Double slider?

We were fortunate enough to qualify for worlds and our final robot will hopefully fix the kinks of our states bot. One of these, I want to eliminate two flips and instead have a 4 stage tray with two of them being sliding stages. I have not witnessed many sliders in our region nor have we ever built one, and the most I’ve seen on YouTube is a single stage slider, so I wasn’t sure what’s holding teams back from creating a double slide.

I’m not asking for a specific design, but I would appreciate if someone could point out the pros and cons I’m theory.

You have 6 stages!? If you do a 2 stage slider it will probably work as long as it doesn’t catch on cubes when letting go of the stack. Make sure it has some sort of low friction surface at the top to slide away when you back out. Also it will probably be pretty thick when folded up so make sure you have space. Other than that, obviously don’t use the vex sliders. Some sort of cascading 1×1 L-channel would be best.
Edit: you’re going to worlds so you probablu know that last tip already


A double slide would definitely begin to have bending issues, because the supports for the 2 sliding stages would be so far down, and there would be so much weight on the sliders.
Also you’re going to have to nest the tray walls within each other.
On top of all of this, the sliding joint between the sliders will have to be flush, otherwise cubes will catch and not go up.
Overall, I think teams have just considered double sliders to not be worth the effort.


Oh no, we will have a total of 4 stages, not 6.

Ok that makes more sense. I wasn’t sure but I wasn’t doubting it.

I just did the math and found that with 5 inches of overlap with each stage, I will still be able to hold 12.5 ish cubes. I’m quite certain that this will be enough since I’ve seen single sliders hang on without severe bending with only 1.5 inches. what do you mean by cubes catching on the sliding joint?

The sliding joint is where the 1st slider meets the 2md slider. It has to be almost level or else cubes will catch and create friction.

Also, while 1 slider may not bend that much, the problem will be greatly increased when you stack 2 sliders, because now they are holding twice the weight with twice the length (the cubes get more leverage)

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A double slider is definitely a viable and effective solution in comparison to a 4-stage flipout tray. I believe that our team has come up with an effective design for this “double slider” and being able to stack upwards of 10-11 cubes.

Here is a video of a match-


@ThirdDegree had a good double slider… might wanna ask him. It did however use a lot of custom cut lexan

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We actually didn’t use much custom lexan at all but there are a couple methods that do.

Pros of double slide:

Deploying is super easy. With only 1 flipping stage, and especially on robots with no-deploy rollers, simply intaking cubes deploys your tray.

Added mobility especially during the scarcity period in the last 30 seconds of the match is huge. It also helps for skills, and not knocking stacks (we’ve all done it😬)

Cons of double slide:

Constantly needs lubricant, or it’ll cause intakes to have a bit more trouble around 10+

Has the potential to get stuck on top of stacks, although this is something that a number of teams have solved, and becomes a non-issue with time.

I’d highly recommend trying a double slide for worlds. They’re a bit of work to get going, but they give a few small advantages that might distinguish you from the sea of 4 or 3+slide standard trays.

@ParkerT_9457B also has a lot of experience with double slides. He inspired me to build mine. I’d recommend checking out his reveal video if you want some inspiration.


This is a very intriguing concept for a tray. If you can pull it off, this would be excellent. I have been seriously debating this idea for a month and brainstorming on how to do it, but I can’t figure out how to make it have

  1. Little to no friction
  2. Sliders not bending
  3. 1st slide connection bending (where the slider is attached to the tray)
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Actually I think you would want a balanced amount of friction so that when you are stacking the slider does not fall onto the stack as you are backing away. If there were no friction the slider would pull the stack down as you backup

if there’s friction in the slider the purpose of the slider is defeated. There isn’t any retraction and the drivability of the robot doesn’t change. While it’s harder to make a slider with no friction, it’s completely worth the time.


As @ThirdDegree said, I have built three double sliders now, starting back in December, and I am currently building my worlds slider. I would recommend the double slider over the simple flip out tray for sure. The pros and cons have already been listed out, so I won’t go about repeating this information, but I second all points made so far. If the slider is made correctly, it will come out with almost no friction. Similarly, bending has never been an issue for us. Our new slider holds 12, and is as straight as can be. Also the drop off issue of having the cubes grab will always be there, no matter what you try, but if you have the right coding when it comes to dropping off a stack, it negates these issues significantly. Additionally, having a small and smooth surface at the top, of maybe a rolling surface, would help significantly.


The biggest reasons I have seen teams not use double sliders is they are so heavy, and they can cause stacks to buckle and tip because of the sliders weight pushing down.

There are teams in north Texas that use a Double slider made out of 3d printed parts

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That’s illegal in VRC, you can only use 3D printed parts in VEXU.
If the 3D printed parts aren’t functional, then it’s legal.


My bad, then using a cad model to cut away the plastic until it is the desired shape, my team does not use this, but this is popular in our area, and the teams refer to the process, incorrectly, as 3d printing it

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I’ve never experienced such buckling. Our sliders weigh less than a standard L-channel 4 stage.

Custom cnc’d lexan is a really cool build technique but it requires expensive machinery that I doubt everybody has access to. Word of warning don’t laser cut lexan. The advantage of this method is nested side walls can make much better use of the surface area of your 2x1ft sheet.

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