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MINI-BERGSTEAD Model – 1/24 scale

Home Forums Research Engineering MINI-BERGSTEAD Model – 1/24 scale

This topic contains 78 replies, has 13 voices, and was last updated by Avatar of shredder7753 shredder7753 2 years, 6 months ago.

Viewing 15 posts - 1 through 15 (of 79 total)
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  • #1601
    Avatar of shredder7753
    shredder7753
    Participant

    UPDATE – this was gonna be 1/12 scale but it turned out to be too large.

    UPDATE II (9/2) – i will try really really really really hard to sell my model. then i will try to keep on sellin. a lot of them, as i try new and different techniques. i just really need to recover the material costs and hopefully a little extra for the labor. when im confident with their ability to become serious-steads, then i will prob start making 1/12 size and that way i can put almost all the mechanical systems in for a complete, albeit small, demonstration. and then maybe i’ll submerge a cat for a few days with a litter box and food out on the atlantic.

    Hi all!

    i decided its time to build a 1/12 scale concrete model of the mini-bergstead design. i purchased an 80lb bag of basic mortar mix. so far all i have done is mixed a little bit and played with it to learn how to work with it. i plan to build the outer shell first. then construct the interior levels in as much detail as i can. i want to make this model submersible and have started looking for a decorative fountain water pump (or a pump for a water-cooled cpu). i want to make the pump activated by remote conrol, so i can submerge and surface the model without me having to get wet. i plan to drill out the holes for circular windows. the floors will be implemented in such a way that i can lift them out separately. this will make the demonstration more easily viewable.

    if the shell and floors are complete within a few weeks, i will ask the council president of my condo’s association to let me try out the floating structure in our community pool before they drain it for the winter. they usually close it in mid to late september. hopefully, if it works as planned, i might be able to actually moor it in the christina river (wilmington, de), submerge it there, and even leave it over winter to see what happens. the model will be 1.25m square to simulate a 15m real life dimension.

    heres a picture from the computer model. i’ll update u guys as progress is made:

    #14841
    Avatar of Mad-Dog-Tannen
    Mad-Dog-Tannen
    Participant

    cant wait to see pics.

    I was also going to say be careful you are sure you can get it outside the house before you make it, but it seems you have thought of that too.

    best of luck, hope the model works as well as we hope the real thing can.

    #14840
    Avatar of shredder7753
    shredder7753
    Participant

    hey all!

    right now im just about done fabricating the outer form work. i have the materials for the inner form work which will support the back side of the exterior walls. so tommorrow all i have to do is put that together and iron out the details before i actually pour the concrete (im using mortar mix). this is exciting for me.

    got a question tho – does anyone know how i can attach the mooring line to the corner? my idea is to get a large eye hook and set it into the cement while im pouring it. but the walls in this model will only be about a half inch thick, so im concerned about the strength of that mortar mix. let me know if u have a better idea.

    it turns out this thing is actually huge. i mean really big. wait till you see the form work next to my couch. im concerned about getting it out the patio door and over the railing – its that big. (1.25m x 1.25m x 0.5m high)

    also its gonna be tuff to make this thing submersible. a 12 volt battery and a dc powered water pump are not that expensive ($60), BUT if you want the flow to be reversible, omg! make that $250! $380 for a kit that has fittings and hoses. so i might be filling it with a bucket. or maybe i’ll just use 2 cheaper pumps. one for intake and the other to release. like any construction project theres always costs you dont foresee. and sometimes they’re a lot! we’ll see how much of a cheap bastard i can be.

    ALSO- i just did a weight calculation, which i hadn’t done b4 cuz i figured it was just a little model. turns out this thing is gonna be 400lbs! AND i was thinking – what if i put it in the river and someone gets scared thinking its a disguised bomb!

    guess im gonna have to find out.

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    #14842
    Avatar of shredder7753
    shredder7753
    Participant

    im prolly gonna shelve all the stuff i made today and start over at the 1/24 scale. 400lbs is outrageous. and there’s nowhere to store it. 75-100lbs is a lot more manageable.

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    #14843
    Avatar of OCEANOPOLIS
    OCEANOPOLIS
    Participant

    Hmm. It won’t float bro. The MMK scale model that I build is 60 cm LOA x 30 cm BEAM X 15 cm HIGH. It weights 12 lb and it was build exactlly like ferrocement method. Wire mesh and mortar plastering on top. It still came very heavy built for its size since I used a screen rather than a mesh and I overdid the mortar application to get a full capacity load “feel” to it. I think yours won’t be heavier than maybe 50 lb??…judging by the specs you mentioned. My oppinion.

    If it hepls you, this is how I build it: First, I made a mold of styrofoam (Home Depot sells sheets that I glue together-regular paper glue, the sprays will melt it!, than I cut it out to specs). Yours will be easy since square. Second, I covered with a mesh, Home Depot too. I used a really dense one and also used wire to tight it up in place. Third, I plastered Quikrete on top, the fast drying one. I used mortar not cement, it’s a finer powder, holds better and the finish is much smoother. Have to work fast in small batches since it will dry up on you quick. Give it 3-4 days to dry up well before you splash. Have fun!

    http://www.youtube.com/watch?v=m18La4buJNI

    http://youtu.be/8YwUKKe8ds0

    PS. Pretty stable, no roll, no pitch, ARHHH:)

    #14844
    Avatar of shredder7753
    shredder7753
    Participant

    Octavian – ur MMK model looks really well crafted. i dont plan to use any wire mesh. i just wanted to make the forms and pour it. this form work above is getting put away for possible use in the future. time to start again with a smaller design.

    the reason it is so heavy is that its not ferrocement. its just solid concrete. .017m wall thickness.

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    #14849
    Avatar of Ellen-Re-Generate
    Ellen-Re-Generate
    Participant

    Not for nothin’, but are you really planning on pouring concrete in your living room? Just askin’.

    If the floors and walls and what-not are all going to be flat and uniform, why not just use blue board, cut to shape, mortar the pieces together, and then face it with a skim coat of your eventual concrete mix?

    I have a thorium reactor under the hood of my car. I get ∞ miles per gallon.

    #14850
    Avatar of shredder7753
    shredder7753
    Participant

    yes Ellen, i live on my own so theres no need to keep the place nice and tidy all the time.

    blue board is foam right? i need something cementitious because the way the bergstead was designed, it should sit at least about 1/3 of the way down in the water – BEFORE adding ballast water. if it were made out of foam it wouldnt work. with ballast its expected to submerge like a submarine.

    i did a bunch of calculating to find out where it should sit in the water based on its displacement. of course thats all theory until this thing actually works.

    as u can see, the new form work is a lot smaller next to the 1/12 scale panels.still gonna be pretty heavy. it’ll be a couple weeks before i can test its submersion performance. i can float it a few days after its poured, but then i have to build exterior stairs and the landing

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    #14851
    Avatar of OCEANOPOLIS
    OCEANOPOLIS
    Participant

    That you can get it out of the house. That’s pretty big man. An “indoor” mini-burgstead won’t float too good. :)

    PS. Keep in mind that concrete without the ferro mesh (or steel reeinforced for VLFS) is not that strong, specially for marine aplications….I mean in the real life.

    #14853
    Avatar of shredder7753
    shredder7753
    Participant

    ocean, i just figured for this model that the wire mesh was not really necessary. but for a full scale berg its def crucial.

    so here is the inner/outer form work, layed up but not fastened:

    and here is the stuff i got to moor it down in the river. the hook attached to a piece of track will be sunk in a bucket of concrete. im gonna find a way to use that spring in the line, somewhere. and then the “O” ring will get fastened to a corner (either underneath, or directly on the edge. i bought a dog run kit. that had almost everything i needed for the mooring assembly.

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    #14863
    Avatar of Ellen-Re-Generate
    Ellen-Re-Generate
    Participant

    I can understand the confusion over rigid blue foam insulating panels, but “blue board” is a common slang term for the cementitious panels used to line bathrooms, kitchens, and other wet areas in contruction.

    https://secure.wikimedia.org/wikipedia/en/wiki/Cement_board

    Making the basic structure out of this would be faster and easier than pouring concrete in your living room. After that, you can face it, inside and out, with the concrete/mortar mix you are proposing to cast the whole thing out of. this would give it the density and water resistance you are looking for.

    I have a thorium reactor under the hood of my car. I get ∞ miles per gallon.

    #14869
    Avatar of shredder7753
    shredder7753
    Participant

    Hey i finished pouring the mortar for the outer shell of my berg

    (the links will work now)

    heres a video of the form work before pouring

    here’s one after pouring

    im gonna let it sit until friday with the forms. when i take them off its just to smooth out the corners a little, it will have to sit a few more days after that.

    Ellen i didnt think to use concrete board. that does sound like a great idea though. im happy to have this shell already done in one solid pour, but if the form work is not reusable i’ll try it ur way later on.

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    #14870
    Avatar of Ellen-Re-Generate
    Ellen-Re-Generate
    Participant

    Those walls are quite a bit thinner than I expected it to be.

    You can always use a trowel and/or float and reface with a thinner version of the same mortar the inside, outside, and edges of whatever comes out of that mold. My concern will be how you remove the dowels. The mortar can seep into the cellulose fibers of the wood and grip it pretty strongly. And what are you going to put in the dowels’ places? My suggestion would be to apply duct tape to the inside and pour some clear epoxy straight down into the cleaned out holes. If need be, you can use a sander to clean up and polish the finished “window”.

    Looking forward to seeing it floating in the pool.

    I have a thorium reactor under the hood of my car. I get ∞ miles per gallon.

    #14880
    Avatar of elspru
    elspru
    Participant

    shredder7753 wrote:

    Hey i finished pouring the mortar for the outer shell of my berg

    (the links will work now)

    heres a video of the form work before pouring

    here’s one after pouring

    im gonna let it sit until friday with the forms. when i take them off its just to smooth out the corners a little, it will have to sit a few more days after that.

    Ellen i didnt think to use concrete board. that does sound like a great idea though. im happy to have this shell already done in one solid pour, but if the form work is not reusable i’ll try it ur way later on.

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    Wow! Excellent work shreddy Rich.

    You got all the pieces together, and made it happen.

    I myself, yesterday finished on the interior plastering,

    and today was installing a drainplug from nut/bolt,

    note to self to get polyurethane sealant.

    If I add a top hatch viewport, can make the dinghy submersible.

    calm aware desire choice love express intuit move

    #14882
    Avatar of shredder7753
    shredder7753
    Participant

    Ellen u are exactly right – the only problem i am having right now is those dowels. i feel like once the cement hardens it would be easy enough to break that little bond. the problem is that i selected a dowel that fits snug in the hole. once they got wet from the mortar, they expanded. now im just hoping they shrink well enough to pop out without disturbing the rest of it. i dont regret making it one solid pour though, at all. i think its much better this way, if it can be done, to model it the way it would be constructed in full scale. ur epoxy idea is interesting, but i prefer cutting a thin sheet of Lexan plastic with a hole saw and sealing it in there. the epoxy is more certain to hold up to water pressure when it submerges, so i’ll keep that one in mind.

    SRUSKI! – knew i could count on u to pop in! u better show us some updated fotos of that dinghy. have u tried riding in it? have u tried riding someone else while u were in it? lol j/k. i like the idea of polyurethane sealant. is this what u had in mind?

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

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