1/3 scale scratch build super cub
#1
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1/3 scale scratch build super cub
So it's time to start a new scratch build. My scratch built 1/4 Scale L4 from my plans was a great success. I hope I can repeat the performance with the Super Cub Plans are drawn from the Full Scale. I will be also running a build thread on another forum and my website. This will not be a speed build, but feel free to ask questions and make recommendations. I have been a builder for about 25 years now. Buy the plans
Last edited by Cub Man; 10-19-2017 at 07:18 AM.
#3
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Gentlemen, have for sale a Balsa USA 1/3 scale gear and tires for $150.00 Used but in good condition. If interested email me at [email protected]
[email protected]
[email protected]
Last edited by ReneAlv; 03-20-2018 at 03:49 AM. Reason: Sold
#6
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Fuselage build
As with all builds, it is recommended to place wax paper over the plans. Build one side at a time.
Start by laying out the 3/8 x 3/8 spruce top and bottom longeron. Using 48-inch-long longeron, the section trimmed from the top can be used to extend the bottom stringer using a diagonal splice.
Detail showing the top and bottom 3/8 x 3/8 spruce longeron. Bottom is a diagonal splice shown by the blackline.
Grab a few sticks of 3/8 x 3/8 balsa and get ready for some fun. Recommend hard balsa for all braces. Take you time and start cutting the braces with good tight joints. Do not glue till you have all braces for one side ready. I recommend numbering your braces and when you are happy with the fit, mark and cut a second one for the other side. I cut 1/16 on the long side for second set so it can be trimmed to fit.
After completing one side remove it from the plans and build the second side repeating the steps above.
Let’s start working on the ply sides for the front. Right or door side shown in this step. Transfer the location for all the braces and longeron to the ply.
As with all builds, it is recommended to place wax paper over the plans. Build one side at a time.
Start by laying out the 3/8 x 3/8 spruce top and bottom longeron. Using 48-inch-long longeron, the section trimmed from the top can be used to extend the bottom stringer using a diagonal splice.
Detail showing the top and bottom 3/8 x 3/8 spruce longeron. Bottom is a diagonal splice shown by the blackline.
Grab a few sticks of 3/8 x 3/8 balsa and get ready for some fun. Recommend hard balsa for all braces. Take you time and start cutting the braces with good tight joints. Do not glue till you have all braces for one side ready. I recommend numbering your braces and when you are happy with the fit, mark and cut a second one for the other side. I cut 1/16 on the long side for second set so it can be trimmed to fit.
After completing one side remove it from the plans and build the second side repeating the steps above.
Let’s start working on the ply sides for the front. Right or door side shown in this step. Transfer the location for all the braces and longeron to the ply.
#7
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With 1/4 x 3/8 balsa cut the needed braces for the ply side. Hard balsa grade recommended and make tight joints. Leave the bottom open for the landing gear block along with the are for top and bottom longeron.
Braces installed and now ready to attach to the fuselage frame you made above. IT critical that you get it aligned perfect.
The finished assembly
Now repeat the left ply side remember it’s a mirror image of the right except the door opening.
Reminder the left ply side is a mirror image of the right except the door opening.
Lay both finished assemblies on top of each other and they should match perfect.
Braces installed and now ready to attach to the fuselage frame you made above. IT critical that you get it aligned perfect.
The finished assembly
Now repeat the left ply side remember it’s a mirror image of the right except the door opening.
Reminder the left ply side is a mirror image of the right except the door opening.
Lay both finished assemblies on top of each other and they should match perfect.
#11
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Worked on the front sides of the boot cowl area Cut from 1/8 ply and laminated with 1/4 balsa Marked the offset on the bottom and front for the 3/8 balsa bottom and 3/8 ply firewall. The right side is shorter due to the firewall offset.
As you see i put a little wight on the part as it dries.
repeat for the other side. Remember two sides left and right, balsa is applied to the inside only
As you see i put a little wight on the part as it dries.
repeat for the other side. Remember two sides left and right, balsa is applied to the inside only
#16
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Landing gear block is from 3/8 ply I use a glue stick to attached the pattern to it. Drill all the holes at this time. This next part I designed on my ¼ scales and it aids in assembling the wings at the filed. Using my dremle with a router bit and router base start routing out the shapes first for the strut fitting 1/8 inch deep
Next remove the area for the 1/16 ply plate.
Make the strut fitting from 1/16 aluminum stock Only drill the other two holes. Next cut the 1/16 ply sheets to fit and glue in place.
Next remove the area for the 1/16 ply plate.
Make the strut fitting from 1/16 aluminum stock Only drill the other two holes. Next cut the 1/16 ply sheets to fit and glue in place.
#17
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Time to bend some wire for the reinforcement.
Using 1/8 music wire. Bend it flat to match the layout on the plans. Make two sectionsNow make two spacers blocks one .615 and one .715 inches tall.Start bending the wire at the arrows until the .715 block is under the front and the .615 is under the back. The bottom sections from the arrows down should be flat on the table. Repeat for the other side
Using 1/8 music wire. Bend it flat to match the layout on the plans. Make two sectionsNow make two spacers blocks one .615 and one .715 inches tall.Start bending the wire at the arrows until the .715 block is under the front and the .615 is under the back. The bottom sections from the arrows down should be flat on the table. Repeat for the other side
#18
Watching this one come together should be a great experience... Subscribed!
I have your L-4 plans. I am hoping this thread can serve as a rough "Build Guide". I have never scratch built from plans before so I am a little intimidated to start. For now the plans are safely stored away until I feel up to the task. Most likely, I will build that plane after a Spacewalker build.
SunDevilPilot
I have your L-4 plans. I am hoping this thread can serve as a rough "Build Guide". I have never scratch built from plans before so I am a little intimidated to start. For now the plans are safely stored away until I feel up to the task. Most likely, I will build that plane after a Spacewalker build.
SunDevilPilot
Last edited by SunDevilPilot; 11-04-2017 at 04:57 AM.
#19
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Watching this one come together should be a great experience... Subscribed!
I have your L-4 plans. I am hoping this thread can serve as a rough "Build Guide". I have never scratch built from plans before so I am a little intimidated to start. For now the plans are safely stored away until I feel up to the task. Most likely, I will build that plane after a Spacewalker build.
SunDevilPilot
I have your L-4 plans. I am hoping this thread can serve as a rough "Build Guide". I have never scratch built from plans before so I am a little intimidated to start. For now the plans are safely stored away until I feel up to the task. Most likely, I will build that plane after a Spacewalker build.
SunDevilPilot
With any of my plans, I'm just an email or call away willing to help you build from them.
#20
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So when one is the designer, what looks good on paper is not always good in life. SO we made the insertable tabs for the struts. After setting the landing gear mounts in place they were blocking the holes for the tab bolts, so back to the drawing board. Did a little redesign and updated the plans.
For the holes you want to drill thru the ply plate, tab and the landing gear block for the bolts. For the ply plate enlarge the holes so the bolt heads can go thru the ply plate only.
For the holes you want to drill thru the ply plate, tab and the landing gear block for the bolts. For the ply plate enlarge the holes so the bolt heads can go thru the ply plate only.
#21
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Now take two strips of ¼ x 3/8 spruce 36 inches long. Cut a 1/8 square groove down the strip. Now take the right-side wire and start cutting the groves spruce you made above. For the bottom back side, you will need to angle the spruce to match the bend in the wire. Next cut the covers from 1/8 x 3/8 spruce.Mix some 30-min epoxy and place in the groove, insert wire and press out excess. Follow this by gluing the top cap on and clamp.
Now repeat for the left side.
Now repeat for the left side.
#22
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Cut the slot in the back of the cabin area for the Cabin supports.For the front trace, the outline and remove the balsa. I like using a Dremel as a router. Using scrap 1/4 x 3/8 u channel spruce you made above, cut some block for attaching the wire to the cabin sides. Mix some 30-min epoxy and attach.Now with the side flat you should be able to insert the spacer blocks (you made when bending the wire above) just under the top as in the photo below.
#23
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With the upper cabin sections now attached, let’s put the sides together.
The landing gear block should have a 2 deg angle cut on both sides. The top will be a little wider than the bottom due to this angle.
Use a small triangle with a block taped to it to check that both sides are at the same angle. When happy with it apply 30-min epoxy and clamp. Check again for proper angles.
I like to use a laser level in my builds. I placed a center line on the back of the firewall. Test fit the parts to get proper alignment before using 30-min epoxy. The firewall has a 12 deg angle from back to front on the sides with the back being the widest. The two front side walls have a 4.5 deg angle this allows them to turn inward.
The landing gear block should have a 2 deg angle cut on both sides. The top will be a little wider than the bottom due to this angle.
Use a small triangle with a block taped to it to check that both sides are at the same angle. When happy with it apply 30-min epoxy and clamp. Check again for proper angles.
I like to use a laser level in my builds. I placed a center line on the back of the firewall. Test fit the parts to get proper alignment before using 30-min epoxy. The firewall has a 12 deg angle from back to front on the sides with the back being the widest. The two front side walls have a 4.5 deg angle this allows them to turn inward.
#24
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We are working with the bottom for now. First cut the 3/8 x 3/8 balsa cross member to size, label them in order and mar the center line on them. Next place the plane over the plans and get the front area around the landing gear are centered on the plans. I use some old 12 V battery for weight and help to hold it in place. Using my laser again to send a line down the center. Start from the front and work your way to the back, clamp the sides as needed. Keep checking alignment after each cross member is put in place. Finish with some light trim work to get the longeron to meet at the end.
Cut gussets from 1/16 ply and apply to the inside of all intersections on the sides along with on the bottom of all intersecting cross members. Add all except where TD2 is located. Apply this gusset after TD2 is in place.For the back top, apply a gusset to the inside and outside of the joints.
Cut gussets from 1/16 ply and apply to the inside of all intersections on the sides along with on the bottom of all intersecting cross members. Add all except where TD2 is located. Apply this gusset after TD2 is in place.For the back top, apply a gusset to the inside and outside of the joints.
#25
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For TD3 thru TD7 glue the half’s together.
On bottom of TD1 thru TD7 apply a strip of 1/4 x 3/8 balsa.All the TD parts stacked and ready.Now with everything still lined up lest start working on the top side. With the laser going again check that all place is still centered over the plans. I started with TD2 and dropped it in spot. Check alignment with the laser. I made a small gauge showing the angle of the TD parts 2 thru 6. Keep working your way to the back. Install the TD # then glue and clamp. With some small trimming, the top two longerons should meet per the plans.
On bottom of TD1 thru TD7 apply a strip of 1/4 x 3/8 balsa.All the TD parts stacked and ready.Now with everything still lined up lest start working on the top side. With the laser going again check that all place is still centered over the plans. I started with TD2 and dropped it in spot. Check alignment with the laser. I made a small gauge showing the angle of the TD parts 2 thru 6. Keep working your way to the back. Install the TD # then glue and clamp. With some small trimming, the top two longerons should meet per the plans.