we are wondering how to program our sim motor to just turn 90 degrees in labview programing could any one help.thank you
What are you trying to accomplish? More details (and pictures!) of your setup would help us help you.
You could turn the CIM motor on for ~0.0027 seconds. That would make it turn for 90 degrees (given that the motor was under no-load conditions).
But… I don’t think that’s what you’re asking.
I think you’re asking “How do I make [device that CIM motor is connected to] rotate 90 degrees?” That is a little more interesting. It’s particularly interesting once you figure on the gearbox changing the output RPMs (you DO have a gearbox, RIGHT?), and whatever else you have in the system.
You may want to use a potentiometer to measure the angle, and a control loop to tell the CIM which way to go and how far to put the device at that angle. Or an encoder might be easier.
Either way, more details would be extremely helpful (what if any sensors do you have, what’s the gearing, is there some sort of way to mount a limit switch, that sort of thing) and you’ll get better advice.
there is no gear box it is just a plane sim motor that we are usuing like a servo for a arm
does it have a stop to run into on either side of the “servo arm” you are trying to control?
no there is no servo the sim is what we are using in place of the servo and there is not stop but that stop idea should be put into consideration for the build thanks
How heavy is that arm? How much weight are you trying to lift with it? How far is that weight from the arm’s pivot?
Please post a picture.
Given your description, a cim motor is probably not the best thing to use in this situation. Without feedback, an andymark planetary gearbox motor or a denso window motor would be more effective because of their gear reduction. Because the cim has no gear reduction, there is so little resistance to turn the cim shaft that your arm would fall back to its original position due to gravity.
A geared motor will fix that problem, and may move slow enough so you can turn the motor on for a fixed amount of time instead of using feedback sensors. A servo would work too if it is strong enough for your application.
If you are already using pnuematics on your robot, I’d suggest using them to rotate your arm because then you don’t need any kinds of feedback or stops.
You forgot about the CIM’s 5500 RPM at free speed. As noted, you’re talking TWO HUNDREDTHS of a second to make that 90* motion. Leaving aside the problem of keeping it there, that’s fast enough for someone to consider that dangerous.
I’d take a window motor for this any day, if the arm was light enough. At least the rotation will be measurable in tenths of a second. (Speaking from experience: 120* in well under a second for about 5 lb of lexan, though that was on one of the older window motors.) Pneumatics would be even better, though you might need to do some interesting linkages.
And seriously, you’ll want some sort of feedback, particularly if you want to use this like a servo. (For that matter: would a servo work?)
it seems to me like there is a an issue here between what mechanical team members think electrical and programming team members can do, and also a tad bit of inexperience in working with actuators leading to the belief that a cim is the best choice for a servo replacement. Its not too uncommon to have this sort of confusion especially for newer teams who don’t quite know all the tools they have at their disposal.
A NeveRest40 or NeveRest60can produce more torque than the CIM and have built in encoders, cost the same, weigh less, and use MUCH less current in this application. The NR60 was in FirstChoice, but is “sold out” there. We’re using an NR60 for our gear-pusher which also requires about a 90 degree rotation.
The built-in encoders can be wired back to two DIO ports and code written to read those ports and stop the motor at the right time.