Can the 3L worm gear drive the 7L rack?

[Hrafn]

If the 3L worm gear (15457) is placed parallel with and 1 stud above the 7L gear rack (87761), will the gear and rack mesh? Thanks!

[Attika]

I'm afraid it won't work. The 7L rack mesh with the 12 tooth gear what is bigger in diameter than the wormgears are. Wormgears have the diameter same as the 8 tooth gear. But if you use one of the old type of racks that should do the job. Sadly those aren't odd number of studs. (6,8,10,etc)

[jgw]

It works NOT with the 7L, but it DOES with the 11L. The worm gear fits between the 7L with some studs magic, but you only have 1 stud of movement. If you use the 11L you got way more movement.

http://www.eurobricks.com/forum/index.php?showtopic=128437&view=&hl=&fromsearch=1

Here you go, post #4 or something shows the trick

[Didumos69]

It works NOT with the 7L, but it DOES with the 11L. The worm gear fits between the 7L with some studs magic, but you only have 1 stud of movement. If you use the 11L you got way more movement.

http://www.eurobricks.com/forum/index.php?showtopic=128437&view=&hl=&fromsearch=1

Here you go, post #4 or something shows the trick

Nice trick! In fact the 7L rack only has about 3L of actual teeth, so will get you nowhere. The longer one is 13L and has a 9L span of teeth if I'm not mistaken.

As has already been pointed out, getting a worm gear in the right height would be the same as bringing an 8 tooth gear in position. In general you can state that for every extra stud you need to bridge, you need 16 extra teeth in your mesh. Given that the 12 tooth bevel gear alignes perfectly with the 7L rack, you would have to bring the gear rack up .25 of a stud (<=> 4 teeth) to mesh with a 8 tooth gear or worm gear. Apparently a studded beam placed up-side-down does just that. :wink;

Edited June 16, 2016 by Didumos69

[Hrafn]

Thanks, everyone. For my application space is at a premium and I need to keep everything in this part of the construction at integer-stud spacing, so the 3L worm won't work. I have other options fortunately.

[TheItalianBrick]

only if it has a driving licence :laugh:

[jgw]

Nice trick! In fact the 7L rack only has about 3L of actual teeth, so will get you nowhere. The longer one is 13L and has a 9L span of teeth if I'm not mistaken.

I think I messed up my facts :-/ anyway, good luck building!