Trainer Plans ?????
10-09-2007, 01:58 PM
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Trainer Plans ?????
I downloaded the plans and have started building this trainer. It looks like a big (68" span) docile trainer. The question is does anyone know who designed this plane or does anyone have any more info other than what is on the plans? Thanks
10-09-2007, 03:11 PM
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RE: Trainer Plans ?????
It looks like one someone has drawn up themselves using CAD and made available on the internet, rather than being done by a professional designer
The reasons I think this are:
Not a lot of info on the plans
Use of colour - professional plans are drawn to print in black and white
CoG should be located under wing, not in the middle of the fuse
Nosewheel - seems like it is inserted into the bottom of the firewall instead of using a bracket
Rudder looks a bit small to be effective
That K&B engine drawing has been floating around on the net for quite a while available for anyone to download
The wing foil looks like a TLAR (that looks about right) section
But I may be wrong.
The reasons I think this are:
Not a lot of info on the plans
Use of colour - professional plans are drawn to print in black and white
CoG should be located under wing, not in the middle of the fuse
Nosewheel - seems like it is inserted into the bottom of the firewall instead of using a bracket
Rudder looks a bit small to be effective
That K&B engine drawing has been floating around on the net for quite a while available for anyone to download
The wing foil looks like a TLAR (that looks about right) section
But I may be wrong.
10-09-2007, 03:39 PM
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RE: Trainer Plans ?????
The plans are actually quite well drawn. The PDF I posted is only the overview sheet. There are 4 more DXF files that have a ton of detail and instructions. I have built the stabs and most of the left wing and it seems to be working fairly well. The plan calls for 1 1/8 stock for the flight controls, but I am going to increase them to 1 1/2 in.
10-09-2007, 04:38 PM
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RE: Trainer Plans ?????
that wing is not really a trainer type wing. it is almost full symetrical. a trainer should have a flat bottom wing. IMHO. it looks like it would be a good 2nd plane. if you are new to the hobby, IMHO, a scratch build wouldnt be my first choice at all. there are alot of great kits that are under $100.00 bucks out there. there is also a great trainer on the spad site. I wish I had seen it before I built my trainer, there cheaper and more durable. Welcome to rc universe!!
10-09-2007, 04:46 PM
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RE: Trainer Plans ?????
ORIGINAL: draftman1
that wing is not really a trainer type wing. it is almost full symetrical. a trainer should have a flat bottom wing. IMHO. it looks like it would be a good 2nd plane. if you are new to the hobby, IMHO, a scratch build wouldnt be my first choice at all. there are alot of great kits that are under $100.00 bucks out there. there is also a great trainer on the spad site. I wish I had seen it before I built my trainer, there cheaper and more durable. Welcome to rc universe!!
that wing is not really a trainer type wing. it is almost full symetrical. a trainer should have a flat bottom wing. IMHO. it looks like it would be a good 2nd plane. if you are new to the hobby, IMHO, a scratch build wouldnt be my first choice at all. there are alot of great kits that are under $100.00 bucks out there. there is also a great trainer on the spad site. I wish I had seen it before I built my trainer, there cheaper and more durable. Welcome to rc universe!!
I never said anything about being new to R/C. I just have never done a scratch build, and I figured this would be a good way to get my feet wet. I am not interested right now in building with coroplast. I wanted to scratch build a ply and stick plane.
10-09-2007, 09:06 PM
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RE: Trainer Plans ?????
If the plans are faithful to the little PDF you attached above then the tail surfaces are too small. The fin and rudder area is too small and the size shown for the chord of the stabilizer would suggest that it too will be too small unless it has a long span. Longer than normal and therefore a rather high aspect ratio.
The wing's airfoil is a bit "wedgy" as well. The forward upper portion between the leading edge and the spar should have a slightly fuller curve to it. As it sits now it's rather sharp and I suspect it'll have a rather abrupt and nasty stall.
If the other sheets are faithful to this one then I'd seriously suggest you scrap the stabilizer you've made and then blow up the plans for them so that the stabilizer and elevator total 20% of the wing area. Similarly blow up the fin and rudder so that they end up being 9 to 11% of the wing's area. As they are right now the model won't fly for long.
The wing's airfoil is a bit "wedgy" as well. The forward upper portion between the leading edge and the spar should have a slightly fuller curve to it. As it sits now it's rather sharp and I suspect it'll have a rather abrupt and nasty stall.
If the other sheets are faithful to this one then I'd seriously suggest you scrap the stabilizer you've made and then blow up the plans for them so that the stabilizer and elevator total 20% of the wing area. Similarly blow up the fin and rudder so that they end up being 9 to 11% of the wing's area. As they are right now the model won't fly for long.
10-10-2007, 10:07 AM
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RE: Trainer Plans ?????
ORIGINAL: BMatthews
If the plans are faithful to the little PDF you attached above then the tail surfaces are too small. The fin and rudder area is too small and the size shown for the chord of the stabilizer would suggest that it too will be too small unless it has a long span. Longer than normal and therefore a rather high aspect ratio.
The wing's airfoil is a bit "wedgy" as well. The forward upper portion between the leading edge and the spar should have a slightly fuller curve to it. As it sits now it's rather sharp and I suspect it'll have a rather abrupt and nasty stall.
If the other sheets are faithful to this one then I'd seriously suggest you scrap the stabilizer you've made and then blow up the plans for them so that the stabilizer and elevator total 20% of the wing area. Similarly blow up the fin and rudder so that they end up being 9 to 11% of the wing's area. As they are right now the model won't fly for long.
If the plans are faithful to the little PDF you attached above then the tail surfaces are too small. The fin and rudder area is too small and the size shown for the chord of the stabilizer would suggest that it too will be too small unless it has a long span. Longer than normal and therefore a rather high aspect ratio.
The wing's airfoil is a bit "wedgy" as well. The forward upper portion between the leading edge and the spar should have a slightly fuller curve to it. As it sits now it's rather sharp and I suspect it'll have a rather abrupt and nasty stall.
If the other sheets are faithful to this one then I'd seriously suggest you scrap the stabilizer you've made and then blow up the plans for them so that the stabilizer and elevator total 20% of the wing area. Similarly blow up the fin and rudder so that they end up being 9 to 11% of the wing's area. As they are right now the model won't fly for long.
I am going to scrap this build, chalk the tail and the partially built wing to experience and move one.
Thanks again.
10-10-2007, 11:11 AM
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RE: Trainer Plans ?????
yeah your right about the wing but it is semi-symetrical. have you looked at the falcon 25 plan? it looks pretty good. just enlarge it for a 40 size. I would like to see the rest of the files on your plane, could you post them?
10-10-2007, 03:11 PM
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RE: Trainer Plans ?????
ORIGINAL: cdnarcher
Thanks for the advice. I sat down last night and figured out the areas for the wings and the tail group and have concluded, just as you stated, that it may fly, but not for long.
I am going to scrap this build, chalk the tail and the partially built wing to experience and move one.
Thanks again.
ORIGINAL: BMatthews
If the plans are faithful to the little PDF you attached above then the tail surfaces are too small. The fin and rudder area is too small and the size shown for the chord of the stabilizer would suggest that it too will be too small unless it has a long span. Longer than normal and therefore a rather high aspect ratio.
The wing's airfoil is a bit "wedgy" as well. The forward upper portion between the leading edge and the spar should have a slightly fuller curve to it. As it sits now it's rather sharp and I suspect it'll have a rather abrupt and nasty stall.
If the other sheets are faithful to this one then I'd seriously suggest you scrap the stabilizer you've made and then blow up the plans for them so that the stabilizer and elevator total 20% of the wing area. Similarly blow up the fin and rudder so that they end up being 9 to 11% of the wing's area. As they are right now the model won't fly for long.
If the plans are faithful to the little PDF you attached above then the tail surfaces are too small. The fin and rudder area is too small and the size shown for the chord of the stabilizer would suggest that it too will be too small unless it has a long span. Longer than normal and therefore a rather high aspect ratio.
The wing's airfoil is a bit "wedgy" as well. The forward upper portion between the leading edge and the spar should have a slightly fuller curve to it. As it sits now it's rather sharp and I suspect it'll have a rather abrupt and nasty stall.
If the other sheets are faithful to this one then I'd seriously suggest you scrap the stabilizer you've made and then blow up the plans for them so that the stabilizer and elevator total 20% of the wing area. Similarly blow up the fin and rudder so that they end up being 9 to 11% of the wing's area. As they are right now the model won't fly for long.
I am going to scrap this build, chalk the tail and the partially built wing to experience and move one.
Thanks again.
I'm sorry I had to be the bearer of bad tidings but like the old saying goes "it's better to cut your loses and run than to spiral down in flames"..... or something like that....
