LegoTechnic, Gear Rack 11 x 11 Curved 24121

[knotian]

I was going to post a negative post, but I won't.

Why did Lego design this part with no logical spacing to the pin holes?

Is there some logic that I have not seen yet?

I've thought of a few ways to use them but fastening them to a technic structure is really a problem. Is there some part that I don't know that has the same spacing as the holes in 24121, so it can be attached to other parts? I've figured out that the holes will fit studs separated by 4 holes,( 6 stud spacing) but not in any common orientation. Any examples of their utilization, or link, would be appreciated.

Thanx,

Ed

[efferman]

The holes are match if you some holes down and then some holes to the left or to the right.. The direct way doesnt work. Its like a circle on a paper sheet with a squarebox pattern.

Edited September 15, 2019 by efferman

[Zerobricks]

I suggest you check instructions for the BWE and Rough terrain crane to see how they are fixed.

[suffocation]

Since you're likely to need a beefy structure to support the ring, you're just as likely to use these:

https://www.bricklink.com/v2/catalog/catalogitem.page?P=55615&idColor=86

which are great for securing the racks.

[Lyichir]

If you're interested in why the spacing is the way it is, this Brickset article goes into detail about the many geometric possibilities it offers: https://brickset.com/article/23288/the-geometry-of-the-new-11x11-circle-gear-rack

[Jeroen Ottens]

Interesting article, but they missed another obvious geometrical feature of the holes:

Some holes are actually at the position of the pythogarian triangles with the square corner of the triangle in the center of the circle. They use the 6x8x10 triangle in two orientations. This gives the following coordinates that are all perfectly on the circle:

(0,10)
(6,8) (the hole next to the middle crosshole)
(8,6) (the other hole next to the middle crosshole)
(10,0)

And then you can also mount the circle 45 degrees rotated (hence the crosshole in the center), which gives another 2 extra holes that fit in this rotated pythagoras triangle (the holes next to the outer crossholes to be precise)

The middle crosshole is close to the (7,7) coordinate, but it is just off sqrt(2)/2*10 = 7.1 studs.

 

 

[knotian]

Thank you for the fast replies and link to the article. There is some sanity to it after all

Ed

[doug72]

BLACK BEAMS 18L APART / RED BEAMS 17L APART.

Edited September 17, 2019 by Doug72