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Tutorial Novice - Convair Charger -A guide to solid models - Convair Charger

Started by lastvautour, October 13, 2008, 01:11:09 AM

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lastvautour

#15
Moving right along, we need to be careful not to get ahead of our selves. The next step has to be done slowly to achieve decent results. And that is shaping the wing. The temptation is to go right at it and carve that shape. I ruined more wings that way.
First is to look at the drawing and determine that the thickness part of the wing is roughly 1/3 from the from the leading edge so I measured 1.2cm and made a pencil line (softly) the lenght of the top and bottom of the wing. I them placed a line on the front face of the block 0.2cm from the bottom. That leaves 0.3cm above the line. On the rear face of the wing block I placed a line 0.1cm from the bottom and that leaves 0.4cm above the line.

Now the fun part: The airfoil shape. We are not trying to perfectly make the curvature of the wing, but will settle for a nice smooth airfoil shape. Slowly shape the top and bottom leading edge of the wing. You can draw the shape on the tip face of the block to help you. This can be done using the knife blade(easy there not too much at a time) a file, sandper glued to flat stick or a hand planer if you have one.

You will find that the bottom of the wing from the 1/3 back will be flat.

http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-2047
Once the leading edge is nicely shape, the rear 2/3 is shaped. It is not flat but has a long curvature to it.

http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-2048
once you enlarge the picture you will see the curvature of the wing is smooth although not perfect. Not to worry about the hole in my wing. I am using recycled wood so nail holes are easily filled later. Try to get a fairly smooth finish using 180 or 220 grit paper.

Next the tail plane. It is symetrical so the front and rear face lines will be centered on the wood, but that will be in another post.

Rafael

Hola, Lou!!!

Each lesson-step is more entertaining than the previous one.

I already notched the air scoops on the engine booms. One thing I worry about is that my shapes are not exactly 90 degrees from the drawing face, courtesy of my poor cutting technique/pulse.
I believe that can be leveled/filled later.

The wing is also almost ready. I gently curved/sloped the profile towards the trailing edge, more or less in shape with the drawing. I have not yet smoothed/finished the surface. The bottom of the wing also needs sanding/filling prior to smooth it out, thanks again to my cutting marks.

This is what I have, so far:
Marked Pod

http://smm.solidmodelmemories.net/Gallery/displayimage.php?album=180&pos=8

http://smm.solidmodelmemories.net/Gallery/displayimage.php?album=180&pos=7

Main wing airfoil

http://smm.solidmodelmemories.net/Gallery/displayimage.php?album=180&pos=10

http://smm.solidmodelmemories.net/Gallery/displayimage.php?album=180&pos=12

Saludos,

Rafa

lastvautour

#17
Good work Rafa. I was at my Thursday Card Night that I organized and run. When we have odd numbered players I sit out and work on my models. Tonight I mated the wing to the fuselage and the booms to the wing. I will post the photos tomorrow as I am tired and will be going to bed shortly. The minor slips can be corrected. After all it is wood which is very forgiving.

Lou

lastvautour

#18
The vertical stabs or fins are next. The fins are tapered from bottom to top but still flat front and aft. Next shape the front half to a symmetrical airfoil shape. Leave the rear half for now. Look at your pictures to get an idea of the basic shape. Remember this is an ID model destined to be a reasonable facsimile

http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-2058
.
Next the horizontal stab is also shaped symmetrical. Draw a center line all around the block and slowly shape to an airfoil contour. Shape the tips and round off using sand paper. Careful not to take to much off. Final trimming can be done later.

http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-2057

More to come

lastvautour

The booms are next. Cutout a copy of the top view for the booms and glue them on. I only did one but you can do both if you wish.

While the glue is drying, you can flip the boom upside down and mark the leading and trailing edges of the wing. Continue the line all the way around both booms. As you erase a line while carving, replace it from time to time to keep things aligned.

Now carve the boom keeping the sides vertical at this point. You can use whatever tool you wish. I prefer a wood chisel for the majority of my carving, but an exacto knife will do just fine. Once roughly carved, use a sanding stick (flat wood stick with sandpaper glue to it) to smooth things out. Do both booms and compare to make them even.

Another method to make them the same is to do one and flip it over the other and measure then cut. Keep comparing to make use you don't take to much off that second boom.

And now, attached the fins using your favorite glue. I use white carpenter glue or some times I use superglue. Either is OK just make sure you have a good straight bond. Check them frequently to make sure they do not shift. You will notice that the rear of the fin is wider than the tip of the boom. That is OK for now.


The only thing else at this point is the rounding off of the front propeller spinner area. Mark the centre and then mark a circle where the prop spinner will be attached. Carefully sand the area round(so-so for now)

Take a break, more to come.

Lou


lastvautour

#20
Wing tips get the next treatment.
Make a line on the wing bottom 2mm from the edge of the wing tips. Then using a copy of the drawing cut the shape of the wing tip as viewed from the top.

Make a line on the wing bottom 2mm from the edge of the wing tips.

The wing tip should look something like this.

Holding the wing upside down, shave the tip until it is bevelled as shown. Do not go beyond the line you drew on the bottom of the wing and do not cut the top of the wing. things should look like this at this point.

Do the other side and voila! the tips are shaped. Viewed from the bottom, you will note that the bevel flattens out a bit at the rear and that is the desired result we are looking for.


lastvautour

#21
Joining the Wing to the fuselage can be made many ways. I prefer the tongue and groove method whenever possible. First mark the location of the fuselage and boom centreline on the upper and bottom wing. Make sure the lines are straight as this will affect the overall look of the model.

Make a vertical line to indicate the wing leading edge location and continue the line around the fuselage.

Make a horizontal line to indicate the bottom of the wing. Remember we have a flat bottom wing so line up the line with the lowest part of the drawing's wing shape.

Make a line at the base of the canopy's rear. Make a vertical line to line up with this. Then measure 1cm on the horizontal wing line. Also line off the width of the fuselage on the top and bottom on the wing. You can use the fuselage pod to do this.

In the next post we will carefully remove the blacken sections to mate the wing to the fuselage.

TAKE A BREAK, go for a coffee or a beer, easy on the beer.

More to come.

lastvautour

#22
Using your saw, make cuts inside the black area and slowly test fit the fuselage to the wing. Remove small amounts at a time until you get a snug fit.

When doing the fuselage, make sure you mark both sides to ensure you don't take off too much wood.

Note that I removed the paper from the fuselage where the wings will fit. The thickness of the paper, if left on, will make the wing loose when removed later, so take it off before final fitment of the wing.

Take your time in fitting the wing to the fuselage. Keep checking to make sure the wing and fuselage are aligned. If not, remove a bit here and there to get it straight.

Then after many tries and lots of small cuts, the wing will just slide on in. Note that if the wing contour is as we discussed before and the fuselage was cut to plan, the wing and rear fuselage should mesh quite nicely. Any deviation can be quickly remedied with sandpaper.


PS, Money is from our Euchre night. I charge each player a small fee and give out money prizes at the end of the night.

More to come

Rafael

Hola, Lou!!!

This is fun and fun and fun!

Ok, this morning, when I saw your posts, I took my pieces and started measuring. I found that my engine booms were totally wrong. Well, I was using a different set of plans, and made some mistakes more. I then made a new set of booms, and started cutting the wing.

The wing and fuselage pod were also a little off, note the different cut I had to make to have the wing and fuselage pod marks match. In the end, I got to the current stage.

Lines and lines and lines in my confusion:


How It was finished



(I put my images directly from photobucket, since the Gallery keeps giving me a "disk storage quota exceeded" message) ???

Rafa

R.F.Bennett

"The Dude Abides"

Rafael


lastvautour

Very good Rafa. The booms are notched as per the drawing. I used the flat section of the wing's top as the spar for the wing. Mark and cut out the parts required and again, work slow and take little cuts. As you have already found out, if we mess up it is relatively easy to remake a piece.


Continuous test fit will get you there.

And voila!

And things should look something like this.

Once the other boom is notched, test assembly can proceed. The reason I notched the wing in such a fashion is that it is easier to smooth the transition from boom to wing.





Again it is time to take a break and visit with the wife or take a walk.


More to come

lastvautour

We will now blend the rear fuselage pod to the wings. Mark the shape of the rear canopy area.

Make a vertical cut to remove the excess wood.


Next do the same for the booms. I neglected to take a p[icture with the wing in place while doing this.


More to come

lastvautour

#28
We will now start to shape the booms. Run your pencil approx 1.5mm from the edge of the boom and make a line on both sides of the 4 corners.

Remove the materiel from in between the lines.

We now have a rough squarish shape to the boom that when place with the wing starts to take form.

If you look close, you will see I removed too much wood next to the wing. A bit of putty will fix that latter.


I was a bit careless and damaged the front of the tail fin. This will be repaired so that is not visible after finsihing the model. Also the notch behind the fin will also be fixed later.

More to come.

Rafael

This is the most fun, instructive and fulfilling modeling experience I've had in my entire life. I was always on the lookout for ways to translate 3-views and diagrams into model form. I believe solid-models are the way. A little study and lots of practice will ensure it. Thanks, Lou. Thanks, Solid-model builders and members of this forum.

Well, today my city, Caracas suffered a massive, general electric power outage.....twice. Just when I entered the site and found today's lesson, by 10:30 am. Power came back at 4 pm and my ISP resumed Internet service by 6 pm. What a boring day, except for a good reading session.

Back to modeling, I followed all the steps, and arrived to the current stage, more and more alike to a live Charger. Again, my inexperienced hand made the cuts, and some gaps were the result, but so far, everything matches.....Here's the piccies...


http://smm.solidmodelmemories.net/Gallery/displayimage.php?album=180&pos=17

Saludos,
Rafa