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Friday Facts 8: Makelangelo sewing patterns

Here’s a use for Makelangelo plotters that I never considered, offered up by Discord member Jolo: Sewing patterns for home sewing, cosplay and costume design!

It turns out that there’s many free pattern sites. Here’s just one example of a hoodie.

I used Freesewing.org to get a pattern for a hoodie and then chose export pattern > SVG and saved to my desktop.

In Inkscape I opened the file, set the document size to A2 and used that as a guide to split up the file into sections that fit on the paper for the Makelangelo. Just to be cautious I used Object > Ungroup and Path > Object to Path to prevent any import questions. These might not be necessary, but I do them with my laser cutter and it’s a habit now.

I had to delete everything except the part on the paper for each export. Then I used Save As > DXF R14. Makelangelo also understands SVGs – another habit from my laser cutting work. (this post was not paid for by Big Laser – Ed)

Then I loaded it into Makelangelo software and drew it just like any other drawing.

Final thoughts

The HUGE extension for Makelangelo draws up to A0 (841 x 1188 mm aka 33-1/8 x 46-13/16 in)

Do you have other great uses for a large plotter? Share with us and we’ll share it with the world!

You might also get a kick out of open source, parametric pattern design app callled Seamly.

Makelangelo News

Friday Facts 6: Makelangelo software 7.28.2

Today I’m pleased to announce the stable release of Makelangelo software 7.28.2. I’d like to thank everyone in the community for your support, especially the Discord users working to find and report bugs.

Lookin’ good, good lookin’!

Goodbye, Makelangelo Firmware

The big news is that Marginally Clever is no longer maintaining Makelangelo-firmware. It was too much esoteric work taking up all my time. Instead I teamed up with the good people that make Marlin 3D printer firmware. Together we’ve added polargraph robot support. Check out FF4 if you want the open source code or to make your custom machine tweaks.

New plotter controls separate making art from driving robot.

Get Makelangelo Software

The newest makelangelo software is available in our store, by donation. You can also get releases from our open source github repository.

In order to make it run you will need to install Java JDK 17 or later.

Use Makelangelo Software

Video time!

video late because editor is AFK. one more pandemic shortage!

Contribute

We’d love more people translating the app and sharing ideas about how to make it better. Join us on Discord or submit a ticket to github today.

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Friday Facts 5: How (and why) be a Makelangelo Tester

To describe the mood here this week in a word it would be “challenged”. My productivity is greatly affected by the all-grey of Vancouver winters – I can’t work if I’m not happy and it takes a lot more time to find my happy place each day in the winter.

How (and why) be a Makelangelo Tester

Not too long ago, with the help of the Marlin 3D printer firmware team, I managed to switch to Marlin. This was a huge time savings for me as I can now focus on making the software better. To make it great – for me, for you, for everyone – as fast as possible I need to shorten the cycle time – the time it takes to check a new feature works right.

Maybe you’ve noticed the app is missing something you need. Maybe you found a bug. Now for a lot of programs out there the way to tell them about a bug is not obvious, hard to achieve, and the turnaround time is … who knows.

I want to make a great app and put new issues to bed quick-fast. To me, the report-fix-test loop should be as short and fast as can be. I hope you agree! That is why I’m asking you to help me help you. Become a tester: to shorten the loop.

Report

With our without being a tester, the process starts by going to the Makelangelo code project and filing a good bug report. The bug report comes with a template to fill out that should make writing your report painless.

Fix

Then I or some other brave soul will (maybe) ask follow up question and (definitely) work to make the thing happen. Some are easier than others in surprising ways.

Test

Now this is the sticky part of the loop. When I write code I bang away in the magic language of the drow elves, cursed to roam the underdark. When the machine says I have atoned enough, it produces a jar file. This is then packaged with other essentials like the README file and somehow delivered to you to give it a little run-see, a little double sanity check, a thumbs up or down.

The packaging and delivery process is slow. So slow. In a more perfect world you should be able to say “get me the latest update from Dan!” and moments later be able to run it. Two clicks, right? Well friends, read on.

Thank you

Making it easy to make you happy is … it’s the greatest gift. A win/win. Thank you. It’s very easy to get lost in the weeds with code, and your input gives me clear focus and direction.

Special shout out to CaptFuture, Headly, and OopsHeIsDead for being awesome contributors this week.

Final thoughts

Here’s a gallery of recent Makelangelo Software updates to the app. Many of these changes were brought about by you and yours. I’ll continue to write, you continue to stay awesome. Until next week, be well!

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Friday Facts 4: How to Marlin Polargraph

Assuming you have two stepper motors, two limit switches, some timing belt, a 3D printer control board, and a hobby servo then you have everything you need to make a wall hanging plotter of your own that will work with Makelangelo Software. Read on for firmware configuration.

All the changes described herein have been applied to the fork of Marlin we maintain on Github. Make sure you are working with the branch called polargraph-bugfix-2.0.x which should match this blog post. (Thanks, Coliss86!) You can modify this setup for your custom board. Many people have successfully built RAMPS+mega derivatives and shared their success stories in the Discord channel.

You’ll need to open the firmware in an Integrated Development Environment like Visual Studio Code and install the PlatformIO plugin.

The main files we’ll touch are Marlin\Configuration.h and Marlin\Configuration_adv.h. First I will show the line to find and then explain what is changed and why.

Marlin\Configuration.h

#define MOTHERBOARD BOARD_RAMPS_14_EFB

This sets the type of brain board you are using. The full list can be found in Marlin\src\pins\pins.h. In my case I change BOARD_RAMPS_14_EFB to BOARD_RUMBA.

#define CUSTOM_MACHINE_NAME "3D Printer"

Change 3D Printer to Polargraph. It’s aesthetic and non-essential.

#define EXTRUDERS 1

Polargraphs have no extruders. Change 1 to 0.

//#define POLARGRAPH

I remove the // part in front of # so that it becomes defined.

#define POLARGRAPH_MAX_BELT_LEN 1035.0

Makleangelo uses 1m belts. The pen holder adds a small amount to that and so my length for both belts is 1035. Correct belt length is essential to getting square drawings. While this is the default number in Marlin, you may have to change it – especially if you are making a huge machine.

For Makelangelo huge 2035 worked great on 2m belt. From this I conclude that (the length of the pen holder arms) – (the part of the belt lost inside the motor mount) = +35mm. If you make a custom pen holder or different motor mounts your 35 will change.

#define X_MAX_PIN       35
#define Y_MAX_PIN       34

These are the digital pins that are connected to your limit switches, uses for homing. You’ll have to look up your board and know your circuit to set the right numbers here. When homing the machine will move the pen down and the counterweights up until the weights touch the switches. That is the maximum reach of each belt, and thus the max limit switch.

#define USE_XMIN_PLUG
#define USE_YMIN_PLUG
#define USE_ZMIN_PLUG

I disable using minimum limit switch by adding // at the start of these lines.

//#define USE_XMAX_PLUG
//#define USE_YMAX_PLUG
//#define USE_ZMAX_PLUG

I enable using maximum limit switch by removing the // at the start of these lines.

#define X_MAX_ENDSTOP_INVERTING true // Set to true to invert the logic of the endstop.
#define Y_MAX_ENDSTOP_INVERTING true // Set to true to invert the logic of the endstop.
#define Z_MAX_ENDSTOP_INVERTING true // Set to true to invert the logic of the endstop.

I have switches wired to go LOW when they are clicked. If you have it the opposite then you’ll want to leave these set to false.

#define E0_DRIVER_TYPE A4988

There is no E0 Driver and the sanity checks in Marlin will get mad if this is defined. Put another // at the start of the line.

#define X_DRIVER_TYPE  A4988
#define Y_DRIVER_TYPE  A4988

If you are using something other than an A4988 stepper driver for your motor… this is where you’d list it.

#define DEFAULT_AXIS_STEPS_PER_UNIT   { 80, 80, 400, 500 }

There are only three axies of motion on this system, so we have to change it from { 80, 80, 400, 500 } to { 80, 80, 80 }. That assumes 200 step-per-turn motors and a 20 tooth GT2 pulley at 1/16 microstepping. (200*16) / (20*2)=80. Adjust your numbers accordingly. a 400-step motor would be 160 for the first two. The third is not really important because we don’t use a third stepper motor. Marlin won’t let me set two axies so it dangles on the end there like a vestigial tail.

#define DEFAULT_MAX_FEEDRATE          { 300, 300, 5, 25 }

I have changed these to { 90*60, 90*60, 90*60 }. Experiment with this number and see what kind of speeds you can get!

#define DEFAULT_MAX_ACCELERATION      { 3000, 3000, 100, 10000 }

I set mine to { 40*60, 40*60, 40*60 }. Another area I encourage you to experiment.

//#define CLASSIC_JERK

I don’t remember why I had to remove the // part but I did to appease the sanity checks.

#define INVERT_X_DIR false

By default Makelangelos are built with the left motor physically wired backwards so that “pull in” and “push out” was the same for both. So I have to change false to true. Discord user CaptFuture pointed out if you are building a DIY machine be aware mixing the wiring and the inversion might make some motors behave backwards.

//#define NO_MOTION_BEFORE_HOMING // Inhibit movement until all axes have been homed.
//#define HOME_AFTER_DEACTIVATE   // Require rehoming after steppers are deactivated.

I removed // from both. Safety third, right after chainsaws and LSD.

#define X_HOME_DIR -1
#define Y_HOME_DIR -1
#define Z_HOME_DIR -1

I changed these to 1 so that it homes to the maximum limits.

#define X_BED_SIZE 200
#define Y_BED_SIZE 200

Here I set the X_BED_SIZE to the width of a Makelangelo. The width is measured from one motor shaft center to the other motor shaft center. Makelangelo 5 is 650mm. For the Makelangelo height I used 1000mm (1m). More on this in a minute. Note: this number cannot be an odd number.

#define X_MIN_POS (-X_BED_SIZE/2)
#define Y_MIN_POS (-Y_BED_SIZE/2)

The bottom-left corner of the drawing area would then be – X_BED_SIZE/2 and -Y_BED_SIZE/2, or -325 and -500, respectively.

#define X_MAX_POS (X_BED_SIZE/2)
#define Y_MAX_POS (Y_BED_SIZE/2)

The top-right corner of the drawing area would then be X_BED_SIZE/2 and Y_BED_SIZE/2, or 325 and 500, respectively.

//#define BED_CENTER_AT_0_0

I removed the //. You can tell from the math that it should be true.

//#define MANUAL_X_HOME_POS 0
//#define MANUAL_Y_HOME_POS 0

First I remove the //. Then the MANUAL_Y_HOME_POS is equal to -492.65. I get that number from

Y_MAX_POS - ( sqrt( sq(POLARGRAPH_MAX_BELT_LEN) - sq(X_BED_SIZE/2) ) )

Remember using the triangle adjacent and the opposite to get the hypoteneuse? well here we use the opposite (machine bed size) and the hypoteneuse (the belt length) to get the adjacent, and then adjust by the Y_MAX_POS.

Note that the final value has to be inside the allowable drawing area of the machine – you can’t home to a spot that’s outside the printable area. That means the -Y_BED_SIZE/2 has to be a larger negative number than the MANUAL_Y_HOME_POS. With my settings -Y_BED_SIZE/2 is -500 and everything is fine.

//#define EEPROM_SETTINGS

remove the //. EEPROM_SETTINGS will allow you to tweak some firmware settings like acceleration and steps/mm from the LCD panel and then save them to the printer’s (very tiny) memory. Worth it!

//#define SDSUPPORT

If you have an SD card slot, remove the //.

//#define NUM_SERVOS 3

I set this to 1. As Jack Black said, one’s all you need.

//#define DEACTIVATE_SERVOS_AFTER_MOVE

Remove the //. This keeps the servo from jittering when not being used, which makes for a more pleasant sounding machine. It is reactivated every time it is used, don’t worry.

Marlin\Configuration_adv.h

#define AXIS_RELATIVE_MODES { false, false, false, false }

Change to { false, false, false } because there are three axies and zero extruders. Keeps the sanity check happy.

#define MICROSTEP_MODES { 16, 16, 16, 16, 16, 16 } // [1,2,4,8,16]

Change to { 16, 16, 16 } to keep the sanity check happy. Same reason. This is where you’d set your microstepping values.

#define MANUAL_FEEDRATE { 50*60, 50*60, 4*60, 2*60 }

I changed to { 50*60, 50*60, 4*60 }. Three axis! THREE.

#define G0_FEEDRATE 3000 // (mm/min)

I changed the number to 12000. What can I say? I like to go fast.

LCD panels

Discord member Headly pointed out that there’s no mention of LCD control panels. Search Configuration.h for “LCD / Controller Selection” and then start reading. There are many choices from which to choose. For Makelangelo I use

#define REPRAP_DISCOUNT_SMART_CONTROLLER

If your Makelangelo has no LCD panel you must DISABLE this feature. When the robot is told to change pens (Gcode M0) it will wait for the user to click the dial. With no dial and no LCD, the user will be confused while the robot patiently waits forever.

While the previous Makelangelo-firmware talked at 57600 Baud, Marlin defaults to 250000. If you connect the app to your firmware and nothing is “heard” from the robot then the app and the robot are on two different baud rates.

Discord member Mesut asked about the minimum temperature settings in Marlin. There is no extruder so minimum temp settings are ignored by Marlin.

Every G0 move goes to 0,0

Reinitialize your EEPROM with an M502 factory reset, then recheck that your machine width and height is not zero. If the machine dimensions are zero or not-a-number then inverse kinematics will silently fail, return 0, and your machine will think you asked for it to go to 0,0 no matter where you actually requested.

Final thoughts

After all these changes you should be able to upload the firmware and start running your polargraph drawing robot. Take it in small steps – try homing your machine with no belts on and then touch the switches to see if it behaves. Also check the pulleys turn the correct direction before putting the belts on.

By default Makelangelo software uses a servo position of 90 (middle of the range) for pen up and 40 for pen down. Keep that in mind when you install the servo horn (the finger thing that lifts).

If you have any trouble with this, please join me and other polagraph fans on the Discord channel. It may be you’re doing something exotic; maybe this document needs a refresh; or you just want to find people with similar tastes. Join us!

Further Reading

The Marlin Configuration guide online

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Friday Facts 2: Makelangelo Java GUI

This last week there has been work on Makelangelo software to make it work with the new firmware.

I spent a lot of time using design patterns to decouple classes so they can be independently tested. Usually this means an Observer pattern common in Java: a visible Panel on the screen has a list of registered Listeners and when something interesting happens in the Panel it calls notifyListeners(interestingEvent). This way Panel can be run and tested without needing any specific Listener.

A single sub-panel

I’d like to change up the code for a MakelangeloRobot to be decoupled from the NetworkSession – the source of data from the real machine. Then data could come from, say, a piece of code reading from a file. That way the state of the machine could be recorded and played back for testing things like “is the machine connecting to you a Makelangelo 5, a 3, a 2, or something else?”

I’m also plagued by ideas about how a Turtle path is used by a MakelangeloRobot. Turtle is a class that contains TurtleMoves, which describe the movement of the pen over the paper. One Turtle per color! Based on the old Commdore 64 turtle, one of the first procedural drawing programs I used as a kid.

Many classes in the Makelangelo app read and manipulate the history of TurtleMoves in a Turtle.

Drawing speed vs quality testing

In a cartesian plotter the velocity, acceleration, and jerk have the same effect everywhere across the work area. Testing such a machine to find ideal speeds is not onerous. I would draw a grid of squares and on the x axis each square would have more velocity while on the y axis each square would have greater acceleration. In this way the sweet spot is easy enough to find.

In a polargraph plotter the challenge is much greater. What works at the top doesn’t work at the bottom, what works in the center might not work on the sides. Simply drawing a set of squares isn’t enough! Long story short I need your help to find the sweetest of sweet spots. Together we can do it. Right? Right??

Spiral improvements

before
after

…and that’s all I have to say about that.

Final thoughts

These changes can be downloaded from the Makelangelo project on Github.

Did you know you can add bars to your timing belt? I didn’t.

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