The professor ask me to build to machine that can cut an extruded rubber in to an specific dimension.
1.My job is to cut the extruded rubber in to 1cm bead.
2.The rubber will be extrude 37cm/min in linear @83c , and the rubber already have 1.0cm daimeter
The problem I can not find the mechanical properties of NA at 83c any where. My Professor also not have it and say he can't do a test for me. His advice is to use the exist data of NA at room temp.
Here is my plan
I want to cut the rubber mid air using the wind mill cutting machine < 2blade, 1 each side>
From the calculation i need approximately 80nm torque to do that using 5cm blade.
So i decide to use the step motor and a gear box.
I use 12nm nema 34 with a 1:30 gearbox so i can fix the torque problem.
Now i need a to program my arduino for control my driver.
But After watching some tutorial on youtube i can't find what i am looking for.
So i come here for help If i want to run my stepper half rev at the time with the fixed speed. For the example those rubber come out from the machine 37cm per min. I have 2 blade on my cutting mechanism, so 18.5 rev per min is what i am looking for. After looking Torque vs Rpm curve it feels like i need to run this motor at 500 rpm to archive torque i need.
the system control don't need to be very nice just turn on and off is okay.
I plan to connect my arduino mega to the labtop anyways so i can just run and stop when ever i want.
will do the control part later.
Can u guys post some useful sample code here for me to take a look and learn.
Does the extruder stop during the cut? If not, the cutter will have to move at the same speed as the product being cut to get a clean cut. Can you post a drawing of the machine?
The torque on a stepper motor is largely independent of speed.
You need a stepper driver that can provide the required current. Because of the way stepper drivers work, you don't need to over-size the driver. A 2A driver can run a 4A motor just fine, although a 4A driver will give more output torque.
aekahunai:
I want to cut the rubber mid air using the wind mill cutting machine < 2blade, 1 each side>
From the calculation i need approximately 80nm torque to do that using 5cm blade.
So i decide to use the step motor and a gear box.
I can understand the use of a stepper motor to control the extrusion precisely. But I cannot see why the precision of a stepper motor is needed to operate a blade.
run this motor at 500 rpm
That is a high speed for a stepper motor.
Please post a link to the datasheet for your stepper motor.
This is exactly what i trying to make. The reason of using step motor is because of we need to match the cutting speed with the rubber machine extrude rate.
From the torque above here is idea of using the gear box.
First is use 1:30 gear box @ 500rpm. Therefore 114 NM @ 16.6 RPM
Second is use 1:15 ratio gear box @ 400 rpm. Therefore 87nm @ 26.6 RPM
Rather than use a stepper motor for the blade, why not use a suitably geared DC motor for the blade and a sensor that measures the speed of the cutter and then use a stepper motor to advance the rubber at a speed that is matched to the blade speed. Put a substantial flywheel on the cutter shaft to provide the extra energy needed to make a cut without significantly dropping the speed.
Alternatively get a BIG stepper motor that can provide enough torque without any gear reduction, or maybe with a 2:1 or 3:1 ratio so that the motor is operating at a speed where it can deliver high torque.
It's because my professor say it would be easier to cutting precisely. I cant effort the bigger stepper because of the budget and this is the biggest one i can find. According to calculation this one can generate enough torque though.
Can u help me on the coding part. For the example if i want my motor to rotate 1/2 rev per times at 500 rpm what should i write on my arduino. if you can i will feel very appreciate.
Um Robin. Is all stepper need the driver to control them. For the example i have my nema34 12nm torque with the MA860H DRIVER and i just want to run it at 500rpm. doesn't really care about resolution. how to set the motor rpm if the driver already control the resolution. I,m so confusing right now.
I don't know what you mean by "resolution" - perhaps you mean the number of steps per revolution?
A stepper driver can cause a stepper motor to stay stationary or to move one step. The speed of a stepper motor is determined by the interval between steps.
Experiment with the simple code in the first link in Reply #14 until you understand the process.
// Create Instance of Stepper Class
// Specify Pins use for motor coils
// The pins used are 1,2,3,4 'arduino pins'
// Connect to MA860H Motor Driver 1,2,3,4 'driver pins'
// Pins entered in sequence of a-b-c-d for proper step sequencing 'จับคู่สาย'
Stepper steppermotor(STEPS_PER_REV, a, b, c, d);
void setup() {
// put your setup code here, to run once:
aekahunai:
Hey robin could you check this code for me
Three things ...
{A} the standard Stepper library is not suitable for use with a stepper driver that takes step and direction inputs. Either use the AccelStepper library or write your own code.
{B} have you tried the code in my examples?
{C} when you post a program you should tell us in as much detail as possible what it actually does and what you want it to do that is different. It will make it much easier to focus on the parts you need help with rather than wasting time on things that you can do.
