I would like to life cycle torque slip clutches and record data to a PC . Currently I have to manually attach a ametek electronic torque meter and twist the unit back and forth and manually write down torque readings. THe ametek has an rs-232 output connector on it.
If I could put the slip clutch in a fixture and attach the torque head to a motor that automatically rotates the clutch for a certain amount of cycles it would automate my life testing. I am a mechanical engineer so I know how to do all the fixturing, bearings etc. but building the control system is another thing. Unfortunately running a business saps a lot of my time. the torques readings are between 2 in-lb and 40 in-lb. I have two ametek torque meters to cover the appropriate ranges. I would probably build two systems.
Do you think I could build a system easily with the arduino? I know stepper motors can be slightly expensive but It might be worth it if the arduino components are not to pricey
Reading and recording serial input is easy enough, but if that's all you need to do and given that you already have an RS232 interface, it would seem more sensible to connect the meter to a PC and log the data there. Various PC applications such as RealTerm make that very easy to do.
Do you need to do any more than just capture the serial stream from the meter?
The Arduino is a good with controlling something like a geared stepper motor.
You could use a PC as PeterH wrote, and use the Arduino to control the motor.
Or you could use an Arduino to control the motor and read the sensors.
Both options are good.
Thanks for the responses.
I will take a look at the Realterm software to see how it works.
I would like the process to be :
put a clutch in the fixture.
start motor to turn ~120 degrees then stop for a second; reverse and go 120 degrees
cycle like this 30,000 times
during this cycling I would like to record 4 torque data points during the forward and reverse cycle ( each cycle) from the torque meter.
when cycling is ended I can use the data in excel to make torque vs cycle graphs .
Basically it it a tester that monitors the torque over the lifetime usage of the clutch. The results will tell you if the torque is dropping or rising over the 30,000 cycles which can indicate component or lubrication failure.
I saw a stepper motor which can reach 30 in-lb for $49usd which is pretty good. But I never had to design a control system for one.
So if I understand your replies. I could use the arduino and various components to control the stepper motor and independently collect data from the ametek rs-232 port into a PC.
I was also looking into sensors for the start position and end position of the motor. Any suggestions for this?
There would need to be some sort of communication between the motor position sensor and the PC so the data can be collected in sync with the motor movement. Right?
Any suggestions?
OK, I did a little reading on the stepper motor section on the arduino website.
Controlling the motor should not be a problem. Since I am using a larger motor I will need an independent (larger) power supply.
I will need input on reliable arduino suppliers and suggestions on motor controllers.
SN754410ne was suggested. Also, I would like to count the motor cycles. I think an LCD could be hooked up and programmed to increment.
Any suggestions on parts?
Which ardunio should I get?
Thanks
The Arduino pins are digital outputs. They can drive a led, but not a stepper motor. You need a 'motor driver', a circuit board with components that are able to supply the current and the voltage for the stepper motor.
Add-on boards that can be attached to the Arduino boards are called 'shields'. There are also 'motor shields'. You simply attach them to a Arduino (for example a Arduino Uno) without the need to solder.
Take a look at that link to Sparkfun again in my previous post.
Thanks for your response. I took a look again at those motor shields offered by Sparkfun.
I checked the specs and it appears that none can handle the current needs of that motor.
I could be reading the specs wrong. Could you check the motor I have a link to and see what motor shield will work with it.
I really appreciate the help
I was also looking into sensors for the start position and end position of the motor. Any suggestions for this?
Limit switches should do the job here, but since you're using a stepper motor, they may not be necessary as long as the start position is constant - the stepper just needs to move a known number of steps in each direction.