35 replies to this topic

[KEvron]

so, the last technic set to include a 40t gear was the 8051 motorbike, released in 2010, and that set had only one 40t gear (10212 imperial shuttle was released that same year, with eight 40t gears). we've seen a lot of changes to the theme over the last decade; is the dicontinuation of the 40t gear the final blow?

KEvron

p.s. i'm not going to pull this punch: bevel gears suck.

[nychase]

I was looking at that too.  The thing is... they really don't have anything that can act in its stead so its possible that it will come back as needed.  

When I was a kid I got one 40T red on a silly bioncle set and I thought it was the coolest thing ever.  When I came out of my dark ages I still thought they were cool so I started to try and collect as many as I could.  I easily have over 300 of them (in various colors) including over 40 black ones!

[parda]

The 9695 set includes 4 of them...   the 8051 motorbike 1, and the 10212 Imperial shuttle UCS has 8  

2010 sets... well the gear is still in production... and is a very good gear for reductions 5:1

Edited by parda, 30 April 2012 - 10:51 PM.

[rgbrown]

KEvron, on 30 April 2012 - 10:29 PM, said:

p.s. i'm not going to pull this punch: bevel gears suck.

I agree! Have you ever done any efficiency measurements when building your clocks? What's your opinion on meshing bevel and spur gears?

[KEvron]

nychase, on 30 April 2012 - 10:45 PM, said:

I thought it was the coolest thing ever

that one element speaks of lego precision like no other, imho.

parda, on 30 April 2012 - 10:50 PM, said:

The 9695 set includes 4 of them

i omitted mention of that one because it's a mail-order supplemental set, but, yeah, it does have four of them, and i suppose it's fair to consider that set as still available, as opposed to the shuttle and the cycle. still, 'been two years....

KEvron

Edited by KEvron, 01 May 2012 - 06:06 AM.

[Paul Boratko]

Did you call Lego and ask if they still have them in stock...?

[KEvron]

rgbrown, on 30 April 2012 - 11:27 PM, said:

Have you ever done any efficiency measurements when building your clocks?

no, but i've compared their masses, as reported at bricklink, and i've found that the bezels are heavier than their spur gear counterparts; 12t weighs more than 16t, 20t weighs more than 24t, etc. superfluous mass can really have a pronounced effect.

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What's your opinion on meshing bevel and spur gears?

you have to get jiggy with the axle hole layouts, but i've found some pretty good meshes for most of them. for 20:8, i like to use two 20t half-bezels, face-to-face. makes a kind of a cage gear. very smoothe.

no, my main gripe with them is that tend have a sloppy fit on the axles, and in that regard, they can be tough to align. poor alignment can really have a pronounced effect.... heh! the half-bezels are worse than the doubles, but they're both worse than the spur gears. spur gears are easier to align, too. usually fall right into place.

and they rub. i can get away with eliminating a bush between a spur and a technic brick, but bezels will rub.

and they're plain ol' ugly. spurs have style.

KEvron

Edited by KEvron, 01 May 2012 - 11:07 PM.

[Paul Boratko]

After checking, There are a lot of them on bricklink, so it doesn't look like there is going to be a shortage anytime soon...

Speaking of bevel gears, I have noticed that the Black 20t bevel gears don't seem to mesh quite as nicely with the 12t Bevel gears as the tan ones do...

[KEvron]

Paul Boratko, on 01 May 2012 - 05:32 AM, said:

Did you call Lego and ask if they still have them in stock...?

no, i didn't pursue it that deeply. i'm up to the gills in them, myself, so lego direct didn't occur to me. they tend to keep an educational supplemental set available, so i wouldn't know how to interpret a positive response from them.

to be honest, i've been hoping beyond all that they'd give us at least one more round of color palette gears. the gear's continued absence from the theme only further dashes those silly hopes.

KEvron

[Paul Boratko]

There's a seller on Bricklink who has over 4,500 of them new for 89 cents, so you should be in good shape for awhile..

That gear has been around since the 70's, so I don't expect it to go away anytime soon...

It comes and goes every few years...

[KEvron]

Paul Boratko, on 01 May 2012 - 05:54 AM, said:

There's a seller on Bricklink who has over 4,500 of them new for 89 cents, so you should be in good shape for awhile

like i say, i've got enough of them to last 'til perdition. i just see it as a bad omen.

it'd be nice for them to occasionally release a round of color palette gears, like they did with the slizers. if they were to mix the color choices right, people like me would buy the entire line just to complete the palette (i've got a project in mind that would make use of the various color gears, but it depends on using at least one - two would be better - blue 40t gear, which don't currently own and, considering the asking price at bricklink, i likely never will).

KEvron

[mahjqa]

I don't want lighter gears. I want gears that don't break when I do stupid things with them. I don't need colors. Lego keeps a limited amount of parts; with each new color gear, it takes away another part.

You call them ugly, I call them functional. You're just not used to them. They do what they need to do, and they do it very well.

[KEvron]

mahjqa, on 01 May 2012 - 08:43 PM, said:

You call them ugly, I call them functional.

the two are not mutually exclusive. to wit: the 40t spur gear is both.

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You're just not used to them.

a rather hasty assumption, and one that doesn't change the fact that they're crap compared to the fine precision and sleek styling of the original spurs.

KEvron

Edited by KEvron, 01 May 2012 - 11:04 PM.

[mahjqa]

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You call them ugly, I call them functional.

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the two are not mutually exclusive. to wit: the 40t spur gear is both.

The bevel gears are shaped like that because of their function; they need to work at a 90 degree angle. I'd love to see a more 'beautiful' bevel gear that still has the same versatility.

It's nice to see you agree with my two other points.

Edited by mahjqa, 02 May 2012 - 11:05 AM.

[Erik Leppen]

I think it's a pity that the 40t gear and the 36t bevel gear are used so little. The 36t gear is currently the only way to achieve a large reduction over an angle, without using the worm gear. And 36 : 12 happens to be a nice 3 : 1 ratio. The 40t gear is nice for large reductions, has a factor 5 and is one of the few gears that fits the worm gear in the current system. The additional axle holes are useful to connect the gear to beams more rigidly. I've used that more than once: worm gear to 40t gear, central axle hole as pivot points, other two axle holes used to connect a liftarm to the gear. It's a very strong system.

Edited by Erik Leppen, 02 May 2012 - 11:46 AM.

[Zblj]

My only gripe about the 40 tooth gear is its massive friction when inserting axles in any cross shaped axlehole.

[KEvron]

mahjqa, on 02 May 2012 - 11:03 AM, said:

I'd love to see a more 'beautiful' bevel gear that still has the same versatility.

i wouldn't mind that, either. a better fit on the axles would be nice, too.

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It's nice to see you agree with my two other points.

have i unwittingly stumbled into youtube? *snort!*

Erik Leppen, on 02 May 2012 - 11:46 AM, said:

36 : 12 happens to be a nice 3 : 1 ratio.

i would think the 24:8 is stronger arrangement, owing to their smaller diameters.

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The additional axle holes are useful to connect the gear to beams more rigidly.

those holes complete the element. a million and one uses!

Zblj, on 02 May 2012 - 01:09 PM, said:

My only gripe about the 40 tooth gear is its massive friction when inserting axles in any cross shaped axlehole.

i'm not following you, zeeb; do you mean the other + holes on the gear, itself?

KEvron

Edited by KEvron, 02 May 2012 - 11:36 PM.

[mahjqa]

@KEvron If you don't agree, care to refute?

[DLuders]

Who would have thought that a simple piece of plastic would cause so much consternation?

    [img]

[KEvron]

mahjqa, on 03 May 2012 - 12:29 AM, said:

@KEvron If you don't agree, care to refute?

generally, personal opinions are not subject to refutation. i addressed the points i wanted to address; was there something more you wanted to say, yourself? don't be shy.

DLuders, on 03 May 2012 - 12:32 AM, said:

Who would have thought that a simple piece of plastic would cause so much consternation?

not on my end. it's a beautiful part. the quintessential technic element, imho.

KEvron

Edited by KEvron, 03 May 2012 - 06:17 AM.

[dhc6twinotter]

I used a 40t gear on my 16 cylinder radial engine project, and I briefly thought about using it on my forwarder project.  It may come in handy on a future project as well.  

It has it's uses, so I hope LEGO doesn't get rid of it, but like Paul said, there are plenty on Bricklink.    

Edited by dhc6twinotter, 03 May 2012 - 01:41 AM.

[rgbrown]

Haha, this thread is getting hilarious  

KEvron, on 02 May 2012 - 11:35 PM, said:

i would think the 24:8 is stronger arrangement, owing to their smaller diameters.

But larger diameters give less friction. (everything else being equal)

[KEvron]

dhc6twinotter, on 03 May 2012 - 01:38 AM, said:

like Paul said, there are plenty on Bricklink.

bricklink is for afol geeks like us, not the general public.

rgbrown, on 03 May 2012 - 03:10 AM, said:

Haha, this thread is getting hilarious

who'd have thought such an innocuous observation would elicit contention?!

....but yeah, it's fun.

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But larger diameters give less friction.

ah, i wasn't aware of this. could you explain?

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(everything else being equal)

but the masses are substantially different; 36t weighs 3.5g, 24t weighs 1.14g.

KEvron

Edited by KEvron, 03 May 2012 - 07:18 AM.

[Lipko]

rgbrown, on 03 May 2012 - 03:10 AM, said:

Haha, this thread is getting hilarious  


But larger diameters give less friction. (everything else being equal)

I don't think that "everything else" is equal. For example the force on each tooth is smaller, since bigger radius means smaller sum force between the gears (if torque is constant) and more teeth are in contact so this force is divided even further. That means the gears are "stronger" (can cope with more torque).

Less friction (at constant torque) seems to be correct, as the contact forces are much smaller on each tooth (and the more contacting teeth can't compensate that).


I may be wrong though, studies about gears were long ago and I didn't really think it over...


EDIT: I'm not sure about the friction thing now, as the friction force is smaller, but acts on a bigger radius. I guess other factors come in to play when calculating friction torque.

(Morning=no habla england)

On topic: I have never had the 40 teeth gear, but I always wanted one. It looks awesome.

Edited by Lipko, 03 May 2012 - 07:19 AM.

[KEvron]

Lipko, on 03 May 2012 - 07:11 AM, said:

the force on each tooth is smaller, since bigger radius means smaller sum force between the gears (if torque is constant) and more teeth are in contact so this force is divided even further. That means the gears are "stronger" (can cope with more torque).

okay, i get that. by dispersing the sum force over more contact surface, the gear teeth are able to better withstand the force.

...but you don't get something for nothing, right? the greater the diameter, the more input power required to overcome the torque. wouldn't proportionality come into play?

the friction stuff is (even further) over my head. studied mu factors and all that in high school physics, but that was more than a dark age ago.

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On topic: I have never had the 40 teeth gear, but I always wanted one. It looks awesome.

oh, you need to get on that! a bag of 25 will run you $10 at legoeducation (u.s.).

KEvron