Scioly.org

I was thinking of something like this:
A slim rectangular base with two pieces of wood on both the bottom and top of the block, placed a hook's width apart.

Basically the same base as last year except without a hole + some extra pieces on the top and bottom to "sandwich" the hook.
What ideas do you guy have?

I wrote earlier, maybe a 3/16 or 1/4"+ dowel, filed the width of the hook in the middle for accurate positioning with two holes drilled on each side.
Also, why not have a hole for the J-Hook? The hook may be curved, but with a slightly larger middle hole, and different shaping, why can't you just slide the base over the top of the hook and move it down?

Our team started to look at mounting blocks more closely... Someone correct me if my observation is incorrect. The so called center line of the J hook is about one cm higher than the horizontal line that the J hook is mounted thru the back board. The 15cm (C div) horizontal contact depth line in now 16 cm below the block mount center line. Anyone else see this? Not that this is a problem, just something to consider...
http://www.soinc.org/sites/default/file ... lation.pdf

Yup, that looks right. Interesting, but I'm curious to see how 1cm really helps scores, probably not much.

Didn't really consider what the scoring difference might be. It was just an observation while looking at the set up in real time instead of on paper. The angle difference could change the pull on the tension members. Yeah, I know it will be small....

Now it's 44.775kg vs 47.434kg before, if we can take advantage of an extra cm. 3kg sounds more significant than I thought, but it's only a matter of maybe .1g or .2g at the lighter end of competitions, probably. So maybe 50 points. But I'm just kinda fudging around with guesses... I don't have any data to actually back up the .1-.2g number

The effect on forces is actually a bit larger (with the centerline of the T=member going thru the center of the....J-hook circle. See my post, previous page. The centerline intersects the wall at about 16.4cm...

I just tested my boomilever. It broke at the center of the compression members at 6.2 kg. The buckling strength of each boxbeam compression member is about 1kg and I braced them every 8 cm. if the force is 31 kg, then each compression member only needs to carry 15.5 kg. I really don't understand why my 1 kg buckling strength compression member with 6X bracing (6^6=36) failed that early.

Balsa Man wrote:The effect on forces is actually a bit larger (with the centerline of the T=member going thru the center of the....J-hook circle. See my post, previous page. The centerline intersects the wall at about 16.4cm...

If that's how high the centerline sits in regards to the wall, how far from the wall is it? I know that the hook itself is 2.5 cm from the wall before the actual hook part, for lack of a better word; however, the length will have to include part of the actual hook part and it will most likely not sit at exactly the middle part of the hook meaning the distance won't be the maximum length of the hook from the wall, if I'm not mistaken.

jma wrote:I just tested my boomilever. It broke at the center of the compression members at 6.2 kg. The buckling strength of each boxbeam compression member is about 1kg and I braced them every 8 cm. if the force is 31 kg, then each compression member only needs to carry 10.5 kg. I really don't understand why my 1 kg buckling strength compression member with 6X bracing (6^6=36) failed that early.

Which way was it braced? And how did it fail? I'm guessing it was braced horizontally and it failed by bending up or down vertically? Did you have any kind of tension-compression brace?