Review of Manipulator.pdf

I would appreciate any edits, comments, additions, critisms, or deletions you may suggest for my .pdf on manipulators. It is intented to provided a description of different manipulators for new teams. The response for the review of my .pdf on drive systems was fantastic and I was able to incorporate all the ideas into my last draft and it made it such a better document. I am hoping for the same help with this document.

I am especially interested in any additions that I may not have thought of and any links for pictures or CAD.jpegs that I might include to make the descriptions make more sense.

the .pdf can be found at:

Again, another great resource for starting teams. I love that you’re doing this!
I do have one thing to say from a quick glance over it. About single sided claws, the document says:

If a sensor such as a potentiometer or encoder is used, it minimizes the change of this happening. While this might be meant for new teams who may not be pros at programming, they shouldn’t be scared off by the thought of their motor burning out. Perhaps you could include a section on where and how to include potentiometer or encoder in your manipulator design.

Plow section might mention using low-friction plows, or rollers (like spacers strung on an axle) if the game objects are round and likely to roll when you push them.
VRC games are typically designed so a plow-bot/dozer can get non-zero score:
eg: Gateway floor goal.

Activators: Might mention that servos are included here only because they are part of starter kit. They are frustrating to use in autonomous in competition because they lose control between sections.

If your series is just two parts (mobile base & manipulators), then all the arm joint stuff has to go in manipulators.
If you have three parts (base, arm, hand), then you can split the arm and hand(manipulator) parts.

An overview (base, tower & arm, hand) early would be good.

The discussion of pivot points is overly detailed (many types of gears mentioned) compared to the other parts. Many repeated warnings about twisting drive shafts without showing how to avoid this (don’t pass torque through the axle; Axle should be for pivot-only; bolt the gear to the moving part and drive the gear directly.=) which is a critical point that rookie teams need to learn.
A pivot point is a good generic discussion, but maybe put the details after then general types, since most of the types use pivot points.

There are robot reveal pictures showing hybrid (chain) 4bars, and linkage claws (titan-roundup).

Some discussion of concept of “storage” would be good.

  • A claw picks up one object and puts it down elsewhere.
  • A roller claw, or conveyor belt type pick up several objects and put them down elsewhere in order (or reverse order)
  • A continuous pickup can pick up lots of objects and stores them on the robot.
    =Permanent storage can be used to hoard the opponents objects.
    =Temporary storage holds more objects than you can pickup, but allows you to unload them in your own goal later. Usually, the unload method is different than the pickup method.

Another really really really really awesomely good summary - I hope that lots of new students will be able to use this great resource! The only thing I would say is that if possible, more pictures would be helpful for the newest students who may not be able to visualise some of the things you’re talking about.

Also, we have a couple of diagrams of arms and lifts that you are welcome to use if you like (a credit to us would be nice but not essential):

If I can find them I’ll upload the drivetrain ones we had as well.
EDIT: I just found that the drivetrain ones aren’t particularly useful, so nevermind…