Discussion in 'Science Fiction & Fantasy' started by Alien99, Feb 1, 2009.
Amazing Work...just a credit to the whole hobby
what about using a paper or wood dowel (cylinder) that runs from bow to stern?
Truly magnificent work! This model is a milestone in card modeling history!
I like your idea for building the structure from cubes. Should be simple and strong.
About the torsion problem - it's not clear to me what is causing it. So, below are three ideas for dealing with the problem, depending on the cause. I hope these ideas might be useful in helping you find a solution.
(1) Stacking Alignment
Are the cubes attached together so that they are "stacked" one directly on top of another? If so, then there are vertical seams through the entire structure. Is the torsion happening along one (or more) of these seams? If that is true, then "staggering" the cubes (so each cube "straddles" the two below it), will break up the vertical seams, and maybe eliminate the twisting
This is what I mean:
Below, "|------|" represents a cube.
If you are stacking your cubes like this:
Try this instead (like bricks in a wall):
(2) Paper Grain
Is the twisting being caused by the paper curling after becoming damp from glue? When paper curls or warps from dampness, it will usually curl across the grain of the paper. If the torsion is caused by all the cubes curling in the same direction, rotating half or all of them 90 degrees on the printed paper might eliminate or minimize the problem by changing the direction of the curl.
Maybe you could alternate the cubes so every other cube has the paper grain in a 90 degree different direction from its neighbors on each side, above, and below.
(3) Internal braces
Attach an internal brace across one or more sides of each cube to make the cubes more stiff. I design 1/87 scale architectural models. At this scale, some models are like big empty boxes, so twisting or warping can be a problem. I prevent it by using a simple standard brace attached to the inside of my walls. The braces are very rigid because the cross-section of the base of the brace has the form of a triangle. This prevents the brace from twisting. These braces work well for me. I like this solution because the brace is very stiff, easy to make, and it doesn't require some additional material (e.g. wood). I will attach a JPG below.
Further to the points above, it might pay to ensure that the individual cubes are fully cured prior assembling into the larger structure. That way, they will not be curing internally while also subject to the stress of the larger structure. While none of us wishes to see this development build delayed in anyway (need my daily fix!) a couple of days between assembly stages may make a difference.
I'm not too au fait with the effects on glues upon paper, but possibly an adhesive that does not soak into the paper might also help and then there would be less potential for deformation due to the paper's qualities changing when then glue is absorbed into it?
What about thick matte card with mortised edges to create the boxes.
Then apply the card skin over top.
thanks guys for all the ideas...
Art Decko: good idea with the braces..
I´ll try to think about it.
I m creating the cubes into the "brick wall layout" for sure.:thumb:
And you are right...I ve noticed that the screwing is created by the wet aspect of the water-based glue on the large areas....
SJPONeill: maybe I ll try another glue..
I've had success using spray adhesive on projects requiring glue spread across large surface areas. A quick spray on both surfaces, a pause allowing them to "tack" and the parts stick without the warping or screwing. I'm not sure what would be available overseas but you might try this option before altering your brilliant design. Best of luck!!
few days passed and I have some new parts to show.:thumb:
First is the new structure on the belly...:twisted:
following by the upper "head" section (the EEV´s are located here)....
..nice skyscraper again :mrgreen:
and the dry completation of this beast....just look at the dimensions.
and one different angle...the Sulaco is taking her shape finally...
and we are still somewhere around 23% of finished parts...wall1
that´s all for today sign1
ever think of making a tutorial on creating textures?
oh my god !! thats going to be a papercraft classic jawdrop
You know, when this is ready for download and building the Earth is gonna be short a rain forest.....
Well Done Jan
Maybe i have an explanation.
If you glue the parts togehter, the glue must cure.
This means it will shrink a little bit due to loss of mass (the dissolvent)
So if you have a glue surface with different sizes top and bottom there will be an different shrink. And because the glue is stronger than the paper it will bend the paper. Depending on the rigidness of the glued togehter parts there could ( or is ) an bending and torsion of the overall structure.
My solution would be an super stiff and strong internal sturktur where the outside is glued on. This will also help with the overal strongness of the model...
In this certain area i could offer an solution in terms of engineering.....
You could make the narrower middle part some 20mm higher and build some recess, which have to be greater as the increase of the middle-part, in the top and bottom parts. the middle part can slit in the recess of the top and bottom. so you need some high limiter as extra part or message.
if there is some bending of the parts this will not affect the bulding so long as is it is not a too big torsion.
by the way ......
You may be have covered 23% of the size of the model, but i think its well more in area of around 10-15% of parts.......
Just keep on trucking
Looking bloody marvelous man..
Perhaps keeping an eye on the humidity level in your workspace. I know that can warp wood. Sealing the ends as well can perhaps resolve puckering as well. I would almost want to put it in a empty aquarium when not being worked on to keep the parts from picking up moisture in the air. Or installing (ramping up) a dehumidifier to keep the card from picking up ambient moisture.
Send a note to Koolik over in the Big Boy thread. He had similar difficulties when building the tender. He painted it after construction so he added moisture directly to the model..
I think that Nosports has identified the possible cause of the distortion. This would be aggravated for large areas where rate of cure may be different between the edges (faster) and the centre (slower). I was reminded of this last night when a simple 3 layer laminate of 300gsm card from a couple of nights before, developed a notable twist lengthways (wish I could get it to do this when I am making props!). I had been a bit lazy and hadn't followed SOP in plonking a heavy flat object on top of the part while it was curing (for 3-4 days and it was only a couple of inches long).
Perhaps with large parts like Jan's Sulaco, it maybe necessary to secure them in a frame/support while they are curing. It would be easy enough for the flat/square section parts, not too sure about curved ones...
I mentioned the internal supports at first to prevent this and large panel deformation.
That torsion problem is the reason why I avoid water based glues for my paper models.
I use always the german "UHU", a solvent based glue. It comes in a tube (for smaller parts) as well as in a large stick form (used for large parts). No problem with torsion / bending since I use only this stuff.
Basically, if you make sure the outside parts are dry, and glue the internal boxes together with supaglu, it shouldn't warp at all...
Also, Jan, the graphic you showed us with the top section and what appears to be a panel with an "explosion star pattern" on the side, what is the smokey star pattern? what causes it? is it even relevant?
The ship is a military machine and spends its time in space. Battle scars, small objects banging against the hull...
exhaust port from stabilizer/maneuvering jet
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