1/48 DHC-2 Beaver

[Gearup]

Greetings all.
I am starting my new project. My son flys these aircraft for an all floatplane airline here on Canada's west coast. So it's a DH2 Beaver!

I am attaching pictures and descriptions of the build as I progress. Many of you know the techniques, but I am going to show them for the benefit of newcomers. Of course these are only a few ideas and not the way anything must be done. Hey, I'm not a professional model builder 

Using 1:48 scale will give a wing span of 12". It will be basswood (also called lemon wood) and will require a piece 1 inch thick, 4 inches wide and 16 inches long. The fuselage will be built up from two, 2"x8" pieces. Try to use wood that is fully 1" thick as it will allow for the floats to fit without needing to add a piece to fit the float width.

Picture 1. (3292)
I have cut the fuselage blocks to size and am going to glue them together. A soft artist charcoal was used to blacken both faces to be glued. Doing this will provide a perpetual centerline during the carving of the model. I had used a light coat of spray paint on my previous Mosquito, but the charcoal was faster as it did not need to dry.

Picture 2 (3301)
Placing the side plan.
I drew a centerline on the side to position the side-plan view.

I used a paper punch to make two holes over the plan centerline and intersection of a station line. Cut the backing of the tape with a razor across the plan at about mid point. Without removing the backing I aligned the plan centerline by viewing the side centerline on the block through the punched holes. Hold either half of the plan tight to the block, lift the free end up and remove the backing from the tape. Now lay the plan back down ensuring the centerline has not shifted as viewed through the hole. Then press the plan down firmly and repeat with the remaining end.

Aligning the top plan on the block centerline to match the side plan.
I used a "saddle square" to transfer the station lines from the side plan to the top of the block. Make sure the top plan also has station lines that correspond to the side plan. If not, mark them on the top plan.

Prepare and apply the top plan piece as described above. When laying the plan on the centerline, shift the paper back and forth to align the station lines and centerline through the punched holes.

[Gearup]

Beaver continued

Picture 3 (3298)
Using a 1/16" twist drill on a drill press to ensure a 90 degree hole, drill a hole at each intersecting station-line / centerline on the top and side. The holes will provide an excellent leveling and alignment reference when used with 1/16" pins inserted through them. Note the drill is too short to pass completely through the 2" block but it will have gone through the fuselage.

Picture 4 (3304)
Important – do not cut the top profile with any pins installed! This picture shows the pins in place in an "exploded" view after the block top plan has been cut.

The top profile of the fuselage has been cut free and sanded to the lines. Then the two scrap sides are secured back into their original positions using 1/16" pins.

With pins holding the sides in place and providing a flat stable face, cut the side profile out and sand to the line. Then remove the pins to free the roughed out fuselage.

The floats can be cut out using the same procedures as above. I did not use the split block and charcoal method to mark the top centerline as I felt the block was small enough to work with a hand drawn line.
Speaking of hand drawn centerlines...

Picture 5 (3305)
To draw or redraw a reference line, insert a pair of pins through drilled holes on the face. The pins extend far enough from the other side to allow them to be held in a vise for support. Use a flexible ruler against the pins to redraw the line as needed. Try to angle the pencil away from the rule about 1/32" inch to account for the pin diameter offset

[Gearup]

pictures

[Gearup]

Beaver continued

Picture 6 (3310)
You may notice the floats still have a plan stuck to the side. After I cut out the top profile, the waste was so thin at the max width of the float that they were unusable to pin back together as described previously. Since I still had the reference holes in the block, I used those to align and apply a side view to the curved face. I hot glued the wedge shaped pieces cut from the top view to get a flat and square surface to work with on the band saw.

The major parts are laid out here for illustration. The fuselage stations, float stations and airfoil templates have been made from 0.010" styrene. They have been attached to Popsicle sticks on the back side using double sided tape to provide stiffness. Since each station line was drilled in the block, it allows a better reference to position the templates. The templates were cut using my Silhouette vinyl-cutting machine.

Also note the engine in work for now. More about that as it may be a bit of a project on its own......

[lastvautour]

Thank you for the tutorial Fraser. Everyone, not just novices will enjoy your posts.

We have a float plane group build at http://smm.solidmodelmemories.net/SMF/index.php?topic=139.0

Please post some completed photos there when you are finished.

I look forward to more updates.

Lou

[Gearup]

Will do. I'll post when I am a bit further along. Thanks
Fraser

[Boomerang]

 Looking forward to further updates.
Be interested in how your engine turns out.

Cheers

Gordon

[Flying T]

you do great work,what is your background?mine came from plastic kits,i use plastic kit instructions to find out the details and where they go for my solids, also i belong to facebook pages and learn how others do things.

[Gearup]

Hello Larry.
Thanks for the kind words of encouragement.  I'm a newly retired aircraft mechanic and a lifelong aviation enthusiast. Small things have always fascinated me and I enjoy looking at the detailed hand work put into models. I enjoy wood working and problem solving so figuring out the build on the solid models is a lot of fun for me. The SMM forum has inspired me to try my hand at building using the techniques shared by the members.

Regards, Fraser

[Gearup]

A bit of progress on the DH2 Beaver.
Here are a a few pictures.

2520 shows the v-fin held in a hand clamp for carving. I had to make another vertical fin leaving the large tang on the bottom to get a better grip for carving. I made the fin from spruce which I enjoy working with. After carving, it was cut free along the pencil line for fitting to the fuselage.

2521 The h-stab after shaping. I marked out a slot on the fuselage to cut out using the scroll-saw.

2522 The h-stab fit into the slot. I double-side taped a wedge on the fuselage side to allow it to remain level and square while cutting on the scroll-saw. The clear packing tape works as a blade lubricant and you get a smoother splinter free cut.

2524 On floats. Well not quite. The fuselage is sitting on temporary popsicle stick spreader-bars without any struts. I think I will mount the wings the same as the Storch using brass pins and epoxy. I can't seem to get the hang of carving a single piece wing with the dihedral built in.

2527 Front on shows the concave fluting on the float bottoms. It was fun to carve using a 1/4" (6mm) #5 gouge and sanding blocks. Also I got a bit out of spec on the cowl shape so I built it back up using thin layers of body glazing putty. I might have further plans for the cowling details, but we'll see.

Regards,
Fraser

[lastvautour]

Excellent job on the Beaver Fraser. You captured it perfectly.

Lou

[Gearup]

Wing and a miss....

Turns out the drawing of the airfoil shape was totally out of whack. My son had mentioned that he did not recall such an under camber on the Beaver. So looking at many photos, I guess that's correct; no under camber i found a website containing the airfoil numbers for almost anything with wings.  https://m-selig.ae.illinois.edu/ads/aircraft.html  The DH 2 Beaver is a NACA 64A416/4416  Great, but what does it look like.  https://en.wikipedia.org/wiki/NACA_airfoil shows how to develop the airfoil shape given the NACA number. I basically stopped at the first formula as my slide rule jammed up....  So i found http://airfoiltools.com/airfoil/naca4digit  Using the last 4 digits of the specification 4416 , plug it into the online boxes. First digit 4 percent Second digit 40 percent (you add the 0 after the 4) The last digits 16 percent. Select send to airfoil plotter and there is, a neatly drawn NACA airfoil shape. Save it in a PDF or what ever file type is listed. Worked fantastic. I could scale the airfoil to any size to fit the model.

Long story short, I made two new wings. Now I've got a practice set 

Fraser

[lastvautour]

You now have experience on bi-plane wings.

Lou

[Gearup]

Bit farther along on the Beaver. All major components are fitted. just need more detail on the cowling. finished marking the lower flight controls on the wing with the corrugations. Refined the technique used on the Storch ribs. Turns out to be around 160 or so on the lower surfaces. Having fun so far......
Fraser

[lastvautour]

Looking good Fraser.

Lou