THE MIGHTY, MINI, MAXI MONSTER DR1

Michael G

Active member
All these big planes gave me a wild hair you know where. So I blew up the mm dr1 200%. I started the fuse and tail I'm gonna make the wings tomorrow. Because I blew it 200% I had to laminate foam boards together to get the right thickness.
NOW!!!! before I take this monstrosity and and cram it in my Jeep to take it to my local hobby shop to try and figure out what prop, motor, esc and battery. I thought I'd ask the flite test community what you think would work. Keep in mind this is 200% it's double the normal size including the laminated double thickness of foam boards....🤔
IMG_20200320_190708_6.jpg
 

Figure9

Elite member
NOW!!!! before I take this monstrosity and and cram it in my Jeep to take it to my local hobby shop to try and figure out what prop, motor, esc and battery. I thought I'd ask🤔

Cool! What kind of performance are going to want to get from it? I stick to pretty simple builds so far but I like seeing what ideas this forum produces. FT has used some huge motors on their giant size projects.
 

sundown57

Legendary member
what ever set up you use I'm guessing you will need to extend the motor out a LOT. these birds are tail heavy from the get go. when you scale them up it moves to tail further back plus is a lot heaver then it was meant to be. so even a huge motor and battery won't balance it.
 

sundown57

Legendary member
Sounds like the voice of experience.
not really , I've only built about 25 to 30 of 150% to 250% biplanes like the SE51, DR1 and a bunch of biplanes made out of the Old speedster, here are a few.
 

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Michael G

Active member
Cool! What kind of performance are going to want to get from it? I stick to pretty simple builds so far but I like seeing what ideas this forum produces. FT has used some huge motors on their giant size projects.
It's just gonna be the usual 3 channel... Throt, rudder & elevator
 

TDL

Active member
If I were you, I would build her as light as possible to keep her AUW under 4 lb. The reason is, once your go over 4lb, you will spend a lot more on the electronics. I estimate the foam parts for the mini DR1 is around 7.5oz, enlarge 200% with laminated foam board will bring it over 60 oz (a lot of hot glue!) and then you add motor (3542 minimum), 4 metal gear servos, lead extensions, esc, Rx, 3 or 4s 2200 lipo, and other small things, it will be around 5 lb or 80 oz. I personally would not go under 0.9 to 1, thrust to weight ratio, so you need a power plant that can produce at least 72 oz of thrust., and then you would go to this site to find the motor-battery-prop combo. https://www.flybrushless.com/motor/view/478

I think laminating foam board at this size range is overkill. I would reinforce the edges of the fuselage but single sheet on most of the flat surfaces, and I would convert the wings to the “folding airfoil” design that is commonly used in FT standard size planes. folding airfoil is much stronger than laminated sheets and you need plywood wing spar on both ways. If you can keep the AUW under 4 lb, then I would buy a cheap 3542 kv1000 motor (real work horse and easily available) from eBay, 3s 2200 (the most common lipo) and Apc 12x6. if you go over 4lb, a 3548 motor on 4s lipo and 60a esc will cost you a lot!

Good luck!
 

TDL

Active member
It's just gonna be the usual 3 channel... Throt, rudder & elevator
In my experience, once the wingspan reach 36” and up, you would need a larger motor and prop (9” and up] and then it would be very hard to find a thrust angle Just right for your plane to fly level, as a result, you would need ailerons to compensate the torque roll. At least you need ailerons to trim your plane flying level at maiden, and then you can use rudder and elevator only. However most people would rather use ailerons and elevator then rudder in this size of planes.
 

Figure9

Elite member
Agree with @TDL. Keep it light as possible even if you need to make another wing. Consider a big tail fin with no rudder, just ailerons & elevator.
 

sundown57

Legendary member
maybe take all electronics and set them in the fuse with battery and then set the wings in place just to get an idea of total weight and where the CG is. that would give you heads up on what to look for
 

Michael G

Active member
I'm sure this is going to be heavier. All boards were laminated with spay adhesive. And minimum amount of hot glue giving it's size. Believe it or not she doesn't weight a ton. 100% or 200% the balance point should be the same. I'm building the plane the same way in the build video. As far as needing extra weight front or back I have peel n stick wheel weights. I've been to my hobby shop enough times to see that props, motors and esc's come in some pretty big sizes and amps and prices. So whatever the total weight is I'm sure they make something to get this bird off the ground. I just need to know what???? And if the guy at the hobby shop comes up with the same combo of gear then I know it's the right gear. Because I asked all of you first.
Prop size?
Motor size / kv. yada, yada, yada,
Esc. Amps
Battery- size - cells? blah blah blah
 

Figure9

Elite member
maybe take all electronics and set them in the fuse with battery and then set the wings in place just to get an idea of total weight and where the CG is. that would give you heads up on what to look for

Agree, I use small pieces of removable adhesive Velcro to install all components & mock up a build long before making a commitment to where the wing will will be located on the fuselage. I’ve only built high wings that I can pick up at the wing tips balanced on a finger tip. I’m looking for a slightly nose down balance point, 30 to 40% of the chord in back of the leading edge on a hershy bar style wing. I’ve seen in the forums where low wing models can be flipped over upside down & checked the same way but dihedral would make it tricker on a low wing. The temporary Velcro attachment might make it possible to flip the wing end for end on low wings so the dihedral is inverted & helps hang the model by the wing tips with just the fuselage velcroed on upside down.
 

BATTLEAXE

Legendary member
I'm sure this is going to be heavier. All boards were laminated with spay adhesive. And minimum amount of hot glue giving it's size. Believe it or not she doesn't weight a ton. 100% or 200% the balance point should be the same. I'm building the plane the same way in the build video. As far as needing extra weight front or back I have peel n stick wheel weights. I've been to my hobby shop enough times to see that props, motors and esc's come in some pretty big sizes and amps and prices. So whatever the total weight is I'm sure they make something to get this bird off the ground. I just need to know what???? And if the guy at the hobby shop comes up with the same combo of gear then I know it's the right gear. Because I asked all of you first.
Prop size?
Motor size / kv. yada, yada, yada,
Esc. Amps
Battery- size - cells? blah blah blah
You could do a 3542, like previously said, but in a lower Kv, like the 600-800 range. This will keep the amp draw down, and open up options like 4s on the same motor, and allow you to run a smaller ESC, 40 amps would be more then plenty, you could even get away with a 35 amp easily. If you go with 3s battery you could spin a 14x6 prop. If you are running 4s, you may want to drop the prop size to a 12-13"
 

Michael G

Active member
If I were you, I would build her as light as possible to keep her AUW under 4 lb. The reason is, once your go over 4lb, you will spend a lot more on the electronics. I estimate the foam parts for the mini DR1 is around 7.5oz, enlarge 200% with laminated foam board will bring it over 60 oz (a lot of hot glue!) and then you add motor (3542 minimum), 4 metal gear servos, lead extensions, esc, Rx, 3 or 4s 2200 lipo, and other small things, it will be around 5 lb or 80 oz. I personally would not go under 0.9 to 1, thrust to weight ratio, so you need a power plant that can produce at least 72 oz of thrust., and then you would go to this site to find the motor-battery-prop combo. https://www.flybrushless.com/motor/view/478

I think laminating foam board at this size range is overkill. I would reinforce the edges of the fuselage but single sheet on most of the flat surfaces, and I would convert the wings to the “folding airfoil” design that is commonly used in FT standard size planes. folding airfoil is much stronger than laminated sheets and you need plywood wing spar on both ways. If you can keep the AUW under 4 lb, then I would buy a cheap 3542 kv1000 motor (real work horse and easily available) from eBay, 3s 2200 (the most common lipo) and Apc 12x6. if you go over 4lb, a 3548 motor on 4s lipo and 60a esc will cost you a lot!

Good luck!
Thanks I'll take those prop, motor, Battery sizes to my hobby shop and see if he comes up with the same stuff.😄
 

Tage

New member
Just had the DR1 plan copied 200%
Using foam board 10mm thickness
Board size 1400mmx1000mm
Try to build as original
Any recommendations ?
 

Tage

New member
Just finishing DR1in 200%
Original in background
First flight tomorrow , weather permitting
 

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