Category Archives: Building Projects

This is a general category used for various building projects.

TF Cessna 182 – Stab Work Continues

I finally got a chance to get back into my workshop for a few hours this weekend and made a bit more progress on the stab. The stab sheeting is done, trimmed, and rough sanded.

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I also sorted out the elevator parts and begun shaping the elevator LEs and made up the skins for the elevators. I tried to select the hardest pieces of balsa from my kit for the elevator skins, saving the softer pieces for the fuselage (which will require some tight bends). Unfortunately, the harder pieces were a bit warped, so I may have some trouble with these skins. I will see how they look after cutting to shape, but I may need to dig into my stash of 1/16 balsa and scrap the warped kit supplied pieces.

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As an experiment, I tried using Titebond as an alternative to Ambroid for joining the sheeting. While it worked well enough, I found it a bit messy to clean up the excess that squeezes out of the joint. This time, I tried using Super ‘Phatic from Deluxe materials. As Super ‘Phatic is much thinner than Titebond, it is easier to get a thin bead along the joint, and the excess cleans up quickly with one quick wipe with a paper towel. The resulting joint was invisible and strong, so I now have a new favorite adhesive for edge joining. I do miss that Ambroid smell though! :)

Total build hours to date: 24 hours

TF Cessna 182–Stab Construction Continued

Since I will be using Robart hinge points instead of CA hinges, the next step in the stab construction was to locate and drill the holes for the hinge points in both the stab TE and the elevator LE. I started by marking a centerline down the stab LE and the holes based on the location of balsa blocks installed when assembling the stab.

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Looks good, but there were two problems; 1) I did not notice that the ribs in the elevator are offset from the ribs in the stab, so the center hole ended up right on a rib. 2) I used an older twist drill and despite best efforts, I did end up with a small bit of drill wander and some of the holes were not aligned with the center-line. So, plugged up the holes with some scrap balsa glued in with Titebond, and started again, this time with using a sharp spade-point bit.

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After getting a good set of (near) perfectly aligned holes in the elevator LE, I clamped them LE to the stab and transferred the holes to the stab TE.

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Although holes are lined up perfectly in the TE, when drilling through the balsa blocks, I got a bit of drill wander again (ugh), with on hole exiting above center and another exiting below. It should be good enough though as the LE moves freely when mocked up with the hinges.

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Next up is the cross grain reinforcement between the center ribs, and finally the sheeting.

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After removing the pins, I added an extra fillet of Titebond around all the ribs, the LE, and the TE.

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I will be traveling a bit for work, so it will be a while before I will be able to get to the bottom sheeting. At least it will give the glue plenty of time to dry!

Total build hours to date: 19.5

TF Cessna 182–Construction Begins

After sorting out the problems with my building board, I am ready to begin building! As is typical, construction begins with the tail feathers. The dies must have been new and sharp when this kit was punched out, all the parts have very clean crisp edges with no sign of “crushing”.

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The die cut lines are so crisp, that it is hard to tell the rib bottom from the building tab, so I flipped over each rib and used it to mark out the rib profile on its mate.

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Then I used my angle sander to bevel the edge of each rib to fit tightly against the leading edge.

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The rear trailing edge is made up of three pieces. The instructions call for them to be positioned on the plans for marking, then removed and glued together. I was afraid that it would be too hard to keep the assembly aligned and straight doing that, so I started by gluing the center section of the TE to ribs S3 to establish a horizontal datum.

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Next, I glued the outer sections with Titebond while aligning to the outer ribs and using my laser to ensure all was straight and true before the glue set. I’ll confess that it took me two tries to get it right.

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After that, it was straightforward construction. I did deviate from the plans slightly to add balsa blocks for hinge points.

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Here is the stab ready for sheeting.

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And finally, I have prepared the sheeting using a few drops of my last precious tube of Ambroid.

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Note: I am keeping a log of my build time and will be recoding it with each post.

Total build hours to date: 13.5 (no one ever accused me of being a fast builder)

New Build Project–Top Flite Cessna 182

The building bug bit me again, and I decided to start on a new project. I know that I should finish one project before starting another, but I get bored easy and like to mix things up.

The woodworking phase is my favorite part of building, so I wanted a large(ish) project that involved a lot of wood. After looking at my stockpile of kits, I opted for the Top Flite Cessna 182, which I picked up for a very attractive price several years ago.

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While I will be no-where near Top Gun level, I will try to keep this as close to scale as possible. My plan is to ‘glass and paint this plane (as opposed covering with film). As of right now, I am leaning towards finishing this off in a Civil Air Patrol scheme, similar to the photo below.

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Of course, I will convert it to electric power. Other plans include the installation of the Top Flite interior kit, lights, and replacing the static front strut with the Robart articulated one.

After unpacking the box, I discovered that the front windscreen, although still in its factory wrapping, was damaged. Its a bit hard to see in the photos, but there was a crease on both sides of the windscreen. Perhaps with a bit of coaxing, it could be salvaged, but I didn’t want to start a new project with a major component like this in question.

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These units are out of production, but I placed a “wanted” ad on couple of RC boards and was able to find someone with a “new old stock” canopy set from Top Flite that he was willing to sell. The seller only charged the me original price of the set plus his shipping cost, but that still added up to $53 (which is just bit less than 1/4 of what I paid for the original kit INCLUDING the interior set)!

Next up will be start of construction.

Building Board Blues

I was about to get started on a new building project (more on that later) and pulled out my balsa building board. It’s been a while since I last used it, and much to my dismay, I discovered that it had taken on a bit of warp. The mid section of the board had taken on a crown of about 1/32” – 1/16” relative to the ends.

My first attempt to flatten the board was to clamp and weight it down to my bench. This worked and between the clamps, weights, and few paper shims, I was able to get the board to within about 0.010” of flat. Not pretty, but this could work. Then I discovered that the clamp was blocking my bench drawer from opening … oops!

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I really wanted a more permanent and less awkward solution anyway. After a bit of searching, I found this post on RC Universe. Eureka, I can do that too!

A trip to my local big box store yielded some 1” square aluminum, corner brackets, and assorted screws. A few hours later, I had the the following:

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I am back to being within about 0.010” of flat (measured with a straight edge and feeler gauge). Good enough!

I still want to build a true torsion box table one of these days and have a truly dead flat surface, but this should give me a very flat and stable surface.

On to my next building project!

Hog Bipe–Cowl Design

I haven’t posted any progress on the Hog Bipe in quite some time, but I have been picking away at it and I am almost ready to start final assembly. I’ll try to catch up and post some of the key build steps.

The biggest deviation from the stock kit was the creation of a custom cowl. A while back, I posted a Sketchup model of the Cobra 4130 motor to be used in this plane. I then went ahead and built a Sktechup model of the nose of the Bipe including my new cowl.

I started by scanning front section of the plans to use as a guide to the fuselage shape. I then modeled the fuselage for the first few inches back from the firewall and placed the model of the motor in place with the prop plane at the stock location.

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Next step was to try different section shapes and use the Curviloft Sketchup extension to generate the final form of the cowl. This was a bit of a trial and error process until I came up with a pleasing shape that blended to the fuselage and cleared the motor.

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Once again, I ran into the basic limitations of Sketchup where tiny computational rounding errors would add up and cause small gaps and imperfections in the generated surfaces. I had to blow up the cowl to 10x size to work with the design, then shrink it back down once I was done. While this helped quite a bit, I still had to do a lot of fussing and tweaking to stich surfaces together and close up gaps.

Here is the final shape.

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Next step was to design the structure of the cowl itself. I decided to use standard formers and sheeting for the back half of the cowl, but with all of the compound curves, I decided to carve the front half from balsa rings stacked together like a wedding cake.

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To generate the “layers” I created sections in Sketchup and then projected them forward. In order to minimize end grain in the final cowl, instead of cutting each layer out of a single sheet, the base form of the layer would be made by gluing  together square strips arranged with as much of the grain running lengthwise around the perimeter as possible. A horizontal and vertical line is used to align the layers.

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I then exported the final design to DXF and used a free DXF CAD editor to create a “blueprint” for each layer.

On to actual assembly. Each layer was built up from balsa stock. The outer edge was cut to the final shape using a scroll saw using the printed out layers.

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Here are the layers ready for assembly. Note that I did not yet cut out the center of the last layer, which is cut from a a single sheet  of 1/8” thick balsa, as I was afraid it would be a bit too flimsy. It will be cut out as the last step in shaping the cowl.

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The rear section was then built and sheeted using stringers and formers.

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Then each layer of the “wedding cake” is assembled using the horizontal and vertical tick marks for alignment.

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Then with a bit of carving and sanding, the final shape emerges.

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Using a Dremel with a sanding drum, I smoothed out the interior. I was afraid to get too aggressive with this step and sand through the wall. Note, I forgot to snap a picture of the cowl inside until right before I was ready to assemble it to the back section of the cowl.

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Here is the cowl assembled to the fuselage, ready for final sanding. I use three 1/4” dia rare earth magnets to hold the cowl to the fuselage along with a pair of 1/8” dowels as locating pins.

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Hog Bipe – Custom Battery Tray

Next up is to put together a custom battery tray. When performing a glow to electric conversion, often you can use the fuel tank floor for the battery tray. In this case, the floor needed to be lowered about an inch to have enough room for a 6S lipo pack. The stock floor is aligned by sitting in a notch formed by the fuselage doubler. Since I intended to lower the floor, I started by adding some balsa tri-stock to create an upper alignment point. I wanted an upper alignment so that I could easily add some cross-braces (see below) to reinforce the tray from beneath.

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I cut a new tray from 1/8″ lite plywood. Unlike the stock tank floor, I cut this to fit the full length between F1 and F3. This will give me plenty of room to adjust the pack fore and aft when balancing. I also wanted to add slots for a Velcro battery strap on either side of the middle of the tray. To cut these slots, I clamped a piece of straight scrap-wood to my drill press table, then drilled a series of holes along the length of the slot.  This arrangement allows you to quickly drill a series of holes along a line. The slots are then cleaned up with a popsicle stick with some sandpaper attached.

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The tray is then glued in against the tri-stock. Given that a 6S battery can weigh in at over 1-1/2 lbs, I wanted to reinforce the battery tray. I added some 1/4″ x 1/8″ basswood cross braces beneath the tray. This creates a light but rigid platform for the battery. I may add some balsa tri-stock to the corner formed by the fuselage side and the tray floor before is close up the bottom of the fuselage.

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Hog Bipe – Fuselage Top Sheeting and Battery Hatch

I finally got a few days to spend working on the Hog Bipe. I am deviating from the original kit a bit more now. I plan to add a custom scratch-made cowl (more on that coming in a future post), so I cut the fuselage cheeks off at this point.

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Another significant modification is to add a custom battery access hatch. I started by cutting the hatch floor from some 1/8 lite ply along with a new F1A and two sets of F2 formers. I used lite ply for the formers in stead of balsa since I felt balsa would end up getting damaged with routine handling of the hatch. One of the F2 formers was glued to the fuselage top at a slight rearward angle, allowing for easy installation and removal of the hatch with no interference. The new F1A was installed square at the front of the new hatch floor. I then positioned the hatch on the fuselage and glued the other F2 to the hatch floor at an angle to match the F2 previously installed to the fuselage top. Stringers were then added.

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To secure the hatch, I added a short 1/8″ hardwood dowel to the front and a pair of 1/4″ dia x 1/16″ thick rare earth magnets in the back. A strip of 1/8″ ply was added in front of F2 on the fuselage top for the mating magnets. The magnets were epoxied into 1/4″ dia by 1/16″ deep counter bores made with a forstner bit.

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Sheeting proceeded more or less per the kit instructions (sheeting the hatch and the fuselage front separately). I sprayed down the sheeting with a bit of ammonia based window cleaner to soften the wood, then  formed it around the fuselage using tape to hold it in place. After letting it dry overnight, I then trimmed it to final shape.

I added some scrap 3/16″ square stringer material to provide something to attach the sheeting bottom to.  Instead of CA, I installed each piece with Titebond, holding it in place with pins and tape. I let the glue dry for each piece before moving onto the next. A bit time consuming, but for me, this approach yields the best results.

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Sharp eyes will also note I also added a bit of sheeting to the F1 firewall bulkhead so that it would match the battery hatch. I am happy with how the sheeting came out. The hatch fits nice and snug, and all of the seems are nice and tight and will only require a small amount of filler.

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Next up is the battery tray, motor mounts, and then the custom cowl.

Hog Bipe – Fuselage Construction Continues

Spent a bit of time working on the fuselage this weekend. After installing the T-Nuts for the Sullivan tail wheel in the fuselage bottom, I spent some time fussing about with the formers and the fuselage top and bottom pieces. I followed the basic approach that SeamusG used in his very well done Hog Bipe Build Thread on RCU. I used some 1/4″ balsa blocks to pin the forward section of the fuselage to the building board, I then dry fit the formers and other parts together with clamps, tape, and rubber bands, fussing about until everything was square.

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To ensure that I had everything straight, I set up my laser level with a vertical beam, and lined it up with the fuselage, checking that it hit the top center of each former. I also dry fit the rudder to ensure that it would install square. When happy with this, I went ahead and started to apply medium CA working from the bottom up as described in the instructions. Hopefully, everything stayed straight and square while gluing.

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Just like SeamusG described in his build thread, I also ended up with a bit of a gap between the in the fuselage bottom plate and sides near the front of the plate. I decided, the fill the gap in with a bit of aliphatic resin (Tite Bond). As a bit of extra insurance, I used some balsa triangle stock to reinforce the joint between the bottom plate and fuselage sides and F5. I probably would not have done this if I had gotten a good wood-to-wood bond joint between the sides and the bottom near F5, but the area right behind the wings tends to be a weak spot in many planes, and for a gram or two of weight, this will add a lot strength.

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I also started planning out the battery hatch. Although SeamusG built a glow plane, his build included a mod to add hatch to access the fuel tank. Following his lead, I will add a hatch between F1 and F2. With this in mind, I realized that I should not have glued F1A to the back side of the firewall F1. This double really is not there for strength, but as a place to attach the stringers used to help shape the forward section sheeting. Instead I want to use this piece as the front section of the hatch.

With a little care and a long X-Acto blade, I sliced F1A off from the firewall. The back side is a bit damages and the part will be too week to use for the hatch, but it is in good enough shape to be used as a pattern to cut a new piece. A little sanding and the back of the firewall looks like F1A was never there!

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Next up will be the creation of the hatch floor and bulkheads in order to prepare for sheeting. I also will need to modify  and reinforce the fuel tank floor to serve as a battery tray.