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Re: 1/32 scale HK4 Spruce Goose

PostPosted: Tue Dec 21, 2010 9:11 am
by MrWidgeon
I concur re. the Convair book.
An amazing collection of what if designs amongst the few that had metal cut.
Good stuff.

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Sat Jan 01, 2011 7:42 pm
by HO229
My Port wing stub, still needs a little smoothing
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The starboard blank & the port stub
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The stub shape
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relief cuts
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off to the bench
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chiseling off the chunks of waste
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drawing off large amounts of waste with the knife
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cross grain waste removal (Fast)
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the spoke makes a nice finish, no. no! we don't use sand paper it rounds things off
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Ready to be developed, about an hour of work


Tip: The champagne cork makes a nice addition to the finger planes, I do not like blisters on my hand so a small slit cut into the cork makes a nice ergonomically correct, soft push handle.

I will use this stub to develop the starboard side stub

The incidence has been sketched on the fuselage and verified, just a matter of tweaking the stub a bit.
The stub is also little proud and will be developed at final fit

The dihedral angle can be easily planed to the correct angle with a hand plane

The next step is to drill the stub & fuselage for two alignment dowel pins but first the starb. stub
Happy New Year
Dave

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Tue Jan 04, 2011 3:46 pm
by solidmodeler
A couple of questions-

What is the long workbench fixture (with turnbuckles) used for?

Why did you choose to apply the wing root to the outside of the fuselage rather than having it go through?

A fine show of carving and shaping, by the way.

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Tue Jan 04, 2011 8:13 pm
by HO229
Solidmodeler,
Thank you…

The Jig supports the Fishbone (¾ X ¾ backbone also supporting the fuselage sections).
The posts slide up and down the slot and can be secured by tightening the wing nuts.
The backbone is carefully marked for section placement and sections are hot glued in place on the backbone.
If you look at the front view of the fuselage you can still see the ¾ X ¾ square hole that I will fill with wood when the fuselage is near completion.
The turnbuckles are used to true the Fuselage Reference Line (FRL).
Not show but used are several turnbuckles used to true random sections to the Horizontal Reference Line/plane (HRL). True in the horizontal axis/plane is obtained with the use of several Winding Sticks (longer sticks offer greater fidelity) http://en.wikipedia.org/wiki/Winding_sticks
(can't say enough about the use of winding sticks, simple but extreamly accurate)

When I start the Princess Build I’ll post some pics of the fishbone being planked on the jig.
The fuselage becomes inflexible/rigid when 90-120 degrees of strip planking has been applied to the model. The model can be removed and planked on foam pads after the 90-120 degrees of planking has been accomplished but I typically plank to 180 degrees.

The choice of applying the stubs to the outside of the fuselage is personal preference.
1) I like that I can fair the whole fuselage in one step
2) The development of the stub is a simple process that does not require much effort. (chisel of the big chunks of waste, cross grain spoke, scorp out the ugliness, hand plane/spoke to final shape)
a. The chisel removes the loin’s share of the waste quickly; fitment periodically one can quickly obtain data points for additional waste removal.

Kind Regards,
Dave :D

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Wed Jan 05, 2011 12:20 am
by BillG
Looks great. I see you've been going through similar wing stub fitting tasks to the the ones that I've been involved with recently. You know K would say you have too much positive wing incidence :D but I think it looks fine.
I've been watching videos on mold making lately, and am really tossing around the idea of using the countless clay sticks from Guillows planes that I have around here for molding dams. It doesn't seem as if it would be terribly difficult to mold half fuses around mine, and join them for a plug to work with. If the glass is not laid too heavily, I could easily pull the glass fuse halves rearward as I work them off, to get them off of the exhaust bulges.

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Wed Jan 05, 2011 1:28 pm
by HO229
Thanks Bill,
Everything so far in this build is per the H4 spec sheet, Incidence airfoil ex., I belief it will fly fine :?: , could the wing foil be optimized for low drag & better lift? Yes but it would not look as scale as the spec foil. I do believe I have the luxury of size offering me better Rn.
Allot of great videos and books on mold making out there, not a difficult process to master, I believe the plug is the most difficult step and you have that step well in hand. I believe your Squirt would not require much Clay, only enough to fill the small voids between the parting lines. I would suspect you would require additional parting lines in the area of the exhaust bulges but only 1-2.
I must be nuts for thinking this but the thought of making a squirt plug has crossed my mind in the last few days after looking at your build; my goodness…! What am I saying…? I do not need any distractions! :?

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Wed Jan 05, 2011 11:12 pm
by BillG
The stubs are a good idea. I built a Mig17 from the John Dutkowski (EAM) glass fuse kit. The stubs were well placed, thus they were used to set wing incidence during the build, without having to use tooling. A well known review builder setup tooling during his build, and determined that the stubs were dead on. It is enough of a struggle to set dihedral, without having to worry about incidence. I spent some time adding indexing pins to the LE and TE of the wings, making the final wing panel installation quite easy. You will be able to do something similar, as you have wing panel mating stubs.

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Thu Jan 06, 2011 4:53 pm
by HO229
Bill,
I considered the use of Datum Targets on this plug but did not install them; I have made the decision to use them on my next build. I will use my plug cutter set and install 6 contrasting plugs/targets, ¼ inch black walnut/black cherry plugs into the fuselage centered on the horizontal & vertical reference planes (fore and aft).
This plug has a small hole in the top (fore) that I sight the ref. longeron, I will fill the hole with a plug when all geometry is complete.
The use of the targets while not required does make reacquiring the vertical and horizontal datum’s much easier.
Dave

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Thu Jan 06, 2011 9:45 pm
by seawings
Hey you two....!

Can I just jump in here - sorry for the interuption - to mention that I for one am absolutely enthralled reading these posts, HO229 and BillG. You Guys are doing something that I personally always wanted to do, but never got round to, but I have to say that your authorship skills are such that I feel as if I'm looking over your shoulder.........

The skills that you two have, and others such as Roy (Tasse), are something that today's youth's sadly lack, but it is fascinating to those that have always wanted to do it, but have never quite got round to it.

So, please do continue to share your skills and knowledge with us all. The time it takes to build, and then after that take the pictures, put them on the pc and sit and write about it - I personally know how long that takes - I just wanted you to know that it is so much appreciated , by me and I'm sure the rest of the 'Gang'.

Thanks, Guys..! ;)

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Thu Jan 06, 2011 10:35 pm
by HO229
Thanks Bryan,
Bill is a Jedi Master!

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The starb stub Fits perfect but I still need to cut it deeper as it does not mate with the vertical center plane yet
(a dime shows scale to the finger planes)

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under the starb stub is my 1/8th scale C2A Greyhound T56 engine nacelle rough out
Something I tinker with when I get tired

Dave