General Part Discussion

[shroomzofdoom]

On 11/9/2024 at 1:01 PM, LegoTT said:

I guess as soon the new 12t spur gear came, people did try it with chain links, as the 16t spur gear was working well with them, but the 8t spur gear not at all.

You said 8t spur gear, I think you meant 12t? Just wanted to make sure I haven't missed a new part. That would be quite a feat!

[gyenesvi]

49 minutes ago, shroomzofdoom said:

You said 8t spur gear, I think you meant 12t? Just wanted to make sure I haven't missed a new part. That would be quite a feat!

I think he meant 8T. And that's just the normal 8T gear that has been around for ages. Not sure what else it could mean, if you look up the definition of a spur gear.

[LegoTT]

37 minutes ago, gyenesvi said:

I think he meant 8T. And that's just the normal 8T gear that has been around for ages. Not sure what else it could mean, if you look up the definition of a spur gear.

Indeed, by spur gear I meant oldest, non-bevel gear, but I'm not an english speaker and I believed spur gear was as a lingo used on eurobricks to differentiate from bevel gears, I should maybe using bricklink links of picture of gears instead.

[NV Lego technic]

1 hour ago, LegoTT said:

I believed spur gear was as a lingo used on eurobricks to differentiate from bevel gears,

Isn't it?

[gyenesvi]

4 hours ago, LegoTT said:

I believed spur gear was as a lingo used on eurobricks to differentiate from bevel gears

3 hours ago, NV Lego technic said:

Isn't it?

Well, if you look up spur gear, it means a gear that has straight teeth, perpendicular to the direction of rotation. So it is not diagonal, and the gear is not cone shaped or beveled, just the most basic one you can imagine. Since in lego there are no diagonal teeth gears or cone shaped ones, only bevel ones, hence in lego a spur gear equals the plain ones that are not bevel gears.

[SNIPE]

11 hours ago, gyenesvi said:

Well, if you look up spur gear, it means a gear that has straight teeth, perpendicular to the direction of rotation. So it is not diagonal, and the gear is not cone shaped or beveled, just the most basic one you can imagine. Since in lego there are no diagonal teeth gears or cone shaped ones, only bevel ones, hence in lego a spur gear equals the plain ones that are not bevel gears.

One strange thing is that the old 14 tooth gear and 24 tooth crown gear can act as either a spur gear or a bevel gear yet either of them are a double bevel gear or spur gear.

So, I wonder what a single bevel gear is called when it has fully open teeth (like the old 14 tooth single bevel gear)

[LegoTT]

I guess it qualify as bevel gear only if it's conical, so while you can make two parallel shaft work together with 12t single bevel gear (one on top of another, one facing the front and one facing the rear) it have to much friction.

 

20t double bevel gear can be used for parallel and perpandicular shaft, but with more friction than the new 20t spur gear and the new yellow bevel gear on the differential.

 

So I think all the 12t, 20t bevel and double bevel gear are not proper bevel gear nor spur gear, only a compromise to allow more possibility with only one piece mold. 

[gyenesvi]

On 11/13/2024 at 9:44 AM, SNIPE said:

One strange thing is that the old 14 tooth gear and 24 tooth crown gear can act as either a spur gear or a bevel gear yet either of them are a double bevel gear or spur gear.

So, I wonder what a single bevel gear is called when it has fully open teeth (like the old 14 tooth single bevel gear)

Actually I forgot about those old gears, I think they are closer to real conical gears than the single bevel gears, which are also kind of an approximation for conical ones. Also, the new gears in the Audi diff. And then the old crown gear is just that, a crown gear :)

And year, I guess a double bevel gear is just a mix of conical and spur gears to allow more possibilities. However, something that's good for many things, is not really good for anything; double bevels have more friction than necessary in both configurations, and Lego is starting to realize that, and now making separate spur and conical gears (Audi). I hope this trend continues, including other types of parts (for example, currently there's not good way of making a heavy duty smooth 90 degree 1:1 gear mesh in a 3x3 space). There are so many parts that try to be multiple things, but in the end are not great for any of the options, and eventually need to be replaced by a proper part. It would be better on the long run just to have parts that are good for one clear purpose without compromising.

[Thierry-GearsManiac]

This does highlight the philosophy differences between a construction game and "real world"/"industry" etc... (I don't know how to name it) :

• in construction games, multipurpose parts are often preferred : cheaper (a single part) but less performance, as it is the case with the double-bevel gears (a central spur section and two beveled sizes)... and even with the single-bevel ones
• in real world usages, performance is the first requirement, hence the specialized parts like, for example, pairs of truly conical gears for a defined ratio/angle, special teeth profiles for meshing with worm gears etc...

Therefore, is it really a good idea to demand high performance to a construction game, at the expense of parts multiplication ?

 

And a little word about beveled gears from LEGO (as well as in some other construction or educational games) : rather than true conical gears, they could better be considered as crown gears with 45° teeth because, like regular crown gears (with 90° teeth), they can mesh with several different gear sizes at once.

[gyenesvi]

31 minutes ago, Thierry-GearsManiac said:

This does highlight the philosophy differences between a construction game and "real world"/"industry" etc... (I don't know how to name it) :

Therefore, is it really a good idea to demand high performance to a construction game, at the expense of parts multiplication ?

I get what you mean, but why do you think Lego started making separate spur gears and smooth running conical ones? Because they realized that they do need that performance (less friction) after all.

Double bevel gears are strange for me for another reason as well. In my experience it's very rare to use both sides of it in a double-mesh, however it is really common that the unused side causes friction with a beam next to it. So they were basically opting for a rare case while not bothering with the frequent disadvantages. That feels counterintuitive. Thicker single-bevel variants with a smooth other side could have been better.

But it's not always about performance. Sometimes a part wants to fulfill two distinct functions. Consider this recent one for example (or its 5x2 counterpart):

It wants to be both a curved panel section and a 2x3 L shaped liftarm at the same time (on lego.com it is categorized in "beams with shapes"). As a panel, it is more-or-less okay, can join to a similarly curved 7L or 11L panel, but it has an inner corner with the cross-hole, unlike its long counterparts, which can be in the way (though can be useful for mounting in other cases). However, as an L shaped liftarm, it is often not usable, because the curve is in the way in most dense builds, exactly when a 2x3 L shape would be required (in not so dense builds, often a 2x4 or 3x3 L shape can be used instead). What is worse, is that I'd predict, that the existence of this part will block the introduction of a proper 2x3 L shape for quite some time. Sad, because it would be a very basic, very useful part.

[NV Lego technic]

I often find myself using that part instead of a conventional L shape, but sometimes it doesn't fit. Hope they fix this.

[ord]

On 11/15/2024 at 5:46 AM, gyenesvi said:

currently there's not good way of making a heavy duty smooth 90 degree 1:1 gear mesh in a 3x3 space

Have you considered this? Someone posted it in a MOC recently and I thought it was smart. Not sure about it's real world performance.

[bruh]

Ooh, that’s quite nice! Also, why are the larger gears gray? Aren’t they usually tan like the smaller ones?

[ord]

In some sets they come in grey, I guess for aesthetics.

[astyanax]

11 minutes ago, bruh said:

Ooh, that’s quite nice! Also, why are the larger gears gray? Aren’t they usually tan like the smaller ones?

https://rebrickable.com/parts/32198/technic-gear-20-tooth-bevel/71/

They appear occasionally in LBG, also in recent years

[keymaker]

12 hours ago, ord said:

ave you considered this? Someone posted it in a MOC recently and I thought it was smart. Not sure about it's real world performance.

This is nice, more smooth solution than the one with knobs. And it works well. But you need to consider 2 things. First: perfect match of teeths to provide smooth rolling, second: under any circumstances the axle cannot slip out from this setup, even a little. If it does, only a little and small gear skips a tooth, you are toasted. Resistance will be unbearable.

[anyUser]

13 hours ago, ord said:

Have you considered this?

 

1 hour ago, keymaker said:

perfect match of teeths to provide smooth rolling

I could be beneficial to bracket the suggested gears:

The extra gears may prevent the load bearing ones to be pushed apart.

If you push either of the axles towards the center I'll notice increased resistance on the rotation. so any pushing force towards the center of the gearbox should be avoided.

Edited November 16, 2024 by anyUser

[Aurorasaurus]

Hear me out... I know it's inefficient, but it wont skip, and it fits a 3x3 space.

https://www.bricklink.com/v2/catalog/catalogitem.page?P=32072#T=S&O={"iconly":0}

[gyenesvi]

16 hours ago, ord said:

Have you considered this? Someone posted it in a MOC recently and I thought it was smart. Not sure about it's real world performance.

That's an interesting solution, I haven't thought about that, only problem is that in the incoming end I cannot use a stop axle to secure the small gear because that has to be a heavy duty CV joint in a live axle.. so I'm also afraid of what @keymaker is saying..

3 hours ago, anyUser said:

I could be beneficial to bracket the suggested gears:

The extra gears may prevent the load bearing ones to be pushed apart.

This is also a nice trick to improve it, but it mainly protects the large gears, not the small ones. If the incoming axle (without stop) slips out a bit of the 12T gear, then heavy forces can still move it and grind it up I guess..

3 hours ago, Aurorasaurus said:

Hear me out... I know it's inefficient, but it wont skip, and it fits a 3x3 space.

https://www.bricklink.com/v2/catalog/catalogitem.page?P=32072#T=S&O={"iconly":0}

Yeah, that's stable but the inefficiency part rules it out in heavily motorized stuff :)

[msk6003]

Icons FW14B has blue half bush with wide/printed wheel!

[SNIPE]

22 minutes ago, msk6003 said:

Icons FW14B has blue half bush with wide/printed wheel!

Nice find

[msk6003]

Seems like we will get white 2L frictionless axle pin on next year.

Wheel is also new. Size is same with 42610 but has different shape on side.

[astyanax]

16 hours ago, msk6003 said:

Icons FW14B has blue half bush

They look regular LBG to me 

[Stereo]

7 minutes ago, astyanax said:

They look regular LBG to me 

It's how the actual car is, blue nuts on the right side, dk grey on the left, since they have opposite threads and can't be mixed up.

[Lyichir]

5 hours ago, Stereo said:

It's how the actual car is, blue nuts on the right side, dk grey on the left, since they have opposite threads and can't be mixed up.

Oh wow, that's nice attention to detail!