Solar-powered model planes
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- Joined: 16 Feb 2018, 14:11
- Location: Warwickshire
Re: Solar-powered model planes
I flew mine today in a relatively strong breeze - we measured it at 12 mph with gusts to over 15 mph. There were people at the strip with large glow powered models who said they didn't want to fly because it was a bit windy for their liking. It was tricky to hold the solar flyer for launch but once away it flew well and penetrated into the wind easily.
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- Posts: 44
- Joined: 25 Feb 2018, 13:10
Re: Solar-powered model planes
I got some cells from Martin, solder 6 together, +'ve marked red.
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- Posts: 44
- Joined: 25 Feb 2018, 13:10
Re: Solar-powered model planes
All the work is done on this flat board, old table top that my eldest daughter did her school work on in the late 1990's. This ensures that these long wings end up without warps. Once the solar cells are fixed it adds to the torsional strength.
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- Posts: 44
- Joined: 25 Feb 2018, 13:10
Re: Solar-powered model planes
The other wing has had the solar cells soldered together, fitted to the wing carefully get them the right way around, only to find they were turned around. So had to alter the wiring. I am using 2 old Graupner servos which remain excellent and work fine with this low voltage.
The servo connection I use is a 1.5mm ply horn, 30mm long, 20swg pushed and then connected to a clevis with a short piece of brass tube 2mm diaameter threaded for 2mm. Fixed with Loctite.
The fuselage seemed a bit fragile so have added 1.5mm ply doubled and covered in glass cloth.
The servo connection I use is a 1.5mm ply horn, 30mm long, 20swg pushed and then connected to a clevis with a short piece of brass tube 2mm diaameter threaded for 2mm. Fixed with Loctite.
The fuselage seemed a bit fragile so have added 1.5mm ply doubled and covered in glass cloth.
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- Posts: 44
- Joined: 25 Feb 2018, 13:10
Re: Solar-powered model planes
Tip fins were stuck on with Por. On my previous models they were just painted, this time to make them more durable wither increased weight, they have been covered each side with glass cloth before fitting.
The wing servos have a tight hole cut in the top Depron sheet, this time I put an edge of glass cloth around the hole, then when ready they just have 2 strips of Sellotape Clear to hold them.
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- Posts: 44
- Joined: 25 Feb 2018, 13:10
Re: Solar-powered model planes
Had the test flight, no video today. The first flight needed full up trim and the controls were sluggish. Landed altered the sub trim and moved the aileron link to the outer hole in the servo. There is a better power then the 8c model but not as manoeuvrable, also on a dive test it recovers easily, so the CoG can go backwards.
At home I have now tried a 2812 but I did not get enough power on an 8" prop, and I'm so not t,think a smaller faster revving motor will improve things, so back to the 2822 1400kv motor, wait until the 1000kv motor arrives and then try some different props. I may then shorten the nose to move the CoG backwards.
Motor and prop selection is far more critical than with battery planes, it just needs to be adjusted to the power V and A available. The motors are easiest fitted it you can find short hexagonal bolts, and use a long handled driver, unfortunately I have some from he'll maintenance.
So a successful first day, had flights of about 20 minutes before deciding to land. On bright blue sky days then it really is just keep flying for as long as you want to. When clouds come I expect chasing after the clear sky and missing the clouds will become important and another task.
At home I have now tried a 2812 but I did not get enough power on an 8" prop, and I'm so not t,think a smaller faster revving motor will improve things, so back to the 2822 1400kv motor, wait until the 1000kv motor arrives and then try some different props. I may then shorten the nose to move the CoG backwards.
Motor and prop selection is far more critical than with battery planes, it just needs to be adjusted to the power V and A available. The motors are easiest fitted it you can find short hexagonal bolts, and use a long handled driver, unfortunately I have some from he'll maintenance.
So a successful first day, had flights of about 20 minutes before deciding to land. On bright blue sky days then it really is just keep flying for as long as you want to. When clouds come I expect chasing after the clear sky and missing the clouds will become important and another task.
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- Posts: 748
- Joined: 16 Feb 2018, 14:11
- Location: Warwickshire
Re: Solar-powered model planes
I was there for the first test flight (in fact I launched it ) but I'd arranged to dash off to another flying field so I didn't have the time to shoot any video. Hopefully we can do that on Sunday, weather permitting. I can confirm that Mike's new solar model flew great from the first flight, and I'm sure after a little more adjustment to the c.g. position and some motor/propeller experiments, it will be the best performing one yet.
I was going to the different flying field to meet someone about arranging a venue for test flying my jet (hopefully that will now happen on Monday).
I was going to the different flying field to meet someone about arranging a venue for test flying my jet (hopefully that will now happen on Monday).
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- Posts: 748
- Joined: 16 Feb 2018, 14:11
- Location: Warwickshire
Re: Solar-powered model planes
Here's a short video of Mike flying his 12-cell solar model (the one detailed in the build log in this thread) this morning.
At the moment it doesn't seem to be climbing any better than the 10-cell model, despite the extra power available. This may be due to the heavier weight (spruce spar versus balsa on the smaller models) but the wing loading is about the same so more likely it's just that the optimum motor / propeller combination to suit the 12 cells is still to be found.
At the moment it doesn't seem to be climbing any better than the 10-cell model, despite the extra power available. This may be due to the heavier weight (spruce spar versus balsa on the smaller models) but the wing loading is about the same so more likely it's just that the optimum motor / propeller combination to suit the 12 cells is still to be found.
- RON
- Site Admin
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- Joined: 12 Jun 2017, 15:09
- Location: Stokesley North Yorkshire
Re: Solar-powered model planes
Nice job there
In some of the video there it actually looks like a bird of prey, think it’s the black on the wings.
Looks great fun
Ron.
In some of the video there it actually looks like a bird of prey, think it’s the black on the wings.
Looks great fun
Ron.
G0MBV Class A Radio Amateur, North Yorkshire