how to build a drawing machine

[PraveenAlexis]

i could find some motors from my old brocken DVD-Rw

[Neo]

New topic added, How to control Hard Disk motor using a microcontroller

Rksk,
Remember I was talking about the tray motor of the CD ROM. Accidentally I found a video on that. It's a stepper motor.

Ability to control position accurately without a feedback system (such as using an encoder) is a feature in a stepper motor. Since the angle movement per pulse is well defined, it is easily possible to control the angular velocity using a little microcontroller.

[media]http://www.youtube.com/watch?v=dSKac6EPkrc[/media]

[Neo]

Information here are related to donation topic here.

According to the doc How it Works.docx, you will need to apply an edge detecting filter to convert the source picture to machine printable drawing. This subject comes under Computer Vision -> Edge detection. I would like to propose either Sobel or laplacian filters.

Source Picture

original.PNG (118.44 KiB) Viewed 23607 times

Destination machine printable drawing

sobel.PNG (97.39 KiB) Viewed 23607 times

First you need an image reader (Such as JPG reader) and then apply this sobel filter to get the edges that are ready to be sent to the printer. Finally output the data line by line (called vector graphics).

I can help you to do this since I have done these in past. Let me know.

[Neo]

Keep these circuit diagrams with you guys.

Power supply
Since the motors are 12V, find a 12V / 2A transformer to suit both needs. 7805 will provide essential 5V and power to the uC (microcontroller).

Power supply.jpg (29.95 KiB) Viewed 23606 times

Stepper motor control with ULN2003

uln2003.gif (12.27 KiB) Viewed 23606 times

Oscillator & MAX232

MAX232.jpg (252.53 KiB) Viewed 23606 times

Lots of exiting things to happen

[PraveenAlexis]

motors.jpg (33.9 KiB) Viewed 23580 times

1) The two accells
2) Cartridge Holders
3) Stepper Mortes x 3
4) Normal DC motors x 2
5) Belts x 2

Neo, can you make this pic small i dont know how to do it

[Neo]

So you have enough items to give a start. Next thing is to give a start. I'll give you some guidelines.

First thing is to design the structure. I think threaded rods can be easily used for moving parts. You can easily find them in local hardware shops.

1. Sample structures

   

   struct.jpg (61.59 KiB) Viewed 23579 times

   1, 2 and 3 are 3 threaded rods that are fixed to 3 stepper motors to move along x, y and z.
   
   Another sample structure:

   

   struct1.jpg (18.31 KiB) Viewed 23579 times

   The one in https://robot.lk/viewtopic.php?f=75&t=2594#p7607 is also a good example.
2. Threaded rod

   

   threaded-rod.jpg (11.88 KiB) Viewed 23579 times

3. Mounting motors to threaded rod

   

   threaded-rod-motor.jpg (34.99 KiB) Viewed 23579 times

   

   threaded-rod-motor1.jpg (16.71 KiB) Viewed 23579 times

4. Fixing the other end to a Ball bearing

   

   threaded-rod-ballbearing.jpg (35.9 KiB) Viewed 23579 times

5. Fixing a nut to moving part

   

   threaded-rod-move.jpg (15.97 KiB) Viewed 23579 times

6. Once we are done with the structure, it's about moving the motors in x, y and z directions using electronics.

Since you have few people on the group, you can ask someone to identify the wires, voltage & current ratings and angle per step of each stepper motor.

We can discuss about the electronics part later.

[PraveenAlexis]

shenal is working on the electronical parts, and im working on the structure shenal have an idea about moving the pen up and down without the stepper, he will explain you when hes done with it,

[Neo]

shenal have an idea about moving the pen up and down without the stepper

I guess he is going to use a solenoid? If that is the case, I think it's a good idea as long as he can control the pen on hitting the paper slowly (using a spring may be) to avoid damage to both paper and pen. We can discuss that later.

im working on the structure

Good luck!!!

[PraveenAlexis]

we finished making the structure! Nw we have to do the electronic part! I wish shenal will reply here soon!

[Neo]

A picture is worth a thousand words !!!

Can you update with some pictures.