Twin-VW engine Push-Pull design idea (The "Beetlemaster")

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Pops

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I would like to see someone finish the design and start building the Beetlemaster prototype. Maybe take me for a ride someday ?

Rear seat easily to remove for a large cargo space or long range fuel tank that is over the CG. Front engine feed from left wing fuel tank and rear engine from right fuel tank and use the long range fuel tank to transfer fuel to top off both wing fuel tanks. Would be nice to have at least 7 or 8 hrs of range with reserve with the long range tank along with the wing fuel tanks.
 

Nicholette

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Well any sort of coaxial flying would be great, on the basis that two engines are always better than one. Also ideally if it 'scaled' I know the wing was good as it could take off from the carrier without using the catapult in zero wind. Your right though compromises would have to be made even loosing weight with size reduction the engines are going to have to try hard to replace two turbines. Hmm they were heavy though , oh and few tonnes of stores, so on balance it may fly and even 'loiter' on one engine like the original too if lucky.
 

Doggzilla

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You would be surprised at how much you dont want to have to land west of Denver during the wintertime. Plenty of places, but wind and weather often make them very very unpleasant places to land. Being able to completely cross the mountains without stopping is a huge advantage out there.
 

Doggzilla

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And if its going to be able to haul 50 gallon drums might as well hang it from the ceiling, as its the wing spar anyways. Cant be having a drum rolling around and will need to secure it anyways. Slinging it is by far the easiest way to secure something and you dont have to worry about your straps accidentally buckling the fuselage by pulling it inwards.
 

Vigilant1

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I would like to see someone finish the design and start building the Beetlemaster prototype.
Piece of cake, right? 10 steps:
1) Weld up a cage for the pod. Make sure there's a place to hook on the wings, engines, three wheels (little one in front), two seats.
2.) Make a mold for the CF fuselage skins. Stanislavz knows how to CNC cut big slabs of XPS for the molds. Probably take him 15 minutes. Get them on a boat to the US. (Do something else while they move). The molds are here!! They are beautiful. Lay up the skins, put foam backer rod/CF reinforcements around the edges. I saw Boku's pictures, looks easy!
3) Build the wings. First cut the nose D-cell out of XPS, lay up the spar web on the back of it, wrap it around the CF pultrusion spar caps layed into the pockets at the top and bottom of the foam D-cell. Next, cut plywood cradles in airfoil shapes, put AL trim coil in them to form a female mold for the top of the wing and nose. Lay in 12 oz/yd CF biax for the top skin and nose, then lay in the foam nosepiece with the attached spar. Add epoxy via infusion. Put in peel ply where the ribs will go. Let it cure. Next, put in some CF ribs (formed in pan molds, they have corrugated stiffeners and flanges). Finally, mold the closure skin (bottom of the wing) in more cradles/AL sheet forms. Make depressions/offsets for the corrugated split-flap panels (no flap seams/discontinuities on the top of the wing). Cut out the ailerons with a Fein tool (oscillating cutter), put in hinges and bellcranks for ailerons (glad we have that wing lower skin still off!!)
Then, build the other wing the same way.
4). Build the booms as Boku built his tailcone. Mount pulleys for rudder and elevator cables. Get out the Fein tool again, carefully cut the wing skins and put the booms in. Bond the booms to the spar and skins. Lots of tapes. If they seem wiggly, put in a brace.
5) Hotwire cut the V-stabs/rudders and the H-stab/elevator. Cover each with CF biax, spread on epoxy, cover with a perforated mylar sheet, blotter/bleeder, vacuum bag. When cured, remove thr mylar and sand down the "pips" at the perforations. Hook up cables.
6) Buy main gear legs from OKeefe Aero. Ask them to make suitable ones if the CX5 ones won't do. Attacg wheels, tires, brakes. Attach a nosewheel strut on the fitting already welded to the cage. Castoring nosewheelbis good enough.
7) Add the engines, electrical system, fuel system (tanks in the bays between ribs. Rotomolded polyethylene tanks.). Add instruments and some seats. Good seats, but light. Tasteful colors
With logos. Don't rush the seats-take the time to it right. Seats make the plane!
8) Landing light and radios-- consider a handheld in a jazzy mounting (we're broke).
9) Flat-wrap windshield. The other windows are already in the CF panels (step 2).
10) Done. Do some FAA paperwork, fly off the hours, go to Airventure and get your trophy! 140 MPH TAS the whole way here and back, 5 GPH on pump gas. Everyone loves it!! Rutan "Wish I'd built something like this!! The seats are marvelous!

This is what happens during quarantine lockdowns.
 
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Pops

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Pops:

Where would you go with 7 hours endurance?


BJC
The world is a big place.

I have gotten used to flying 9 to 12 hrs a day. One week I flew 76 hrs. Fuel stops are a waste of time. Give me a relief tube and everything is OK.


Piece of cake, right?
1) Weld up a cage for the pod. Make sure there's a place to hook on the wings, engines, three wheels (little one in front), two seats.
2.) Make a mold for the CF fuselage skins. Stanislavz knows how to CNC cut big slabs of XPS for the molds. Probably take him 15 minutes. Get them on a boat to the US. (Do something else while they move). The molds are here!! They are beautiful. Lay up the skins, put foam backer rod/CF reinforcements around the edges. I saw Boku's pictures, looks easy!
3) Build the wings. First cut the nose D-cell out of XPS, lay up the spar web on the back of it, wrap it around the CF pultrusion spar caps layed into the pockets at the top and bottom of the foam D-cell. Next, cut plywood cradles in airfoil shapes, put AL trim coil in them to form a female mold for the top of the wing and nose. Lay in 12 oz/yd CF biax forvthevtop skin and nose, then lay in the foam nosepiece with the attached spar. Add epoxy via infusion. Next, put in some CF ribs (formed in pan molds, they have corrugated stiffeners). Finally, mold the closure skin (bottom of the wing) in more cradles/AL sheet forms. Make depressions/offsets for the corrugated split-flap panels (no flap seams/discontinuities on the top of the wing). Cut out the ailerons with a Fein tool (oscillating cutter), put in hinges and bellcranks for ailerons (glad we have that wing lower skin still off!!)
Then, build the other wing the same way.
4). Build the booms as Boku built his tailcone. Mount pulleys for rudder and elevator cables. Get out the Fein tool again, carefully cut the wing skins and put the booms in. Bond the booms to the spar and skins. Lots of tapes. If they seem wiggly, put in a brace.
5) Hotwire cut the V-stabs/rudders and the H-stab/elevator. Cover each with CF biax, spread on epoxy, cover with a perforated mylar sheet, blotter/bleeder, vacuum bag. When cured, remove thr mylar and sand down the "pips" at the perforations. Hook up cables.
6) Buy main gear legs from OKeefe Aero. Ask them to make suitable ones if the CX5 ones won't do. Attacg wheels, tires, brakes. Attach a nosewheel strut on the fitting already welded to the cage. Castoring nosewheelbis good enough.
7) Add the engines, electrical system, fuel system (tanks in the bays between ribs. Rotomolded polyethylene tanks.). Add instruments and some seats. Good seats, but light. Tasteful colors
With logos. Don't rush the seats-take the time to it right.
8) Landing light and radios-- consider a handheld in a jazzy mounting (we're broke).
9) Flat-wrap windshield. The other windows are already in the CF panels (step 2).
10) Done. Do some FAA paperwork, fly off the hours, go to Airventure and get your trophy! 140 MPH TAS the whole way here and back, 5 GPH on pump gas. Everyone loves it!! Rutan "Wish I'd built something like this!!"

This is what happens during quarantine lockdowns.
YEP, Called homebuilding If it was easy everyone would be homebuilding airplanes :)

You didn't forget to do the honey-do-jobs did you ? Remember they come first.

Dan
 

Pops

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IF I was a few years younger I would start building the BeetleMaster. I'll be 80 years old in a few weeks and if I start another project, it will not be as large as the Beetlemaster. But, I would love to see someone else build one. There is lot of work to do in just the designing part before starting construction.
With a simple airplane as the JMR , I spent 2 years in the designing and doing drawing before starting construction. I'm sure lots of people could do it a lot quicker than I did but it still takes a lot of time added to the time needed for the construction.
 

Blackhawk

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This is the Aeronix Airelle.

Aeronix Airelle.jpg

Aeronix Airelle 1.jpg

Aeronix Airelle 2.jpg



  • Capacity: 2
  • Length: 5.88 m (19 ft 3 in)
  • Wingspan: 9.46 m (31 ft 0 in)
  • Height: 3.015 m (9 ft 11 in)
  • Wing area: 15.00 m2 (161.5 sq ft)
  • Empty weight: 295 kg (650 lb)
  • Max takeoff weight: 472.5 kg (1,042 lb)
  • Fuel capacity: 60 l (16 US gal; 13 imp gal)
  • Powerplant: 2 × Zanzottera MZ 201 flat twin, 30 kW (40 hp) each
  • Propellers: 3-bladed Duc, Arplast or Ecoprop, 1.60 m (5 ft 3 in) diameter ground adjustable pitch
Performance

  • Maximum speed: 230 km/h (140 mph, 120 kn)
  • Cruise speed: 200 km/h (120 mph, 110 kn)
  • Stall speed: 58 km/h (36 mph, 31 kn)
  • Never exceed speed: 290 km/h (180 mph, 160 kn)
  • Range: 700 km (430 mi, 380 nmi)
  • Rate of climb: 10 m/s (2,000 ft/min)
 
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Wayne

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IF I was a few years younger I would start building the BeetleMaster. I'll be 80 years old in a few weeks and if I start another project, it will not be as large as the Beetlemaster. But, I would love to see someone else build one. There is lot of work to do in just the designing part before starting construction.
With a simple airplane as the JMR , I spent 2 years in the designing and doing drawing before starting construction. I'm sure lots of people could do it a lot quicker than I did but it still takes a lot of time added to the time needed for the construction.
Hey Pops! Happy Birthday a little early! One of the IA’s in our maintenance shop is 87 and frequently puts in a full day - often outworking my two 21 year old A&P’s. I love having the experience and age difference - the kids love him and he brings tremendous depth to the bench. w
We have the perfect Millennial/experience mix. One of my A&P’s is a lady and the intern/apprentice I just hired is a lady too - she is 20. It brings me tremendous satisfaction to have a very high functioning Maintenance shop with this unusual mix.

I have not seen this much enthusiasm from you about a project since I have been on HBA and that has been years. Please don’t write it off too early - you are nowhere near too old to do this, especially given your family longevity. Additionally your track record, experience, and informative posts make you one of the few people who has the level of respect on this forum to garner support from the short list of highly capable people on this list. Maybe you could project manage as a benevolent Dictator so that you can avoid the paralysis that comes when you have a committee.
 

Pops

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Don't say that :) Dallas spent the day here yesterday and mentioned that he misses us spending the day working an building aircraft fuselages. He is a couple years younger than me and we have been friends , like brothers , since 1970. Also had the same flight instructors. He has a hanger next door.
My wife thinks she has the dictator job sowed up but what she don't know won't hurt her :)
I have a couple other projects in mind and I would like to build one of them at least. Not so large and wouldn't take that long to finish. Maybe VW flywheel drive engine powered or I have enough parts to build a Cont A-75.
 

Vigilant1

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IF I was a few years younger I would start building the BeetleMaster. I'll be 80 years old in a few weeks and if I start another project, it will not be as large as the Beetlemaster. But, I would love to see someone else build one. There is lot of work to do in just the designing part before starting construction.
With a simple airplane as the JMR , I spent 2 years in the designing and doing drawing before starting construction. I'm sure lots of people could do it a lot quicker than I did but it still takes a lot of time added to the time needed for the construction.
Pops,
This idea is a good one, and will probably outlive all of us. The thread will still be here for anyone who wants to chime in on it.
It >would< be a very big project. Lots could be done to keep it as simple as possible, but just doing the design will require hundreds of hours.
Maybe it never gets built, and (IMO) that would be a shame. But it is fun to dream, to "what if?" That can be its own reward. Our days are numbered, and the number of projects we'll see to completion are, too. But, IMO, it is good if our imagination exceeds our grasp.
For me, a smaller, simpler project should come first. Maybe the MicroMaster. But I know the BeetleMaster will be on my mind. When/if I get to the Beetlemaster, I'll have built more skills and have a better idea of what type of construction I'd enjoy doing.
Your ideas, with those of a lot of other people, will be right here to serve as a good foundation for the next step, whenever it happens. Or maybe some more "wouldn't it be great if . . ." ideas--which can be a lot of fun, too.

Enough of that.

Tail boom(s).
I've been thinking again of that single low tailboom. (I know, everybody hates the idea). Straight control runs, lighter weight, less wetted area, simpler construction (bolt it to the welded frame of the cabin), no aerodynamic interuption of the wing surfaces/flaps, more room for fuel in the wing, etc. The Cessna development team had fits with the control friction in their C-336 prototype (more here-- The C-336 Skymaster Story. It is a good read about the development of the Skymaster, but I've linked to it before).
For the reasons above, I still think a single tailboom has some merit, but when I sketched out the BeetleMaster with a 43" tall cabin, a 57" rear prop, 22" tall main gear and 6" wheels + tires (where I thought they might go), there didn't appear to be an easy way to fit it in. With as much upslope as I could get (before reaching the bottom of the prop arc) and using the tail lengths we'd previously discussed, would give a max deck angle of about 10 degrees, so a maximum wing AoA of about 13 degrees (assuming 3 deg wing incidence, flat tires). Not enough. And that's with a pretty thin boom (about 7" dia). So, if a single boom is desired, the rear engine might need to go up few inches (not entirely bad-- just add a wide scoop up there in a nod to the Skymaster. Heck, Rotax 618 wants our engines higher anyway!). A shorter rear prop wouldn't be a good idea. Taller gear would help a little, moving the gear back a little would help more, a shorter tailboom would help more (but have other challenges). Letting the tailboom hang a bit below the cabin floor (just a little streamlined blister as seen from the front) might be enough to let it work, and wouldn't have any impact on rotation, etc.

But, without the twin booms, is it still kin to the Skymaster?

Another bit of grist for the mill.

Mark
 
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Doggzilla

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You could actually use an A-10 like tail with the center cut out. Or shaped like a Boeing airliner wing, as the prop is only about a third the width of the elevator. So sweeping the tail around the rear prop is feasible without extreme angles.

If the rear engine sticks above the fuselage slightly, the prop tips could be at belly level. This would also allow a nice cooling duct.
 

Pops

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Pops,
This idea is a good one, and will probably outlive all of us. The thread will still be here for anyone who wants to chime in on it.
It >would< be a very big project. Lots could be done to keep it as simple as possible, but just doing the design will require hundreds of hours.
Maybe it never gets built, and (IMO) that would be a shame. But it is fun to dream, to "what if?" That can be its own reward. Our days are numbered, and the number of projects we'll see to completion are, too. But, IMO, it is good if our imagination exceeds our grasp.
For me, a smaller, simpler project should come first. Maybe the MicroMaster. But I know the BeetleMaster will be on my mind. When/if I get to the Beetlemaster, I'll have built more skills and have a better idea of what type of construction I'd enjoy doing.
Your ideas, with those of a lot of other people, will be right here to serve as a good foundation for the next step, whenever it happens. Or maybe some more "wouldn't it be great if . . ." ideas--which can be a lot of fun, too.

Enough of that.

Tail boom(s).
I've been thinking again of that single low tailboom. (I know, everybody hates the idea). Straight control runs, lighter weight, less wetted area, simpler construction (bolt it to the welded frame of the cabin), no aerodynamic interuption of the wing surfaces/flaps, more room for fuel in the wing, etc. The Cessna development team had fits with the control friction in their C-336 prototype (more here-- The C-336 Skymaster Story. It is a good read about the development of the Skymaster, but I've linked to it before).
For the reasons above, I still think a single tailboom has some merit, but when I sketched out the BeetleMaster with a 43" tall cabin, a 57" rear prop, 22" tall main gear and 6" wheels + tires (where I thought they might go), there didn't appear to be an easy way to fit it in. With as much upslope as I could get (before reaching the bottom of the prop arc) and using the tail lengths we'd previously discussed, would give a max deck angle of about 10 degrees, so a maximum wing AoA of about 13 degrees (assuming 3 deg wing incidence, flat tires). Not enough. And that's with a pretty thin boom (about 7" dia). So, if a single boom is desired, the rear engine might need to go up few inches (not entirely bad-- just add a wide scoop up there in a nod to the Skymaster. Heck, Rotax 618 wants our engines higher anyway!). A shorter rear prop wouldn't be a good idea. Taller gear would help a little, moving the gear back a little would help more, a shorter tailboom would help more (but have other challenges). Letting the tailboom hang a bit below the cabin floor (just a little streamlined blister) might be enough to let it work, and wouldn't have any impact on rotation, etc.

But, without the twin booms, is it still kin to the Skymaster?

Another bit of grist for the mill.

Mark

Yes, it would be a large project and take a lot of time. Good things never come easy. I have built 2 houses from scratch and as I had the money. First one took 5 years and I did 100% of all the work. Very nice house that we lived in for over 20 years. Also built the house we live in now and also the hanger . Hired the foundation and roofing and drywall of the house. I did 100% of everything else, took 2 years of 6 days a week work. So building an airplane has a lot in common with building a house and doing 100% of the work. You learn to do a lot of different things.
On building 4 homebuilt airplanes and restoring 7 factory airplanes from bare shells. I can work with wood and aluminum and steel tubing . For FG and epoxy I have made several fuel tanks, cowls, wheel pants, fairing, and a lot of small parts. Even a sunroof for my V-8 powered 1968 VW bug hotrod.
I need to learn a lot to build a structure part of an airplane in FG or CF, let alone design any structure part. So in designing the BeetleMaster, making the CF fuselage shells is about all I could do without a large learning curve or a lot of help.
If I start another project it will be in something that I know so it will not take so long to finish.

A SINGLE low tail boom BeetleMaster. Got to go, think I'am getting sick :)

Dan
 

cluttonfred

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On that single low boom, I’ll just leave this here

F1A02945-33B5-483E-BA2A-608BF8A50497.jpeg

That’s a Tucano Delta3 VTW light twin based on a microlight with roots that go back, at least conceptually, to the old Weedhopper ultralight. I think the configuration could be made to work and look good with a slim single boom.
 

Doggzilla

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Just realized that most of the problems with this layout can be solved by using a shaft driven prop like a P-39 Aircobra.

The cockpit vision would vastly improve, the CG and wing would move backwards, and most importantly the gear would move rearward with them, allowing better rear prop clearance angle.

A Cobra type drive shaft was very reliable and extremely well liked by Soviet pilots. Nearly all of their top aces flew them. So its not a design to shy away from.

But of course this requires forced cooling, either centrifugal fan or liquid cooling. But the benefits are huge.
 

Doggzilla

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On that single low boom, I’ll just leave this here

View attachment 96528

That’s a Tucano Delta3 VTW light twin based on a microlight with roots that go back, at least conceptually, to the old Weedhopper ultralight. I think the configuration could be made to work and look good with a slim single boom.
Only goes like 85 knots but climbs at 1500ft min with two Rotax 582s.

It’s like a dude in a wheelchair who can bench 500lbs. It’s not very useful, but still everyone is like “Holy crap that’s impressive”
 
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