Hey all, so currently I have a functioning arduino setup with a Nema 23 Stepper motor that is 3Nm and it's purpose is to travel 90 or 180 degrees aka in one direction with an arm attached aka a piece of metal tubing or pvc probably PVC due to it being lighter. The end of said arm will have a prop on it for halloween that swings out at a reasonably fast pace in front of the person walking down a hallway of sorts, thus scaring the person. Anyways I have a dilemma with the motor I am using if I have the motor go slower than I'd like it to go it can handle the weight of the pvc tube that I've tried on it but if I have it go faster it moves inconsistently, the pvc will move the motor out of it's exact path, for example if I can explain this correctly, if you have it swung once 90 degrees, too fast and it will kind of stutter so to speak and not move the full 90 degrees, then on the return trip it wouldn't be back at it's regular position, it will be behind the starting position.
Which makes me wonder if the motor I am using is too weak for my project. The PVC pipe is maybe 8-10 oz I have to weigh it still and is about 18" long. Now if I understand correctly, and my calculations are correct, 3Nm is 26.55lbs per in, now divide that into the 18" length of the pvc pipe I should in theory be able to move 1.475lbs Now the PVC pipe is say 10oz at the most, should it not be able to move it back and forth even at higher speeds easily without skipping or stuttering? Unless I am misunderstanding something and my calculations are off. So I was thinking an 8Nm motor would suffice especially with a 1-3lb prop attached to the end of the arm. If I have not miscalculated something the motor I have should have no issue moving the PVC arm, but correct me if I'm wrong please. The model of the stepper motor I'm using is 23HS45-4204S
So you want to use a 1/5 scale servo (I use Savox brand, powered by a separate battery with a buck converter) or a windshield wiper motor using a relay.
My issue with stepper motors is they are very slow (in my limited experience). For Hallowe'en scares you want it sudden, right?
I cut 12 or 14" shelving brackets in half, attach that to a skeleton forearm on a pivoting joint (zip tie) and attach the other end of the cut shelving bracket to the servo horn.
The behavior means you need more torque to do a faster twist of a kilogram on the end of a 0.46m long arm.
You don't mention how fast you want to stop and start the motion, or if you are using acceleration. If those were clear, you could calculate how fast it start, moves, and stops, and how much torque you need.
A kilogram on the end of a
I would prefer to use stepper motors due to their accuracy, I have used wiper motors in props before though, certain props that I can use them in. I may check out servos as long as they're fast enough.
I have it set to 900 microseconds for the speed, I can get the motor to go all the way down to 400 microseconds that's the fastest if I dip below that number it won't move at all. As for acceleration I am still learning Arduino so I don't have any acceleration added to the code. The start and stop is immediate.