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Subject: 
 Re: I wish Lego made an "Anti-Backlash Gear"
Newsgroups: 
 lugnet.robotics, lugnet.technic
Date: 
 Thu, 5 Apr 2001 05:16:40 GMT
Viewed: 
 5140 times
  
Interesting , but  we need one for Lego! I do see what you are saying, and
It is an interesting solution,, although a little hard to visualize...Thanks!


In lugnet.robotics, Thomas D. Fulk, Jr. writes:
> 
> 
> > Tech question for us: Any body know what an Anti-Backlash gear
> > is? If Lego made one, we would all have super precise Robots and
> > mechanisisms! BERG carries them... Anybody know what I'm talking
> > about?
> 
> 
> 
>  I know of 1 type of zero-lash/anti backlash geartrain.
> 
> 
> It's hard to put it in words but I'll try.  My example assumes there
> are only 2 shafts but it can be applied to as  many shafts as you
> need.
> 
> 
>  In my example S1 represents  our first shaft.  Drive or driven, you
> choose.  result is the same.  S2 represents the other shaft in our
> gear train.  G1and G2 are 2 separate gears on S1, and  they are both
> in mesh with G3 which is located on S2.  G2 is not splined to S1 like
> G1 is, and is only there to act with the spring to remove the lash.
> 
>     Now.... Our first gear is actually  2 thin gears (G1 and G2)
> together on the same shaft (S1), working as 1 gear... mating to a
> single thicker gear (G3) with a torsional spring force causing G1 and
> G2 to rotate in opposing directions, except the teeth of G3 stop them
> from rotating more than the lash between the G1/G2 pair and G3.
> Really the G1/G2 pair is acting a variable pitch gear that perfectly
> mates to G3 at all times.
> 
>   If the force required to move the load is more than the spring
> force between G1 and G2  there can be lash in this setup.  In the
> real-world application where I have seen this used (Toyota 3.4 V6
> engine, to mate the two camshafts located in each cylinder head) there
> is a way to lock G1 and G2 together before you separate them from G3.
> I assume this is because the spring is so strong that it would be hard
> to rewind in the field.
> 
> Thomas
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 



Message has 1 Reply:
  Re: I wish Lego made an "Anti-Backlash Gear"
 
(...) I was going to say this solution is easy, but then I tried it. There are only two shaft's in this example. As lego don't make don't make a 'double width gear' You'd have to use four to make it in lego. All you'd need is three normal 16 tooth (...) (25 years ago, 5-Apr-01, to lugnet.robotics, lugnet.technic)

Message is in Reply To:
  Re: I wish Lego made an "Anti-Backlash Gear"
 
(...) I know of 1 type of zero-lash/anti backlash geartrain. It's hard to put it in words but I'll try. My example assumes there are only 2 shafts but it can be applied to as many shafts as you need. In my example S1 represents our first shaft. (...) (25 years ago, 5-Apr-01, to lugnet.robotics, lugnet.technic)

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