

Good video, I must admit I’ve YouTube’d many a Pulse Jet video.

Back in about 1986 I visited an annual Model Aircraft show at RAF Woodvale (near Southport). It may actually still run? I dunno.

There was a Pulse jet there then, run by a ‘Team’ from Holland if my memory serves correct.

My god it was loud, absolutely deafening - when they finally got through the procedure (multiple times) to actually getting it started. It took an age of pumping air in and fannying around.

And then it got going, eventually, and it was only up for a couple of minutes.

It had a fuselage the dimensions similar to a pencil, swept wing section like a razor blade. Mounted on top: A massive Pulse Jet.

I still can’t get my head around how a pulse jet actually works, I’ve got a rough idea. It’s a brilliant concept as there are no moving parts. But they just don’t really work do they - efficiently. So obviously binned

Back to 1986 and the display of this. Jeez it was shifting along rapidly, how the servos and linkages and control surfaces were holding up against the laws physics and ‘flutter’ on a projectile travelling at over 300 mph. Next to a crowd stood feet away…

Different times.

Have a great weekend folks .

tim0409

4,896 posts

167 months

Friday 9th August
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Jim H said:
Back in about 1986 I visited an annual Model Aircraft show at RAF Woodvale (near Southport). It may actually still run? I dunno.
That takes me back; my mum took me down to the Woodvale show (from Edinburgh) when I was young and we stayed in a B&B in Southport. My mum was very patient as it can’t have been much fun for her.

From memory there were quite a few stalls selling kits etc and I recall I went to the Solarfilm stall and mentioned to them that I had tried to use their Solarlac paint and it didn’t work….they gave me a free replacement as they said it must have been a bad batch, and I remember being quite excited that I was given something free! It’s strange what you remember. I went on to work in a model shop and the Solarlac paint wasn’t a faulty batch, it was just rubbish!


Edited by tim0409 on Friday 9th August 21:41

tr7v8

7,315 posts

236 months

Saturday 10th August
quotequote all
Jim H said:
I still can’t get my head around how a pulse jet actually works, I’ve got a rough idea. It’s a brilliant concept as there are no moving parts. But they just don’t really work do they - efficiently. So obviously binned
They do have moving parts, albeit not many. They have petal valves on the intake. So air enters the front, goes through the open valves, mixes with fuel & ignites (glow plug or spark plug). The rising pressure closes the valves, the very hot air exits the back. That pressure drop opens the valves, rinse & repeat. That is why they have that warbling sound. None of the fields I have ever flown from will allow them because of the noise. I did have some plans years ago.
They are easy to make.

https://en.wikipedia.org/wiki/Pulsejet

Baron Greenback

7,237 posts

158 months

Sunday 11th August
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Not a RC person, like them but never bitten built just seen this on youtube blew my mind can't belive there no difference on handling swept and not.


Jim H

1,150 posts

197 months

Wednesday 14th August
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Oh hello! What have we got here then?scratchchin

It turned up yesterday. I got suckered in over the weekend by my favourite model shop having a bit of a sale - the buggers!


Hmmmm yeah. So, the AcroWot has a lovely powerful engine as it is - but! You can never have enough (power), and this being Pistonheads where Speed Matters, I thought a bit of an increase in capacity and revs wouldn’t hurt.

It’s a brand new OS 55 AX.

Now hang on a minute, there’s a bit of a method in my madness. I’ve got a winter project build on the horizon so I needed an engine for that, so it made perfect sense to free up the existing lump from the AcroWot. Well, to me it did. biggrin

And come on, that new OS was only £139 - bargain.

I’m not sure if it will go in the AcroWot immediately. I’ve been having a think about practicalities. I’m entering the last few weeks of available flying evenings now, due to nights drawing in etc. And obviously, after a fairly poor summer for weather - that’s another factor.

Every night flying from now on is going to be a bonus, I don’t want to prejudice any by niggles with installation and CofG stuff.

It should actually be a straight swap as the mounting holes are exactly the same as the 46 already in the ‘Wot, but I don’t know if it’s going to fowl on the cowl etc..

Mind you, if I get a few combined days of bad weather, and no flying, I’ll be shoeing it in with glee. I mean obviously I can’t wait to fire it up and find out what it sounds like on song. biggrin. My neighbours probably not.

Have a great evening folks. Regards Jim.

GliderRider

2,528 posts

89 months

Wednesday 14th August
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Jim H said:
It should actually be a straight swap as the mounting holes are exactly the same as the 46 already in the ‘Wot, but I don’t know if it’s going to fowl on the cowl etc..

Have a great evening folks. Regards Jim.
Jim, if it looks like major cowl surgery may be required, an exhaust extension is available which might make the difference. I uses something similar on my model very recently, except mine was an extrusion sold by DuBro that one cuts to length to suit what is needed.

This is the OS Extension


Edited by GliderRider on Wednesday 14th August 19:23

Jim H

1,150 posts

197 months

Thursday 15th August
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GliderRider said:
Jim H said:
It should actually be a straight swap as the mounting holes are exactly the same as the 46 already in the ‘Wot, but I don’t know if it’s going to fowl on the cowl etc..

Have a great evening folks. Regards Jim.
Jim, if it looks like major cowl surgery may be required, an exhaust extension is available which might make the difference. I uses something similar on my model very recently, except mine was an extrusion sold by DuBro that one cuts to length to suit what is needed.

This is the OS Extension


Edited by GliderRider on Wednesday 14th August 19:23
Hi GR and thanks for the advice.

I don’t really think it’s going to be much of a modification to make the new engine fit. I need to take off prop, spinner, cowl and work it all out.

Looking at the specs for both engines, the new one is only about 30g heavier than the old. And I have room to move ballast aft. The nicad was right up front above the forward landing gear - so well in front of the leading edge of the wing. I can actually move that to the point of CofG and further back - if required.

Now, bearing in mind the cowl on the AcroWot has a repaired crack in it after my ‘tip stall’ incident a few weeks ago. And I’m incurable perfectionist, it’s going to be replaced anyway. I found a chap on the internet that does fantastic quality replacement cowlings, actually much better than OEM. And extremely reasonably priced.

So I don’t actually mind trimming away at this one until I get it right, for when I order the next one (cowl) which I was already going to do.

Numpty mistake: looking at the spec for the new 55, I’d forgot about prop size. And I don’t have one to suit, as a minimum it requires a 12 x 7.

So.. I’ve just been back on line to my favourite model shop - and ordered up a few props. And another load of fuel. I’m glad I don’t run my cars on Model Technics!

Just want to give myself a little wriggle room in case. A good weekend weather forecast here.

I’m either sticking with the 46, or going all in with the 55 and doing static runs to break it in. I’ll probably need some ear plugs. biglaugh

GliderRider

2,528 posts

89 months

Thursday 15th August
quotequote all
That moving batteries around sound familiar. I've been trying different engines in a couple of models (Herr Flick and and Chilli Wind) The receiver batteries have been moving from the back of the wing to in front of the tank and back.

Your comments aboutr cowls struck a chord too. It infuriates me how kit manufacturers use ABS for cowls despite it being so prone to cracking.

Jim H

1,150 posts

197 months

Saturday 17th August
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Good afternoon folks, I hope you are enjoying your weekend.

Right, I’ve gone against my reasoned wisdom. The BIG thumping 55 - I’ve managed to shoe horn in. biggrin

I just couldn’t wait to get it started.

I had it running last night. I mean, you honestly can’t fault the quality of OS engines - it was running second flick. They really do sell themselves. Awesome engines.

I’ve had a few IC nitro glow engines in my experience, nothing, but nothing beats the quality of OS. They just work.

Last night was cowl off, it required a bit of trimming around the cylinder head (5mm). Everything is looking good now.



I’ve been let down a bit today by the courier, I was expecting a new big prop for it. I’ll be firing it up later for a ‘rich’ low rev tank-full.

Ear plugs in, big leather glove (yeah it can bite).

My poor neighbours !

Brother D

Original Poster:

3,980 posts

184 months

Saturday 17th August
quotequote all
Jim H said:
Good afternoon folks, I hope you are enjoying your weekend.

Right, I’ve gone against my reasoned wisdom. The BIG thumping 55 - I’ve managed to shoe horn in. biggrin

I just couldn’t wait to get it started.

I had it running last night. I mean, you honestly can’t fault the quality of OS engines - it was running second flick. They really do sell themselves. Awesome engines.

I’ve had a few IC nitro glow engines in my experience, nothing, but nothing beats the quality of OS. They just work.

Last night was cowl off, it required a bit of trimming around the cylinder head (5mm). Everything is looking good now.



I’ve been let down a bit today by the courier, I was expecting a new big prop for it. I’ll be firing it up later for a ‘rich’ low rev tank-full.

Ear plugs in, big leather glove (yeah it can bite).

My poor neighbours !
Looks fantastic Jim - you'll need more aeroplane with that engine : )

I swear I used to have an OS motor that had a small fuel pump(?) mounted to the crankcase (which I never got to use and ended up selling to fund going to Uni). I'm guessing that was more of a gimmick and the engines don't really need a fuel pump?



tr7v8

7,315 posts

236 months

Sunday 18th August
quotequote all
Jim H said:
I’ve been let down a bit today by the courier, I was expecting a new big prop for it. I’ll be firing it up later for a ‘rich’ low rev tank-full.

Ear plugs in, big leather glove (yeah it can bite).

My poor neighbours !
That's not the way to run in ABC engines (assuming its ABC?) It looks it in this pic, certainly not ringed.
https://www.os-engines.co.jp/english/2006autumn/ma...
Short runs, rich but not far off of full revs, after 10 minutes of 1 minute runs, fly it.

Jim H

1,150 posts

197 months

Sunday 18th August
quotequote all
Brother D said:
Jim H said:
Good afternoon folks, I hope you are enjoying your weekend.

Right, I’ve gone against my reasoned wisdom. The BIG thumping 55 - I’ve managed to shoe horn in. biggrin

I just couldn’t wait to get it started.

I had it running last night. I mean, you honestly can’t fault the quality of OS engines - it was running second flick. They really do sell themselves. Awesome engines.

I’ve had a few IC nitro glow engines in my experience, nothing, but nothing beats the quality of OS. They just work.

Last night was cowl off, it required a bit of trimming around the cylinder head (5mm). Everything is looking good now.



I’ve been let down a bit today by the courier, I was expecting a new big prop for it. I’ll be firing it up later for a ‘rich’ low rev tank-full.

Ear plugs in, big leather glove (yeah it can bite).

My poor neighbours !
Looks fantastic Jim - you'll need more aeroplane with that engine : )

I swear I used to have an OS motor that had a small fuel pump(?) mounted to the crankcase (which I never got to use and ended up selling to fund going to Uni). I'm guessing that was more of a gimmick and the engines don't really need a fuel pump?
Yeah I remember those, I’m sure a bit of a gimmick of the times. They certainly don’t need a pump.

Jim H

1,150 posts

197 months

Sunday 18th August
quotequote all
tr7v8 said:
Jim H said:
I’ve been let down a bit today by the courier, I was expecting a new big prop for it. I’ll be firing it up later for a ‘rich’ low rev tank-full.

Ear plugs in, big leather glove (yeah it can bite).

My poor neighbours !
That's not the way to run in ABC engines (assuming its ABC?) It looks it in this pic, certainly not ringed.
https://www.os-engines.co.jp/english/2006autumn/ma...
Short runs, rich but not far off of full revs, after 10 minutes of 1 minute runs, fly it.
Hi TR, and thanks for the advice. I’m not so sure it is ABC?

OS certainly don’t brand their engines this way now. What was it A - Aluminium piston, B - brass ring, C - chrome liner?

I missed a step in the dance here, I did two initial runs following OEM instructions on Friday night. I always follow OEM as they know best. Essentially the first two tank fulls were full throttle for 10 seconds rich, (4stroke motion) then 10 seconds leaner at (2 stroke motion) and keep repeating till it runs out of fuel. OS then state it’s fit to fly but ‘avoid nose up’.

I like to get at least 5 tank fulls through before flying it. I like to run it a mixture of lean and rich through the rev range. Set up a nice tick-over and throttle cut position. Etc.

There’s is a lot to go wrong after all. And anything can with an RC aircraft check and double check all the time. I want a certain degree of confidence in my first flight after a fundamental change around what makes it fly.

And it was proven today, yesterday I was having really poor throttle response. I could see the barrel sliding in the carb, so I knew it wasn’t a servo issue. I figured a block in the carburettor.

I’ve just had two hours working on it, yes, the throttle servo was dropping out, and all the the others! Turns out it was an intermittent fault on the on/off switch for the nicad to the receiver.

Thank goodness I found that on the ground! I’ve praised Futaba earlier in this thread. A very rare failure and not one you’d expect.