bvm super balsa bandit
11-29-2003 | 10:45 PM
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From: utica, NY
bvm super balsa bandit
i need expert help with a couple of questions. first can the balsa bandit be built without a speedbrake, keep in mind ill be using a small engine like the jf-50 or pst 600 or 600r my goal is to build a super light weight jet. li-po batteries,plastic fuel tanks, jr new 7 channel micro pcm receiver,electric brake and gear valves. also want to know if you can sort of do a half gear door just on the struts, and a wheel well? ill be using bvm landing gear, wheels, and brakes. im trying to take the complexity, time , and weight of hinging and cutting all those surfaces out and rigging door cylinders. with all that said, if this is possible to do and yeilds a feather weight bandit will it be loaded light enough for a first turbine aircraft. what would be a quesstimate approach/landing speed of this setup. what is the top speed with 12lb. class engine? any info on this setup would be greatly appreciated, thanks
11-30-2003 | 05:18 AM
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From: kenilworth , UNITED KINGDOM
RE: bvm super balsa bandit
Im my opinion the SB does not need a speed brake. Unlike its older brother the classic bandit it does not float on. I always used mine on the classic and have only tried it on my S bandit one and that was enough as it needed half power to keep flying with the gear and flaps down too. Pastic fuel cells?? I wouldnt, if you are going to fit a smaller engine just dont fit the front tank but fit a UAT.The tanks are light enough anyway so no worry about the weight there.
You say you are thinking about the jf 50 or PST engines, but what about the new Wren Supersport? it`s the same size and weight as the PST and normal Wren but has 18 lb thrust! and its due out next yr fuel consumption is very low too.
jason
You say you are thinking about the jf 50 or PST engines, but what about the new Wren Supersport? it`s the same size and weight as the PST and normal Wren but has 18 lb thrust! and its due out next yr fuel consumption is very low too.
jason
11-30-2003 | 01:28 PM
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From: Longwood ,
FL
RE: bvm super balsa bandit
Techjet1,
The reason for the Balsa Super Bandit's existance is two-fold. It has about 35 sq. in. of wing area more than the composite version, and has larger flaps than it's composite brother. In the USA, it is about $1,000 cheaper too.
The idea behind the larger wing is to reduce the wing loading, by increasing the size, and reducing the weight of the whole airplane.
The airplane has about an 8% geometric fuselage volume increase over the original Bandit to allow more installation room, and provide the volume needed to increase the fuel supply. It also comes in a pound lighter. I've built two composites, three balsa versions, and now my first Super Bandit, a balsa version. I really like the new design.
By far, the Super version fuselage build-up is much easier than the legacy airplane, and as well, contains some very much appreciated changes in construction, as a result of BVM increased experience. There are a myriad of improvements in the new airplane, making it a much easier to construct aircraft, and a better flyer.
I don't agree with the idea of eliminating the kevlar fuel cells. They are designed to fit the airplane, and are much less complicated than any other method. They also have much better hardware than the Du-Bro type. Any plastic fuel tank won't fit the tank area within the fuselage the same as the kevlar.
No speedbrake? Why not build it and keep it closed, enabling you to make it operational in the future? I like the ability to use the brake, and and keep the engine RPM up so it will spool up quickly when/if needed. Be advised, that you can build it any way you want to...don't use the inner landing gear doors unless you want to clean it up completely. If you have a very small engine, you might appreciate the extra cleanliness (reduced drag) the inner doors provide.
When I built my new Super Balsa Bandit, I was able to build and rig the entire door system in a couple of evenings. It's not hard to do.
The Super Balsa Bandit is just not designed for 11-12 lbs of thrust. You can run a larger engine and throttle it back, rather than keep a little hummer turnin' anrd burnin' as fast as it will go.
I wouldn't try to guesstimate the speed of your super light (but draggy) doorless version.
If you build it like the plans, you won't go wrong. It will also have better market value should you choose to part with it.
For your first turbine aircraft, I feel that you might have more success by building it as designed.
Just my $0.02 worth..............no flame war intended.
Regards and best holiday wishes,
Harley Condra
BVM REP
Team JetCat
The reason for the Balsa Super Bandit's existance is two-fold. It has about 35 sq. in. of wing area more than the composite version, and has larger flaps than it's composite brother. In the USA, it is about $1,000 cheaper too.
The idea behind the larger wing is to reduce the wing loading, by increasing the size, and reducing the weight of the whole airplane.
The airplane has about an 8% geometric fuselage volume increase over the original Bandit to allow more installation room, and provide the volume needed to increase the fuel supply. It also comes in a pound lighter. I've built two composites, three balsa versions, and now my first Super Bandit, a balsa version. I really like the new design.
By far, the Super version fuselage build-up is much easier than the legacy airplane, and as well, contains some very much appreciated changes in construction, as a result of BVM increased experience. There are a myriad of improvements in the new airplane, making it a much easier to construct aircraft, and a better flyer.
I don't agree with the idea of eliminating the kevlar fuel cells. They are designed to fit the airplane, and are much less complicated than any other method. They also have much better hardware than the Du-Bro type. Any plastic fuel tank won't fit the tank area within the fuselage the same as the kevlar.
No speedbrake? Why not build it and keep it closed, enabling you to make it operational in the future? I like the ability to use the brake, and and keep the engine RPM up so it will spool up quickly when/if needed. Be advised, that you can build it any way you want to...don't use the inner landing gear doors unless you want to clean it up completely. If you have a very small engine, you might appreciate the extra cleanliness (reduced drag) the inner doors provide.
When I built my new Super Balsa Bandit, I was able to build and rig the entire door system in a couple of evenings. It's not hard to do.
The Super Balsa Bandit is just not designed for 11-12 lbs of thrust. You can run a larger engine and throttle it back, rather than keep a little hummer turnin' anrd burnin' as fast as it will go.
I wouldn't try to guesstimate the speed of your super light (but draggy) doorless version.
If you build it like the plans, you won't go wrong. It will also have better market value should you choose to part with it.
For your first turbine aircraft, I feel that you might have more success by building it as designed.
Just my $0.02 worth..............no flame war intended.
Regards and best holiday wishes,
Harley Condra
BVM REP
Team JetCat
11-30-2003 | 02:49 PM
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From: Mother Earth, the Sunny side!
RE: bvm super balsa bandit
I agree with averything Harley, the creator of "Egyptoids" [&:], has said. BTW, The Balsa SB was also designed for flying at higher altitudes like CO.
But I think the P80 would be a better choice than the P70 IF you decide to go that route. There is only a few oz of weight difference btween the two.
The Original Bandit was flown with an 8-10 lbs DF, I think the PST600 would fly it fine and it will do 180 mph flat out (the DF did 180mph easily).
For a 1st turbine jet, I do not think the SB is the one UNLESS you have someone guiding thru the building and flying process. Like Harely said, a King cat may be your best bet due to its light wing loading by design and the cost is very close with less building time!!!
But I think the P80 would be a better choice than the P70 IF you decide to go that route. There is only a few oz of weight difference btween the two.
The Original Bandit was flown with an 8-10 lbs DF, I think the PST600 would fly it fine and it will do 180 mph flat out (the DF did 180mph easily).
For a 1st turbine jet, I do not think the SB is the one UNLESS you have someone guiding thru the building and flying process. Like Harely said, a King cat may be your best bet due to its light wing loading by design and the cost is very close with less building time!!!
11-30-2003 | 05:04 PM
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From: Rosamond, CA
RE: bvm super balsa bandit
techjet1
IMHO all your ideas are very good ones. I have yet to start on my SBB, but I intend to do some of the things you've brought up. Not installing the inner main gear doors and not using an aft nose gear door will lighten and simplify the model. It does add a little drag, but so what? With the small engine you will not need the speedbrake, and that will lighten the model some more. The flaps will be plenty to slow the model down. Not installing the clear canopy and cockpit would probably save another 1/2 pound. You may even want to consider using monokote or ultrakote on the flying surfaces. They structures are built plenty strong enough to do so, and that would save quite a bit more weight. I do have to agree that it may be tough to install different fuel tanks. The conformal kevlar tanks do fit well in the model. I would consider just using the saddle tanks and a UAT. That would be plenty of fuel for a 12-14 pound motor.
I don't have any personal experience with the smaller receiver, it may be fine in a turbine, but do a thorough range check prior to flight. You may find that the electric air valves are not really any lighter then a micro servo on a robart valve, although they are simpler and may be more reliable.
I think you would have a great flying model with this set-up. Lightly loaded and easy to fly. Go for it!
IMHO all your ideas are very good ones. I have yet to start on my SBB, but I intend to do some of the things you've brought up. Not installing the inner main gear doors and not using an aft nose gear door will lighten and simplify the model. It does add a little drag, but so what? With the small engine you will not need the speedbrake, and that will lighten the model some more. The flaps will be plenty to slow the model down. Not installing the clear canopy and cockpit would probably save another 1/2 pound. You may even want to consider using monokote or ultrakote on the flying surfaces. They structures are built plenty strong enough to do so, and that would save quite a bit more weight. I do have to agree that it may be tough to install different fuel tanks. The conformal kevlar tanks do fit well in the model. I would consider just using the saddle tanks and a UAT. That would be plenty of fuel for a 12-14 pound motor.
I don't have any personal experience with the smaller receiver, it may be fine in a turbine, but do a thorough range check prior to flight. You may find that the electric air valves are not really any lighter then a micro servo on a robart valve, although they are simpler and may be more reliable.
I think you would have a great flying model with this set-up. Lightly loaded and easy to fly. Go for it!
12-07-2003 | 02:11 PM
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From: Mother Earth, the Sunny side!
RE: bvm super balsa bandit
I have a Balsa SB that is built and ready for primer. I had been thinking about keeping the weight to a minimum too. I took some accurate weight measurements to see what can be done:
Speed brake: 4 oz
med servos 1.4 oz (for elev, ail, flps)
full size servo: 2.1 oz (for elev, ail, flps)
BVM SS pipe weighs in at 12.8 oz, Tam MAY be able to make a smaller one for a PST600R around 7-8 oz.
BVM bypass weighs in at 7.3 oz, may be one can delete it for an open bypass.
Cockpit and clear canopy is 3.1 oz w/o pilot.
Use 2 1/4" wheels for 2.5 oz less weight.
Fill main tanks to half only, the 600 will fly 7 min on 55-60 oz (I am told by PST).
I would personally leave all the doors in.
I have added all of the above weight reduction including the lesser fuel capacity and I come up with about 3.5 lbs minimum (this is all other things been equal such as paint, servo ext..etc)
This will yield a SB at about $19-20 lbs wet (my last composite bandit was 25 lbs wet with 24oz of smoke). I think that would make a super super bandit!!! I may try it myself....
Speed brake: 4 oz
med servos 1.4 oz (for elev, ail, flps)
full size servo: 2.1 oz (for elev, ail, flps)
BVM SS pipe weighs in at 12.8 oz, Tam MAY be able to make a smaller one for a PST600R around 7-8 oz.
BVM bypass weighs in at 7.3 oz, may be one can delete it for an open bypass.
Cockpit and clear canopy is 3.1 oz w/o pilot.
Use 2 1/4" wheels for 2.5 oz less weight.
Fill main tanks to half only, the 600 will fly 7 min on 55-60 oz (I am told by PST).
I would personally leave all the doors in.
I have added all of the above weight reduction including the lesser fuel capacity and I come up with about 3.5 lbs minimum (this is all other things been equal such as paint, servo ext..etc)
This will yield a SB at about $19-20 lbs wet (my last composite bandit was 25 lbs wet with 24oz of smoke). I think that would make a super super bandit!!! I may try it myself....
