Mini-challenge
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@unknownuser said:
fwiw, the reason i keep stressing SU native tools is because i'd like to encourage people to find a geometrical relationship in this situation.. something like -- divide the height into thirds, divide the width in half, take a segment from each then add the board width and viola.. this is the length of the crossmember .. something similar that would be repeatable every time regardless of dimensions.. i'm beginning to think this type of relationship may not occur in this situation.. (but i'm hard headed.. i guess i would need proof that it is impossible to find such a geometrical relationship
)I think in this case, we're trying to hit a tangent, and thus with the segmented circles in SU, we will never get there with the native tools as they are now.
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@jason_maranto said:
OK, I broke down and looked at the math on this -- it seems dirt simple to do so I think this is the solution (based on the math).
[attachment=0:n6vj9qbd]<!-- ia0 -->challenge solved.skp<!-- ia0 -->[/attachment:n6vj9qbd]
In this instance the desired width is 2 inches.
Best,
Jason.You have a closed form solution to this?
Hcos(theta)-d(1+cos(2theta)) /2-Ssin(theta)=0
Where H post height; d dimensional lumber width; s post spacing; theta rotation angle at post base.
If you have a closed form solution should not the measured width be exactly 2.00000??
IMHO all focus of the accuracy is questionable. Jeff is not building a watch. One will have to deal with dimensional lumber tolerance, crowning the lumber and maybe using a side winder to cut angles not to mention the angle layout. Maybe a good chop saw is at hand.??? -
mac1
I was hoping it's already been established in the thread that the challenge isnt about accuracy from a real world construction standpoint. I mean, depending on the time of day (temperature) and humidity, a board will expand/contract far more than the results being given in the thread. -
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Jason. the problem with that is you're going 90° from the diagonal. which isn't the same thing as going 90° from the edge of the board.
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All that mathematical notation is greek to me, but here's what we know:
- we know the diagonal length and position (call it a hypotenuse if you want but it's really a diagonal to me).
- we know the desired width of the beam.
- we know that the angle should be 90 degrees on the opposite corners from the diagonal.
As far as I can see with that information we should have no trouble drawing the thing directly using nothing but the line tool and a few guides... because the actual numbers (aside from what we already know) should completely irrelevant.
Here's a video -- it works, and consistently (not to mention dirt simple)... it's just that SketchUp seems to have lower than perfect tolerances for the 90 degree guides.
[flash=960,720:5o5ld983]http://www.youtube.com/v/OfHaC40zvxM?rel=0&hd=1[/flash:5o5ld983]
Best,
Jason. -
@moujiik said:
Hi
May be like this?
Moujiik
im curious to see what you've come up with. I'll be able to download your file in an hour or so.
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I'm not sure why you think so -- all 4 corners are 90 degrees, and since we know where 2 of the corner are why not use them...
It works fine and you get about as accurate results as any other non-plugin solution put out here.
Best,
Jason. -
@jason_maranto said:
I'm not sure why you think so -- all 4 corners are 90 degrees, and since we know where 2 of the corner are why not use them...
It works fine and you get about as accurate results as any other non-plugin solution put out here.
Best,
Jason.nah.. the corners won't end up square when doing that
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OK... did you watch the video? Those results are as accurate as any other non-plugin result I've seen in this thread -- it works, you can say it shouldn't if you want to but it does.
I guess the thing here is I don't think square corners matter anyway, since they will be trimmed off -- what matters is the width... I mean after all this is a cross brace.
Best,
Jason. -
you're right.
And it's the same solution as Tig's.
I miss my real wood planks. It is so easy to do that for real!moujiik
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yep. watched it.
the corners need to be perfectly square if thats where you're drawing a line to determine the boards width.
upon finishing your method, delete the diagonal (as to avoid confusion) then measure the angles of the board's corners. they won't be 90°
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@moujiik said:
you're right.
And it's the same solution as Tig's.
I miss my real wood planks. It is so easy to do that for real!moujiik
sometimes.. I'll upload a picture a little later which shows a situation where you can't just put a long board in there and trace/cut it.
another reason for having a precut board is that you can use it to plumb a wall with. (instead of needing two people do it -- one to use the level and one to trace the board)
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Yeah, I already said that several posts back -- but it is consistently the same regardless of the distance between the beams, which is why I said I think there may be an accuracy issue with the engine somewhere.
If the method was faulty there would random results each time... right?
Best,
Jason. -
@jason_maranto said:
Yeah, I already said that several posts back -- but it is consistently the same regardless of the distance between the beams, which is why I said I think there may be an accuracy issue with the engine somewhere.
If the method was faulty there would random results each time... right?
Best,
Jason.in this particular case, the fault isn't sketchups. the approach is geometrically flawed.
edit-- for instance, doing what you're doing.. the wider you decide to make your board, the further away from 90° you'll get in the corners.
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Gotcha, yeah, I see that now -- so it was just an illusion created by the long rectangles/aspect ratio of the beams here.
I guess nothing is as simple as it seems with math (which is why I avoid it as much as possible).
I'm ready to just use Fredos tool and call it a day
Best,
Jason. -
@jason_maranto said:
Gotcha, yeah, I see that now -- so it was just an illusion created by the long rectangles/aspect ratio of the beams here.
I guess nothing is as simple as it seems with math (which is why I avoid it as much as possible).
I'm ready to just use Fredos tool and call it a day
Best,
Jason.me too. fredo solved it..
I'm still curious to see an alternative solution but as far as actually drawing the thing, the fastest method will win and I think it's going to be fredoScale's latest addition. -
Jason,
You're right.
The native Rotate tool seems to find inference in alignment of edges with others. You have to play around with it, but it seems to find it in the end.
Fredo
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Yeah I was trying for stupid simplicity, and just ended up with stupid
BTW I'm playing with the protractor a bit more and it seems to be snapping to something, I can't tell what -- and it's not giving me any feedback, but the result is the missing correct 90 degree reference... maybe they (SketchUp Devs) already solved this problem and we just never found it.
It's strange though because you have to kind-of slide the protractor along a guideline until it just decides to snap for some reason.
Best,
Jason. -
@unknownuser said:
Jason,
You're right.
The native Rotate tool seems to find inference in alignment of edges with others. You have to play around with it, but it seems to find it in the end.[attachment=0:1qducgxr]<!-- ia0 -->Jeff Challenge3.gif<!-- ia0 -->[/attachment:1qducgxr]
Fredo
what the heck ??
at first i though 'this guy is nuts' but then after fiddling around for a minute or so, it eventually snapped exactly into place ???
so i guess the quest now is figuring out what it's doing and how to gain better control over it..
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