Linear slides
 

The use of a telescoping or vertical lift system has been avoided by our team since our rookie year back in 2001. We had tried using the tape system with the window motor glide system but we needed a lot of help.

I have been looking at some samples sent to our team from igus and those new parts donated by them to BEST. They look pretty solid and easy to use.

Does anybody have any experience with these types of items? Here is a flash animation from their website that really looks adaptable ;)

http://www.igus.com/dwflash.asp

This is a page with pictures of the many examples shown in the flash movie.

http://www.igus.com/show_dw.asp



APS

Re: Linear slides
 

Most people have the most trouble with these sort of things when they don't understand the accuracy required. The first part of that flash demo shows two round rails connected to a solid piece and the second part shows a couple round rails on separate pieces. I would strongly suggest using a single piece rail because of how tight you need to hold your parallel tolerance - very likely this is in the thousandths of an inch range, depending on the rail system.

I have a personal, relatively unfounded bias toward 80-20 extruded aluminum and their linear bearings in FIRST applications. Though a bit pricey, the linear bearing on the 1" size extrustion has force ratings that are appropriate for FIRST, are pretty forgiving in terms of misalignment and don't require lubrication.

But to answer your question - from a first glance, this looks descent. Check out the force ratings and make sure it'll hold up to what you need. The even more important (IMHO) design question is, how are you going to make that carriage move? I think finding a rail setup is the easier part of a linear system.

Matt

Re: Linear slides
 

Team 294 quite effectively used heavy duty industrial drawer slides for their vertical telescoping action this year.

Team 980 (also quite effectively) used round aluminum tubing where one precisely fit inside the other and they drove it in and out with a timing belt.

Re: Linear slides
 

Team 617 used Drawer slides, too. They were preaty cheep at $12 for 2 large slides from Lowes. The tricky part is installing them. You will probably need to get other screws than what is supplied and make sure they work. Inside clearences are tricky. There should be a pic/movie on our site.

Re: Linear slides
 

There are many ways to accomplish a reliable telescoping system. You can build both square and round "tube in tube" systems like teams 175 and 980, and a host of others. You can purchase off-the shelf drawer sliders and the like, similar to 111, 294, and 1071. We personally used the 8020, 1" linear bearing with much success. You can see examples of it on our website, along with teams 56, 103, 222, and many others.

I'm not all that familiar with the IGUS system, though I know that many teams use their products, again with much success. Tolerances are the key, as is maintaining the proper overlap between the two pieces. The more you extend one leg with respect to the other, the stronger the bearing needs to be, and the tighter the tolerances need to be. We tend to keep a 4:1 ratio of extended length to overlap.

If you need more detail or answers to specific issues, let us know.

Bengineer

Re: Linear slides
 

As much as I like hearing that number, I must make the correction that we did not make a telescoping arm of any sorts. Haven't ever built one really, tried once in 2002 and failed. In 2005 we built a double jointed (shoulder and elbow) using very thin (.040) sheet aluminum bent and riveted together so we could get a very lightweight, thin-walled, yet still strong arm.

Anyhow, carry on.

Re: Linear slides
 

Is the previous post referring to linear slide mechanism that was not a telescoping arm :confused:

Mere speculation on my part :)

APS

Re: Linear slides
 

I believe 1072 used them on their robot in 2005, you may want to contact one of them -- Veselin Kolev visit's these boards once in a while, maybe you can drop him a PM.

Re: Linear slides
 

A great solution is the Item linear slides. If your already using item extruded, you simply put the nylon sliders into the extruded and away you go. We did this in 2004, and it worked great. We got completely flipped up off the bar and fell to the ground, but our mast had no problem performing the naxt match. Item also sells some nicer, bearing/rail type carriage stuff too, although I have no experience with that.

item

Re: Linear slides
 

For the past 2 years I've built my teams arms, all of which are telescoping. We use extruded aluminum. If you have any questions or need any help just PM me. If your only doing 1 extension it's quite easy, but as you get to 2 or 3 extensions, it gets a little tricky. You can use both cable and chain. As of right now I only know how to use chain for 1 extension :( , but i hope to change that soon.

Re: Linear slides
 

3 stage IGUS Drylin system. Worked pretty well except the winch had to be rewound by hand(foot) after every match.