So, a couple days ago, I started to learn how to use Inventor. So here’s my first project.
Two designs seem to be very prevalent this season: top roller and spatula-bot. This spatula-bot is very similar to our actual robot, which we shall be demonstrating at the World Championships this year! Think of it as a “teaser”.
This took me about 10 hours to assemble and then another 5 minutes to render. Huge thanks to 24C for making their library so easy to use.
I still need to make the most important part of the robot, the spatula. How would I create a polycarbonate sheet? I have had absolutely no CAD instruction outside of 1200B’s instructional videos.
Do you know how to make standard inventor parts? just make a new part file for your spatula and make it out of the default material, though I suspect there is a polycarbonate material.
Create a new part
Create a sketch in the shape of the spatula, perhaps it is just a rectangle.
Save the sketch, extrude in 0.065 inches.
If you need to bend it.
Create a new sketch on the surface, draw a line where you want to bend it.
Save the sketch.
Select bend, select the line, set the radius of the bend small, set desired angle.
Set the material of the part to polycarbonate.
Save and enjoy.
It’s actually a bit different from 8000’s lift. It’s more compact and reaches higher. You shall see (if you’re coming to Tracy or Santa Clara or Anaheim?)
The only problem we’ve had with the lift was when we accidentally placed the C-channels upside down and they cracked. But we haven’t had any problems with the 1x25 bars. They’re very sturdy. And they look nice, too.
We admired your pneumatic spatulabot at the Ceres tournament – thanks for sharing your rendering! We struggle a lot with “geometry issues” (i.e, where do you put things without them bumping into something else), so seeing the placement of details is really helpful. I hope you don’t mind if we ask (quite) a few questions:
On the 4-wheel part of your H-drive, I’m assuming that you’re using chain to connect motors to the wheels. How do you keep the axle of the motor sprocket from falling out?
Are the motors coupled to all 4 wheels, or only the back ones? If all 4 wheels, how do you anchor in such a way to keep the width of the 2 layers of chain (and anchoring) from bumping into the center wheels of the H? Does the chain ever scrape on the edge of the center C-channel of the H-crossbar?
How do you coordinate/couple the left and right sides of your lift? Do you use programming, mechanical means, other, or none?
Regarding the 5-wide C-channel supporting your lift, it looks like you have 4 pieces mounted to the back piece of L-channel (2-wide). Are there other attachments to the driving base to provide added stability?
Sorry for all the nitty-gritty questions – our team has not yet attempted anything of this magnitude because in the past, we’ve been stumped by these kinds of problems, in addition to a limited budget.
Refer the the image above. Our motors are attached only to the back wheels. You can see that our C-channel on the drive is flipped so that the sprockets are contained inside the lips, so we don’t have any problems with spacing.
We just ensure that the right an left sides are perfectly symmetrical and make sure the friction on the arm joins are the same so the motors are able to move the arms the same rate. The spatula assembly also helps keep the two sides even.
We also attach plates on the sides of the towers for stability.
Thanks for your detailed answers to my questions. Got distracted, but am finally getting back to looking at this in more detail. Good luck with your robot at Worlds.
You shall see (if you’re coming to Tracy or Santa Clara or Anaheim?)