I still have a few more hours of work on the DC-3. Once I have completed it I will build this biplane.
This will be the 4th one I have built.
Pitts 1- 18" span (150% enlargement) with an E-Flite 280 on 3 cells- flew well
Pitts 2- 14" span (115% enlargement) with an E-Flite 180 on 3 cells- ballistic and flew it in 30 kmh winds
Pitts 3- 12" span- as per the original plans with an E-Flite UMX radio system- See photo below next to a roll of Scotch tape. Indoor only, marginal power.
Pitts 4- this one 14" span- 115% with an E-flite 180 on 3 cells. Same as Pitts 2.
The plans are a free download on the website: https://dragif.com/pdf/aIBV?epik=dj0yJnU9ZTZoN2RIWndTLWVJblZVUTlLeDY2ZGVPNzdWZWxkcHMmcD0wJm49dzY1T3lfR2tGSnJXX3BaRE1FSmVjdyZ0PUFBQUFBR0FaXzAw
I printed them at 115%.
These things are a blast to fly and impossible to land properly. The best way to land is fly over tall grass and cut the throttle. When they slow down to a certain speed they just tumble out of the air. A repair required every flight.
They are easy to build and only take about 10 hours. 4 channel.. with ailerons.
Frank
I've seen UMX, but ...... this is a whole new level!
This very cool Frank
Mark,
The one you saw me fly at TEMAC was the large Pitts #1 (18" span).
The smaller 14" one I am going to build is much faster and much tougher to fly.
I flew it on 3 cell 100 mah batteries.
Frank
Let's get started.
Picked up the new E-Flite 180 motor at John's Hobbies today.
Found 3 small servos and a Berg receiver (72 meg- with long antenna).
See photo. A dime shows the relative sizes. The motor is a little gem. Note the dental floss on the servos. They pop apart (no screws) without dental floss and a drop of glue.
I use a 72 meg receiver on these small planes for two reasons:
1) the trim levers can be shoved over immediately if it needs immediate trim.
2) for the take-off. I stand on the antenna, give full throttle, give full "up" elevator and release the antenna. The take-off roll is measured in inches (about two!)
It is almost impossible to do a normal throttle-up, pick up speed and rotate for take-off routine.
Now I will look in my balsa forest for the woody bits.
Frank
Cut out all the parts. The fuse sides and wings are 1/32 balsa. The firewall, formers and ribs are 1/16.
Tomorrow we start slobbering glue onto the building board. Only one joint is glued on the board. The rest of the fuselage is built in mid-air.
It's a really interesting... and strong process.
F.
The only glue joint on the building board. The back of the fuselage is joined together. It is the turtle deck behind the cockpit. (the knife blade points to it).
F.
Building the fuselage:
Step 1- dampen the wood by laying it between two wet paper towels. Half hour is fine. Photos 98,99
Step 2- lay wax paper on your hand* and place the fuselage on top. Use your thumb and middle finger to curl the wood. Photo 00
step 3- Insert F2 at the back end of the cockpit cut-out and glue. Hold until dry (1 minute?) I used medium CA. Photo 01
Step 4- squeeze the back end together and glue.
Step 5- glue the top deck of the fuselage together at the front of the plane and hold until dry.
Step 6- insert F3 just ahead of the stab slot and glue.
Step 7- Insert and glue the firewall to the fuse top and sides with down thrust and right thrust. How much? Just enough! (3 degrees each? the instructions say 3 and 6). Leave the bottom unglued because this has to be trimmed to fit..
Step 8- double-cut the bottom fuse sheeting to make it all the way around the firewall.
Fuselage is finished. Photo 02.
Total elapsed time was 8 minutes and that included taking the photos.
Frank
*if you use fast CA you will learn "why?" immediately!
Cute as a button!!! And about the same size too! ;D
Thanks Guy.
Da Wings.
Step 1- Pinned the ribs onto the plans. Two ribs on each lower wing half and three ribs on each upper wing half. The only change versus the plans is that I made the ribs longer so they would stick out of the leading edge and trailing edge so the pins would not get in the way.
Step 2- wet the wing halves. Top surface only. Put a wet paper towel over the top only. Photo 03.
Photo 04 shows the curves caused by the water treatment.
Step 3- take each wing half, run a bead of medium CA over the ribs and hold the wing down until the glue cures (30 seconds).
It took longer to pin the ribs onto the plan than it took to build the wings. Total time for pinning and gluing: 20 minutes.
Frank
Next Steps:
Hinging the rudder and elevator- The first time I tried this. Used pieces of rubber band as hinges. Cut slots in the elevator halves and stabilizer and fin and rudder. The pieces of rubber are laid in the slots and one drop of CA and......miraculous. Works beautifully On previous planes I have used clear medical bandage tape (Blenderm) but they eventually let go. See photos 10 and 13.
Cut the bottom wing slots through the fuselage. The bottom wing halves are slipped into the slots and glued in place and joined in the center. The part of the fuselage below the wing becomes the root rib. Photo 14
Servo installation: Installed one balsa servo rail with 5 minute epoxy. Once dry, I will install the second rail. The 3 servos are side by side but the aileron servo is installed upside down so the horn sticks out of the bottom of the fuse.
Frank
Servos installed.
View from the top (photo 15)- the rudder and elevator servo visible. The center servo is for the aileron and is installed upside down.
View from the bottom (photo 18)- the aileron servo is sticking up from the center. Note that I left some bottom sheeting open to help in routing and attaching the servo control rods.
Frank
Quote from: Frank v B on February 05, 2021, 08:38:56 PM
Servos installed.
View from the top (photo 15)- the rudder and elevator servo visible. The center servo is for the aileron and is installed upside down.
View from the bottom (photo 18)- the aileron servo is sticking up from the center. Note that I left some bottom sheeting open to help in routing and attaching the servo control rods.
Frank
So
@Frank v B , where exactly do the IKEA instructions fit into this beautiful piece of aeronautic jewelry?!!! ;D
Andy
- tail feathers glued in place
- bottom wing joined inside the fuselage
- photo of the bottom shows the wing joint.
photo 22- just had to do it. ;) ;)
F.
Quote from: Frank v B on February 05, 2021, 11:05:16 PM
- tail feathers glued in place
- bottom wing joined inside the fuselage
- photo of the bottom shows the wing joint.
photo 22 23 - just had to do it. ;) ;)
F.
@Frank v B has taken ARF's to a whole new level with the addition of knock-down hardware and the provision of the required assembly tool, which also doubles as a starter crank for his seized up brushless motors!.
Andy
@Frank v B , what will the colour scheme be? Starburst? Painted feathers? Monochromatic? Fluorescent?
Asking for a friend... ;)
Just came back to the world of the living!!!
My life sure went south at the end of Saturday's Temac video Board Meeting at 2pm. Locked myself in a spare bedroom from Saturday afternoon until noon today. At noon got the Covid test back- negative. Couldn't take any chances. No access to my workshop, a tv or a computer. As Andy would call it "Heavenly silence".
It may have been a bug, or even a chance of a mini concussion since I slipped on ice and hit my head last Thursday.
Whatever it was, it is over and done with. Back to the workshop tonight after picking up some business loose ends this afternoon.
I will answer Guy's colour question later. It will be red. At 50/50 you can't see it! The entire plane that is. ;D
Frank
@Frank v B sorry to hear about your misfortune, still glad to hear you are negative.
But please remain positive as there are great things to look forward to, such as a Maiden Flight. ;D
Also, how will you know if it is upside down f the colour is the same all over? ???
Guy,
Thanks.
re: your comment "how will you know if it is upside down (i)f the colour is the same all over? "
Basic airplane design helps people like me. The fin and rudder point up and is a polite way of the plane saying "this way up, stupid". Form follows function. :D
Done today:
- installed the motor. Andy, notice the sharpness of the writing on the motor. Just for you.
- made the cowl so the motor fits in the middle of the opening in the cowl
- formed the landing gear (see photo) and installed the landing gear mount inside the fuse.
Frank
@Frank v B Now I get it, that is why they have the arrow pointing up on some planes... ;D
Quote from: Frank v B on February 09, 2021, 06:23:18 PM
Guy,
Thanks.
re: your comment "how will you know if it is upside down (i)f the colour is the same all over? "
Basic airplane design helps people like me. The fin and rudder point up and is a polite way of the plane saying "this way up, stupid". Form follows function. :D
Done today:
- installed the motor. Andy, notice the sharpness of the writing on the motor. Just for you.
- made the cowl so the motor fits in the middle of the opening in the cowl
- formed the landing gear (see photo) and installed the landing gear mount inside the fuse.
Frank
Hi
@Frank v B ,
Excellent photography sir. I did indeed notice the tack sharp writing on the motor: "Waarschuwing! Niet voor gebruik door Nederlanders!"
E-flite has clearly thought of everything! ;D
Last thing before painting: cutting and hinging the ailerons (bottom wing only).
F.
Not painting yet* so here are some tricks for the fiddly bits:
1) Could not find small light wheels so made them out of indoor plastic wheels. Photo 31 shows the wheel on the left; glued it onto scrap 1/32"; sanded and finished one on the right. Will paint it black .
2) Getting the axle ready. Commercial wheel collars are too big. Tied about three wraps of dental floss on the axle and added the smallest washer I could find and added a drop of glue. When the wheel is installed I will add another washer and then a few more wraps of dental floss and another drop of glue. If the landing gear were larger diameter wire I would have used brass servo grommet liner as a bushing.
3) Control horns- cut them with scissors from 1/32" plywood and then used a pin to make the hole. The wire is the same diameter as the pin. Photo 33 shows the aileron horns at6 the top. Pushed the pin through both of them at once so they are carbon copy. The other two are for the elevator (smaller) and rudder (larger).
Accurate control rod installation. It is always tough to find neutral on small planes to get pushrods the proper length. Here is a 100% accurate installation method:
i) cut a slot in the control surface so the plywood horn can be pushed into the slot.
ii) slip the plywood horn into the slot and cut the control rods to length.
iii) Tape the control surface in the neutral position (both ailerons, rudder, elevator), center the servos, attach the rods to the servo arm and the plywood horn, slip the horn into the slot and add one drop of CA (medium is best). Guaranteed all surfaces will be perfectly neutral.
The best part- the plywood horn and the glue are always across the grain and significantly strengthens the wood.
Frank
* No access to the part of the house I can use spray paint.
Quote from: Frank v B on February 10, 2021, 07:22:17 PM
Not painting yet* so here are some tricks for the fiddly bits:
1) Could not find small light wheels so made them out of indoor plastic wheels. Photo 31 shows the wheel on the left; glued it onto scrap 1/32"; sanded and finished one on the right. Will paint it black .
2) Getting the axle ready. Commercial wheel collars are too big. Tied about three wraps of dental floss on the axle and added the smallest washer I could find and added a drop of glue. When the wheel is installed I will add another washer and then a few more wraps of dental floss and another drop of glue. If the landing hear were larger diameter wire.
3) Control horns- cut them with scissors from 1/32" plywood and then used a pin to make the hole. The wire is the same diameter as the pin. Photo 33 shows the aileron horns at6 the top. Pushed the pin through both of them at once so they are carbon copy. The other two are for the elevator (smaller) and rudder (larger).
Accurate control rod installation. It is always tough to find neutral on small planes to get pushrods the proper length. Here is a 100% accurate installation method:
i) cut a slot in the control surface so the plywood horn can be pushed into the slot.
ii) slip the plywood horn into the slot and cut the control rods to length.
iii) Tape the control surface in the neutral position (both ailerons, rudder, elevator), center the servos, attach the rods to the servo arm and the plywood horn, slip the horn into the slot and add one drop of CA (medium is best). Guaranteed all surfaces will be perfectly neutral.
The best part- the plywood horn and the glue are always across the grain and significantly strengthens the wood.
Frank
* No access to the part of the house I can use spray paint.
Hey @frank,
Where did you get that giant size dental floss? That looks like something you would use on a mastadon! 8)
Andy
Andy,
Say "Macro setting" fifteen times.
Frank
First coat of spray paint- 5 minutes.
Second coat will be tomorrow morning.
Just held it in in my gloved hand and sprayed it outside my front door.
Good thing my car is already red. It was downwind. ;)
Frank
ps: the two red triangles are the landing gear legs.
Quote from: Frank v B on February 11, 2021, 09:23:31 PM
First coat of spray paint- 5 minutes.
Second coat will be tomorrow morning.
Just held it in in my gloved hand and sprayed it outside my front door.
Good thing my car is already red. It was downwind. ;)
Frank
ps: the two red triangles are the landing legs.
Hey
@Frank v B ,
What colour is
Cynthia's car now?!! 8)
Andy
Terrific but simple idea for the wheels!
I like that!
Quote from: Frank v B on February 10, 2021, 07:22:17 PM
Not painting yet* so here are some tricks for the fiddly bits:
1) Could not find small light wheels so made them out of indoor plastic wheels. Photo 31 shows the wheel on the left; glued it onto scrap 1/32"; sanded and finished one on the right. Will paint it black .
In
@Frank v B 's next episode, Micro Off-Road and Edible Wheels for the Pitts!
For better traction in the snow, you may wan to consider the following wheel type,
@Frank v B .
Spray painted the wheels black and five toothpicks red for the cabane struts (fuselage wing mount). Photo 36.
Setting the top wing. Photo 37.
step 1- glue the top wing onto the two interplane struts (5 min epoxy). View wing from the top to make alignment with bottom wing.
step 2- Cabane struts. Install one at the back by poking the painted toothpick through the wing and fuse. Glue with two drops of CA.
Step 3- install the second toothpick in the back and glue.
Step 4- install one of the front toothpicks put pull the leading edge of the wing down about 2 degrees (visual). two drops of glue.
Step 5- install the second front toothpick and glue. This is your final chance to adjust the squareness and angle of attack of the upper wing.
Step 6- clip excess toothpicks at the top wing with side cutters.
Now final assembly (radio, pushrods, etc.)
Frank
You left out step 7 - clean the black and red paint from your finger tips :)
Excellent point
@pmackenzie !
@Frank v B is so lucky to have so many folks looking out after his better interests! 8)
Andy
Pat,
Good thing it was not pink! :)
Getting to the finish line:
- picked the wheels from the internet (Photo 38) and shrank the appropriate one to 1" diameter. Glued it to the balsa wheels: (photo 40, special focus on the background for Andy to analyze).
- adding the rear skid/tail wheel and the pushrods (photo 43). Note the plywood horns. The skid was glued into a 1.5" piece of small aluminum tubing that went through the stab.
The pushrods are small piano wire the diameter of a dress maker's pin sliding inside an aluminum tube. The tubing is just to eliminate flex of the thin wire.
The only thing left- to answer Guy's question of the trim stuff (flames, feathers, stripes, etc.). Stay tuned.
Frank
FLIGHT READY!!!
Photos of the final flight-ready plane.... before the trim decision.
14" span, 2.8 oz ready to fly!!
Frank
ps: Chris O'riley, the designer of this Pitts also designed a TigerMoth which could have been the one I Pat MacKenzie fly when indoor was in its infancy. I saw it fly in an Oakville gym.
http://www.chris3d.com/files/micromoth.pdf
@Frank v B Your Pitts Looks absolutely AMAZING!
So small and yet unmistakably a Pitts.
Great Job, looking for Maiden Flight.
Beautiful
@Frank v B !
I love the close and flush fit of the cowling around the motor bell.
Super job on the "photo-finish" wheels.
Photo 3440 was very well executed. It left no doubt as to the subject of the image, yet still conveyed the ethereal environment whence came the Micro-Pitts.
And photo 3444 shows perfect landing attitude!! (I like the big control knob on your watch!) 8)
Bravo!
Andy
Quote from: Frank v B on February 13, 2021, 05:03:30 PM
ps: Chris O'riley, the designer of this Pitts also designed a TigerMoth which could have been the one I Pat MacKenzie fly when indoor was in its infancy. I saw it fly in an Oakville gym.
http://www.chris3d.com/files/micromoth.pdf
Yep, my old micro Moth was his other design.
Still have it, but it needs some TLC. I have thought about doing a brushless outrunner upgrade, never liked the gear box noise.
And of course it has an old 72 mhz RFFS actuator rcvr, which if I recall only worked with Futaba. I don't have one of those anymore. JR I have, but no Futaba.
I bought a Spektrum compatible Deltang actuator rcvr a while back, so I could stick with the actuators. They worked just fine and are very light.
Might post some images......
Very nice indeed Frank!
Bonus photos!
I know it's a long way to Halloween, but....
#5625 - The spectre of spring balsa planting waiting to emerge from his chrysalis!
#5627 - At first glance this is a mobile precision gull dropping target, but in fact it is just
@Frank v B 's spray paint test platform. With sufficient use this morphs into
two fully formed monocoque stressed-skin fuselages, ready for wings!
Andy
See, Mark is nice to me and.....Andy is just Andy.
To answer Guy's issue about decorative issues: Stripey things. Yes, artistic versions of directional arrows.... this way you idiot! ;)
Will have to do something about the colour of the prop*.
Frank
* these GWS props are best for these small motors but hard to get. Went to HobbyHobby and found 4 of them. Bought them all. Good to see Tom B. again. We have known each other for over 30 years (same flying club).
@Frank v B You are getting perilously close to making your Pitts too beautiful to fly. Gravitational forces increase exponentially with the aesthetic appeal, starting with an exponent of 2 for a great paint job, and increasing by one integer value with each subsequent increase in trim decoration!
Andy
Andy,
Are you OK?? That is getting awfully close to a compliment.
Go get tested please. ;)
Frank
Quote from: Frank v B on February 14, 2021, 02:03:08 PM
Andy,
Are you OK?? That is getting awfully close to a compliment.
Go get tested please. ;)
Frank
Thanks
@Frank v B I'll bet it's that darned Dutch variant of COVID-19. I'm pretty sure I know where I picked it up!! ;D
"Scheveningen!" (Oops. Pardon me. It just slipped out. Doesn't leave much room for doubt. I guess I'll have to do a 14-day quarantine in the Polders.)
Andy
@Frank v B these stripes just set the Pitts apart. It was beautiful, now it is gorgeous!!