As we know, some parts have been redesigned by TLG over time, and this is also the case of many Technic parts.
Sometimes existing parts are discontinued, others replaced by new alternative designs, but in some cases certain parts receive just some small design changes. Either to strengthen them, to facilitate the production process and/or reduce production costs.
Several Technic gears have suffered redesigns in the past and it was now also the case from Z16 gea.
According to the BrickLink database, it seems the change was first noticed within set 8043, whose first boxes were shipped with the previous Z16 version (4019) and are now being shipped already with the correspondent new design (94925).
The old (left) and new (right) Z16 gear designs, side-by-side.
I don't know exactly what motivated this change, or which problems the previous design had that lead into this modification, but guess that the strengthen was the purpose. The fact that the previous design didn't have a closed surface immediately close to the place where to insert the Technic axles, might have been the issue to address.
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15 comments:
I found these new gears also in the 8051 motorbike ordered from German Amazon this month.
Ya, it is expectable that soon it has replaced the old version in all new packaged sets.
This is a good change too. I have broken many of these in the past. Under alot of load the old design would split in two. Some would even explode and i would hear and see them bounce off walls. These were the weakest of all the gears.
I've never had a problem with these breaking, but I really do wish they would re-design the 8 tooth gear, not so much for strength (there isn't much room for improvement), but to make it the correct width! The rim around the axle hole fits inside the counterbores in beams for the ends of pins, consequently it can move side to side. I’ve broken lots this way as the corners of the teeth get chewed up. I've never really thought about this in detail, so maybe it can't be done due to the dedendum of the teeth being smaller than the hole counterbore.
@me00rjb,
I've also noticed the same problem on Z8.
The solution I envision, is to make the rim thicker, so that it won't fit inside the hole counterbore.
It would mean a lot more plastic used in this small part. :-/
Whilst that would also make the gear much stronger, it would also require a mold with many more parts and would have to come apart in a way that does not facilitate having more than one gear being made in each mould, making them much more expensive to produce.
@Al
That's definitely true!
But then, there are other solutions possible, like for instance making the teeth wider.
The new Z16 in someone's 8043 set:
http://www.brickshelf.com/cgi-bin/gallery.cgi?i=4796052
full gallery:
http://www.brickshelf.com/cgi-bin/gallery.cgi?f=454947
I still like the old Z16--I never broke any and it still looks good. But I like the new design more. I also want the width of the Z8 improved--I think this improvement is long overdue. Gears are one of my favourite LEGO parts.
If a gear breaks, the design of all the rest is also a failure.
In the past I only had troubles with the oldest Z24 breaking.
In my opinion all the gears should have the design like the Z12, Z20 and Z36 series, because they make less noise. :-)
Nevertheless this gives hope for the universal-joints and the perpendicular thingies; they are the example of weak parts!
People the are breaking gears are pushing them past their limits. You have to remember people, these things are only plastic.
Ah but pushing the limits is what is FUN. Since These gears are very low cost under 20 cents. Is one of the many great things about Lego robotics. We had a contest back a few year ago at nxtasy. who could lift the most weight and move it a meter. We had one entry that lifted over 100lbs! Talk about PUSHING limits.
The universal-joints are very weak. In my V4 LPE they snap like twigs.
Yep, gears can be weak... but you can also stack them to have less torque per gear.
I'm ambivalent about the new Z16. The old one had an interesting (if unintended) advantage: the small round holes were just the right size as the thin tubing that is used for decoration in some sets. This allowed you to make a novel (and very useful) "dual Z16" gear, that allowed some interesting constructions (such as a gear directly on the old-style motor, plus an axle coming off that motor:
http://www.brickshelf.com/cgi-bin/gallery.cgi?i=2273811
(look at the lower right frame... i really should document more MOCs this way, it's kind of fun).
@Brian Davis
Nice way to document MOCs indeed.
It means however a lot of extra work...
But I didn't got the purpose of this arrangement???
Maybe you can still do it also with the new gears, if you compress a bit the tubes, into the new holes.
@JAMS tahts my gallery, those gears came with 8043 and only that s set. Tubes cant be squieezed there, the teeth are same width as old ones.
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