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1/32 scale HK4 Spruce Goose

PostPosted: Fri Dec 17, 2010 9:21 pm
by HO229
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The engine nacelles, nothing fancy... Tulip poplar spun down to the correct diameter.
Will develope when I am finished smoothing the wings to the final shape
Love turning poplar, it is a great wood to turn.

My Goose plug crafted with traditional woodworking tools and lofted with traditional naval architecture lofting practices

2010-12-21
Well it’s crazy busy in preparation of the Christmas holiday, I managed to glue up some slow growth SPF for the wing stubs, it’s been very cold and my wood glues viscosity is not flowing well but I triumphed over the Elmer’s glue (I prefer slow growth soft woods; in my humble opinion they behave well with hand tools, unlike fast growth…).

I have been reading many boat building books to broaden my traditional lofting and building skills; contained within a few of the books is a process called “Taking Off Lines” A simple but fascinating process of obtaining geometry from an object that has no plan or Table Of Offsets. I have often pondered how to obtain geometry from museum aircraft without complex & cumbersome equipment, thankfully the boat builders have figured all this out. One other outstanding facet of these nautical books is the methods of construction and the amazing illustrations contained within them (priceless).
http://www.museumsmallcraft.org/Boats/Boats.pdf

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Sat Dec 18, 2010 4:23 am
by BillG
Good to see you here HO229
When I first read the thread title, I thought: You know there is a forum for small plastic models here too. :D
It amazes me to see how large your model is, as a scale that is normally that of a hand held plastic model.
Your plug has got me thinking of using my Saro as a mold for making several glass fuses, before completing the model. They are both rarely modeled, thus it would be good to have a few more of them. I could wrap it in plastic and make the glass parts as fuse halves, to be trimmed and joined at the fuse centerline. I would only have to temporarily fill the negative draft areas at the exhausts with something like foam wedges, so that I could pull the glass parts off of it. They would be positive molded, and thus would require a lot of finish work. They also would not have perfect exhausts, as I would not be able to pull them off of the mold, if I molded around the entire exhaust nacelle, but they would still look close and could be reworked afterward.

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Sat Dec 18, 2010 11:53 am
by HO229
Bill,
Consider integrating parting lines in the areas where you do not have the draft angle to pull the part from the mold, I believe you will be happier with the end product and it will yield better looking parts.
My plan:
Currently (subject to change) is to have parting lines surrounding the wing stubs.
I desire this in an effort to have the ability to integrate different wings into the mold.
Example:
Currently I have the scale wings built but I also have a set of S8036 foils cut at the same scale, because I have the removable wing roots (extra parting lines) I can swap out the wing stub area from the fuselage molds.
Yes… the Goose is a massive aircraft, when I first sketched it at 1-1 in CAD I had no idea how big this was. I tinkered with nominal scale numbers and 1/32 seemed to make the most sense and was in the size I desired. 8-)

Dave

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Sat Dec 18, 2010 7:52 pm
by TASSE
Hell! Thats big enough to fly, its a shame that its static. Well done.

Talking of moulds, the best material for a female mould is silicone rubber. you can pull it off any thing and there is no need for a release agent.

TASSE.

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Sun Dec 19, 2010 10:50 am
by Kuni
Hi Roy,

but thinking of making a 2m long silicone mould wouldn't make me sleep better. You never could say if the hull is straight.

I'm a fan of classic epoxy-resin-moulds, maybe 3-parts for better opening.
Regards,
Rene

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Sun Dec 19, 2010 11:23 am
by seawings
If the Spruce Goose wasn't enough, the kids are a pair of real 'cutipies' ! :D

That's one for the scrapbook..............!

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Sun Dec 19, 2010 12:44 pm
by Cameraman
Hi There,

is the first shot of the girls what is known as Wing In Ground effect?

Sorry for that one!

For sure that's a shot to keep when they turn up with the first serious partners eh!!!!

Regards

Reggie

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Sun Dec 19, 2010 1:55 pm
by HO229
Thanks guys,
My girls are beautiful and I love them allot. I like getting them into the mix as they give scale and character to the project. One element that I enjoy is seeing the kids grow up as I am building the project. Photos taken in the early stage of a project and photos taken at the later stages I have come to discover their looks have changed significantly.
Progress is slow right now with the holiday season, so many wonderful things going on.
I am almost to the point where the wings can have the control surfaces sawed out (still smoothed) (exciting).

Will be starting on the wing stubs soon, always a fun and challenging fitment, if it goes as smooth as the rudder tail pad I will be very happy.

I would like to talk about the silicon mold offline sometime, maybe a PM.
I spun out a huge part Radome (MDF) on the lathe a few years ago for a friend who was making an E2C
I applied an ultra thin coat of silicon to the MDF mold when I turned it but my friend for whatever reason chose to stick builds it. I am kind of curious how well the mold will release the part.

PS
I have been lofting the Saunders-Roe Princess & the Convair R3Y-1, both exciting projects at 180+ span scales. Will post some data when the Goose is in the home stretch; I enjoyed the Princess that the fellow did out of resin.
Merry Christmas,
Dave

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Mon Dec 20, 2010 2:05 am
by seawings
HO229 wrote:Thanks guys,
My girls are beautiful and I love them allot. I like getting them into the mix as they give scale and character to the project. One element that I enjoy is seeing the kids grow up as I am building the project. Photos taken in the early stage of a project and photos taken at the later stages I have come to discover their looks have changed significantly.
Progress is slow right now with the holiday season, so many wonderful things going on.
I am almost to the point where the wings can have the control surfaces sawed out (still smoothed) (exciting).

Will be starting on the wing stubs soon, always a fun and challenging fitment, if it goes as smooth as the rudder tail pad I will be very happy.

I would like to talk about the silicon mold offline sometime, maybe a PM.
I spun out a huge part Radome (MDF) on the lathe a few years ago for a friend who was making an E2C
I applied an ultra thin coat of silicon to the MDF mold when I turned it but my friend for whatever reason chose to stick builds it. I am kind of curious how well the mold will release the part.

PS
I have been lofting the Saunders-Roe Princess & the Convair R3Y-1, both exciting projects at 180+ span scales. Will post some data when the Goose is in the home stretch; I enjoyed the Princess that the fellow did out of resin.
Merry Christmas,
Dave


If it helps I owe a set of the original Saro Princess plans - the are huge! They are also accurate and extremely rare! ;)

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Mon Dec 20, 2010 3:44 am
by HO229
Bryan,
Thank you, I would love to look at what you have, I purchased a general arrangement drawing from Mr. Mike Roachwood a few months ago that is very helpful. The drawing has no drawing number on it but the last date in the rev block is 1956.

I downloaded copies of the hydrodynamics reports the Aeronautical Research Console (ARC) did and these documents are very robust and detailed, if you do not have these reports please refer to the attached link. The ARC did extensive testing on the Princess amongst several other aircraft, I found no less than 6 reports that made mention of the princess in the ARC database.

I would really like to find a complete table of offsets for this aircraft; currently I am using the offsets from the ARC report and scaling up to 1-1 & lofting in the unknowns to calculate the missing data.

If the drawing you have is available electronic and the file size is such that it can be e-mailed that would be very helpful.

I had a tough time finding a report that had coordinate data on the Goldstien airfoil but after an extensive search I did find a report that had some point data; I would be interested in any foil coordinate data if you have it so I can compare the foils against each other.
It would appear Goldstien made several flavors of airfoils and from what I have read he was a gifted Jedi Master of aerodynamics.

ARC report N0.2 (key word search database “princess”)

http://aerade.cranfield.ac.uk/ara/arc/rm/2834.pdf

PS
A flying boat book must read
"CONVAIR ADVANCED DESIGNS SECRET PROJECTS FROM SAN DIEGO 1923-1962"
Cheers,
Dave