Grumman Albatross - RC Groups
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Mar 31, 2017, 10:04 AM
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Build Log

Grumman Albatross


This Albatross was stuck in my head from the moment I found it on the net.
I love the shape of this flying boat but to see it with this paint scheme, wow.
This design will be turned in to the AMA as a construction article and is now available on the Parkflyerplastics website as a short kit. LINK.
Be sure to read the description, there is not that much in the kit, most of the plane will come from your Home Depot.

This build log will seem like crib notes at times. You can only type this stuff so many times.
My book "Building with foam" goes into the process in great detail and is available Here LINK
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Mar 31, 2017, 10:07 AM
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Reserved for the video when I get it done.

Here is what comes in the short kit.

Plans with lots of patterns and illustrations.
Laser cut Plywood for where it counts
Plastic parts: canopy, cowls, dummy wheels and the crew.
Last edited by sparks; Mar 31, 2017 at 11:34 AM.
Mar 31, 2017, 10:10 AM
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Patterns


To start the Albatross build I bond the fuselage patterns to card stock and fold them in half and cut them out for a complete pattern.
A nip with scissors will help make the waterline the same.
The patterns are transferred to 2 inch extruded form sheets and cut out with a scroll saw.
A square block is used to transfer the center and water lines to the sides of the segments.
Mar 31, 2017, 10:14 AM
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tack Bonding


One drop of epoxy will make a bond the size of a dime.
Four drops will do the job just fine and hold the blocks for the next few steps.
Bond just a few segments to give you plenty of time to align them.
Once you have several stacks you can join them into sections.
When the stacks get too tall to use weights for clamp pressure use tape strips.
Mar 31, 2017, 10:16 AM
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Sanding


Here comes the fun, sanding.
It may look like allot of work but if you start with 90 grit it starts looking like a Albatross really fast.
Sand in a petting motion toward the tapered ends.
I used a highlighter pen to mark the steps in the segments to make it easier to see when the segments edges are flush.
When it looked like it is getting close I reduced the grit to 120 grit so the surface will be smooth when completed.
Mar 31, 2017, 10:26 AM
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Hollow the hull.


There are several ways to make a hollow fuselage, since this was made from scratch and the shape was not completely defined yet my first fuselage was solid. The second fuselage was built hollow using the patterns that I have on the plans.

1 The fuselage can be taken apart by pulling a fine string thru the seams to form sections. Tape is applied to the sides of the fuselage and a hot wire is used to cut the center from the sections.

2 The fuselage can be taken apart by pulling a fine string thru all the seams and the centers are cut using a scroll saw.

3 The segments could have the centers cut out before assembly since we have good patterns now. however the center has to be cut from the smaller of the tapered ends.
Mar 31, 2017, 10:29 AM
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Once the centers of the blocks have been removed we go back to stacking and bonding, use the alignment marks to align the segments and expect that there will be a very slight miss match between parts that was perfect.
When we removed the center of the foam internal stresses was released, no big deal.
Bond only the inner half of the segments edge and only apply enough epoxy to make the surface glossy.
if the epoxy squeezes out to the outer edge it will complicate any further sanding.
Mar 31, 2017, 10:34 AM
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First Glass


Sand the fuselage smooth with 180 grit and apply 3/4 oz glass cloth to protect the foam from handling damage . It will be a while until the fuselage will be needed, this time can be used to apply additional ply's to the belly since that portion is done. I put 4 layers of 3/4 oz and 1 layer of 1/2 oz cloth on this models belly.
Mar 31, 2017, 11:25 AM
Slip the surly bonds...
Sopwith Mike's Avatar
Fascinating, Sparky. I'm following.
Mar 31, 2017, 11:55 AM
71% of the world is runway . .
Bart83's Avatar
Very nice project. Following with great interest.

Kind regards,

Bart
Mar 31, 2017, 03:57 PM
DHG
DHG
Kinetic Sculptor
Subscribed!
Apr 02, 2017, 12:43 PM
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Wing


The wing panel cores are cut from beaded foam. The taper and thickness of the panels is not totally Albatross scale to make the model fly better. The patterns to cut your wings are included in the short kit but will need metal tape applied to their edges so they can be used with a hot wire. Bar sanding blocks are used to smooth any hot wire lines.
Apr 02, 2017, 12:44 PM
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The wing panels are bonded together with the top surface flat on the building surface. masking tape is used for clamp pressure. use the plans to lay out the path the wiring will take to the nacelles and aileron servo bays. It's all on the plans
Apr 02, 2017, 12:50 PM
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Grooves.


The building with foam book covers all the methods available to you to cut grooves in foam , hot wire, soldering iron , cutting blades.
The material is very soft so its easy. Here I used a dremel bit and a shelving rack to cut the servo wire/spar groove.
The motor wiring groove required three passes to make it wide enough.
I used a brass tube to cut a hole thru the wing at the ends of the groove since the wire will have to exit the wing on the top side.

The wiring is pushed into the groove and a space is cut in the servo area to store the wire till needed.
light plywood is pushed into the groove and marked for trimming, do both sides.
Apr 02, 2017, 12:56 PM
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Spar installation

The spar is not part of the laser cut parts because they are straight cuts and I have no control of how deep the groove depth is.

Push the plywood into the groove and mark for trimming .
trim both spars ind bond in the wing along with the spar joiner.
the weights are there to keep the wing flat on the table while the glue sets up

Note pull the servo wire out at the ends while bonding the spar.


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