Need an engineer..

[brtc]

I'm about to put together a tray with two extendable monopods. It might not work, but it's winter and i'm bored. anyway, i'm having trouble with the trigonometry. I understand, angles are affected by length with a triangle, but with this being more of a polygon, i'm a little confused. The two trays in question are the ones with the v-shape in the pictures. one has a significant angle, and the other one has a slight angle. Will I be able to fully extend the tray without affecting the angles. I'll probably just make it square, just lookin at ideas.

 

[Tigerman]

Given the fact that you want to extend the camera away from the handles (Im "reading the pictures" right, am I not?) I would consider what configuration would be more stable for a start..
The angles of a triangle will always add up to 180 degrees, so as long as you keep the two angles at the handles constant, the angle at the center of the camera mount should never change either..

Edit:
Extend the lines on your drawing beyond the camera. Youll see that what youve been drawing is a triangle, just that your camera mount acts as one of the "crossbars" like the one on the handle and the one next to the first extension part in the drawing

Meh, Im too tired to think of details like how thatll effect your design, but my brain kinda try to tell me that by keeping the angles but increasing the length, youll skew the distance between the legs (because youre effectively pushing the camera towards the apex of the triangle) at the point where the camera mount cross the triangle but Im going to go to bed and rest my brains now

 

[dumpsterDiver]

unless the camera tray has slots that alow the arms to slide laterally, no...

 

[brtc]

Thank you. I do want the poles to extend away from the handles, I just couldn't figure out if my angles would change due to the fact that the tray set up is not actually a triangle, more of an irregular quadrilateral. However, i'm no engineer and i don't wanna add any slots or make it complicated, so i will probably just square it off and call it a day. Thanks for the help.

---------- Post added January 6th, 2013 at 08:22 PM ----------

Probably coulda put this in the DIY section.. Mods?

 

[3D diver]

Need a hinge at the handles and the cross bars have to be able to extend, or no, you can't extend the trapezoidal shaped designs.

 

[victorzamora]

brtc, the "overall" shape of your two designs are triangles....whether or not you decide to look at it that way. Extend your two longest two arms out further and you have a triangle. That'll make all of your math easier. The cross beams (where your camera mounts as well as the extra support, AND where your hands go you can create another triangle). This would make 3 triangles, all sharing an angle which is where your camera would be looking. You can then make 3 triangles that are all stacked on top of eachother with all three of them being triangles with the same angles, sharing the smallest angle, and just differing in size. This is called "shared triangles with shared parts" in technical terms. Since it's symmetric, you can then draw a line to split your support in half long-ways. That way, you get a series of three right triangles. The math from there is really easy. However, the math proving that it wouldn't work is kind of difficult. I can upload a few drawing if you want me to expand on this, but suffice it to say that either the cross beam for your camera mount AND the support would have to telescope, OR the central support would have to telescope (or pivot) and the "main" (longest) beams would have to pivot. I know that doesn't make it easy for you to visualize, but just know that square is 1000x easier.

 

[brtc]

Perfect explanation victorzamora, exactly what i was having trouble understanding. Thanks for the help everybody. I'll post a picture when i finish it if anybody is interested.

 

[300winmag]

What program are you using for this? looks nice!!
So how long are you extending out? cause if you are using lights they would have to be beside the camera and the more you extend the more awkward and heavy your rig will become.
Post some pics when your done please!

 

[brtc]

I just made those on tinkercad to explain the scenario.They are not accurate by any means. It will extend from about 9 inches to 30, and I don't have lights. Thanks for the help. I have to get a piece printed and when that's done i will post some pics of the tray.

 

[victorzamora]

How's the design/build coming along? I'll be excited to see this whenever you finish it up!