RE: RC scratchbuilt Albatross in progress  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> RC Airplanes >> Seaplanes >> RE: RC scratchbuilt Albatross in progress
Page: <<   < prev  1 [2] 3   next >   >>  

Login
Message << Older Topic   Newer Topic >>
RE: RC scratchbuilt Albatross in progress - 7/30/2007 11:12:20 PM   
TooLow


 

Posts: 146
Joined: 12/7/2001
From: Hemet, CA, USA
Status: offline 		love the retracts---do you have a job with Disney in the Animatronics division? You ever get some plans inked put me on the list!
!

(in reply to www.stef.com)
       Post #: 26

RE: RC scratchbuilt Albatross in progress - 8/1/2007 3:12:47 PM   
Miniflyer


 

Posts: 856
Joined: 12/20/2004
From: Neuburg, GERMANY
Status: offline 		Hi stef,

amazing work, great details on the stabi.
Have you considered making a mold and going full composite? With all those rivets it would be a shame to get only one model from all the work :-)

Best regards
Hank

(in reply to TooLow)
       Post #: 27

RE: RC scratchbuilt Albatross in progress - 8/1/2007 9:08:11 PM   
www.stef.com


 

Posts: 32
Joined: 11/12/2004
From: , CA, USA
Status: offline 		Thanks guys for your comments No animatronics job, but perhaps a watchmaker in a past life! Growing up with lots of legos helped for sure!

I have thought about making molds of the final model but there is a bit of assymetry in my fuse (I'm building this thing fast, no slowing down!!) and there are definitely things I want to update in the plans. Mold making is also such a pain in the @#$* that the final costs to the consumer I fear would be outrageous. But if there is interest, I'm interested! I figure when the plane is done, and she is put through her paces, and doesn't spiral into the drink - I'll think about everything from plans, to plans + parts, all the way to fully molded. But for now, just have to finish the plane first!!! -stef

(in reply to Miniflyer)
       Post #: 28

RE: RC scratchbuilt Albatross in progress - 8/1/2007 9:57:04 PM   
Miniflyer


 

Posts: 856
Joined: 12/20/2004
From: Neuburg, GERMANY
Status: offline 		Hey stef,

making a mold is really no big hassle with the "new" materials available. I threw together the mold for a 65" long jet fuse on a weekend.....for under $130. My guess is you can come in at under $500 for a full set of molds and not spend more than a week on them.

Taking them off a finished model will be tough though, you might need to end up building a new plug model.....but please build straight then :-)

Best regards
Hank

(in reply to www.stef.com)
       Post #: 29

RE: RC scratchbuilt Albatross in progress - 8/3/2007 2:08:55 PM   
www.stef.com


 

Posts: 32
Joined: 11/12/2004
From: , CA, USA
Status: offline 		Hank - I like those numbers! My only molding experience has been with RTV, epoxy, and now latex. But a new plug would certainly be in order

Okay, more progress to report

Front Gear:

I primed, filled and sanded the forward portion of the bottom hull so I could create my front landing gear bay doors and hinges. I had to use quite a bit of filler to compensate for my sloppy planking job, but I'm happy with the weight of things thus far so I'm not too worried. Here is a video of the front gear and flaps in operation. They are not perfectly to scale in the way they are hinged, but from a distance I think they'll pass for a likeness. The flaps are held closed by a rubber band, and pushed open by the front gear, a low tech method but simple. I forgot to think about the buoyancy of the wheels when design my landing gear setup, and so I may have to do some bathtub tests to adjust things if I want to be able to taxi from a water landing onto land and vice versa.



Float mold:

After many layers of latex added to my new float mold, I cut it open and found things way too floppy to mold as is. I put the latex halves back over the mold and wrapped everything in fiberglass, added epoxy, and sarranwrapped everything ("poor man's vacuum bag" . I then dremeled it back open and had two halves, sufficiently rigid, but flexible enough to release the parts.



Molding the floats:

To cast and make the hollow positive forms, I started by brushing two light coats of epoxy and micro balloons. Then I added a couple layers of 2oz fiberglass, cut in little pieces and placed on the bias. The halves were quite flexible by themselves and I had to be careful not to tear or crease the parts when taking them out of the mold. I don't have a lot of molding experience, but this latex float mold has been the least hairpulling of them all.



Joining the floats:

I tacked the lightweight halves together with superglue, then poured a heated batch of 30 minute epoxy and microballoons through a top hole, and just rotated the mold around and around until all the seams were covered from the inside. I could see the flow of epoxy so I was able to make sure the epoxy flowed evenly. Blowing air through the top hole revealed a couple bubbles, which I then filled, lightly sucking air so the epoxy would fill the void. Each float at this point is about 75 grams.



Until next time -stef

(in reply to Miniflyer)
       Post #: 30

RE: RC scratchbuilt Albatross in progress - 8/3/2007 6:09:49 PM   
Miniflyer


 

Posts: 856
Joined: 12/20/2004
From: Neuburg, GERMANY
Status: offline 		Hy Stef,

I started making molds a few years back and have gotten quite some experience (both good and bad), so maybe a short intro into easy mold making (i mean durable molds for 100 parts +).

First i take a plastic sheeted piece of wood (like for bookshelves) and cut the contour of the object. The (waxed!!) object is placed into this cutout so that it protrudes exactly halfway. I tack it in place using that colored clay type of stuff the children usually play with. The seam all around is then filled with candle wax (light it and let it drip in, scratch off all the excess after it has cooled with a sharp knife).
Now drill a few holes and place steel rods in there.

Thats all the preperation.
Now you start laying up the mold. First apply a coat of mold surface resin (usually black or blueish) with a brush. Once this gets tacky, i cover everything with a thin layer of fibreglass cloth+epoxy. All the sharp corners and areas where bubbles could form are filled with epoxy goo (thickened with glass bubbles or similar)
Before it starts to cure i mix up a batch of laminating ceramic, sink the special fabric in there and just massage it onto the laid up epoxy. Walk away for 24 hours. Part 1 complete.

Now turn it around, take off the wooden plate (leave the steel rods in there!), clean it off and wax it again, and then repeat the procedure. When this side has cured, simply pull out the steel rods and pull the two haves apart.

With the rods you can always get the 2 pieces aligned just right, and you don't have to join them after taking them out of the molds. They will come out with just a very thin seam....
I buy all the stuff, especially the ceramic and the special "M1" fabric, at r&g : http://www.r-g.de/en/
I'm sure there's a supplier in the US as well. That stuff is cheap, as 1 layer will give you a mold approximately 6mm thick....enough for all molds up to 100"!

Hope this helps a bit....
best regards


PS: attached you will find 2 plugs for a rudder i just made (they were cnc milled)....after placing the part in the wood and drilling the holes it should look just like that.






Attachments
Click to see fullsize image.
Click for fullsize

(in reply to www.stef.com)
       Post #: 31

RE: RC scratchbuilt Albatross in progress - 8/4/2007 9:45:30 PM   
www.stef.com


 

Posts: 32
Joined: 11/12/2004
From: , CA, USA
Status: offline 		Thanks Hank for the moldmaking info, I will look into those materials and try your process on the next moldmaking project for certain. -stef

(in reply to Miniflyer)
       Post #: 32

RE: RC scratchbuilt Albatross in progress - 8/11/2007 1:02:17 AM   
www.stef.com


 

Posts: 32
Joined: 11/12/2004
From: , CA, USA
Status: offline 		Hello again! I'm cruising right along and should finish just in time for my self imposed deadline of August 23rd. (First flights to be Sept 15/16th)

Filling and Sanding:

Nothing too exiting about this step, just hours and hours of sanding then filling, then sanding some more. I know I'm using a what looks like a ton of filler, but what remains after sanding is very thin. It is also very easy to create knifelike edges on the hull which should aid in water release and help this beast get on step sooner.




Main Cabin Hatch:

I drew up the front windows then used chartpack tape to dial in the lines. I made a paper right side that I flipped to the left to transfer the lines, then went to work with the dremel.




Wing Fillets:

I love the rounded wing fillets on the Albatross and recreating seamless fillets with removable wings was a bit of a challenge. After several passes with more filler, and scoring it before it fully cured, I was able to get the wings to mate with the fuselage cleanly. Here is a video of the wing half sliding into place.






Fuselage Windows:

I cut out the rest of the openings in the fuselage. Aside from the side windows I also cut out the nose hole which will give me access to my video camera, and the lense window for my digital camera.



Float attachment:

I started to flush out how the floats attach. I decided against the magnet idea for the floats because I had visions of my floats dropping off the wings after a bounced landing!
I installed tongues that stick out of the wing an inch and a half that with the floats. There will be an inconspicuous screw on the side of each float to hold it on.



All together:

Well this is a view of most of the big pieces together. I have some more finish work of priming, filling, and sanding to do on the fuse and wings, but I should be able to start the riveting process in a couple of days.



Until next time -stef

(in reply to www.stef.com)
       Post #: 33

RE: RC scratchbuilt Albatross in progress - 8/11/2007 1:05:38 AM   
ByLoudDesign



Posts: 288
Joined: 9/19/2005
From: Mesa, AZ, USA
Status: offline 		Beautiful work !

_____________________________

Projects on the board: Stinson SR-9, Orion P-3, Dornier DO-24,Canadair DC-4M2. Pilatus PC-9 Future Projects: Curtiss F11-C2, Osprey C-22, Canadair CL-415, Connie CL-121, Stinson Model A Gruman TBM,
bylouddesign.com "Scale without compromise"

(in reply to www.stef.com)
       Post #: 34

RE: RC scratchbuilt Albatross in progress - 8/13/2007 10:59:13 PM   
www.stef.com


 

Posts: 32
Joined: 11/12/2004
From: , CA, USA
Status: offline 		Thanks Charles

The Albatross factory is running around the clock now!

First Primer coat:

Although the pics make the fuselage look perfectly smooth, the first primer coat revealed all kinds of little holes and deep scratches that needed to be filled. The second image shows all the imperfections filled with acrylic putty. I will wet sand everything and then move on to rivet and groove work.




Detail parts:

I went ahead and made all the little super tiny parts that will make this plane look very realistic. From exhaust stacks to antennas of all sorts, I think I've covered most of the little details. I will make a mooring line that splits and goes around the radome as well. The second pic shows the heat forming of a wing tip light cover with left over yogurt lids. It worked very well.




I will post more updates as parts come flying off the assembly line this week -stef

(in reply to ByLoudDesign)
       Post #: 35

RE: RC scratchbuilt Albatross in progress - 8/15/2007 11:09:56 PM   
www.stef.com


 

Posts: 32
Joined: 11/12/2004
From: , CA, USA
Status: offline 		The floats are finished! Now on to gear mechanism and gear doors. -stef


(in reply to www.stef.com)
       Post #: 36

RE: RC scratchbuilt Albatross in progress - 8/16/2007 6:55:17 AM   
shanksow



Posts: 477
Joined: 1/28/2002
From: Lubbock, TX, USA
Status: offline 		This is amazing work that you have done. I would liek to have a copy of those plans too whenever you get around to making them up. And whou would make the landing gear?

_____________________________

Don W. Shanks
http://aerospacedreams.blogspot.com/

(in reply to www.stef.com)
       Post #: 37

RE: RC scratchbuilt Albatross in progress - 8/17/2007 11:24:58 PM   
www.stef.com


 

Posts: 32
Joined: 11/12/2004
From: , CA, USA
Status: offline 		Thanks Don! Once I got the geometry correct for the gear, it wasn't all that difficult to make the gear out of carbon tubes. It was a bit tedious, but with some fine dremel bits and some patience they came out great.

More progress:

The gear doors and gear are now finished. To weather the parts I just brush on black acyrlic (I think) paint, then sponge off. Then I fix it with acrylic spray. I've attached all the little details to the wings and fuselage, and drawn out all the lines I need to rivet and groove. -stef




(in reply to