Lightest & Strongest way to brace curved gear strips?

[SNIPE]

Hi,

What is the lightest and strongest way to brace curved gear strips, where 4 of them would make a ring.

Any official LEGO part can be used, as I have almos every technic part type ever released and several system parts.

But I would prefer it if the bracing does not extend past the diamiter of the ring

This is to make a drum, so it is important that each ring can be mounted to another in some way, eg having the rings spaced out by 15L beams.

This would need to be sturdy in the following ways:

• The rings do not collapse
• The gear strips dont get pulled apart.
• The entire barrel does not sag
• Each ring section does not pull apart from the next

I have a few ideas and some of them I have built, I spaced the rings using 15L beams and it may have been not as light as some other peoples ideas.

Regards, Snipe

[doug72]

Depends on how rigid you want the them
I would suggest using 3L axles through each axle hole  (8) with two 2L axle joiners either side  & a 11L axle to connect to the next ring.

See photo.

IMG_8193

Edited May 30, 2021 by Doug72
Typos

[SNIPE]

19 minutes ago, Doug72 said:

Depends on how ridged  you ant the rum.
I would suggest using 3L axles through each axle hole  (8) with two 2L axle joiners either side  & a 11L axle to connect to the next ring.

See photo.

Hi,

I tried this with 10/11/12L axles but the problem with this is it is weak in every factor I mentioned.

It lets the gear strip quarters seperate, it lets the rings seperate from one another, and it flexes and twists :/

I built quite a good solution but it was very complex and was a finger buster to build. so since it was so complex, I built some sections back to front or upside down

and as I say this may have been over engineered anyhow.

I also tried clamping each ring quarter together using the bevel gear housing connector 3x3 in black  thing but then connecting this to anything else was too weak. Maybe the large linear actuator mount brackets has better connectivity with beams.

Regards, SNIPE

Edited May 30, 2021 by SNIPE

[astyanax]

2 hours ago, SNIPE said:

Any official LEGO part can be used, as I have almos every technic part type ever released and several system parts.

Have you considered parts in the categories "Technic Special" or "Constraction"? There's some funky stuff, for example:

  

[SNIPE]

26 minutes ago, astyanax said:

Have you considered parts in the categories "Technic Special" or "Constraction"? There's some funky stuff, for example:

  

first two I have but not enough of. the first one I tried just on one ring. I'll try again with these soon I guess.

[Mechbuilds]

 How about using these and just putting a beam to connect them? 




EDIT:

Edited May 30, 2021 by Mechbuilds

[amorti]

Name of the game is form locking. If you're relying on axle or pin connections not pulling out, it's not strong enough.

On each adjoining axle hole, put a 3L axle with stop through two of these guys, one above and one below the gear racks, pointing inward.

https://rebrickable.com/parts/42003/technic-axle-and-pin-connector-perpendicular-3l-with-2-pin-holes

That'll join your circles of 4 quarters, and now you have something to attach liftarms to, in the correct orientation so they're form locked.

Proviso: I don't have any of those gear racks, so idk if the 3l perpendicular connector is long enough.

Edited May 30, 2021 by amorti

[SNIPE]

15 minutes ago, Mechbuilds said:

How about using these and just putting a beam to connect them?

The beams will just rotate then, and the pins can come out.

pins can also rotate and therefore the beam would pretrude past the discs outer edge.

beam can also get knocked out of the pins/connector

2 minutes ago, amorti said:

Name of the game is form locking. If you're relying on axle or pin connections not pulling out, it's not strong enough.

On each adjoining axle hole, put a 3L axle with stop through two of these guys, one above and one below the gear racks, pointing inward.

https://rebrickable.com/parts/42003/technic-axle-and-pin-connector-perpendicular-3l-with-2-pin-holes

That'll join your circles of 4 quarters, and now you have something to attach liftarms to, in the correct orientation so they're form locked.

Proviso: I don't have any of those gear racks, so idk if the 3l perpendicular connector is long enough.

Hi,

This is actually how I did it, indeed, I used 3L friction pins, 15L liftarms, 3x5 bent beams and those connectors.

Maybe this is the best way after all

[amorti]

Seems like the minimum parts you need, to make it form locked.

Could you show how you did it? I'm more a tinkerer than a designer, show me a picture of a thing and I'll tell you how it'll fail and where it wants bracing. 

[SNIPE]

42 minutes ago, amorti said:

Seems like the minimum parts you need, to make it form locked.

Could you show how you did it? I'm more a tinkerer than a designer, show me a picture of a thing and I'll tell you how it'll fail and where it wants bracing. 

Its dismanted but ill do it in LDRAW soon

edit:

I don't renember how I connected the cross beams, as I say this was so confusing.

Edited May 30, 2021 by SNIPE

[astyanax]

Here is an (over-engineered?) strengthening of the above. Connecting multiple circles is just a matter of inserting 5x7 frames I think.

[SNIPE]

26 minutes ago, astyanax said:

Here is an (over-engineered?) strengthening of the above. Connecting multiple circles is just a matter of inserting 5x7 frames I think.

I see, this is fine. but how do you now connect more than one ring together.

you cantt use 3x5 bent beams because you need a cross beam on both sides, so maybe use 3x5 thin T beams so that you can put a beam on both sides.

I only have 2 of those 2x3 rounded beams from seet 42125, they are expensive I think from bricklink but I should be be able to make a substitution,

[Sadap]

I hope I understood all your requirements:

I also experimented with the #4 angled axle connector (135°), but I didn't find a triangle with whole numbers.

[Nazgarot]

Or you could try this. It has self locking braces that should be strong in all directions, and can easily be extended to any length. You can also have cross braces between the 15 l liftarms as well if it is needed for extra rigidity. I did a quick custom selfbracing ending as well for the top and bottom rings.

PS: What are you making? A rocket or large tank maybe?

_ED_

[astyanax]

9 hours ago, SNIPE said:

I only have 2 of those 2x3 rounded beams from seet 42125, they are expensive I think from bricklink but I should be be able to make a substitution,

You can get them at "half price" from B&P. Order half of the number you need, then send a photo to customer service showing how misaligned the axle holes are, and they'll send you another batch.

[SNIPE]

2 hours ago, astyanax said:

You can get them at "half price" from B&P. Order half of the number you need, then send a photo to customer service showing how misaligned the axle holes are, and they'll send you another batch.

*yey*

9 hours ago, Sadap said:

I hope I understood all your requirements:

I also experimented with the #4 angled axle connector (135°), but I didn't find a triangle with whole numbers.

this could work, but ill flip 4 of the beams the other way so that I can add a ring.on both sides of your design.

[Sadap]

2 hours ago, SNIPE said:

this could work, but ill flip 4 of the beams the other way so that I can add a ring.on both sides of your design.

you can also move the beams so that the gear rack is in the center of the beam and then connect them with small beams, that should be a bit more stable. But it's also heavier.

Edited May 31, 2021 by Sadap
typo

[Erik Leppen]

Probably not the solution you're looking for (for example, it slightly sticks out), but I wanted to suggest a "different" approach than what's in the topic so far. If I want strength in a lightweight frame, I immediately think "triangles". I think torque-wise this is the best you can get, but I don't now how well it will hold under all kinds of stress. The gray 1x7 beams acting as braces probably wouldn't hold well, but at least it's all form-locked. Also, as a bonus, the center is completely empty. However, it's not integer-height, and as the rings are 45 degrees offset, the teeth don't line up...

Edited May 31, 2021 by Erik Leppen

[howitzer]

1 hour ago, Erik Leppen said:

<snip>

Probably not the solution you're looking for (for example, it slightly sticks out), but I wanted to suggest a "different" approach than what's in the topic so far. If I want strength in a lightweight frame, I immediately think "triangles". I think torque-wise this is the best you can get, but I don't now how well it will hold under all kinds of stress. The gray 1x7 beams acting as braces probably wouldn't hold well, but at least it's all form-locked. Also, as a bonus, the center is completely empty. However, it's not integer-height, and as the rings are 45 degrees offset, the teeth don't line up...

<snip>

 

I like the solution, triangles are naturally the best way to make a rigid structure. Depending on the stress applied, there might be a problem with the banana gears which are attached to anything only from the thin axleholes at the ends, which is notoriously weak and might break under stress. But I believe this could be solved by using the axleholes at the middle of the gear racks for bracing, and joining the ends with just 2L axles, not attached to anything else.

[Lira_Bricks]

11 hours ago, Erik Leppen said:

and as the rings are 45 degrees offset, the teeth don't line up...

This can be fixed by using the center-holes of the curved gears. If you do that you will have to find another way to connect the curved gears tho

[SNIPE]

21 hours ago, Erik Leppen said:

Probably not the solution you're looking for (for example, it slightly sticks out), but I wanted to suggest a "different" approach than what's in the topic so far. If I want strength in a lightweight frame, I immediately think "triangles". I think torque-wise this is the best you can get, but I don't now how well it will hold under all kinds of stress. The gray 1x7 beams acting as braces probably wouldn't hold well, but at least it's all form-locked. Also, as a bonus, the center is completely empty. However, it's not integer-height, and as the rings are 45 degrees offset, the teeth don't line up..

This is a cool way to do it

I'll certainly give it a try, the only connection point I need is something to attach a large turntable in the center of each end of the entire drum.

I am not using the teeth and the connectors sticking out slightly is probably fine,

[Jeroen Ottens]

Even though I don't think this beats the gorgeous design of @Erik Leppen, it does not stick out and it is easy to add a turntable in the center:

 

[SNIPE]

1 hour ago, Jeroen Ottens said:

Even though I don't think this beats the gorgeous design of @Erik Leppen, it does not stick out and it is easy to add a turntable in the center:

 

this is ok but I already tried something very simular as well as replacing those black connectors with large linear actuator brackets, unfortunately the black connectors have to much play in them, I replaced the half bushes with 2L thin beams and added axle pins but still the problem persisted.

Note to all - I do happnen to have enough of the fairly new 15L alternating hole beams. as long as there is only 2 of them per ring.

[nikolyakov]

I just wanna try my hand. You have to rotate next floor 90 degrees for rigidity. You can extend yellow 5L axles with axle joiners between floors.

[marcus2388]

A different approach could be: not relying on the ring-modules for rigidity. Also: minimizing the use of connector-connections…

You could use frames…

 

Maybe (not necessarily) reduce the space for movement by interlocking them even further…

 

 

And to gain hight you could go for liftarms, or panels…

But I’d prefer bricks. They are super strong.

 

This should allow to stack quite high…

 

And it would leave a lot of free space – always in the same spot – to maybe run elevators through it (if your intention would be to build a tower of some sort)