Issues with arm raising

Well quite honestly that’s still a problem. You want the robot to be as rigid as possible, with no angling unless required by design. One thing I would recommend which may be too late is don’t use those aluminum/steel plates as a chassis base. The problem with them are yes they are good Lego like plates, but for robotics, they are horrible for mounting subsystems and bend relatively easily compared to C-channel. If possible, I would redo the entire chassis, using mostly C-channel with C-channel supports rather than plates. If you use nylocks, 2 to 3 c-channels as bracing should be sufficient. This would help drop overall weight and allow you to have mounting spots for your bot’s lift and such. Another piece of advice, you don’t necessarily have to have a chassis brace near your lift. I see the bulk of your chassis bracing also braces the lift but since the chassis bracing is kinda weak and the plates don’t allow for mounting spots, a lot of your tilting and breaking and maligning problems are occurring here.


more zipties :slight_smile:

1 Like

@LilTree, it is mostly secure by c-channels, but the plates are there to give extra room to build on.

I just do not know where to secure the arms at a point where it’s not too wide or top narrow to intake cubes

I’ve had a similar issue as well, but I’ve realized that I could probably use the high strength axle for certain applications

If your driving gear (12t) is on the long axle, and the gears are mounted on screws
a la This post by @technik3k you may find less bending.

The 12T gears experience 7 times less force than a common axle for the 84T gears. You would need to protect said axle from bending via robot contact, but otherwise, that should fix your setup without needing significant reworking.

1 Like

I want to use the larger gear for more torque, and need to gear it more, so i straightened the channels, i am going to move them, then make it work, i hope lol.

To keep the two uprights parallel to each other and perpendicular to the base, you will probably want to add two bars spanning it in an x formation.

YES, you REALLY NEED to REDESIGN. You NEVER make your towers for you arm tilted. Always add support to the lift arms.

1 Like

Whoah whoah, hang on there, no need for that much aggressiveness. Use italics or bold for emphasis instead of caps.
Also, a redesign isn’t absolutely necessary, all the OP(original poster I think) has to do is to straighten it out and he/she should be fine.


Ok, so issue. I have this mechanism for gearing, and after a second, it strips somewhere. I dont know why, but it does. How do I prevent this?20190918_194751 20190918_194730 20190918_194721 20190918_194712


so you’ve definitely made good progress. the reason your gears are still slipping is that the shafts they are on are flexing. to solve this, you need to add 2 more towers, so that the gear ratio is sandwiched in between them. Also I notice you’re using a compound gear ratio, which really shouldn’t be necessary tbh.

1 Like

@Xenon27 I’m confused what you mean by compound gear ratio, and I held the shafts together with my hands and it performed fine. How would I transfer this to my robot?

so you have a 1:7 ratio, and you also have a 5:7 ratio after that before it gets to your arm, which is a compound ratio. the added support towers accomplishes this effect, basically you need support immediately on either side of your gears

Something like this
Notice the outermost c channel on the right. That is to stop the gears from skipping. Now of course it’s not the same design, but it should give you an idea.

1 Like

Nuts and bolts can be put in place of the zip ties if their is space. You could also get some smaller zip ties two.

1 Like

I’m not very clear on this. Do you want me to have support on the side of the gears attached to arms, or for the gearing to lift the arms? Also, to make more towers to support the gearing gears?

You could but with the gears you might need some more shaft collars.

put more towers like this

1 Like

I have nylon spacers plus collars locking them into place. The vertical problem is the issue.