Help Me Draw A Dome [TUTORIAL]
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Hi Dome,
Indeed long time no se...
First of all, I would suggest to upgrade to SU 8. It has a new feature called "solids" and it calculates volumes automatically. Since the material you need to purchase, will come in sheets (i.e. 2D) and we need to warp this onto a 3D curve, there will probably be issues but no worries, I still remember some maths I learnt some (more than) a quarter of a century ago...
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Thanks Gaieus
I'm guessing the first thing I'd need to do is upgrade to version 8. Busy doing so now.
If you don't mind, can you calculate for me in the mean time the required amount of material but i still need you to show me.
If you hadn't run me through those tutorials, I don't know what i would have done because as my project progressed, i realized i needed to make certain changes and Voila! Thanks to you, i was able to do it all on my own.I have attached just the dome that i need the calculation for.
Thanks
Regards
D0me
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The inner components need to be exploded to make one, big solid volume. There was a bit of mess first and some missing pieces but after a quick fix and cleanup, it reports back as solid and see the volume in the entity info box.
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Thanks for that Gaieus
Can I ask you another silly question?
Now that you've given me the volume, how do I calculate a rough estimate of the length of blanket that I need. Basically
its sold in metres so how many metres of this would I need to buy to cover the volume you've just given me.Thanks again
Regards -
The volume doesn't really give you that - a sphere has the least surface area per volume so your hemisphere will be quite good compared with a square box of the same volume or even worse a spiky form of the same volume which would have a much larger surface area for the exact same volume enclosed...
Don't forget you can't apply a flat sheet exactly over a curved surface, even cut into tiny postage stamp sized pieces each would have to curve and therefore distort and the more 'pieces' you use the more you use as presumably this stuff also has rules about how much each part must overlap!
You need one simple dimension to approximate this.
I recall the dome is about 30" diameter.
The circumference is therefore pi*D =~ 22 / 7 * 30" = 94.24"
Allowing for some end laps the half-circle up the dome is ~48"
The material is 24" wide so two widths should do a run in two strips around the circumference at the base and about half way up.
So the lower strip would be ~96" long [guessing the minimum lap is ~2"]
The upper strip would be around 2/3 of this [it's really not that critical] at say 64".
Because the strips have angled overlaps the offcuts can be used to 'patch' any under sized overlapping ends and even make a top 'cap' - as they'll probably be a messy 'hole' at the apex...
So we need around 96+64=160" which is about 4.1m. If you buy it 'by the meter' then 4m will just about do and 5m should be more than enough, so I'd get 5m...
You also said something about '7m'... so if that's the set roll size then it's plenty...
If you have the dome already made you can easily get some old newspapers cut to 24" wide and taped into lengths of ~2.5 and 2m, wrap them around the dome to see what the laps are like and measure how much you really need... Alternatively get a 3" orange [or similar fruit] cut in half and make some paper strips 2.4" wide and try wrapping the orange-peel dome in them - for the length of paper every 10cm is the real length in meters - approx. This will also give you a good idea of the pitfalls/difficulties of wrapping flat stuff around a sphere, the lapping involved etc !
As I said, the accuracy is not so important as there have to be overlaps and the cut patched because applying a flat sheet to a 3d curving surface will always be inaccurate, also you haven't mentioned the 'tunnel entrance' - wouldn't that need some of this too ?
Also-also, as you buy in 'increments' then the roll at 7m or steps of 1m up to say 5m is all you need to worry over... -
Thanks TIG. I was afraid I'd have to answer this question...
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Hi Guys
I'm trying to get the cu.m volume of the following skp but it keeps popping up this error.
It skips a whole area, what have I done wrong, can't seem to find a solution.
Thanks
Regards
D0me
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For some reason the Volume tool just doesn't like that form
The reported volume under v8 in Entity Info is 2.397cu' - which is 0.0679m3
The old Volume tool [by integration] returns the correct volume [0.068m3] to within tolerance, BUT only after I fixed a longstanding and stupid typo that I am amazed no one has spotted before
I'll post an update...
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By the way, why don't you upgrade to version 8, Dome?
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Hi Gaieus/Tig
Tig: Thanks for confirming the volume.
I have these SKP's and I'm trying to push it into Layout but it just wouldn't sit centred on my page.
Please can you guys help me to send both these SKP's to Layout. The SKP called Pieces have 10 items and each item will fit on a A4 page on a 1:1 scale. The red and blue blocks are grouped and sized in such a way that it should fit perfectly centred on an A4 page. I manage to send it to layout but it's either skew or if i get it straight then it's not centred.
The SKP Called Circle can fit on any size page as long as it's centred and also on a 1:1 scale.
If you can supply in PDF format, it would be appreciated but that's something I should be able to do.
Sorry, I know I'm being a bit lazy but I've been failing with this and I need to submit these drawings to my supplier urgently so he can cut accordingly.
By the way Gaieus, I plan to upgrade this weekend.
Thanks
Regards
D0me
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Hey Guys
Push came to shove and I managed to figure this out. As soon as I made the first guideline, I remembered during Gaieus lessons, he showed me how to use them and that's exactly what I did, used it to align each item and print it individually to PDF, all worked perfectly well.
Thanks
Regards
D0me
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