Homemade plotter

A homemade plotter, or as it is also called a plotter, is much easier to make with your own hands than, for example, a CNC machine or a 3D printer, since the rigidity of the X and Y axes is not needed, and instead of the Z axis you can use a regular servo or any other mechanism raising and lowering the pen.

You can convert any ready-made CNC machine into a plotter - just attach a pencil or felt-tip pen instead of a router and the plotter is ready. But usually homemade CNC The machines have a rather small working field and it will not be possible to draw A0 drawings on them.

Therefore, it is much easier to assemble a ready-made plotter for the task, especially since it can be made from any parts, for example from parts of an old printer, as in the photo below.

As you can see, ready-made printer parts are used here - the carriage and its movement mechanism.

But you can also do homemade plotter from any other material, for example, from plexiglass.

This homemade plotter has two axes X and Y, which move using stepper motors; the pen is controlled using a servo. All this is controlled using an Arduino controller, and power is supplied from a 12 Volt power supply.

What can a homemade plotter be useful for? Of course, for use for its intended purpose - drawing drawings, because, not for nothing, it is also called a plotter! So, for example, ready coursework You can get it on the website 5orka.ru, but printing on A0 sheet will cost 350-400 rubles for one drawing. The thesis includes a dozen drawings, and this is already a decent amount that is several times higher than the cost of a homemade plotter, but if you do it for the entire flow, then printing drawings on paper can turn into a small business.

Tools for making a homemade plotter

A jigsaw or router capable of processing plexiglass
- Drill
- Screwdrivers, pliers, etc.

Materials for making a homemade plotter

Plexiglass (one side is no less than the length you need)
- A small block of linden
- Guides
- 14 bolts and nuts
- 28 washers

Electronic equipment

2 gears for improved drawing accuracy
- 2 high torque stepper motors
- 2 stepper motor controllers (ULN2003A)
- 1 piece of bread board
- 1 Arduino connector (USB compatible)

Assembling a homemade plotter

To begin with, the base is assembled, it is not difficult, all connections are bolted, however, if you are not making a dismountable structure, you can glue it with dichloroethane.

When using bolts, fastening is done at the four corners with two screws and nuts. Slots for bolts and nuts can be easily made using a hand jigsaw.

Look how it looks in the picture.

Guides are inserted into the upper holes along which the Y axis will move.

The main thing is to ensure parallelism of the guides.

Since there is no load, even even wooden sticks can be used as guides. But, it is better to use aluminum tubes or guides from printers.

So, the base has been collected.

Now the carriage is assembled, on which the mechanism for lowering the pen of a homemade plotter will be installed.

This is what it looks like in the picture.

And this is how it is installed on the guides.

Pen attachment, in in this case- a marker, also made of plexiglass, or any other material.

Look at the pen locking mechanism - it is easy to make.

Servo can be used with any weight of 16-30 grams.

The motors do not rotate the toothed belt directly, but through a reduction gear transmission, in this case the gears were laser cut on a CNC machine, but you can take ready-made ones.

The stepper motors themselves are taken from old printers, their power is quite enough.

This is what a homemade plotter looks like assembled.

As you can see, there are no problems in making a plotter with your own hands. All you need is desire and the availability of suitable material at hand.

Posted by "...I decided to build a plotter for drawing printed circuit boards.... Author S.P. Markov

Printer plotter.

I sing an ode to “old iron.”

By the nature of my work, I am associated with not the most modern computer equipment, which, in order to be written off from the balance sheet, must be disassembled into its component parts: separate boards with electronic boards, separate mechanical components. As a result, a number of cases, power supplies, stepper motors, all kinds of guides with plain bearings, etc. have accumulated.

Like any radio amateur, I cannot raise my hand to send this “wealth” to a landfill and I decided from all of the above to collect “something” that is not produced (by the domestic industry), but is suitable for the needs of the radio amateur and quenches his thirst for new achievements. I decided to build a plotter for drawing printed circuit boards.

On the InterNet, I looked at information on this issue and settled on a 2.5D type design “a la” Luberth Dijkman because there are stepper motors from 5.25 disk drives, guides with carriages from OKI dot matrix printers, toothed belts from EPSON dot matrix printers, etc. d. and so on.

The housing from SmartUPS-400 was used as the supporting body, in which the power supply board (pulse from the printer) and the interface board are placed. X guides with carriages are installed on the housing cover using short duralumin corners. The X carriages are driven from both sides, thereby simplifying the requirements for rigidity and distortions. Both carriages are connected by a (lower) Y guide along which the writing unit carriage moves. The pen (felt pen) is raised by a solenoid and lowered by its own weight.

Here's what happened:

The format was calculated on A4, it turned out 1.5 cm smaller on each side.

The X and Y movement turned out to be 11mm per 100 steps, that is, 0.11mm per step (dictated by the size of the HP DeskJet toothed pulley).

The movement speed is quite high (depending on the control computer).

As you can see, the design turned out to be quite simple - no ball bearings, turning or milled parts, and at the same time, allowing you to gain experience in the manufacture of similar structures for other tasks. On it you can check the capabilities of controlling mechanisms from a computer, evaluate the power characteristics of the used engines, see “pitfalls” that you did not suspect, try your hand at programming, etc.

Now about some nuances.

The main nuance is that I do not have the ability to manufacture parts either in house or on the side. That is, you need to think for a long time: how to use this or that existing part to achieve the desired result.

Since the design was planned only for drawing (the requirements for rigidity are reduced), accordingly, all components are as simple and lightweight as possible. The X guides are hollow, the supporting Y guide is plastic, containers from validol and nitroglycerin (inserted into each other) are used as a pen (felt-tip pen) holder, the bottom Y guide and the writing unit carriage are from HP class=SpellE>DeskJet (it contains fastening to a toothed belt), the lifting of the pen (felt-tip pen) is carried out by the solenoid from the fax machine. In general, something is visible in the photographs (though not very much - the camera does not allow shooting at close range).

Hardware solutions.

The power supply produces 24 and 5 volts. Stepper motors PBMG-200-265 with winding resistance of about 80 Ohms. The solenoid winding resistance is 24 ohms. Each axis has two microswitches, one for the initial position, the other for the limit, and on the Y axis the role of the switches can be swapped for operation in ACAD or QBASIC. The interface board provides optocoupler isolation (I highly recommend) and controls motors and solenoid through microcircuits, assembled using optocouplers 4N32, K555AP3 and ULN2803.

To initially check the performance of stepper motors and their phasing, a tester was used (pictured below).

To evaluate the performance of the assembled structure and its characteristics, a QBASIC program was used that allows you to control the movement of the carriage using the cursor keys.

The existing software runs on a 486 computer (DOS) and I am trying to modify the program (with the kind permission of the author Roman Epishev) BDT (Basic Drawing Tool) for drawing printed circuit boards and their subsequent drawing with a plotter.

From the remaining “wealth” I assemble a winding machine (for DOS) and a 3D design in A3 format for drawing and burning with the interface and program of Roman Vetrov.

With best wishes S.P. Markov "

4mm was chosen as the manufacturing material. plywood, in fact, it was the only thing in the garage, and there was no desire to spend money on anything else. The main donor of the future plotter is a wide-format matrix printer epson lx-1050+
With minimal knowledge of the “compass”, a drawing was made (you can see the drawings at the end of the article). It was designed so that it could be cut with a hand jigsaw, but I am a lazy person, so I gave this routine work to a soulless machine.
After she finished I received the following set of parts:
We glue the parts together and get the side panels of the future plotter. I glued the drilling places and the holes for the screws with cyacrine, this makes the connection more reliable.
And this is what the carriage looks like, which will move the solenoid and the knife lowering mechanism. I glued PVA and regretted it, the part is complicated, while I was combining the elements the glue grabbed and it turned out to be a slight distortion, this is not critical, but not pleasant. I still recommend connecting all the parts together and gluing them with cyacrine.
During the process of assembly and fitting, the plywood became dirty and lost appearance, so it was decided to give it a more elegant look and paint it some fun color. I painted it with a regular spray can, as it turned out I was just a painter, but how did it happen? The photo below shows the side wall of the plotter with the film feed shaft bearing installed and the carriage with bronze bushings installed. The bushings were glued in with regular "cyacrine".

This is what the entire set of parts needed to assemble a plotter looks like, with the exception of bolts and gears.
A very important point for the operation of the plotter is the film feed shaft and rubber pressure rollers. The feed shaft on industrial plotters is corrugated, while the printer shaft is smooth and made of very hard rubber. To prevent the film from slipping, it must be covered with sandpaper. The shaft must be covered with tape in a spiral to avoid unevenness. I honestly stole this method and looked it up on the Internet; it turned out to be a very simple and reliable solution. As glue, you can use any shoe glue that glues rubber, fabric, etc.



The knife lowering mechanism is made of a piece of aluminum with holes made in it for guides and a hole for attaching the knife holder. To reduce the noise when the mechanism is activated, it is necessary to stick on porous rubber or, in this case, a felt pad from a hardware store. To lower the mechanism, a solenoid was used that came to hand (I cannot say its origin). The mechanism is returned to its original position by two springs. This solution is not very successful due to the complexity of its implementation (it is very difficult to maintain alignment and avoid jamming of the mechanism, and it also turned out to be very sensitive to temperature)

Now let's talk about moving the carriage. Here I miscalculated a little. The fact is that the engine with the gear for the toothed belt was taken from the EPSON LX300 (it has a direct drive with a 1.8" motor per pitch) and, as it turned out later, their belts are slightly different. As a result, the belts suitable for the gear turned out to be short. I have to redo it I didn’t want anything, so I just took two short belts, cut them and glued them. I tried to glue them with shoe glue for leather, fabric, rubber and other things, but it absolutely did not want to stick. In the end, I just glued it with “cyacrine”
The belt retainer was made from an aluminum angle. I drilled the holes, cut the threads and secured it all to the carriage.


In the photo above you can see a white rectangle; this is a support that prevents the carriage from turning. This part is made of 5mm fluoroplastic. thick. It moves along the U-shaped metal profile.
Now that we have become familiar with the main points, we can begin final assembly. Let's install the engine and assemble the gearbox.

The gearbox is assembled in the same form as it was in the printer. A 7.5" motor is a very large step and, when using a direct drive, will not allow you to achieve the required accuracy. The drawing was calculated accurately, so the gears do not play.
Initially, the belt was tensioned by a spring, but in certain modes it was clear that the belt was stretching, so I removed the spring and shortened the belt so that it was installed with the required tension. This is certainly not the best option, so it is better to provide some kind of tension mechanism.

Now let's talk about pinch rollers. Industrial plotters have independent rollers with independent suspension, they can be adjusted individually. This design solution is very complex for home production. Therefore, a steel rod with a diameter of 6 mm was torn out from the bowels of the printer. and 2 rubber rollers are mounted on it. Exactly 2, there is no point in using it anymore, so the guide rod is pressed along the edges by hogs with a spring mechanism. As a result, the shaft bends and the pressure becomes uneven. The main force falls on the extreme points and the rollers in the middle become almost useless. This problem can be solved by using a thicker guide or independent rollers with individual pressure adjustment. But as tests have shown, for a given working width, two rollers are quite enough.


We have dealt with the mechanics, now we can move on to the electrical part. In order not to waste money, I used the control unit from my CNC machine.
(for those who forgot or didn’t know, here is the article, where you will also find instructions for setting up Mach3)

Budget CNC milling and engraving machine for modellers+309
3 Sep. 2016, 15:12:15 |  Sergei Korotkevich Mogilev
Article http://www.site/blogs/view_entry/14237/
But for those who will assemble the plotter, all the electronics can be placed on the bottom of the plotter; there is plenty of space there.

The XY control of the motors remained the same, only the motor settings were changed, the divider was set to 1:16, the acceleration was set to minimum, the speed was set experimentally and the number of steps per mm. I honestly tried to calculate, but the numbers didn’t add up, so I figured everything out empirically. I will provide the data for the belt drive and gearbox as well as the resulting values, I hope someone will comment on this point and help me understand it.

Gearbox:
Engine gear - 14 forelocks
Feed shaft gear - 68 forelocks
Intermediate gear - 63 x 17
Belt drive:
Gear - 20 teeth.
Belt - 2mm tooth.

As for the control of the knife lowering mechanism, it is driven by a transistor switch; I remove the control signal from the unused “Z” axis driver. The signal is removed from the DIR channel after optical isolation.


The IRF540 transistor already has a protective diode installed inside. We put all this in heat shrink and hide it in the case. In this case, the control unit does not lose its functionality and can still be used on the CNC.
We have become familiar with the mechanics and electrical parts, now we can begin preparing the program.
An important element high-quality cutting with a weathervane knife is compensation for the offset of the knife, good people have already taken care of this and on the Internet a small utility was found that works in the Python environment, which adapts the program to work on a plotter (all necessary programs you will find at the end of the article). The program works simply, in the root of the disk we create a folder with a simple name in Latin letters, drop our utility and the file that we need to convert into it. Next, we simply drag our file onto this utility with the mouse and in a moment we receive an adapted file for our plotter. Then everything is as usual, launch the Mach3 program and open our file, set zero coordinates and start the process.

I would also like to focus on adjusting the knife extension (the less the knife protrudes from the holder, the longer it will last). The knife should protrude so that it cuts through the film and lightly grips the backing. Usually established experimentally. Another important point, which is not implemented in this design, is the adjustment of the knife clamping force. I wanted to implement this using a current regulator, but to simplify the design I abandoned this idea. The plotter is powered from a laboratory power supply and is capable of operating over a wide voltage range. As a result, during the cutting process I can slightly change the voltage, which affects the pressure of the knife. If the knife is pressed too hard, the film will jam under the knife and nothing will be cut properly.

Plotter assembly video:

Testing, cutting various kinds films:

That's all friends, write comments and share your thoughts. If the project turns out to be interesting, we will develop it further using high-quality components. For those who are interested, links to components can be found in the description of the video on my channel, thank you all, good luck, see you next time!

In this project I will show you how to easily and simply build your own cheap mini CNC plotter using Arudino. Of course, you can just buy a plotter, but firstly it’s very expensive, and secondly I don’t need it :)

For the X and Y axes we use stepper motors and guides pulled from two old DVD\CD drives. Work zone our CNC plotter will have 4 by 4 centimeters.

Since the project is based on the use of a serial port, you can also use a Bluetooth module (for example HC-06) to connect the plotter to your computer wirelessly!

Step 9. Program for working with G-code.

Now we are ready to print our first image using our mini CNC plotter! To do this, we need an intermediary program between us and the plotter. It converts G-code into servo movements.

What is G-code? G-code is a file with X, Y and Z coordinates. It looks like this:

M300 S30.00 (Printing unit lowered)
G1 X10.00 Y10.00 F2500.00

G1 X20.00 Y10.00 F2500.00

M300 S50.00 (Printing device raised)

Then you will need to install an addon to it that allows you to export images to G-code. You can download it from this link.

Let's set up Inkscape for the first time. Open the program, go to the "File" menu and click "Document Properties". See the first illustration above and change it as shown in the picture. Then close this window. We will use a print area of ​​4 by 8 centimeters. Next, see the second picture.

How to type text: Enter your text, change the font to Times New Roma and set the size to 22. Then click on the cursor icon and align the text as shown in the third image above. Select a path from the "Object to Path" menu.

How to print images: This is more difficult than text. Images must have a transparent background. Drag the image into Inkscape with your mouse. Click “Ok” in the next window. Then you must resize the image so that it fits into our printable area (see image 4). Click "Path" from the menu and select "Trace Bitmap". Then do as shown in the 5th image. Click Ok and close the window. Then move the gray image and remove the color behind it. Move the black and white image to Right place again and click the “Object to path” button in the “Path” menu. The sixth picture shows how to delete an image.

Export as G-code: Finally, go to the File menu, click “Save as” and select “.gcode”. Click ok on the next window. That's all! Our G-code is ready to be printed on our brand new mini CNC plotter!

In contact with

Creation printed circuit board

After etching the PCB, you can start soldering. I suggest you solder in the order shown.

Microcontrollers and chips:

1. ATmega16
2. FT232RL
3. L293DD
4. ULN2803
5. TCMT1109 x2
6. Resistors:
7. 100 x3
8. 2k4 x2
9. 4k7 x3
10. Capacitors:
11. 22px2
12. 100nx4
13. Transistors:
14. IRLML250
15. BC857 x2

Diodes:

1. LL4148
2. Red LED
3. Green LED x2
4. Pins:
5. 1x2x4
6. 1×6 x2

Jumper x2

Other:

1. 5k potentiometer
2. 16 MHz quartz
3. Buttons x4
4. USB mini B connector
5. AK500/3 Connector
6. Switch 2-channel
7. 16×2 LCD display

There was an error in the photo. I forgot the resistor for the optocoupler output. Don't worry, this has been corrected in the PCB drawing in the RAR archive.

AVR programming

The file attached below contains the Eagle PCB design.

I think that many of you yourself know how to flash microcontrollers.

Additional Information.

It is not so easy to control the entire device with one microcontroller. The hardest part was creating the XY motion signals when there was motion on both axes. In the end, quartz did a pretty good job of this.

The second difficulty is communication with a PC. I had to write my own communication protocol via UART. This is similar to the AT command, but requires much less memory and is much faster.

Step 3: Z Axis

Now you can make the mechanical part of the device. Let's start with the Z axis.

In the photo you can see everything you need to create the Z axis.

The parts were cut rather poorly. Apparently someone did not take into account the width of the laser beam. In fact, all the pieces were a little smaller than what I ordered. I had to sand everything down with sandpaper.

Let's start gluing. I used super glue for plexiglass and laminate. The laminate serves as a spacer between the electromagnet and the plexiglass. I secured the electromagnet with two screws.

Step 4: Y-axis

As in the previous step, you need to glue everything together. I sanded all the plexiglass parts. I also inspected the furniture rail for any defects. I treated the gluing areas with acetone.

Timing belt installation

The easiest way to secure the belt is to use a small tie. One end of the belt must be secured to the movable carriage, and the other end must be passed through the gears. It is necessary to tighten the belt, and then attach it to the carriage.

Installation of limit switches and other things

You need to glue the switch as shown in the photo. You need to solder a red-brown wire to the switch. You also need to glue two pieces of laminate onto the carriage.

The photo contains a description and colors of all cables. These are the cables for the stepper motor (Y +, Y1, Y2, Y3, Y4), electromagnetic cable (Z +, Z-) and limit switches (2xYmin, 2xYmax).

Ymin is the limit switch cable next to the motor.

The last photo shows a 12-core cable with a description of its connections.

Step 5: X Axis

And now comes the most difficult step...

You need to mount 2 parallel sliders. I can't always describe exactly what needs to be done. But you can be guided by the photographs.

After you have glued the sliders. You can glue the carriages to them, and then the Y-axis rail.

You need to mount the stepper motor, toothed belt and limit switches as in the previous step.

Step 6: The rest of the installation

I made a pencil holder from plexiglass and laminate using hot glue.

I decided to use magnetic film as the working field. I'm going to attach the paper to it using magnets.

Step 7: Final Installation

Now everything needs to be fixed on one base. I decided to install the circuits and LCD screen on special holders.

Step 8: Software

As I already said, I wrote my own application. This is my first application in VisualC#, so there are a lot of errors.

Here is a list of available commands in the Command Prompt window:

returnxy - returns to its original position

SetXY xy - moves the pen to the specified position (in mm)

Setxy xy - moves the pen to the specified position (in increments, check application settings)

Getz - returns 1 if the handle is up, 0 otherwise

getxy - returns pen position (in mm)

selectpen - waits until the user presses the OK button

rectx1 y1 x2 y2 - draws a rectangle based on 2 opposite vertices (in mm)

arc X Y R A1 A2 t - draws an arc with a center at point (x, y), radius r, with a starting angle a1 and ending with an angle a2 (from the horizontal)

text x y size spacing text - draws text at (x, y), from the specified size and character spacing

I almost forgot. To run the application, .NET Framework 4 is required.

Step 9: Final

This article shows how to make a plotter. I do not encourage you to strictly follow the instructions, as I said that some of my solutions are ineffective. I wanted to show you something that I think is interesting. A lot of experience was gained during creation.