AFOL seeks SNOT-master

[davee123]

I'm building a technic dealybob-- a GBC, actually. And it's got very large cams in it that are brick built. They're 1-stud thick, and they spiral outwards. However, my SNOT abilities are not quite up to perfection. I've got two small holes in my cam design that I'd love to believe are fill-able, but I haven't managed to get it yet. So... SNOT-masters, can you get a design that fills the gaps? (And hopefully is sturdy enough not to fall apart when spinning)

DaveE

[CopMike]

Hi!

I'm not the expert your looking for (SW reference ;-)!), but for the left one, why.not use the 93273 part Slope, Curved 4 x 1 Double No Studs instead of the 24309 Slope, Curved 3 x 2 No Studs? You just need to replace the 1x8 brick with a 1x3/1x4 combo.

[Swan Dutchman]

This is maddeningly hard! I spend about an hour in LDD, but I am unable to find a solution without altering the outline. Using 1x1 technic bricks with a hole solves some issues. If you want to keep the same outline I think you can use brackets, but that would make it 2 studs thick. I believe the issue is caused by the fact that this section goed 3 studs vertically down. If it was 2 studs of 4 studs it would have been easy. Changing the outline slightly (the 2x1 curved slope and 2x1 slope on the left, and the 3x1 curved slope on the right) may be the easiest solution.

[davee123]

Well, at least I've thoroughly frustrated someone else, too!

Here's the outline I'm trying to follow:

The 1x3 curved slope that's closest to the center should probably be replaced with a 1x2 curved slope-- although... I think I did that more out of part restrictions than actual desirability.

Originally, I started "filling in" the design with the technic brick in the middle being rotated 90 degrees, which aligns it a little more correctly. But for whatever reason, that REALLY screwed me up. I spent a couple hours with it in that orientation before throwing it out and trying it in its current orientation (which seemed to work a bit better for me). But although I'm OK with SNOT-building, I'm not as good as a lot of folks out there, so I figured I'd ask!

DaveE

[GallardoLU]

I like a challenge, I'm no snot master though but I'll take a look at it (after work, few hours from now) alternatively if this can't be solved, is there a way to conceal the gaps behind other parts of the mechanism?

Edited May 13, 2016 by GallardoLU

[davee123]

is there a way to conceal the gaps behind other parts of the mechanism?

I guess technically, yes-- In my current design, the gap that's closer to the center (directly under the central axle hole) is already obscured by the housing.

But honestly, it's mostly about silly aesthetics and a sort of "can it be done?" question. The GBC's already built, and it seems to work fine (until I get it to the event, when I'm sure it'll fail catastrophically!). And I doubt anyone will really notice the gaps, since the cams spin pretty quickly, and the visible gap only pops into view shortly (they spin at about 1 rev per second, and are pretty much lost in the flurry of GBC-ness).

So, even if it stays as is, I don't think it's really a big deal. I was mostly surprised when I sat down to do it that I had such difficulty! Most things that I've designed, if I have enough space to work with, I can often get them nice and smooth. But granted, I don't do that very often, so I'm not as experienced at it as others seem to be. I was mostly curious if it really COULD be done, and what specifically might be making this design as difficult as it was for me.

I'm not stuck on the specific arrangement of the "border bricks", either-- I just wanted to follow the curve above as closely as possible, which this seemed to do pretty well. Obviously, if it sticks out a little here or there, it's not really a big detriment to the functionality.

DaveE

[Aanchir]

Not up to trying to build this right now, but just using a bit of math to see if it CAN be done...

Let's call the area of each of the gaps you're trying to fill "x". The smallest space you can fill with one brick/plate is a 1x1 plate, with an area of 10x. The area of any basic brick, plate, or tile (viewed from the side) is a multiple of 10x. The area of any brick, plate, or tile viewed from the top is a multiple of 25x. Clearly, using just basic bricks or plates you can't fill two spaces with a net area of 2x. In fact, even a headlight brick has a net area of 25x (30x with a 5x cutout). So you'd have to change the size or shape of the outline you're trying to fill if you want the shape to be entirely without gaps.

If you're building a GBC module I'd say just don't worry about tiny gaps like this. They're small enough that they shouldn't affect the function, so they're really just a cosmetic issue.

[anothergol]

Personally, I would be more annoyed by the steps on the outer curve, than by those 2 tiny holes inside.

It is even possible to reduce those steps using more complex snotting btw, so maybe if you do that (or maybe you can't, since you can't use brackets) you will get less (but probably more) problems inside.

I wish Lego had designed its slopes in ways that they can smoothly chain - I can imagine 2 ways to do this.

Edited May 13, 2016 by anothergol

[davee123]

So you'd have to change the size or shape of the outline you're trying to fill if you want the shape to be entirely without gaps.

Huh, I hadn't thought to check whether the math was possible on this, but it seems you're right-- no integer number of plates or headlight bricks will fill the space! No wonder I was having difficulty! I guess if I want something smoother, I'll have to adjust something along the edges, although I don't see anything immediately that'll do what I want. Interesting, though!

If you're building a GBC module I'd say just don't worry about tiny gaps like this. They're small enough that they shouldn't affect the function, so they're really just a cosmetic issue.

Nah, as stated they're just aesthetic issues. Nothing even touches those surfaces, really-- the balls ride along the outer rim of the cam, and an axle goes through the center to drive it (technically that should be an axle-hole pictured, not a pin-hole). So it's just my internal desire to be persnickety.

Personally, I would be more annoyed by the steps on the outer curve, than by those 2 tiny holes inside.

It is even possible to reduce those steps using more complex snotting

I couldn't come up with anything smoother-- as it stands, the stepping doesn't really seem to affect the balls, although I'd guess I've only run through about 600-800 balls or so in practice runs. Thank god for soccer balls being round!

I wish Lego had designed its slopes in ways that they can smoothly chain - I can imagine 2 ways to do this.

That'd be pretty handy-- I was always curious whether this was done to avoid making sharp corners, or perhaps because they were more prone to chipping on the edges if they made them with more pointed ends. Or, I suppose, problems with ABS plastic filling the smaller nooks (maybe air bubbles make those more difficult?) Anyway, yeah, it'd be nice!

DaveE

[rodiziorobs]

I have been looking at this problem since last night and wondered about the conclusion that Aanchir had come to.

Alternately, have you thought of orienting the axle hole piece at 45 degrees to the shape? I wanted to play around with this and see if I could approximate the desired shape of the cam. If I get to it I'll post my results later.

[splatman]

That'd be pretty handy-- I was always curious whether this was done to avoid making sharp corners, or perhaps because they were more prone to chipping on the edges if they made them with more pointed ends. Or, I suppose, problems with ABS plastic filling the smaller nooks (maybe air bubbles make those more difficult?) Anyway, yeah, it'd be nice!

DaveE

Probably more to do with safety than anything else. Case in point: 4865 Panel 1x2x1 was replaced with 4865b Panel 1x2x1 with rounded corners. The corners of the original 4865 had the potential to break skin, though I never had that issue. Or it was just due to toy safety regs.

[anothergol]

That'd be pretty handy-- I was always curious whether this was done to avoid making sharp corners, or perhaps because they were more prone to chipping on the edges if they made them with more pointed ends. Or, I suppose, problems with ABS plastic filling the smaller nooks (maybe air bubbles make those more difficult?) Anyway, yeah, it'd be nice!

I think the best/safest way to get slopes that allow smooth continuity, would be to add them over a 1-plate offset. The downside is that all slopes end point would be thicker, 1 full plate, but the benefits would be better than this little downside.

That would also imply they're all designed like the curved slopes, with no stud.

[emilstorm]

Here is a suggestion ón how to do it. Sorry about the link, I am posting via my phone :)

http://www.brickshelf.com/gallery/muni/Misc/image.jpeg

The slope marked with stripes has been moved in half a plates height towards the center, I am sure it can be placed exactly where you have it if you spend some time playing around with it :)

Edit: by the way, the part marked 1x1tec is of course a 1x1 technic brick turned sideways. And the whole thing obviously has pretty much zero structural integrity, there are only 3 studs facing up.

Second edit: it seems my second upload to brickshelf replaced my first, so this one should solve all problems. It is also a bit stronger.

Edited May 21, 2016 by emilstorm

[splatman]

Cheat alert: Reinforce it with a layer of clear packing tape on both sides.

[emilstorm]

Ok, so I was up feeding my baby son and this came to me:

http://www.brickshelf.com/gallery/muni/Misc/image.jpeg

Math is for suckers :)