1115A Mid-Season Update

Hello, 1115A here with an update video. We have changed robot styles since our 5 tier linear lift (shown here: https://www.youtube.com/watch?v=p1sSZFUQMEA ) Since then, we have changed to a reverse double four bar robot. The only thing we have kept the same is the x-drive.

So, here is a quick video we put together during our last meeting. Hope you enjoy!


If you have any comments, sugestions, or questions please let us know. We love feedback. Thank You!](https://www.youtube.com/watch?v=SiMxLSA_mJA)

Looks like your well on your way to a great robot. We also like the idea of a linear lift, it’s a much more efficient design. We have some parts ordered also, looks like Vex will be busy monday morning shipping out alot of oreders.:stuck_out_tongue:

Looks good so far!

One thing that stood out to me was the pinion gears on the lift. I try to avoid meshing the metal pinion gears with each other, especially not 4 of them in a row :eek:. I’ve found that they have a lot of friction from the metal teeth meshing. Have you done any tests under load yet?

Not much testing so far. (it does lift atleast one cube and the current load of the intake so far) The pinion gears are what I’m worried about too… However, there is not room for two of the slightly larger gears (36t?). What would you recommend we do?

Also, something i had thought about but is confusing me is this: there is not room for two 36t gears. However, would it work to have kind of a redundant compound gearing setup using 12t gears and the 36t gears?

As in: ]0 where the ] are the 36t and the 0 are the 12t? isn’t that 1:1?
…0 ]


Most teams stack/mesh the 84 tooth gears together, then drive each 84t gear. The top 84t gear from the top, and the drive the bottom 84t gear from the bottom. This has worked for us with 100% reliablity.

This is the simplest way to do it; it requires the least amount of gears and space. This reduces friction (increases power/torque).

However, how can this be done while still retaining maximum height? We would rather not resort to a reverse double six bar to gain height, but we don’t want to be too short to be useful.

Jarred, mesh the 84t gears then use a C-channel coupler gusset and extend the length of your c-channel to your maximum length possible diagonally, this should yield you more height then you currently have. We have used it in our prototypes in the past, depending on the configuration we sometimes use this method, sometimes we use the DR6B.

c-channel coupler gusset P/N: 276-2575

You can use 36 tooth gears (or even 60 tooth if you have enough space) in the middle. so your gearing looks like:

12 - motor
12 - motor

this will give you a little more height

Here is another update! This time for our skyrise intake. Hope you like it. If you have any feedback let us know!

Very neat.

I do have to ask though…why not a traditional “horizontal claw”? A regular claw seems require less precision when driving (large margin for error).

Your claw has to be inserted into a fairly small opening (the center of the skyrise) which would seem to require more delicate driving.

We have two robots, one that has a pneumatic claw and another with a passive plunger style skyrise intake. The claw is proving to be much quicker because the driver doesn’t have to be nearly as accurate when picking up the section.

Just my two cents…it looks like a very nice build you have and if it works good for you that’s all that matters!

What are your reasons to abandon a linear lift? When you revealed yours I considered it a seminal example. :slight_smile:

Thank you! We went with design because this clamp seems like it will work much better with our plans toward skyrise building. We definitely didn’t just overlook a pneumatic clamp.

We really loved the old linear lift. However, we came to the realization that it had nearly reached it’s max potential. We didn’t know what we could do to make it better. It was already using 6 motors, but it was still not tall enough and was not as fast as it needed to be to compete well enough with other robots and did not have an amazing potential for cubes. Hence why we have not won any competitions so far this year. So, we switched to a RD4B. It has the height, it has the speed, it has the cube capabilities, it even is linear. So, for these reasons, we made the switch.