This may be a stupid question, but I was wondering what teams thought of using these for linear mechanisms, such as elevators. Specifically for an elevator, these seem more compact than the more common method of 2x1 tubes and bearing blocks, but they also could be heavier (not sure of the exact weight difference). You can buy really strong ones (rated for loads much higher than an elevator would ever see, like this from Misumi).
From my experience the max strokes are usually not enough for the needs of FRC. The one you link has 744mm max, meaning for an elevator that goes to, say 2.2 m you would need 4 stages, instead of 2 if you go with the “regular” method.
Also, it is more expensive, less reusable, harder to intergrate with other robot systems.
I have seen however teams who use it for horizontal mechanisms, say an intake, where it seems nice.
just my 2 cents.
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in 2020 1425 used them on their climber. It worked pretty well. Team 1425 - 2020 Robot Reveal - YouTube
Seems to work fine but I do believe it was pretty heavy and they did have some trouble with mounting hardware onto it.
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We used almost identical slides on an intake mechanism for our our 2006 robot so I have 3 opinions:
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They lasted about 1 regional before having to be replaced because they were not durable enough for the use. Other teams targeted the mechanism they were used on to break it. (different time, different rules)
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They were very expensive and heavy for what they did.
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We had the ability to design and build lighter, cheaper, more robust, and better for the application linear motion using aluminum tube and HDPE/Delrin slides.
I give them 1 
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not drawer slides but we used the Igus slides that come in the KOP in 2020 to lift our hook for climbing. Being aluminum they were much lighter. Was a bit of a pain but worked ok https://youtu.be/fMd4oUUn5Bc?t=63
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I think you will find recirculating linear ball bearing systems or v-wheel systems to be cheaper, stronger, and easier to mount besides being the proper tool for the job. Here is the first random listings on Amazon:
GUWANJI 400mm Linear Rail Guide with 4Pcs SBR16UU Bearing Block for Fully Supported Linear Rail Length 15.7 inch(400mm) https://a.co/d/hQ5feaH
Befenybay Big V-Wheel with Plate for 2020 Aluminum Profile 3D Printer Parts for CNC Kossel Black Wheel https://a.co/d/07SiDQE
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We used drawer slides for our first (and only, sadly) comp in 2020 on our climber extension arms. We replaced each side about 4 times during the competition+playoffs, so a given side lasted about 2 matches.
After that comp we had a new, non drawer slide design tested and ready before COVID shut everything down
I would not recommend their use, but if you do you must figure out how to load them only in the direction they are designed to handle. Any side load and they’ll come apart.
We used drawer slides in for both power up and recharge and they worked great for moving the intake in and out if I remember correctly in 2018 our whole shooter tunnel and intake sat on the slides and it was powered by two pneumatic cylinders and in 2020 it was just the intake I think the only problem we had with the slides was at the 2020 Miami valley regional semifinals we got hit in to the truss in the center of the field and bent the slides slightly and we were able to bend them in the opposite direction before the next match
We used drawer slides for an elevator in 2018. Never again. The slides came apart at the most inconvenient time.
Now we show this video to our new team members to scare them away from the idea: Transformer Table The How To? - YouTube
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Drawer slides seem like a compelling and easy off the shelf solution at first glance, but there are a few factors that make them a less-than-ideal solution for an FRC elevator:
- First consider the fact that drawer slides are meant for a pretty static application, opening and closing drawers. This means that although the load rating seems pretty good initially, once you factor in all the unpredictable dynamic loads an FRC elevator sees as you slam it up and down and into field elements and other robots, the twisting and lateral loads will easily break the slides.
- Secondly given the rise of all the good COTs solutions for FRC elevators, the weight to simplicity tradeoff becomes negligible. Given that you can buy the new REV predrilled tubes and Thrifty Elevator components that have matching hole patterns I think building a standard FRC style elevator is much simpler than even trying to integrate drawer slides and also significantly lighter.
On a side note, I think its great that you asked this question and don’t think its stupid at all! Far better to ask a question here on CD and get the input of the community, especially if you are considering a design decision and are unsure if it is a good choice!
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Our 2019 elevator had those on it and they were really heavy and kinda pricey for the long ones needed for an elevator
I’ve used the IGUS Dyrlin Rails and slide bearings mounted to 1x2 0.062 aluminum tube on two occasions in the past. We found them be lightweight, sturdy and can be very fast. Only downside is it’s a little pricey.
Corrected a typo. from 0.62 to 0.062 aluminum tube.
1986 had some good success with drawer slides on their climber in 2013.
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I have seriously explored them during several seasons, but each time cost and weight become problematic. You can make the dimensions work, but it requires some creative fastening.
From what I’ve played around with in CAD, I could see them being helpful for saving space, though.
(Edit: And, of course, I would check out the teams that successfully used them, as linked by others.)
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Our head coach at the time was always worried about funds so he wouldn’t spend money on anything we could possibly get cheaper even if it wasn’t as good. I understand how he got that way though since he started the team and the team struggled with money in the beginning. We still struggle a bit for funds but we’ve changed our thought process of where to spend a little extra vs. being as cheap as you can.
Hefty.
Oops… Damn typo decimal place. 0.062 or 1/16 walled aluminum
I too started on a team many years ago that didn’t have a lot funds either.
Basically enough to pay the registration fees and little else to build a robot from.
We made choices on where to spend, and where not to spend based on performance value.
In this case, the cost of the elevator was worth every penny and then some.
It’s also a very valuable lesson on how you can work in tight budget, do more with less and still be highly competitive
I’d use an Igus DrylinR or WD-10-40 but wouldn’t go with a stock drawer slide. Cheap slides are only good in vertical shear and expect to be fully constrained everywhere else. Tension delaminating the stages will wreck them quickly, and you can get that delaminating tension from a torsion loading very quickly.
It’s really, really hard to predict loading in FRC. You are a junior designer. Your mechanism will load itself in a way you don’t expect it to. Another team will load your mechanism in a way you don’t expect it to.
The igus DrylinR or WD-10-40 profile dry bearings are at least as expensive and at least as heavy as the tube-and-bearing solutions being developed by FRC vendors specificaly for our application, and are designed for use in <0.02mm (20 micron) repeatability automation applications rather than “an inch plus is fine” FRC applications.
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Thank you all so much!
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