Subject:
|
Re: RCX Tank Base
|
Newsgroups:
|
lugnet.robotics
|
Date:
|
Wed, 4 Dec 2002 11:00:53 GMT
|
Viewed:
|
919 times
|
| |
|
|
"Rob Limbaugh" <lego-robotics@crynwr.com> wrote in message
news:73718FFFA963C045BD5B74B2F9B1EBA53B0D70@gcgpo1.greenfieldgroup.com...
[attaching tracks snipped]
> Now that I'm thinking about it... another option (as tedious as it may • sound)
> might be to take some thread (sewing, embroidery, or cross-stitch) and tie • the
> plates to the tread links.
This may help stop them falling right off (as Roy Nelson says leter in this
thread), but I'd be very doubtful if it would stop them working loose. You
only need to move two Lego parts apart by a couple of mm to separate them,
say 3mm. You can translate this into the maximum your threads can stretch by
while keeping all the treads in place.
To keep it simple, assume we have a 500mm of track and 200mm long "contact
patch" with the ground, and we'll ignore the rest of the track for now. With
no stretching this part is, obviously, 200mm. With a 3mm bump in the middle
you get a triangle, the total length of the bottom two sides (the other side
is 200m) is 2* _/ (3*3+100*100) (from pythagoras for each half, that's a
square root sign) = 200.1mm. The 200mm part would only have to stretch to
200.1mm. For the whole track that's a 0.1mm stretch in 500mm, or 0.02%.
I think you'd need a heck of a lot of tension to ensure your string doesn't
stretch by 0.02%, even with relatively small forces acting on it. I'd doubt
that the tolerances in a Lego model would allow you to get away with
constraining moving parts that tightly anyway, even if you could find the
right string (or wire) and fix it in place with sufficient tension.
I suppose tying individual plates to the tracks would work OK, but tying
tens or hundreds of tight knots and keeping them small enough not to foul
the grears would be tricky and tedious.
Tim
|
|
Message is in Reply To:
 | | RE: RCX Tank Base
|
| <SNIP> (...) I haven't tried any adhesives on my tracks yet, but I was thinking of trying hot-glue if it doesn't melt the LEGO's or some tub caulk. School glue and/or wood glue (leaning more towards wood glue) may have enough strength to hold and it (...) (22 years ago, 3-Dec-02, to lugnet.robotics)
|
7 Messages in This Thread:
 
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
Active threads in Robotics
|
|
|
|
|
|
