Aircraft - Exotic and Special Interest
Martin XPB2M-1 Mars 1943- Scratchbuild
Martin XPB2M-1 Mars 1943- Scratchbuild
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This is the only drawing I found in my searching the web. It is the very early version during trials.
I believe this was during trials in 1942 -3 and the tail gunner and the nose turret was removed and plated in. It was not going to be flown near frontlines action. The Rudder and motor conversions were next.
Did you notice the Piper Cub on the wing?
Mars Testing logo
This logo was repainted over using the logo picture on the right side as the base picture.
First days work 3 pics
Had to make opposite sides with the planking.
This is the second days work with these pics and below.
The plan curved fin and a gusset was added. I also put in another former here. Attention to air flow and water drainage holes were added inside.
Additional formers, widened rear post, and the keel curverture was changed
Almost ready for sheeting.
Measuring and fitting the sheet. I use a straight edge and block sand lightly for a good fit.
All set to put the sheet in place. I ran small beads of glue with the glue gun. Damp spray the glue and the foam sheet.
Held in place for setup after a mist spray of water. Water is the catylist for polyurethane glues.
From behind. Easy to check flat contact to the glue. One pin pushed in holds it flat to dry.
Taping helps keep the glue foaming action flat.
Both sides planked up. The pins can be pulled aftter 1.5 hours. Take a scrap of wood and scrape excess glue soon before it cures.Tommorow is to late. Hard.
The bottom tailsection started. Tape helps prevent cracking. I also ran a straight stick on top under the clamps
Nose area inside looking back. You can see just a little polyurethane glue line that foamed. I know it bonded well.
Battens are behind the outer planks. The piece to be glued in is above the opening. Compound curves require pieces to make it easier to assemble.
The bottom all done for now. 5mm sheet Depron.
Formers in place
Battery tray in. The cross member in the middle is being cut out. A U shaped former will take its place. Lots of room.
The hatch frame is made and nose sheeted. Wood use is preferred ahead of the wing leading edge into the hatch for strength.
The frame in the middle of the hatch was removed and it is easy access now.
The cables are in and the rudder is connected. Ready for Depron covering. A pink foam tail block is in place and will be shaped later
Here is a piece of Depron I rolled with a piece of pipe to help get it in place.
Got the depron on edge with glue and then taped it to prevent foaming. Next pin it in place and put a lightead of polyurethane glue in place. Spray a light water mist and bend it in place.
I use a flat stiff ruler or stick to help in the bending. Us a strip of scrap foam and pin through it. It also stops crushing with clamps.
On to the hatch access.Wax paper first. Lay stringers and formers out just the the height less skin covering
Added stringers to help the covering be more firm.
Layed up with 6 wide strips and CA glue. Setup overnight.
The basic shape of the moved cockpit area 1inch forward. seats are just placed in there. the acces hatch was sanded to shape.
You can see the wood placed in the rear with a slight lip for clear plastic. The rear bulkhead is foan and has a air slot to let air enter the cabin. It should prevent fogging.
The whole interior must be done before I can do window framing.
Seats and steering yokes made. Pilots? Maybe.
Early picture in 2000. More effects and lights were added later.
This was the last Millenium show I did then the sign was changed to "Cruisln' 50's" Much more added then. Last show was in 2003 in - AMERICADE - Lake George, NY
This is a time lapse picture of a drive by. The flames shoot out the exhaust non stop. There is also a smoke generator onboard.
Pics Neons M-Cycle Lights.pdf
Put a foam windsheld seat around the cockpit. Painted the interior and added minimum details..
Framed out the window framework for the clear plastic. Still have to paint the zinc chromate inside the frames
1 coat of green. It still needs another.
Meaured off every 2 inches and glued in wedge shapes and a long 1/8" square balsa strake for the chine edges.
Glued down balsa 1 inch wide flat spray strakes in place with CA and polyurethane glues. Sanded and spackled. It has a nice shallow turndown.
I had to redraw a plan for this version Mars. Outline is in dark ink.
Framed and setting up
The horn is wrapped, soldered, and twisted heavy gauge copper. There are brass sleeves to hold it in place when glued in. This is the inner side of the rudder. .
This is how it sits inplace when it gets drilled into the rudders.The 2 holes allow for the horn to swing with the pushrod.
Here it is all hinged and ready to be glued in place.
Glued the elevator and rudders together. Squared them and secured. The rudders have cables and I added carbon fiber spars
Glued the halves together for setup.
Test fitting the tail feathers.
There is a plywood forward bulkhead and pink foam saddleit is sitting on.It will be secured with a lineup dowel and nylon screws for mounting.
Just put in a cap and sand and smooth out in the V area. Once finished and glazed it should look fine. There are 2 nylon screws on the ply strip.
Here is the Auto-Bailer. I sawed 3/8 inch off. It should not allow water at the hull step over 1/2 inch deep to mess up my CG in flight.
Middle 4 ribs and outer ribs are ply. The spars are hardwood. Leading and trailing edges are balsa. The rest are foam ribs.
10 foot spanning a chair, stool , and onto my saw
Ailerons have to be cut free yet.
That is 2 Honda Wings it is spanning
The right wing had to be carefully fitted to the male on the left. It required routing and then filing the rectangle slot with a square file. .Then fabricating the boxes to snug fit and glued then clamped.
My garage door is 10' L X 8' H
Dropped on the plane. A lot to go yet.
Start by tracing patterns slightly oversize on a couple a foam rectangles.
Cut one side with some edge to spare. Put the etra back and flip the block. Cut the other side out. Ready to sand to shape next.
Here is one float sanded to the lines. Time - 40min.
Here are both. ime 1hr. and 30min. Try to build a balsa float in that time.
Added a hardwood stick mount foe the V mount to secure too. I marked the float and the channeled a dado to take the stick. I used a Dremel with a 3/8 inch stone to route the channel. I glued it in with Poly glue and taped to hold it
The float is lined up and just sitting in place. The servo compartment alomgside.
Brass tube guide and it will have piano wire rod push in and through the plugs. Locked!
rough 1" foam cut to 4" outside and 2" inside. Cut it oversize allowances.
Poly glue clamped and setting up.
I used a squaer foam driver with a dowel. I also put a nail across and through the dowel drive. Hot glued into the blue block A wood screw and a dowe glued in place on the tapered end.l
Setup in drill press.
Setup in my lathe. It has to be knife cut first to near shape.
Finished. I found my sanding bloch on the corner took it down good. Glue lines present problems.
The nacelle fit to the wing and shortened to length.
Not glued up yet.
Note the wires are long on this plane. Voltage spikes can damage the Esc's . Add capacitors.
Concerned about damage due to long wire leads to the Esc's can be corrected by adding capacitors parallel
Tie this unit in each power lead before the Esc's.
Wing being measured at different angles for lineup to secure in place.
Nacelles have a ply firewal. Another solid ply firewall covers this with air duct and motor mounted. It will be radial screwed in place. Forward pins in place.
Mounting screws and blocks are in. They get sheeted over after some formers get glued in.
The cup size food storage are 3 1/2". Hole saw the bottoms out. They have a ridge for the cover. I have plans for that.
All setup for a test fit. Test props
Test fit is good. Notice the turtleback bolt area all faired in.
Race against the camera timer to stand on the wingtip.
Got it - Standing in 10 seconds
Cut 2 layers of 3oz. cloth.
Layed up the 2 layers and setting.
The wing is very smooth. . The floats are started to be glassed.
This is the hatch cover. It is the finish and primer in one paint. It layed beautiful with airbrush. I use folded old newspaper between coats to rub it.
A couple of coats and ready to finih with spckling in some areas
This should easily take panel lines also when ready.
Pine. 3/4"X1/2" Rough cut tapers part way. Drill pilot hole. Route out with a Dremel tool tapered stone. Cut off and sand.
Test fit. It is so much easier to shape while on the pine stick. 15 minutes each.
The oil cooler scoop underneath is dremel routed to a channel with a 1/4" stone. Balsa wood. After drilling an air outlet hole under it, glue in place.
Fitted and primed. Air for motor vent cooling is wood veneer, 1/64" plywood would be better.
Blue all sanded and finished blue. Ready for panel lines now.
Bottom has 2 coats of off white and 1 more coat. The photo color is not quite right. It is white.
Hull bottom coated
The white in the rear needs a softened edge. This is to sharp. Panel lines next.
Ready to spray the dark blue.
Finished the spray on the 2 parts.
Another view. There was also a walk on the elevator.
Bob in his workshop.
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