Category: manufacturing

0-10 to 5 pwm

I purchased a diode laser from amazon. Bigger than my older laser. Has pwm cause im fancy.

But i needed 5v pwm and my mach3/breakout board provides 0-10v analog. The easiest solution I could think of was once again to slap a nano on it.

Here I am testing the circuit.

The circuit uses 2 10k resistors as a voltage divider to accept the 0-10 volt signal into the arduino analog inputs. The other component is a 5v regulator to power the arduino off the cnc power supply and the knob simulates the mach 3 for testing.

The arduino library makes the code so easy. Pin 5 gives a 980hz signal and other pins give different lower signal so choose accordingly. I cant think of a reason to hassle geting into the Timers and increase the HZ.

#include <Arduino.h>

//duty is 0-255
int duty = 0;


void setup()
{
    //pin 1 reads 0-10v /2
    pinMode(A1, INPUT);

    //output a pwm at 980HZ
    pinMode(5, OUTPUT);     

}


void loop()
{  
    duty = map(analogRead(A1), 0, 1023, 0, 255);
    analogWrite(5, duty);

}

 

When its done I put it in a 3d printed case and hot glued it to power supply.

Casting aluminum a bit more

I have had some more practice with casting aluminum and now I have even upgraded my oven. My original ovens electrical plan did not account for wire durability based on wattage and length of wire so it quickly wore out.

I also attached an arduino nano to the oven so I could quickly enter rising and falling temperature times.

Further, because I now havea 3d printer I have been doing lost pla casting. Its much faster and the shrinkage can be predicted pretty accurately.

Below is a cut and paste of the results. Most of the time you need 105% enlargement for parts that can fit in your hand.

 

Name Description 3d length 3d width 3d inside wax length wax width wax inside alum length Alum width alum inside target length target width target inside shrinkage Oversize Post Calc notes
7mm roller pin pin for hypocycloid 7.5 7.41
hypo cam spacer spacer for 100:1 cams 18.8 38.7-38.8 14.92 18.2 38.2 14.75
7mm roller 103% scaled up na/ stem 7.03-7.15 5.02-5.12 6.81 4.79
cam spacer 103% scaled up 19.45 40 15.3-15.4
square block 103% scaled up 11.87 65.37 26.74-26.84 11.4 64.61 26.88-27.12
Eccentric 103% scaled up 82.29-82.38 4.89-5.13 10.10-10.20 4.83 9.8 Stipling came in perfect but required light sanding which quickly pulled .2 of item
tree 6.91 6.71

 

 

Here is an example of how easy it can be to cast. Casting is not really ever easy. Its time consuming.

lost pla casting

 

Below is my whole aluminum casting setup. You can see the oven is upgraded with a control unit and relay. I use a vacuum as normal to draw down pressure during pour. The toaster oven preheats the parts so they don’t have moisture.

Below are two of the parts. I whacked it with a hammer to see if it would do anything. It didn’t.