Construction Of A DIY 3D Printer Part 6 – Y-Axis Testing

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This is the continuation of my attempt to build a 3D printer with a minimum budget of around $400 using new and recycled parts.

I want to see something HEAT!

Plugging in the thermistor on both the extruder and the heat bed was easy. The heat bed is the real one the extruder is not it is just one to temporary do testing.

The wires that come into the heat bed connector need something more than just stranded wire to bite on so I ran some solder over it to make it solid. Then tightened the screw very well.

Under the Prepare menu Under PLA, there is a menu called preheat bed. If you find that menu missing it is because in your configuration file you told the firmware that you do not have a heated bed. Shutdown, change the file and re-upload, then it will appear.

RAMPS 1.4 Display temp settingsThere is a LED on the RAMPS board that tells you that power is going to the bed and one on the bed itself. I shot the bed with a temperature gun and got a very close reading that the thermistor was getting. A reading will be on the display showing the set and sensor temperature. In the photo, we see bed setting, (the three wavy lines over a bar) is 70c and the sensor reading is 55c. See the photo below with the same 55c reading. I was now confident to let it raise the temperature and after about 5 minutes both setting and sensor reading showed 70c. Perfect!

After laying the glass on the bed it shaved off about 10c and over the whole of the 200mm square bed, the corners are around 5c to 7c cooler than the center after 15 to 20 minutes of stabilization of heating.

Testing Heat bed

This is a great success of learning about the heat bed, performance and tuning I will need for 3d prints.

I want to see something MOVE!

Now I just need to make a stepper motor cable and plug it in. Right? No Sorry, nothing but a motor jittering back and forth with a buzzing sound.

I checked the RAMPS 1.4 wiring diagram. I checked the stepper motor pin-out. And after a day of testing and re-checking, I found some clues.

  • The wire gauge is important but not the full problem I had, well maybe not?
  • The connector to the board is very important. I replaced it but not the problem.
  • The driver board could be bad. Nope, I switched boards to test.
  • The Heat sink made be shorting out the pins. Nope, checked
  • The power supply may be weak. Nope, tested voltage.
  • The RAMPS board may have bad tracings in the path. Nope
  • Wiring on the motor may be good on one side, not the other, Nope, did LED test
  • Software code problems. Nope
  • Are the jumpers correct on the RAMPS board that are under the driver board you can’t see, Hum maybe?
  • Stepper driver power adjustment. Yes but do not check this first.

Here is a great trick to help you in the life of your projects. Have it not work right away.

To tell you the truth I got a bit frustrated when I saw this as a simple thing that I could not see the answer to. I work on this as a relaxing break from staring at a computer graphics art job all day. I come home and see my wife we eat together and catch up on our day then as I can I go out to the print room slash Man-cave slash model train room and go play.

In this world, you can believe that everything always works out and there are no deadlines to meet and you can keep from going to therapy for your mental anguish.

Let us go back and have the stepper motor work when I first plug it in. I would not have done research on how stepper motors are wired or that the colors of wire are made differently by different plug manufacturers. I would not know that you can plug an LED into the motor then spin the shaft to test the windings and the connector. But for sure I would have never learned about my jumpers.

If you do turn the pot on the driver board make sure you use a plastic or wood screwdriver, a metal one could damage it.

I still feel that it still needs fine tuning but the motor is working and the driver is sending the correct pulses. I think my problem was more than one and that makes for a hard puzzle.

Tuning the driver is a balance between life and power you can not have both. All NEMA 17 are not made the same. There are $8.00 one and $13.00 and if you look close they have different power capabilities in newtons or turning force. You only want to send the electrical power required to move the build plate resistants. That motor during a job will be in constant motion and the changing of motion is a 3d printer demand for hours at a time. There are high pitch sounds and hums that will and will not be correct for the settings. The best way to learn is to watch it on youtube videos and learn it. Monitoring the temperature of the motor will be needed and may end up requiring a heat sink for cooling.

testcubeFor the real test, I made a 10mm cube in Google SketchUp exported the stl file and opened Cura and with the default settings of a Prusa made the gcode file. Now with a formatted memory card, I stored the gcode file on it.

With the power off on the printer, you can insert the card into the slot. Now turn the printer on and after bootup push the menu button in once. That is your click or select method. Turn the knob and a “>” will move down, now pick memory card. A list of files are now selectable, now pick the file you want to print. Remember it will mediately start the print process. If this was a real print you would need to have the filament ready in a preheated extruder. I did notice that the first thing it does is check the bed temperature and wait for the setting to be met, then it started moving. It did not confirm, “Do you want to print this file?” There are a pause and stop menu items of course if you pick the wrong file. Being careful how you name the file and log each job you do might be a very important practice. And to keep copies in a backup hard drive.

Guess what? It worked the first time!

I only see the Y-axis moving as it runs the code but it was awesome! In my mind, I could see the part forming layer by layer all 98 of them and in just under 10 minutes it was complete.

Previous <- Y-Axis Control Box        NEXT -> Z-Axis and Gantry


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