Aluminum Rack and Pinion Sliders

I would really like to see some aluminum sliders. It would make multiple things much easier due to the less weight. On arms for example, we could down torch our gear ratios see the arm can move faster and we could greatly reduce weight on the overall bot.
Thank You
This is just a suggestion but it would be cool to see in the near future.

this was talked about before
but most decided that they didn’t come out because if they are too weak, they will warp
making the linear “slides” completely useless

The existing sliders are not rack and pinion, they just have holes for mounting a rack. You could also use rope (strong and thin) with pulleys, or chain for slider positioning.

I’ve looked at some ideas to make some rolling aluminum sliders:

  • get a 7/8" x N/16" flat steel bar for tooling
  • put it in a 1x2x1 Aluminum C angle, then crimp the edges over the steel tooling
  • build some kind of rolling slider based on 3/8" hex standoff with a shoulder bolt on each end.
  • re-machine some spacers until then fits as a roller over the shoulderbolt.
  • Start by measuring some spacers to find a starting value of N/16 for crimp.
  • Plan on a couple iterations, since you won’t (at least I wouldn’t) get it right the first time.

I have a sketchup of a college-level-custom-plastic holder for several hex standoffs, but you could machine your own out of a stack of flat bearings or something.

You could also try just using flat bearings as glide-bars inside the crimped C.
This would work more like an Igus slider.

One advantage of reforming 1x2x1 (or 1x5x1 for that matter) is that you can get a one piece longer slide (x35) size, rather than just the existing x25 1foot size sliders.

Can you post the sketch up file for your slider so I can see it better?

sketchup skp is not an allowed extension, so I zipped it.

Also attached are a couple collections of vex parts that might make slides.

slide_roller2.jpg shows that tank rollers are slightly too large for 1x2x1 channel.

  • also, a couple shoulder bolts in a short threaded hex might make a good axle for the right sized spacers.
  • and a manilla folded 1x2x1 model showing the edges crimped in.
  • the flat bearing in the middle represents the sketchup piece, some kind of plastic holder to hold several hexbars in a row.

slide_roller1.jpg shows ideas for other types of roller slides:

  • on the right, 2x2 angles have taller edges to be crimped over.
  • on the left, use two 1x2x1 channels nested in a 1x5x1 for the guide
    and a 1x2x1 channel as the slider-roller-carrier.
  • 7/8" hex nests inside, holds shoulder bolts.
  • spacers, worm gears, or winch pulleys might make good rollers
  • tank tread bogey rollers are 1/16" too large, unfortunately. (18.2 KB)

Wow, I would never have though of that! Very innovative. This could be lighter than aluminum rack and pinion sliders because those kits use a lot of pre-bent metal and it gets really heavy. The metal sliders are heavier than all other metal parts their size.