1/48 DHC-2 Beaver

[buccfan]

Coming on nicely Fraser. Regards Paul J.

[Boomerang]

Looking forward to the next instalment Fraser

Gordon

[lastvautour]

Fraser, where did you get your drawings.

Lou

[Gearup]

Hi Lou. I generally do a google search for 3 view drawings. I simply downloaded that drawing amongst a few dozen others that I thought were interesting. For this drawing i did a search again using the file name attached to it to see what popped up. It appears that "Beaver Model Aircraft Drawing 1-2.jpg"  was uploaded to SMM in 2013!
Fraser

[lastvautour]

After posting to your thread I found the ones you are using. I have them scaled to 1/32 scale. It gives me a bigger than normal model at 18" span. Thanks for the response regardless. I was taking a run a few Sundays ago and stumbled on to this beauty and had to make it.

Lou

[Gearup]

Great!  I have been a bit derelict on working on my beaver due to it being a rather busy summer, even in these COVID times.  I'm trying to keep me models to 1:48 as i find it interesting to see how they relate to each other in size. Also to note, my son thinks the two bladed props are cooler than the three bladed versions. All in the sound I guess..
Fraser

[Gearup]

So I was trying out a new wood lathe today. I made some wheels just to see how they would work out. I started with 1/2" maple dowel and only used a 1/8" parting tool. I used craft paint silver and a black sharpie for the tires. They scale to about 24" at 1:48 so now I will look for an airplane to fit🤔

[Gearup]

now the picture?

[lastvautour]

Looking good. I often wish I had a lathe.

Lou

[buccfan]

Nice job Fraser, I have a small wood lathe but have yet to try it in anger, I'll get round to it sometime. Regards Paul J.

[Jim]

I bought a mini lathe a few years ago, and it completely changed woodworking for me. In addition to  making it possible for me to craft tricky parts like cowlings, spinners and wheels, it opened up all sorts of craft projects. Now I turn my own fishing lures, replace broken wood fixtures — I even built my own 5-string banjo. There's nothing in the world like having the right tool for the job.

I subsequently discovered the even smaller "jeweler's lathe," and, figuring it could be used to make even smaller model parts, bought one on-line through e-Bay. Unfortunately, despite much experimentation and effort, I've found that it really wasn't designed with turning wood in mind, and despite many efforts and consultations with machinists and shop wizards, so far my efforts with it haven't been crowned with success. But I haven't given up hope entirely. Maybe one of these days I'll find some kind of aftermarket fixture or retrofit that will turn the trick...

[Gearup]

Many years ago a friends machinist father showed me some Machined pilot Pins used on rivet countersinks. They were about 3/8" long with a 1/16" diameter shaft and a 3/32" rounded end. The lathe he used was a full sized 12" swing metal lathe. He told me "Sometimes you need big tools to make small things". I have really found that to be true in a lot of crafts!!

Fraser

[Gearup]

It has been awhile since I had progress on the Beaver, but here is the process on the engine.

I spent an inordinate amount of time thinking how I would make the parts and assemble the engine model. Through pictures I was able to determine the main features to make for the R985. Cylinder proportions, and pushrod locations seem to define the look.

There are some very fine models produced by the SMM group and there are many ways to get the effects of the details on the radial engines. So I thought I'd give this way a try.

Picture 1. As mentioned before, I have a small wood lathe. Actually it seems huge when compared to the model cylinders to be made. For cutting tools I used a full sized skew chisel and a 1/8 parting tool. The cylinders started as 5/16 hardwood dowel, which required a smaller chuck than the lathe has. Looking on the web I found an article on making wooden collets to hold small work. It is simply a pattern to cut radial lines into a plywood disk to fit the desired range of dowels to be held. Tightening the lathe chuck to the collet grips the dowel. When the piece is finished, loosening the chuck allows you to pull more dowel through the collet and repeat the process.

I turned the diameters down using the 1/8 cutoff tool. I would gauge the diameter for the head and cylinder barrel to about 1/8" and 1/16" respectively. Then using the skew on edge like a knife, I would cut the grooves to simulate the fins. Then the cylinder was parted off with a fine Japanese saw.And repeat. I made about 25 or so as I figured I would loose some and wreck a few others, plus quality control rejected a few.

The engine case was turned in a similar way using another collet.

[Gearup]

The production sequence of a cylinder is shown in picture 2.
-   Forming and fins defined.
-   Cylinder parted off.
-   Groove cut in head to define the rocker covers. I used a small triangular file and sandpaper.

Picture 3. Now, how to space the cylinders around the case and hold them in the correct orientation of the rocker covers? I used a modeling clay fixture. First a template was printed of the cylinder spacing approximately the diameter of the model (7/8" diameter). I then cut a ¼" thick slab of modeling clay and placed the template on it. Using a sharp pin I marked the center of the case and the top and bottom of the cylinders then removed the template.

Picture 4 I pressed the engine case into the clay to about a 1/32". Then using tweezers, I pressed each cylinder into the clay at the pin-points ensuring the rockers were orientated correctly and the base of the cylinder was touching the case. The cylinders should also be on the same level around the case. Vola, the cylinders don't roll out of alignment and are "clamped" for gluing. Next I shaped the sump that sits between the two lower cylinders and applied thin cyano to each cylinder base.  The cyano does not stick to the clay. Once it has set up, the model can be freed from the clay fixture. Work around the cylinder heads then push the case from the back with a pencil through the clay.

Picture 5 Once the model is freed, clean the clay from the backside using toothpicks and a small stiff bristle brush. The cyano may have formed a "flashing" if it laid on the clay surface so use an exacto knife to clean that up

[Gearup]

cont...