2381X update #11


#1

so i don’t revive an old thread and piss people off.


#2

Your wiring is beautiful


#3

Please do not use pop rivets I see at competitions they fall out. But great wire management.


#4

if you actually opened up the video you’d hear him say “these are nylon screws by the way”
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#5

At any rate pop rivers are usually fine. For instance, some (if not all) Discobots used them on their drive in NBN to very great success.


#6

Oh I have bad experiences with pop rivets. I have never seen nylon screws that color , looks like pop rivets.


#7

thank you. It took so long.

yeah lol we ordered black nylon because it was cheaper. Pop rivets (if used properly, and taken care of), work fine? I find they’re like kepsnuts, a lot of people say that they’re bad, but they end up being just fine (if you do it right). regardless, nylon screws and nuts are pretty cool.


#8

I noticed that your robot, along with many other good robots, like look very well put-together, and tightly knit. Everything works together and fits nicely. I noticed that my team’s robot looks kinda of like shit - with a bunch of individual mechanisms thrown own (which is what it is). How do we make our robot more concisely built as yours is?


#9

they plan out their whole robot in CAD before they build anything


#10

that’s dope. What program is best for CADing in VEX? Would SolidWorks work?


#11

Solidworks works well, but I suggest using Autodesk Inventor. It is both easy to use and has the ability to animate any moving objects.


#12

If you’re trying to animate, Autodesk Inventor is exactly what you DON’T want to be using… You can simulate range of motion and other things like that if you learn the constraints pretty well. You can also work pretty quickly once you learn the ropes. But Inventor is pretty bad at doing other things. In addition, it will ALWAYS find hilarious things to do to get on your nerves.
I have never used solidworks before, but from what I’ve seen/heard from other people, it does a better job at simulating.
Also, have this amazing bent c-channel that I made in Inventor when I was… bored?

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#13

While it is true that we plan a lot of things out in CAD before building, we’ve noticed recently that our team dynamic has shifted from CAD everything to CAD part of it and trial-and-error the rest as the time for the competition draws nearer and nearer. Part of this is due to the fact that I do most of the building and CAD and I can’t be doing both at the same time, and when I get more hands-on time with the robot I’ll play with that instead. But in terms of your question, everything working together and fitting nicely. Before we start any build process, my team and I get together and we talk about ideas and how the robot should end up looking. So, in this instance good dimensions for drive, good motor allocations, etc. Once we know that, I’ll go home and cad up various different versions of the different mechanisms (in isolation), so a flywheel gearbox, drivetrain, lift, etc. And then we pick and choose these different mechanisms. We never felt a need to “rush” - I often find that if we do “rush” our robot ends up being sloppy. We take about a week to pick out what we want to do, so everybody building is on-board and roughly knows the space requirements of the different components, and we all communicate with each other to say that certain parts need to go where, in advance. That way, we don’t waste metal trying to build janky work-arounds, but we can build it with the right tolerance in the first place. My build style is also one where I like to make things small and close, I’m much happier with clearances of 1mm than of 1cm, which is why my robots all end up being smaller and smaller and more packed. The less we use, the lighter, the faster. There are many people who have done big robots with spacing well as well.

One last thing: when you’re putting stuff together, pick out a process. Start with a few important things that you can use to define the aspects of the robot. don’t be afraid to change things around. I find that the first time I build a robot, it’ll turn out not the way I want. I do the first time “bad quality” so I can get a feel for the dimensions of the robot, or to see if having something there will work. Then, I’ll rip everything apart and say “ok. I want this to fit here, how can I do that?” and I’ll start re-assembling to accomodate for it. There are places where you can see that I haven’t done that yet, and parts where I have done that.


#14

For other people who want to start building in this way: keep in mind you want easy access to all screws so you can easily tighten them.


#15

Just a random sidenote.
Im glad to hear of someone using a double ratchet system, im not the only one!

I spent all summer thinking about a double ratchet system and making a prototype for an intake driven completely off the drive, the results were not so good, and I wasted all the summer build time, but hey, that’s what rebuilds are for.


#16

So your scoop is a little light on friction, and goes down way too far. If the ball rolls into a rubber band placed 1.5 in above the ground in place of the scoop/plate, your primary roller will cause the ball to roll against said rubber band, and thus upwards.

Additionally, does your 2-C Channel across the top of the primary roller prevent the roller from acting as a cap-flipper?


#17

We actually need our intake to be so low to the ground because we funnel the ball as it’s coming in (on the ground), and as it’s going up (against the scoop), because we wanted our intake to be as small as possible. More funneling on the ground would have made it harder for us to intake balls quickly. We solved the issue of the scoop with a layer of friction mat - the ball just can’t “slip” against the metal.

Yes, the 2-wide across the top does prevent the roller from acting as a cap-flipper, but that doesn’t matter to us.