1/7 Scale Blackburn Buccaneer All Composite Scratch Build
12-31-2020, 04:44 PM
#527
I have to say that impressive as the they are, the photo's of Ron's Fitter don't do it justice. The detail and quality of the work up close is simply amazing.
I'm really looking forward to seeing it take to the skies - and a fast low pass with the wings fully swept back.
A formation flypast of the Buccaneer and Fitter is just something to imagine for the moment.
Keep at it Ron.
Paul
I'm really looking forward to seeing it take to the skies - and a fast low pass with the wings fully swept back.
A formation flypast of the Buccaneer and Fitter is just something to imagine for the moment.
Keep at it Ron.
Paul
12-31-2020, 07:07 PM
#531
As I'd planned to do for a while, I made a small balsa chuck-glider to check the c.g. that I planned on using, which was based on the full-scale c.g. range.
Reduced in scale to fit some 1/16" balsa wing skins, I made the chuck-glider out of 2 layers of 1/16" to give some rigidity to it. It turned out to be about 16" long by 11" span.
I attached the horizontal tail with an M3 bolt in order to be able to adjust the angle for trimming purposes. The forward and aft c.g. lines were engraved on the wings as a reference.
I used an M4 bolt and oversize washers attached to the forward fuselage in order to adjust the c.g.
Initial test glides showed a nose heavy tendency. Reducing the forward ballast I ended up with a stable glide. Going too far aft with the c.g. and it resulted in the traditional immediate pitch up. The best overall c.g. seemed to be 8mm (chuck-glider scale) further aft than the full-scale aft limit. That worked out to be 53mm further aft when scaled up to the real model.
With the current balance point mid-way between the full-scale forward and aft c.g. limits I am comfortable with that as a starting point for first flight. I may have to give consideration to adding tail ballast as a temporary adjustment method to help in determining the optimum c.g. location, but I feel that what I have is a safe starting point.
Paul
Reduced in scale to fit some 1/16" balsa wing skins, I made the chuck-glider out of 2 layers of 1/16" to give some rigidity to it. It turned out to be about 16" long by 11" span.
I attached the horizontal tail with an M3 bolt in order to be able to adjust the angle for trimming purposes. The forward and aft c.g. lines were engraved on the wings as a reference.
I used an M4 bolt and oversize washers attached to the forward fuselage in order to adjust the c.g.
Initial test glides showed a nose heavy tendency. Reducing the forward ballast I ended up with a stable glide. Going too far aft with the c.g. and it resulted in the traditional immediate pitch up. The best overall c.g. seemed to be 8mm (chuck-glider scale) further aft than the full-scale aft limit. That worked out to be 53mm further aft when scaled up to the real model.
With the current balance point mid-way between the full-scale forward and aft c.g. limits I am comfortable with that as a starting point for first flight. I may have to give consideration to adding tail ballast as a temporary adjustment method to help in determining the optimum c.g. location, but I feel that what I have is a safe starting point.
Paul
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Hustler58 (01-14-2021)
01-01-2021, 03:44 AM
#534
First,sorry me for being picky.I had comenin the past to the conclusion that many jets don't obbey typical cg rules because of the ammount of fuse hanging in front of the wing. I use a program called laengs.exe (german) and put the planform of the fuse as a wing for calculating neutral point .I suggest to add the planform to the chuck glider .
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alasdair (02-08-2021)
01-03-2021, 04:11 PM
#537
Today was intended to be high speed taxy and first flight day at the HOTMAC field in Waco. Unfortunately it didn't end well.......
All assembled and checkout out, the initial run was intended to be a series of high speed taxy tests, with an aim to see if I could get it light on the nose wheel.
Lined up and run up the power until it started to move, then brakes off, check it was rolling straight and then slam to full power.
Rather than just a planned high speed taxy run, pull to idle and then feed in some up elevator before braking to a stop, the model was airborne even before it reached us (approx 300ft ground roll). Idle was selected as soon as it was apparent that it was getting light, but without any elevator applied it got airborne. No pitch up, but it started rolling right and scraped the wingtip before I could catch it. It flew over the HOTMAC bump and came back down. but then immediately entered an uncontrolled bounce, with a rapid pitch up, getting airborne again to a height of about 6-7ft. At this point I was along for the ride, I applied some nose down to try to arrest the bounce and getting the wings level before it impacted in a steep nose down attitude, shedding the main gear doors before one again bouncing up before a third and final heavy impact.
After the run, the telemetry data showed that full power was only applied for less than 4 seconds before pulling to idle.
Dismayed, we collected the wreckage. All 3 main gears were ripped out and some other frame damage was apparent from the initial assessment.
The lift off was in trim in pitch and I can put the right roll on lift off down to being out of trim laterally, but the bounce was unexpected and unexplained. The good news was that it got airborne very early and it would have probably flown away easily if that had been my plan from the beginning.
I plan on stripping it out and patching it up in order to attempt a flight. I'll use this as a test mule to wring out the design before making a new airframe for painting and detailing. So far, it looks like none of the purchased parts were damaged, just the basic airframe that I can re-make.
Some stills from the video that help in the understanding of the sequence of events.
Initial lift off. Airborne before the infamous HOTMAC runway bump. Idle selected by this time, if not before.
Immediate roll to the right.
Right wingtip touching the runway
Back down, but............
into an immediate and violent pitch up.....
Another right wing down, but correcting.
Wings level before impact, but significantly nose down.
Back up into a second bounce
Final resting place.....
Paul
All assembled and checkout out, the initial run was intended to be a series of high speed taxy tests, with an aim to see if I could get it light on the nose wheel.
Lined up and run up the power until it started to move, then brakes off, check it was rolling straight and then slam to full power.
Rather than just a planned high speed taxy run, pull to idle and then feed in some up elevator before braking to a stop, the model was airborne even before it reached us (approx 300ft ground roll). Idle was selected as soon as it was apparent that it was getting light, but without any elevator applied it got airborne. No pitch up, but it started rolling right and scraped the wingtip before I could catch it. It flew over the HOTMAC bump and came back down. but then immediately entered an uncontrolled bounce, with a rapid pitch up, getting airborne again to a height of about 6-7ft. At this point I was along for the ride, I applied some nose down to try to arrest the bounce and getting the wings level before it impacted in a steep nose down attitude, shedding the main gear doors before one again bouncing up before a third and final heavy impact.
After the run, the telemetry data showed that full power was only applied for less than 4 seconds before pulling to idle.
Dismayed, we collected the wreckage. All 3 main gears were ripped out and some other frame damage was apparent from the initial assessment.
The lift off was in trim in pitch and I can put the right roll on lift off down to being out of trim laterally, but the bounce was unexpected and unexplained. The good news was that it got airborne very early and it would have probably flown away easily if that had been my plan from the beginning.
I plan on stripping it out and patching it up in order to attempt a flight. I'll use this as a test mule to wring out the design before making a new airframe for painting and detailing. So far, it looks like none of the purchased parts were damaged, just the basic airframe that I can re-make.
Some stills from the video that help in the understanding of the sequence of events.
Initial lift off. Airborne before the infamous HOTMAC runway bump. Idle selected by this time, if not before.
Immediate roll to the right.
Right wingtip touching the runway
Back down, but............
into an immediate and violent pitch up.....
Another right wing down, but correcting.
Wings level before impact, but significantly nose down.
Back up into a second bounce
Final resting place.....
Paul
Last edited by JSF-TC; 01-03-2021 at 04:13 PM.
01-03-2021, 05:46 PM
#538
Paul the model is amazing, as stout as it gets. Nothing on it is ordinary. The surface details are very nice.
One can always be prepared for a first flight, and perhaps get some altitude and figure it out, but no one is ever prepared for a premature lift off. You fought it like a champ.
We are all very proud of your accomplishment. Let's try again......
David
One can always be prepared for a first flight, and perhaps get some altitude and figure it out, but no one is ever prepared for a premature lift off. You fought it like a champ.
We are all very proud of your accomplishment. Let's try again......
David
01-03-2021, 09:49 PM
#539
Its a shame to see it damaged, but i cant see any issues with the air frame prior to lift off....
You have a huge amount of wing area and a positive incidence, and plenty of power, that thing was ready to lift well before it did. I personally don't understand and never have bothered with high speed running down the runway, ive seen so many aircraft broken and destroyed because of it!
No doubt you will fix and and try again, its a fantastic project.
You have a huge amount of wing area and a positive incidence, and plenty of power, that thing was ready to lift well before it did. I personally don't understand and never have bothered with high speed running down the runway, ive seen so many aircraft broken and destroyed because of it!
No doubt you will fix and and try again, its a fantastic project.
01-04-2021, 05:26 PM
#541
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I am so pleased I stumbled across this thread. I am astounded and in awe at the engineering, craftsmanship and commitment in everything you are undertaking. The passion is incredible. Being a modeler from my mid 20's yet working on Buccaneers in my teens at RAF HOSM, I cannot believe how one mans desire drives them to lengths I've never seen before. You likely have as much documentation as you need but if you ever thirst for more, I can at least try and guide you.
01-04-2021, 07:20 PM
#542
Mister Edge, I think I can speak for Paul, that one never has enough documentation! 
The test day weather probably wasn't the best, since we did have a quartering to sometimes crosswind, that exacerbated the outcome... I know Paul has a few variables he can change to improve on his next attempt - some are already in work. I am confident this bird will be in the air soon again!
(where's the dang "thumbs up" emoji??? insert a few here!)
The test day weather probably wasn't the best, since we did have a quartering to sometimes crosswind, that exacerbated the outcome... I know Paul has a few variables he can change to improve on his next attempt - some are already in work. I am confident this bird will be in the air soon again!
(where's the dang "thumbs up" emoji??? insert a few here!)
The following 2 users liked this post by Ron S:
Canadian Man (01-05-2021),
David Gladwin (01-05-2021)
01-05-2021, 04:17 AM
#543
Its great to see master modellers like you guys expanding the envelope. Unfortunately those of us who have been doing this for many years know its all part of the game. I crashed 2 in the last 2 weeks (JMB T7A and Dolphin S). Tail firmly tucked between my legs but hard at work on next project. Dolphin will be repaired, T7 trashed. Ok men, lets open another beer and head to the shop!
01-05-2021, 11:33 AM
#544
Its great to see master modellers like you guys expanding the envelope. Unfortunately those of us who have been doing this for many years know its all part of the game. I crashed 2 in the last 2 weeks (JMB T7A and Dolphin S). Tail firmly tucked between my legs but hard at work on next project. Dolphin will be repaired, T7 trashed. Ok men, lets open another beer and head to the shop!
I hard landed my F-35 just prior to Paul's event. MLG FWD door stuck open.....it just wanted to roll upside down through the wholefwhole Airframe is ok, but gear needs work. I'm done with it though. It will become a display queen somehwere.
01-05-2021, 02:56 PM
#545
The T7 is a relatively new design, anything adverse about it?
I hard landed my F-35 just prior to Paul's event. MLG FWD door stuck open.....it just wanted to roll upside down through the wholefwhole Airframe is ok, but gear needs work. I'm done with it though. It will become a display queen somehwere.
I hard landed my F-35 just prior to Paul's event. MLG FWD door stuck open.....it just wanted to roll upside down through the wholefwhole Airframe is ok, but gear needs work. I'm done with it though. It will become a display queen somehwere.
Bob
01-05-2021, 07:52 PM
#547
01-05-2021, 08:17 PM
#548
Join Date: Mar 2009
Location: willow springs , IL
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I feel for you Paul. Don't be discouraged. I dropped my scratch built years of work from 50 feet (bad C.G.)
I'm Sure you'll give it another try and figure it all out. I'm waiting to give it another try. Damn virus.
01-05-2021, 11:30 PM
#549
Are you guys in the US not required to have rudders on turbines?
Regards,
Regards,