24C 2.0 "The Vacuum" Build Reveal

24C was planning on attending the HZR September Scrimmage this past Thursday, and afterwards we were planning on revealing our new robot design. However, that event was canceled. But we decided to reveal our new design anyway. So, here it is. Enjoy!

After the REX tournament, we decided to modify our robot to be a design similar to what 24A had built. The concept was to have an intake with a wide vertical wheel roller (no longer the “chainsaw” type of intake we used on the first robot), to pull the sacks in from above, and have a bed of tank-tread running the opposite way underneath, to help pull them in. The tank-tread would keep the sacks from collecting at the front of the intake while we were picking them up, preventing the “in, up, over, and out” problem with vertical wheel roller intakes.

Now, this was not the only change we made to our robot. In fact, since the REX tournament, 95% of the robot has been completely rebuilt. The drive is brand new, which is now using four 2.75" omni-directional wheels, at a 1:3 gear ratio (still using six 393 motors). We were able to use each of the 4-bar systems we had on our old robot, but they were moved much further apart, and still had to be modified.

Okay! Now for pictures! (Probably the only thing many of you want to see, anyway. :P) Click them to see full-size.

Full view of our new robot.

See our new drive.

Very wide intake, for quick “vacuum de-scoring.”

And finally, a back-view.

This Monday night, we are hoping to finish up the robot, so we can begin programming, and test-driving. If I can get a video of it, I will try to post one as soon as possible.

We hope that you like our reveal, and would like to thank you for viewing it! If you have any questions about our new robot design, please feel free to ask; I will try my best to answer.


1 Like

Ah very nice, Jordan! I like it a lot! So can you really get a 1:9 gear ratio to STILL lift that?? We had troubles with 1:9’s on our lift haha.

wow… That looks awesome:) Have you tried stress testing your drive train yet? i would think a 1:3 speed ratio would overheat the drive, despite the 2.75 inch wheels.

Its the same as 1:2.0625 on 4 inch wheels, which with a 6 motor drive should be alright, depending of course on the weight of the robot, and how it’s driven.

nice job Jordan! :slight_smile:
how well can this descore from the troughs?

Nice robot! :slight_smile:

Do the sacks sometimes fall off the back of the conveyor or are you going to add a back to it?

I look forward to seeing a video of it :smiley:


Very Nice - GOOD JOB ? … i am wondering also … what gear ratio you are using for the lift ???

From the images it appears to be a 1:9 torque ratio (1:3 compounded to 1:3). I presume this arm will have elastic assist that isn’t in these pictures though.

It looks like the intake/conveyor is about 12" wide, have you had any issues with the axles bending?

Yep! Lots of elastic should help. :stuck_out_tongue_winking_eye:

We haven’t had a chance to test anything on this robot yet. We’re hoping to add the Cortex Monday night and start testing out different intake roller designs, and hopefully finish the 4-bar, and then finally begin test-driving.

As Telamascope said, it is very close to the ratio we had originally, which seemed to be fine with six 393 motors (except that our chain wrap was very poor on that drive). Also, the robot seems to be very light, so that should help us out.

Oh, and thank you!

Very well, we are hoping! That will be one of the things we will be testing if we get things wired up Monday night. Thanks, Gordon!

Again, something we still have yet to test. We will probably be adding a back plate if we find this to be an issue (which we probably will).

Thanks, George! :slight_smile:

Yes, sorry that I forgot to add that. Again, as Telemescope said, it is a 9:1 ratio, made up of a compounded 1:3-1:3. Also, yes, we will be adding plenty of rubber bands to help us lift this large and rather heavy intake.

We did begin to see this as being a problem, so we hid two 1x25 bars to the middle, with standoffs holding them to the c-channels on either side.

I thank you all for your questions/comments so far! :slight_smile:


How come you guys decided to go with the smaller 2.75" wheels as opposed to the 4" wheels? I’m curious to know because I didn’t think that the small wheels could climb over the sacks and handle them well enough. Also, how many sacks are you guys able to (or thinking of being able to) lift with that 1:9 Ratio? And one last question, can that arm reach up to the 30"? Overall though, looks like a very good robot that should intake and descore really well.

i like the design its i really really close to what we have at our school… just some questions. how many sacks can it hold with a 1:9 ratio? can it score high with a 4 bar? and robot skills score? descore? and any video? I really like the look of the robot, but all that tread/sprockets/metal on the ramp, seems like it would be able to lift less that your previous design? I can say that this design is a big step though, and its looks pretty epic. good job.

Great robot! How do you get the intake and the tanktread to run together? Or are they both powered by separate motors?

ya it there is one motor running the top roller. And then another motor running the tank tread conveyor.

It looks longer than 18" to me… how does it compress into the size limit? Does the roller fold up or something?

Overall, nice robot! Can’t wait to see vids!

One reason was that they would weigh less. Another was that we were originally planning on somehow having the bed of tank-tread lay over top of the wheels. That didn’t end up happening, but I do not think that the smaller wheels will be a problem.

I am not sure how many we will be able to lift off of the ground, but since we’re mostly focusing on de-scoring, we just wanted to be able to hold a whole lot. Meaning at least 15-20 sacks, I would say.

No, the robot [EDIT]probably won’t[/EDIT] be able to score out of the front into the 30" goals. :wink:

Thank you!

First two questions answered above. Also, as I said in the original post, we unfortunately have not been able to wire anything up to test run yet. In fact, the robot hasn’t been touched since last Saturday. :frowning: Poor robot. Anyway, I hope to get some video of the robot running Monday night, or in the next few days, when I’ll most likely have the robot at my house so a couple of the other team members and I can work on programming it.

I am a bit worried about the extra weight, however I actually don’t think it is very much added. We’ll see how many sacks it can lift off of the floor, but again, as I said, this robot was designed around the concept of de-scoring.

Thank you for the compliments, and for your entire post!

Yes, as Clean Sweep Man said, we have one 393 motor powering the intake roller, and another powering the bed of tank-tread.

You are correct. With the roller down, it is outside of 18". We’re planning on cutting those pieces of metal on the roller that stick back into the intake, so that it can fold up before the match starts.

Thank you, and thank you all!



I was thinking that it looked possible for the robot to lift 12 sacks at since it was a 12.5" x 2" intake. then considering the weight of the intake, it would be around 8 pounds in the air. Then due to lifting, the base would need to be heavier to avoid being top heavy. So at most, i was guessing the robot needed to be around 16-20 pounds max.

But since there’s six 393s, that would be almost 1.5 times the amount of power most teams had last year. But also, there’s only 4 wheels compared to last year’s six, which kinda cancels out weight distribution

Very nice robot. Will we see you in Dover on 10/6 in the C4 hangar?


The design looks awesome. Again an innovative approach from SSS.

We’re hoping to hold nearly 20 sacks at once, but the robot will not have to drive very far to score them, and it will collect that many almost instantly, without having to move around while getting them.

Also, we determined that since last year we had a 2:5 ratio with small wheels last year, which was powered by four 3-wire motors and two 393 motors. It was very reliable and never had issues, even when we got into pushing matches. Now VEX has posted specs that say the 393 motors have more than two times the torque of the 3-wire motors, but if they were only double, we would have 1.5 times the torque we had last year. Going from 1:2.5 to 1:3 will only be 1.166667 times the speed we had last year. Looking at those kind of numbers, it’s pretty obvious that we should be okay with a 1:3 ratio this year.

Unfortunately, no. That tournament is not on our schedule. We are planning to be at the PA State Championship again this year, but that isn’t going to be for months. :confused:

Thank you!