About D. Scott Williamson

Compulsively Creative

Prusa i3 MK2S 3D printer kit assembly time lapse videos

Prusa i3 MK2S 3D printer kit assembly time lapse videos

If you’ve ever wanted to see someone assemble a 3D printer from the ground up, I’ve captured every detail, sped it up, and set it to music just for you:

Link to 300x time lapse video (longer, more detail, different background music):
20170323 GoPro Prusa i3 MK2 assembly and print (300x time lapse)

The videos were captured using a GoPro Hero 3 Black in time lapse mode taking a wide angle high definition image every 5 seconds to a 64GB micro SD card.  The camera was mounted to a tripod using parts printed on the Replicator 2 and powered using a USB hub.  The resulting 30fps HD videos were created at 400% and 200% speed respectively.

History…

In 2012 I bought a MakerBot Replicator 2 for my father, which he graciously offered to keep at my house (he’s absolutely the BEST sharer).  He has since moved to a larger house and in December 2016 we happily moved the 3D printer to it’s new and rightful home in his shop where it has been getting good use making parts for an interesting capacitive network antenna power coupling project, and lots of little toys for the grand kids.  It was a great turn-key printer, able to easily slice and print models with its simple intuitive software.  Unfortunately without a heated bed and with limited head temperature it could only print using PLA. This left me without convenient access to a 3D printer, but gave me the opportunity to expand my 3D printing horizons.  I’d been considering buying one for a while, but finally I needed to make a decision.

The search…

For me, selecting a new 3D printer was as difficult as buying a new car.  There are a lot of decisions to make: Cartesian or delta? Retail, kit, or clone? Open or closed source? Which hotend? Cooling fans? Heated bed? Which materials (PLA, ABS, PETG, Nylon…)? What software can be used? and the biggie… How much do I want to spend?

I started my search with the usual “top 10” lists and “3D printer” roundup articles.

# 1 in All3DP top 10 in 2017
(All3DP is totally worth subscribing to by the way)
#1 in Make Magazine 2017 3D printer comparison
Make Magazine review:
Toms 3D review:
If you are interested in 3D printing and are not familiar with Tom, you should be, check out TOM’s 3D  website for some of the best, balanced, scientific reviews and comparisons of 3D printing components, printers, and filaments:
Tom‘s YouTube Channel:
Tom is also a moderator on Google+‘s fantastic 3D Printing group:

I didn’t have to look for very long before one machine started to tick all my boxes:

  • Open Source
  • Kit (and assembled versions available)
  • Cartesian
  • Auto mesh bed leveling
  • Part cooling fan (for PLA)
  • Heated bed (for ABS and other materials)
  • Multi-material
  • Multi-slicer,
  • Affordable
  • … and as an added bonus it has a 4 color upgrade coming later this year.

The Prusa i3 MK2

The machine…

The Prusa i3 MK2 is the latest printer designed by RepRap legend Josef Prusa, and the one at the top of the 2017 best 3D printers lists all over.  If you are not familiar with RepRap (http://reprap.org/) , it is a community of hardware and software makers who have been advancing open source 3D printing for the last couple of decades.  The basic concept behind RepRap is to create a machine capable of creating copies, or improved copies, of itself.  We all have that community to thank for democratizing and popularizing 3D printing to the point where fused filament 3D printing became commercially viable for the public (that, and a couple patents expiring).

Josef has been at the heart of two of the most popular recent open source 3D printer designs: the Mendel, and the Prusa (his namesake), each model undergoing several successful iterations and improvements.  In 2009 Josef Prusa opened shop and began selling printers and kits.  Today, true to his RepRap roots the latest machine, the Prusa i3 MK2 is used to print parts for customers printers in Prusa Research’s “build farm”.

Josef Prusa in Prusa Research’s build farm where Prusa printers are printing Prusa printers.

If you’d like to know more about the printer check out the Prusa website.

The wait…

I was going to order it over Christmas break 2016 but was waffling. I wasn’t sure if the printer was getting too much hype, or if I should get a dedicated dual head printer, or if I should just grab a turn-key printer like a Taz from a local store.  That delay would cost me a lot of time.  I eventually committed to ordering the Prusa i3 Mk2 kit in late January for a whopping $773 (USD) including shipping, an extraordinarily modest price.  Due to high demand and limited supply capacity for parts like the custom heated bed, I would have to wait 3 months.  This was not a surprise, Prusa was very clear about the lead time for their printers.  I received the printer late March.

The assembly…

By now I hope you have watched the assembly video(s).  I could have ordered the printer fully assembled and calibrated for an extra $200 (and extra lead time) but part of the reason I wanted an open source printer is to easily modify and improve it, and for that reason I wanted to know each nut and bolt personally.  It took roughly 8 hours, 5 good beers, 3 cats, and a dog (all featured in the videos) to assemble, test, and calibrate the machine.  The tree frog took 3 1/2 hours to print.  I had already read all the assembly instructions while waiting for the printer, and learned a LOT from watching Tom’s 6 part series about building the cheapest possible clone of the Prusa i3 MK2. (16 1/2 hours of interactive YouTube live streams!!! The clone was eventually named “Dolly” by someone in chat for the first cloned sheep of the same name)

  1. Prusa i3 MK2 live assembly: p1, Y-axis
  2. Prusa i3 MK2 3D printer clone live assembly: p2, X & Z Motion
  3. Prusa i3 MK2 3D printer clone live assembly: p3, X & Y Motion
  4. Prusa i3 MK2 3D printer clone live assembly: p4, Wiring and Printbed (mechanics finished!)
  5. Prusa i3 MK2 3D printer clone live assembly: p5, Electronics and Firmware!
  6. Prusa i3 MK2 3D printer clone live assembly: p6, final setup and first print!

If you decide to get the Prusa i3 MK2 kit or assemble a clone, here are some tips…

  • When there is a captured nut, POUND that nut into place before assembling the parts!!! Both Tom and I had the upper nut from the part cooling fan come loose and bounce around inside assembled parts for tens of minutes before carefully getting it seated.
  • Read ahead.  There are a few steps that provide instruction regarding previous steps like “but don’t over tighten”, or other things that may be should have been said in advance.
  • Look at all the pictures and stay organized.  The instructions are done VERY well in the “Ikea” style.  There are many details that you can only get from the pictures.
  • Be careful to use the correct length/size fasteners, rods, etc.
  • Review each step when done to make sure you didn’t skip or overlook anything.

The quality…

The print quality is amazing.

I haven’t had a lot of time to print many models yet but the resolution and quality of the first PLA print of the tree frog are far and away better than anything I’ve seen before.  It’s only 50mm wide but the surface is so smooth from the .5mm layer height, and the underside is flawless due to the part cooling fan.  The details in the eyes, nostrils, and hips are impressive too.  I’ve also printed a Raspberry Pi case, camera mount, (for OctoPi) and computer stand mounts in ABS.  I’ll be printing some drone parts soon in PETG and ABS, and bought some Nylon to play with.  I’ve tried Slic3r and Cura model slicing software used to convert models to g-code files for 3D printing.  I  preferring Slic3r which was provided by Prusa pre-optimized for this printer, but they are both very good tools.  Stay tuned to blog.workshop88.com for more of 3D printed projects in the future.

Finally, on the topic of Dolly, and a home made clone…

Even though I just bought, assembled, and am still coming up to speed on my fantastic new printer, the idea of building a clone for 1/4-1/3 the price (somewhere in the $250 range) has me and several friends on the verge of starting a group clone build.

Thanks!

Thanks to Kevin Meinert of subatomicglue for letting me use his awesome music in the videos.  If you would like to hear more, visit www.subatomicglue.com.

If you’re interested in building a Prusa or another 3D printer, or a clone, or discussing 3D printing, check out Workshop 88 on Google groups, Slack, or come by our weekly open house any Thursday night after 6:30pm.  Details can be found here.

D. Scott Williamson
Compulsively creative

Maker of CamBam supports Workshop 88 makerspace!

HexRay supports Workshop 88 with a complimentary
CamBam site license & member discount!

Workshop 88 would like to extend a big thank you to HexRay for supporting the our CNC efforts by allowing us unlimited use of CamBam on club Windows and Linux computers plus a discount on CamBam to Workshop 88 members.

For more information about CamBam, check out their website: http://www.cambam.info/

From the website:

CamBam is an application to create CAM files (gcode) from CAD source files or its own internal geometry editor. CamBam has many users worldwide, from CNC hobbyists to professional machinists and engineers.
CamBam currently supports the following:

  • Reading from and writing to 2D DXF files.
  • 2.5D profiling machine operations with auto-tab support
  • 2.5D pocketing operations with auto island detection
  • Drilling (Normal,Peck,Spiral Milling and Custom Scripts)
  • Engraving
  • True Type Font (TTF) text manipulation and outline (glyph) extraction.
  • Conversion of bitmaps to heightmaps
  • 3D geometry import from STL, 3DS and RAW files
  • 3D waterline and scanline machining operations
  • Extendable through user written plugins and scripts

Be sure to check out their CamBam bundles with Mach 3 controller and CutViewer too.  Personally, I purchased the full CamBam + Mach 3 + CutViewer bundle; I couldn’t beat the price and I’ve been happy with them to this day.

As if that wasn’t good enough: “Unlicensed CamBam installations will continue to work after the 40 evaluation uses are up and allow editing drawings and viewing toolpaths.  However, g-code output is limited to 1000 lines, so another option is for people to work on designs at home, then bring them in to the group’s licensed computers to generate g-code.”

This level of support from HexRay is fantastic and something Workshop 88 greatly appreciates!


I have been using CamBam as my go-to CAD-CAM software for many years, to see a sampling of the kinds of things it can do, take a peek at some of my personal CamBam projects:

3D vacuum forming mask mold master for independent movie

Utility shelf for beverages and keys

Wall artwork – Wooden V

Engraved Bahr family crest

Atari Adventure engraved sign

Philosophy Custom Guitars engraved sign

Working miniature TV

Halftone portrait

Stay tuned to see CamBam powered Workshop 88 CNC projects!

…and on behalf of Workshop 88:

THANK YOU Andy @ HexRay!

If you’d like to find out more about Workshop 88, please contact us:
http://blog.workshop88.com/interact-with-us/ or stop by our weekly open house any Thursday evening after 6:30pm.

D. Scott Williamson
Compulsively Creative

Visit to Solid State Depot, Boulder Colorado

I was in Boulder this week and while there I thought I’d check out Solid State Depot, the local Boulder hackerspace (http://boulderhackerspace.com/)… Tuesday is their weekly open house meeting night. It was awesome!

Outside the entrance

This is the entrance, the colored lights flash and cycle, I knew I was in the right place before the Uber driver found a place to park.  The Uber driver’s name was Sam, he earned his masters degree in the arts and started a fine art collaboration and printing company in 2015 which sounded pretty cool.  He didn’t know what a hackerspace was so I explained and invited him to come inside with me to check it out.  We got a tour and while there he got tips where to find laser cutters he can use in town.  Incidentally, while in high school, Sam lived in Glendale Heights, IL, the same Chicago suburb my wife is from.  I thought “wow, small world” but I had no idea… I’ll get back to that later.

Entrance/reception area

This is the entrance area.  It seems like every maker/hackerspace has a coin op cabinet at some point, I think this one may be powered by the Raspberry Pi I spied in the marquis.  They also have free stuff and we all seem to get the same 20″ box fans from the same place.  I felt right at home.  They have a big doocracy poster hanging in the lobby too (not pictured).


The next few pictures are of the main area. The woodshop is off to the right, the CNC area is in back, and the electronics lab and test room are smaller rooms off the entry area.  Ted, in the lower right in the blue sweater, seated in front of the PBR greeted me.  I introduced myself as being from Chicago and a member of Workshop 88 and he showed me around.  He was really nice, I got the feeling they take turns meeting people and giving tours, just like us, which worked well.  Ted told me that a membership costs $65 and gives you the familiar 24 hour full access to the space, equipment, and materials within reason.

They have a large crowd of regulars with deep knowledge of many topics.  Seated high on the right in the green jacket is Sebastian (“Seb”), a contributor/maintainer of Linux CNC.  Paul the left of him in the picture (mostly obscured by Mike M.) is a former NVIDIA employee who wrote the timer ladder for the Linux drivers, he is an expert in GPUs.  On the other side of Seb is Ben in the blue jacket, his recently departed grandfather worked for Tektronics.  Ben had a nice oscilloscope for sale and wanted to offer it to the club at a discount before posting it online which was really nice of him.


They have weekly club meetings at 8:00pm on Tuesdays during the open house.  They open with a call to the meeting and everyone sets aside what they are doing and gathers in the main area.  Alex, this year’s president is starting the meeting in the center of the picture in the black sweater.  Alex briefly mentioned club business which included donations, classes, finances, the need for 6″ duct for the CNC machine, etc.  Brandon, in the red sweatshirt, reported the results of a recent survey: the favorite part of the club is the social aspect, the least liked aspect was that some of the tools are broken.

The last thing they do in the meeting is have everyone introduce themselves, share their interests, and update what they are currently working on.  There were several asks and offers for assistance, it was very cool.  When each person was done they said “Bam” and pointed at the next one  – I don’t  know if that always happens or if it was organic but that type of self organization was really effective.  The meetings are similar to but not as formal as the monthly Chibots meetings if you are familiar with those.

Also pictured above on the left is Ben, or as he jokingly asked to be called “That Bastard Ben”.  On the right with the beard and plaid shirt is John W. who is repairing is repairing and/or enhancing the electric scooter behind him on the right.



John M. is on the left, Nick in the orange shirt works on FPGAs’ and is really sharp.

There was one more really interesting guy I didn’t get a picture of but he suggested members check out the recent hacking/spying wikileaks CIA articles because they point out security flaws and espionage techniques used on common devices anyone could be using.  I want to be clear, he was not suggesting that anyone in the club use the exploits, it was more from the point of view of the security threat.  That was the first I had heard of that news, a day before I heard about it in the news.  He’s a really smart low level guy whose current project was analyzing the voltage/current profile of each pin of a microcontroller to try and find a way to glitch/reboot it into a programmable mode.

Oh, and Andrew…
This is Andrew and yours truly.  Andrew is making an autonomous vehicle with his one spinning single beam LiDAR system and computer vision using an onboard NVIDIA Pascal GPU (~10W GPU running deep nets!!!).  He actually works for the same company I work for, HERE, optimizing deep neural networks for visual segmentation, recognition, and other perception related tasks… and he recognized me as one of the people who interviewed him on the phone several months ago.   He studied Geology (I think) at Wheaton College before getting a degree in Physics.  MAN, SMALL WORLD!  His project is so cool, he had a case full of different single board computers including RPI, BBB, Arduino, ST based Arduino’s and more. We talked work and projects for an hour.  He introduced me to Sebastian and some of the others mentioned above.

The wood shop:

The wood shop was large enough to accommodate big projects, and was well equipped: Combo table saw/routing table, jointer, planer, compound miter saws, lathe, band saw, drill press, scroll saws, sander, and much more. That’s a ShopBot in the background with dust collection.  I also noted that the shop was swept and vacuumed.

The robotics and CNC area:



They are getting their big CNC working with Machine Kit and GeckoDrive G540.  It’s funny because Workshop 88 is going through the same process using Machine Kit and Gecko drives for our mill.  Tom in the red sweater asked what a “Charge Pump” is and I happened to know 🙂


Brandon is about to CNC machine a new aluminum part on the Taig behind him needed by the larger mill to the left.  It’s also using MachineKit, and note the electronics for the mill in the box mounted to the wall behind Plexiglas.  I didn’t find out what the actual part he was machining was.

Robot

This robot was there, I don’t know what if anything it was for but it was cool.  I particularly like the design with most of the motors low in the base and belt drive up and through the joints.


This is their Chinese Laser cutter / engraver.  It was not working at the time I visited.


Those 4 3D printers were donated by LulzBot.  I swear at least some, if not all look to me to be Prusa Mendel or Mendel Max.  Each needed some repair.

This is the electronics lab:
Here are a couple more 3D printers, that look to be in good working order.
Mike S. on the left wearing the hat, Mike W, and Alex working on something, probably Mike W.’s scooter.  In the meeting, Mike S. shared his current project: electronic control of the exhaust fan on his fireplace which he can now remotely monitor and graph the temperature of his fireplace and the running of his fireplace exhaust fan on his phone.


I love a good whiteboard!


Another room with test equipment.


It’s hard to see but the Boy Scout motto: “Leave No Trace” was once written in red marker on the well used bench.
Another friendly clean up reminder.

All in all a great club full of interesting talented people working on fascinating projects.  It was nice to see they face some of the same organizational challenges, and I like they way they incorporate a regular club meeting with introductions and project updates into their open house night.

I’m really glad I made the time to visit and when I go back to Boulder you can bet that I’ll  aim to be there on a Tuesday night to go to another meeting at Solid State Depot.

D. Scott Williamson
Compulsively Creative

3D Printing PLA on a flexible metal build plate

3D Printing PLA on a flexible metal build plate

By D. Scott Williamson

I love 3D printing.  I’ve designed and printed hundreds of models on the Replicator 2 and have developed many useful skills and techniques. The Replicator 2 has a non heated polycarbonate build plate with MakerBot emblems laser cut into one side and the other side is frosted.

I don’t care for having the MakerBot logo in relief on the bottom of my prints so I print on the frosted side of the platform.

These are rafts but I don’t like having the MakerBot logo embossed on my work.

This worked well for hundreds of prints but eventually, scraping the prints off the platform smoothed the rough surface and parts started sticking harder and harder to the build plate.  Ultimately they stuck so hard that the force required to get a spatula or razor under a part started cutting grooves into the build plate.

Two of the most common 3D printing problems are related first layer adhesion to the build platform…

If the first layer does not bond well enough it can result in corners lifting especially for broad parts on unheated platforms.  In the worst cases the part breaks completely free from the platform partway through a print leading to a stringy mess, wasted time and filament, and in rare cases the PLA can stick to and damage the insulation on the print head.

Catastrophe! Lifted corner, parts broke free, filament everywhere, and damaged thermal insulation on the print head.

If the first layer bonds too well to the build platform the part or platform may be damaged when removing the part.  When using blue tape, it may not be possible to completely remove the tape from the part.

I started using blue painters tape and Aqua Net hairspray on the build plate.  I found this combination to work well with PLA, though I’m not sure how necessary the hairspray is.  The problems are that the tape is damaged when removing most prints so needs to be reapplied frequently and can be difficult or impossible to remove from the bottom of finished parts.

Blue tape stuck to part.

Sometimes it’s impossible to remove all the tape residue.

Blue tape doesn’t last long and requires sticky messy maintenance.

I considered a heated build plate, and glass or metal build plates when the idea occurred to me to try to use a flexible metal build plate. I conducted several experiments using a cable chain model that is challenging to print due to fine detail and thin parts that need to bond well in the first layer.

Experiments

Experiment #1: Aluminum flashing with 2 coats of hairspray dried with heat gun and held by binder clips

First I tried aluminum flashing with hairspray.

  1. Measured and cut the aluminum on a paper cutter and nibbler to perfectly fit the build plate

    Aluminum flashing on roll with Replicator 2 build plate

    Rough cut aluminum.  Use gloves, sheet metal is sharp.

    Cut aluminum to size on the paper cutter.

  2. Rolled flat

    Thin sheet aluminum was curled and needed to be flattened.

    Rolling the thin rolled sheet aluminum flat with pipe on foam.  A towel could have also been used underneath the material.

  3. Cleaned with alcohol to remove oils/grease

    Cleaned the sheet aluminum with ammonia and alcohol.

  4. Coated one side with a thin film of hairspray, let it dry, and applied a thicker coat of hairspray

    Two coats of Aqua Net hairspray applied.

  5. Dried the hairspray with heat gun

    Used heat gun to rapidly dry the hairspray.

  6. Clipped aluminum to build plate with binder clips at the edge

    Aluminum plate clamped to build platform.  (The clip in the upper right corner is about to get knocked off.)

  7. Leveled the build plate to account for the thickness of the aluminum plate
  8. Printed a test

    The PLA bonded weakly to the platform and the parts detached easily in the second layer.

    The upper right and lower left clamps had to be moved because the print head knocked them off.

The nozzle interfered with some of the clips and knocked them off.  The PLA did not adhere to the build plate.  Failure.

Experiment #2: Aluminum flashing with wet hair spray and binder clips

Aluminum flashing with wet hairspray yielded the same results.  Failure.

Experiment #3: Aluminum flashing with glue stick held by clips

Using the back side of the same build plate I used a generous layer of glue stick.

  1. Using the back of the cut aluminum plate from Experiment #1
  2. Coated the plate with glue stick
  3. Clipped aluminum to build plate with binder clips at the edge where the nozzle would be less likely to interfere with them

The PLA adhered wonderfully and the print turned out great.
When done I removed the aluminum plate and was able to remove the print by bending the plate – Success!
But the aluminum does not lay flat and the part left dimples in soft thin aluminum plate before letting go.  I need a stronger material.

Experiment #4: Steel sheet with glue stick held by clips

I scrounged around and found a stiffer steel plate salvaged from a magnetic children’s book many years ago.  I did not try to cut the steel plate to fit the platform because I don’t have a shear and did not want to dull my paper cutter cutting steel.  I can cut the steel on the metal shear at Workshop 88.

  1. Using paper towels, I cleaned the steel plate with ammonia to be sure to remove oil or grease, then with alcohol, and finally with tap water
  2. Coated the plate with glue stick
  3. Clipped steel plate to build plate with binder clips at the edge where the nozzle would not interfere with them
  4. Leveled the build plate to account for the difference in thickness between the aluminum and steel plate
  5. Printed another test

The print turned out great!

But the plastic clips that hold the build plate to the printer are raised causing the plate to be irregular and warped and not flat against the polycarbonate platform beneath it.

If you remove a print by flexing the steel it pops right off but it is still possible to dimple the steel this way.  The dimples can easily be gently pounded out with a broad hammer with the steel on a flexible surface like a neoprene mouse mat or a towel.  Parts firmly attached to the steel are easily removed using a spatula and/or a razor so dimpling turned out to be a non-issue.

Experiment #5: Steel sheet with glue stick held by magnetic sheet

To get the platform to lay flat on the platform I attached a sheet of flexible rubbery plastic “refrigerator magnet” material originally intended to be a furnace vent cover to the platform with double sided tape.

  1. Cut magnet to size
  2. Attached magnet to build plate using double sided tape and pressed it flat using a rubber roller
  3. Aligned the steel plate with the platform and when laid flat the magnet holds it firmly and flat
  4. Leveled the build plate to account for the additional thickness of the magnet layer
  5. Coated the plate with glue stick
  6. Printed another test

Best results yet!

Excellent first layer adhesion with fine detail.

The build plate is flat and level, firmly attached to the platform in the center without using clips which makes it very easy to insert into and remove the plate from the printer.  The finish on the bottom of every part is smooth and shiny, far better even than when printing with a raft.

Even though others reported using a coating of glue stick up to a dozen times, I found reused glue stick not to adhere well.  Adding layers of glue builds up, so every couple of prints I wipe the plate down with a wet paper towel before adding a new layer.

I’ve added alignment markings to the build plate to help install the plate consistently, to help center parts, and to help apply glue only where it’s needed for each print.

 Examples:

Markings help guide application of glue and placement of parts in MakerWare software.

Printed right where expected, with a beautiful first layer and finish quality on the bottom without a raft.

Extremely challenging pinhole lens print

This pinhole lens is .2mm thick and each hole is printed separately with 2 shells then the rest is filled in, if any pop off the build plate it will stick to the hot end and gather the rest into a blob of plastic.

This folding phone/tablet stand (http://www.thingiverse.com/thing:692523) is a favorite model in my house.  It’s a hinged phone/tablet stand that prints fully assembled. If you look carefully you can see that there is some slight curling. The plastic is pulling upward at the corners and even though it has not detached from the build plate it is deflecting it slightly up off the magnet.

The finish quality of the base is comparable to printing on glass.

Not every print has been perfect though, this is another phone/tablet stand that started to curl. The print head caught one corner and moved the entire build plate on the magnet. You can see it continued to print offset before I stopped it. It is impressive that it moved the whole build plate without detaching from the platform. I was able to reprint this model successfully. Only a heated bed or chamber can really prevent this issue entirely, but a stronger magnet may require more force to move.

Future work

  • Cut the build plate(s) to size on the shear at Workshop 88. The build plate is still larger than the platform and must bend to go over at least one of the platform holding clips.
  • Cover the entire platform with magnetic material.  The current magnetic material does not cover the entire platform, it is what I had on hand.
  • Find stronger magnets.  The print quality is wonderful but it is still possible for corners of large parts to lift the platform off the magnetic base while staying attached to the platform.
  • After I started printing on steel I found PRINTinZ’s flexible build plates.  I haven’t used them but check them out! http://www.printinz.com/printinz-3d-printer-plates/

Thanks for reading, and good luck with your 3D prints!

D. Scott Williamson
Compulsively Creative

CAD CAM tutorial

CAD CAM tutorial
by D.  Scott Williamson

This tutorial will show you how to use Computer Aided Design and Computer Aided Manufacturing or CAD CAM tools to create and preview a Gcode file of the Workshop 88 logo that can be run in a 3 axis CNC Mill.

Background

There are 5 main types of machine operations

  1. Engrave (follow path): The tool tip will follow the 3D path provided.
  2. Profile: The tool edge will follow either the inside or outside contour of a path down to the specified depth.
  3. Pocket: The tool will remove all the material within a contour down to the specified depth.
  4. Drill: A drill routine will be executed at each point location.  Drill routines come in 2 flavors:
    1. “Peck” used with drill bits, drills to successively deeper depths liftig the bit out of the work regularly to clear chips from the flutes.
    2. “Spiral” used with endmills that are a smaller diameter than the finished hole.
  5. 3D relief: The tool tip will remove material above a 3D surface usually specified in a 3D model or a 2D height map image.  There are two main modes:
    1. “Waterline” similar to inverted pocket operations where bulk material is efficiently removed outside the 3D model to a number of stepped depths resembling waterline in a topological map.  Typically used in a first pass with a large roughing bit to remove the bulk of the material.
    2. “Raster” moves the tip of the bit smoothly over the model in a raster pattern.

Gcode is a “numerically controlled programming language” which is why a Gcode file extension is typically .nc.  It is a human and machine readable text file.  You will rarely if ever need to look at or edit the Gcode.

Overview

This tutorial will demonstrate Engrave, Profile, and Pocket operations, which are the most popular.

There are 4 steps to this tutorial:

  1. Create a .svg file containing paths needed for machine operations
  2. Create machine operations
  3. Export Gcode
  4. Simulate, visualize and validate

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