Adventures in vacuum repair

When using the Shop-Vac the other day I noticed all the dust I was sucking up was being blown out the back of the vacuum… all over me.  Intrigued and filthy, I decided to investigate…

I emptied the vacuum and took the filter outside to knock as much dust and crud off of it as I could.  I employed the standard method of smacking it on the building and quickly twisting it back and forth in the breeze being careful to stay upwind so as not to breathe the fine and disgusting particles liberated.

When replacing the filter I immediately found the problem, or more accurately I didn’t find a key part of the vacuum cleaner.  The filter retainer was missing.  Without it, whatever the vacuum sucks up can shoot through the open bottom of the filter through the impeller and get blown all over me.  Fabricating a quick replacement from parts on hand took no time at all.  Sure, I could have bought the replacement part for $9 and had it next day from Amazon, but where is the fun in that?

I found a suitable scrap of 1/4″ acrylic onto which I traced the inner and outer diameters of the filter.

Using a jigsaw with a coarse blade I cut just outside the outer diameter.  Cutting acrylic or polycarbonate with a jigsaw (or CNC) can be tricky, friction heats the blade and the chips can weld the opening closed behind the cut as pictured here.  This piece was easily broken away with my hand, but I’ve had polycarbonate heal itself apparently stronger than the uncut material when cutting too fast without any coolant or compressed air to clear the chips.

Using a ruler and pen I measured and marked the center of the diameter along several angles.  Using the hammer and punch, I punched the mark for drilling (the dimple allows the drill to center more accurately).  This level of precision was not necessary but I find striking things with a hammer fun and habits like punching before drilling are good to reinforce.

I clamped the burgeoning new cover in the vise and drilled the center hole.  The bolt hardware is the ubiquitous 1/4″-20 (1/4 inch diameter, 20 threads per inch, super common stuff), so I’m going to drill the hole a little larger, 3/8″ to make it easy to slide on and off.  I don’t want to drill a hole that large to start with in the acrylic because it will catch a lot and cause chipping or cracking, so I started with a smaller 1/8″ drill and worked up through a couple sizes.

Now I need to install a mounting rod in the bottom of the vacuum cleaner.  Marking the center of the bottom of the vacuum cleaner filter holder was even easier.  I just connected the lines between the edges of retaining tabs on the outer edge.  This plastic is thin and soft enough to drill directly with the 1/4″ bit.

Then I installed the filter holder pin by putting a 4″ 1/4″-20 bolt through a lock washer, then a fender washer then fed it through the hole from behind (from the vacuum cleaner side) to stick out the bottom.  I followed that with another fender washer, a lock washer and a nut.  The fender washers sandwich the plastic to spread out any load and prevent cracking around the hole.  The lock washers keep the nuts tight even under the vibration of the running Shop-Vac.

The filter slides over the outside, and the cover slides over the bolt to seal it in place.  Another fender washer, lock washer, and convenient wingnut secure the assembly with a good tight seal.

At this point the filter replacement was functional but by no means done.  Workshop88 is a makerspace, and that means nothing is done unless you’ve used the laser or a 3D printer, so Christine engraved the lid.

IMG_5309

Voila!

I could have easily ordered the appropriate replacement and had the fresh new part the next morning, but by creating one myself I get the satisfaction of a job well done, and I was able to vacuum up the acrylic chips from the jigsaw and drill right away.

D. Scott Williamson
Compulsively Creative

 

 

25 Minute CNC digitizing probe

On a whim I decided to whip together a collet mounted Z depth probe for my CNC machine.

It took 25 minutes and works GREAT!

Construction


Select 1/4″ aluminum rod to fit my 1/4″ collet


Measure length that I think will fit into the collet with clearance for the switch and wiring, marked with a pencil.


Clamp into a vise and cut with hacksaw. Be sure to wear eye protection. I used hardboard to protect the soft aluminum from being gauged and pressed out of shape in the vise.


Use a hacksaw to cut a square notch into one end. I cut just off center down the middle by eye about half an inch then cut sideways from the thinner side to remove D shaped slug leaving a D shaped semicircular shaft.


The rod was slightly oversized and would not fit properly into my collet.

 
I clamped it into the chuck of my drill press and used a file on the spinning rod to reduce its diameter until it fit. Files are designed to be pushed away from the operator so be sure to pay attention to the direction of rotation and file, this results in pushing the file away from you pressed against the right side of the cylinder in a standard drill press.  Of course, only test the fit when the drill press is off and stopped.


You could also use sandpaper if a file is not available, but it will take longer.


I used the file to take sharp corners off business end.


Align the switch with the cutaway in the end of the rod and mark the height of the mounting holes in your switch on the round part of the D.
Notice the pencil marking near and on my finger.


Use the hacksaw or file to cut a notch in the back round D part at the height you marked.  This will be needed to hold the switch securely in place later.


I selected a long length of stranded wire with an RCA connector on one end from the junk wire drawer. Just about any flexible wire will suffice, just remember that the wire will repeatedly flex with the motion of the machine so should not be too stiff and ideally should be stranded, not solid conductor type.


I grabbed a microswitch and soldered the wires to the “C” common and “NC” normally closed connections. You want the switch normally closed so that if there is ever a fault or broken wire the CNC digitizer will detect the open circuit right away and interpret that as contact with the workpiece while probing.. If you wire it normally open and a connection is broken then the CNC machine will try to probe right into your workpiece. (unless, you make a mistake I did, but more on that later…)

To attach the switch to the D shaped end of the aluminum rod. I lashed the switch to it using a twist tie, for a more permanent connection add a drop of epoxy between the switch and metal.


Strip the insulation off a twist tie.  It is easiest to remove 1/2″ – 3/4″ sections until you have a fully stripped steel wire rather than try to strip very long sections in a single go.


Thread the twist tie through the mounting hole in the switch twice.


Slide the D shaped portion of the aluminum rod into the wire loop and start twisting the wire ends by hand.  Be sure the wire seats in the slot you sawed or filed in the back of the round part of the “D”.


Tighten the wire using pliers being careful not to break the wire or delicate plastic part of the switch. You may need to wiggle the switch in order to seat it properly on the rod aligning the hole with the groove for a tight fit.

At this point I also bent the end of the metal switch plate slightly a few mm from the end to provide more springy direct contact right under the tip of the center of the probe to ensure the metal arm is what makes contact and closes the switch rather than pressing the microswitch under the arm directly down on the workpiece.


Tie the electrical wire to the shank for a strain relief and attach the wire to your machine so that it does not get pinched or caught in moving parts.


Completed probe elevated and engaged.

Wiring and configuration

Wire your probe. I threaded mine conveniently through the spiral compressed air hose.
Connect your new probe to your controller’s digitizer input.

Note: Wiring and configuring your motion controller is not included in the 25 minutes.
I had already wired and configured a digitizer for Mach 3 using a Xylotex motion controller on the parallel port.

You will need to configure your CNC controller to accept a probe and wire it accordingly. On my parallel port connection on the Xylotex motion controller I wired a 10k resistor from the probe pin to +5 and wired the switch between the probe pin and ground so when the switch is normally closed, the pin reads “0”, and when the switch is depressed the circuit to ground opens and the pin is pulled up to +5 and reads a logic “1”. I offer this as an example for my configuration but you should check your controller and software manuals to determine correct wiring for your equipment.


In Mach 3 I can test my digitizer probe by looking at the diagnostics screen. When I press the button I can see the digitizer input light up telling me that the switch is working and the software is configured correctly.

Test function and repeatability


To test the digitizer function I issue a G31 Z-1 F10 command. This tells Mach 3 to move Z to -1 at a feedrate of 10 inches per minute (ipm) and to stop when the digitizer is engaged.


To test reliability and repeatability I issued this command 12 times and recorded the Z height where the probe engaged each time.  I entered these measurements into a spreadsheet to calculate the minimum, maximum, average and standard deviation of the samples… this probe was reproducible with a standard deviation of 0.000824″, under a thousandth of an inch. This is great for woodworking or PCB engraving.

Test engraving on a non flat surface

To really test it I mounted a piece of melamine on a set of 1/4 inch shims to create a severe slope and performed a standard engraving cut.

As you can see, any slope or irregularity is a nightmare for engraving with a “V” bit. High portions of the work surface are engraved too deeply and lower portions may not be engraved at all resulting in an uneven line width.

I used ScorchWorks G-Code Ripper to generate a new gcode file from the first one that included probing and compensated for the measured work surface elevation in the g-code.


When I engraved the new g-code (on the right) it started by probing the surface, then asks the user to switch to a cutter bit and completes the engraving operation. This sample was engraved to a uniform depth which is an improvement but I still didn’t know how to set an accurate zero depth so it is too deep.

The final missing piece was to figure out a way to register the probe zero height to the cutter z height.


My collets do not allow reproducible tool height location so I had to find a workflow to zero each bit during the machining process. Here is what I found:

Make sure your gcode contains an M6 manual tool change operation and that your controller pauses and allows you to change bits, jog, and reset zero z (or alternative similar functionality)

  1. Install the probe in the router
  2. Move to the X Y origin over the workpiece
  3. Probe to the surface G31 Z-1 F10
  4. Zero X, Y, Z
  5. Start the g-code with probe operations, it will probe the surface, and then pause (be sure your router does not get turned on or it will rip your probe wiring to shreds)
  6. When you resume the gcode it will pause again for the tool change.
  7. Replace the probe with the cutter
  8. Manually jog to X=0 and Y=0
    (In my Mach 3 controller I cannot execute gcode like G0 X0 Y0 during a tool change, I have to jog manually)
  9. Manually jog z to the work surface and manually zero Z.
    I use a 0.001″ thick JOB rolling paper as my machinist mentor taught me. Place the paper under the bit and move it down one thousandth at a time until it just pinches the paper then either type .001 into the Z DRO or just zero Z if a thousandth of an inch is not critical.
  10. Jog Z up a little to clear the workpiece
  11. Turn on the router
  12. Resume g-code program to complete the machine operations

These steps are meant for you to understand the operations I had to go through with my machine to get great results. You may have to adjust these steps for your software/controller.

It works perfectly!

The source artwork is really not intended for engraving, it’s just something I grabbed to run some tests, please don’t judge the it too harshly.  You can see that the depth of cut is uniform across the finished piece.  This would engrave just as well on a curved or irregular workpiece as well.


This is particularly impressive considering how deliberately un-level the workpiece was fixtured.

Not just for engraving…

This isn’t just helpful for engraving, I recently used probing to correct for the irregularities in 4′ x 8′ sheets of 1/4″ plywood.  These sheets can be warpy and wavy by over 1/2″ on a large part.  Normally I would have to cut many passes with the 1/4″ bit potentially deep into my spoilboard to ensure good cuts.  My machine is slow and those extra passes cost a painful amount of time.  With probing I was able to cut each part out of the irregular 1/4″ thick material using a .3″ cutting depth and a 1/4″ endmill in a single pass with excellent results, several times faster than it would have taken me in the past.


Here is a custom organizational shelving unit I made for a friend, it turned out great.

Links:

ScorchWorks G-Code Ripper
Mach 3 CNC Controller
Xylotex CNC Controller and stepper motors

It took less than 25 minutes to make the probe while taking all these pictures along the way!  It took under 20 minutes the second time (see below), and it took waaaay longer to write this blog post.

I hope this was helpful, or at least entertaining.

D. Scott Williamson
Compulsively Creative

P.S. Test your probe and wire it carefully!


At the beginning of the first large scale plywood cut my CNC machine made several successful probes of the surface then plowed into the table with slow deliberate force destroying the probe switch. 
Upon close inspection, the alligator clips I hastily used to mount the probe for initial tests were still in use and shorted together bypassing the fail safe and switch operation resulting in the crash.  It’s a good thing that it did not create a dangerous situation.
I was able to re-cut the end of the rod and install a new switch in under 20 minutes which after careful rewiring has operated reliably ever since.

Performance boost for an aging laptop

I have an aging Sony VAIO VGN-N110g laptop that cannot take more than 1GB of RAM but still has a ton of life left in it for multimedia, projects, and general use. The previous teenage owner ran it on blankets, on the bed, under clothes, etc. Eventually the CPU fan stopped working and something went wrong with SODMIM slot 2, probably heat related. Until recently it was dog slow.  Here is what I found and how I regained significant performance breathing new life into the machine.

Hardware improvements:

First I replaced the CPU fan ($15 on eBay) which allows the CPU to run at 1.2GHz again rather than be permanently thermally throttled to 800MHz or less. With 1GB of RAM the 32 bit Ubuntu 14.04 LTS was still running sluggishly. I have a friend who owns a similar VAIO inherited from a similar family member, he had been down this road before.  He recommended I get an SSD because it’s probably swapping memory to disk. I checked the performance monitor and he was right, it was swapping a lot. I caught a 250GB WD SSD on sale on Amazon for $69.99, which I thought isn’t too bad (bought through the Workshop 88 affiliate link here to benefit the club at no extra cost). I mounted the SSD into an external USB drive case, booted from a Clonezilla live CD, and copied the 80GB boot disk directly to the 250GB SSD (I could have used Clonezilla from UBCD or Parted Magic but I had the Clonezilla the disk handy). Then I swapped the hard disks (removed keyboard, battery, RAM cover, CD Drive, and 26 screws… <dramatic eye roll>). Before reassembling the laptop I plugged in and tested it to make sure it booted and ran properly from the new drive and was thrilled to see how fast it booted and that it worked perfectly so I buttoned it up.

Expand the boot/OS partition

Now there was only one thing left to do: Expand the 80GB boot partition to fill the unused 150GB+ on the new SSD drive.  Directly copying the drive is nice because it copies all bootloaders, file systems, and your data regardless of OS, but it does not resize the existing partitions.  Moving and resizing partitions is always risky.  All the partitions need to be unmounted, which for the boot partition usually means you need to be running the OS from RAM. The best way I know to do this is to boot from either a Linux distribution’s live disk (Ubuntu, Puppy, pick from any on DistroWatch.com…), or a purpose built tools CD/DVD like the Ultimate Boot CD (UBCD) which is what I did. From UBCD I selected Parted Magic and it launched the included image. Parted Magic is intended for just this type of thing and runs entirely in RAM. I used GParted to edit the partitions but immediately ran into an interesting problem (which is really why I’m writing here): The boot partition was at the start of the disk, followed by an extended partition that contained the linux-swap partition, and all the free space was at the end of the disk. I could neither increase the size of the boot partition because it was not adjacent to free space nor could I move the extended partition because it contained the linux-swap swap partition. I was stuck until I found this:

Expanding a Linux disk with gparted (and getting swap out of the way)
https://blog.mwpreston.net/2012/06/22/expanding-a-linux-disk-with-gparted-and-getting-swap-out-of-the-way/

To summarize I had to:

  1. Expand end of the extended partition to consume all the free space after it
  2. Move the linux-swap partition to the end of the extended partition
  3. Reduce the size of the extended partition by moving it’s start location to the beginning of the linux-swap partition
  4. Finally, expand the boot partition to consume the free space I had created.

I created these operations one at a time in GParted, executed them with one click (fast on an SSD!), rebooted, and voila!

Here is what Parted Magic looks like and my partitions in GParted after extending the modifications.

And here is what my VAIO laptop looks like running after the updates were complete.

It works and now I have a faster laptop with 3x the disk space for under a hundred bucks.  This may seem like mundane or even common knowledge to many of you but I thought it was interesting enough to share and maybe some of the information will be helpful to someone.

Here are links to the free tools mentioned above:

I strongly suggest you look at and get the Ultimate Boot CD
http://www.ultimatebootcd.com/ 
Check out all the powerful free tools you get on one FREE disk image.

Drive/partition image/clone/backup tool (also available on UBCD)
https://clonezilla.org/

Disk editing tools that run entirely in RAM so you can work on all disks
(also available on UBCD)
https://partedmagic.com/

Partition editor available in most Linux distributions
https://gparted.org/

D. Scott Williamson
Compulsively Creative

P.S. There is (was) an Ultimate Boot CD for Windows, it hasn’t been maintained in a while but it is still worth trying out.  You can find it on majorgeeks.com here:
https://www.majorgeeks.com/files/details/ubcd4win.html
Beware: The original site, [URL deliberately not mentioned], looks sketchy now; I do not advise anyone go there and if you do, be careful.

Member projects: Thingiverse remix

One of our new members, Josh, has been making great use of the 3D printers at Workshop 88. He had a headlight for his bike that he wanted centered on the handlebars. So he took the Blackburn Flea Bike Light Handlebar Mount file on Thingiverse and remixed it to fit on his bike. Here is his remix – the photo at the top shows the finished print.


Support Workshop 88 through our Amazon links, disable ad-blocking to see:

Member project: Crowd-sourced science

Animation of some preliminary results from the Steelpan Vibrations project on Zooniverse.

One of our members, Andrew Morrison, has a citizen science project running on the Zooniverse website.

The project is called Steelpan Vibrations and is a project looking at understanding how Caribbean steelpans (sometimes referred to as steel drums) work to produce their characteristic sound. What he has done is made high speed videos of the waves that go across the steel pan when it is struck by a player. The problem is that there is no easy way to analyze the video frames to get quantitative data. The project asks for people to go to the website and mark individual frames so that they can be aggregated together for analysis later.

There is a blog where details about the research are discussed regularly, and you can also follow Andrew on twitter where project updates are regularly posted.


Support Workshop 88 through our Amazon links, disable ad-blocking to see:


Member projects: Building a night sky observatory!!

One of our members, Steven Sagerian, has a passion for astronomy and astronomy education and outreach. He has been working on building an observing site outside of the Chicago suburbs in a dark location – and now he has a GoFundMe set up to make this a reality!

Steve also has designed a solar panel system for charging batteries to run the observatory. You can see the solar cells in the photo on the GoFundMe site, and he also has a page dedicated to the design and construction of it.

Solar panels for charging power supply at observatory.


Support Workshop 88 through our Amazon links, disable ad-blocking to see:

How to create and install custom ringtones on an iPhone without iTunes or a USB cable

In this step by step tutorial you will learn to:

  • Download individual and playlists of movies and audio from movie websites including YouTube, Vimeo, Daily Motion, etc. and convert the files into numerous audio and video formats using youtube-dl.
  • Edit audio file clips, adjust volume, and save in different formats, including .m4a needed for iPhone ringtones and songs using Audacity.
  • Send audio files to your iPhone using email, save them, import them into GarageBand, and process them into usable ringtones for your iPhone
    (and even delete them when you are done with them).

All off this is done with free software and without iTunes, or connecting your iPhone to the computer!

These PC instructions are for Windows, but all the tools, youtube-dl, Audacity, and FFmpeg are also available for Linux and OS X.

Capturing sound file from YouTube

You will need:

  • youtube-dl An awesome tool to download and convert videos and playlists from YouTube and other sites.

Instructions:

  1. Find a video you like on YouTube
  2. Copy the URL
  3. Navigate in Explorer (file browser, not internet browser) to the folder you would like to download the sound file to.
  4. Type cmd into the address bar to launch a command prompt
  5. Enter youtube-dl –extract-audio –audio-format mp3 -o “%%(title)s-%%(id)s.%%(ext)s” your_url_here
    i.e.
    youtube-dl –extract-audio –audio-format mp3 -o “%%(title)s-%%(id)s.%%(ext)s” https://www.youtube.com/watch?v=B7MIJP90biM
    * See footnotes for additional options

Footnotes:

  • You may omit -o “%%(title)s-%%(id)s.%%(ext)s” or replace it with your own filename format string
  • If the video is under 30 seconds long and you want to use it without editing, you can save it directly as an .m4a like this:
    youtube-dl –extract-audio –audio-format m4a -o “%%(title)s-%%(id)s.%%(ext)s” your_url_here
  • You can download entire playlists as audio with numbered tracks as .mp3 files like this:
    youtube-dl –extract-audio –audio-format mp3 -o “%%(playlist_index)s – %%(title)s-%%(id)s.%%(ext)s” https://www.youtube.com/playlist?list=PL3KyodHSvyYL2qAyXGli1CCd5IS0ENfBh
  • You can download and convert video files from many sites for watching like this:
    youtube-dl -o “D. Scott Williamson, Expert.%%(ext)s” https://www.youtube.com/watch?v=B7MIJP90biM

Editing your sound file

You will need:

  • Audacity sound editor
  • FFmpeg extension for Audacity needed to save .m4a files (Use their download even if you already have FFmpeg)

Instructions:

The sound file must be 30 seconds long or less.
Remember, it will loop; some files benefit from some silence at the end or a long decay.
Audacity is too large a tool to describe in depth here, here are some basic commands that will allow you to select the section of the audio file interesting to you, adjust the volume, and export as an .m4a file.

  1. Open the file by either dragging it onto Audacity, Selecting Open… ffrom the File menu, or pressing Ctrl-o.
    When the file opens you will see a waveform display in the center of the Audacity window.
  2. Mute | Solo On the left side of your waveform display you will see Mute and Solo buttons.  If you open multiple files, they will behave as multiple tracks in the same project.
    • Mute will silence the track.
    • Solo will mute all other tracks and unmute the current track.
  3. Selection Click and drag on the audio waveform display to select a subset of the sound file.  You can carefully click and adjust the start and end of the selection which is useful to refine your selection.
  4. Zoom allows you to magnify or shrink the sound file to enable you to work carefully on the section that is important to you
    • Zoom in, Zoom out Magnify or shrink the view of your sound
    • Zoom Selection will zoom so the selection fills the display.  I typically will select a slightly larger section than I want, Zoom Selection to make my selection fill the display, and refine the start and endpoint.
    • Fit Project to width will zoom all the way out so that your (longest) sound file will be fit to the window width.
  5. Scroll When zoomed in, you can use the scroll bar at the bottom of your sound window to pan left and right.
  6. Play There are a couple ways to play your sound:
    • Click the play button to play your selection, or the entire file if none is selected.
    • Click anywhere in the timeline above the waveform to play from that position to the right edge of the window, useful for quickly locating key points in your sound file.
  7. Copy Use this to copy your selection either by clicking the copy button or pressing Ctrl-c.   I find it easiest to copy the portion of the sound I like and paste it into a new Audacity project.  Not only is it less likely to damage the original file, but I think it is fewer steps too.
  8. New Create a new sound file by selecting New from the File or pressing Ctrl-n
  9. Paste Click the paste button or press Ctrl-v to paste your previously copied selection into the new file.
  10. Volume There are a lot of effects you can apply to an audio clip in Audacity, perhaps the most common is adjusting the volume.  Click on Amplitude in the Effects menu, you will see a dialog with the suggested amplification already filled in.  The suggested value will make your sound fill the volume range.  If you would like more amplitude than suggested, be sure to check Allow clipping.  The volume can be reduced too.
  11. Undo you can undo any mistake with a click or by pressing Ctrl-z
  12. Export as .m4a by selecting Export from the File menu and selecting Export audio file… or by pressing Ctrl-Shift-e.  Navigate to where you’d like to save the file, select save as type “M4A (ACC) Files (FFFmpeg)“, and save your file.
    (The first time you do this, Audacity will ask you to locate avformat-55.dll, it will be where you unzipped ffmpeg-win-2.2.2.zip)

Creating a ringtone

You will need:

  • GarageBand app on your phone (made by Apple)
  • Access to email from your PC and iPhone
  • One or more sound files that must be .m4a (or .m4r) format and 30 seconds long or less.

Instructions:

  1. Install GarageBand on your iPhone from the App Store
  2. Send your .m4a files to yourself as attachments to an email (be aware of email attachment size limits, you may need to send multiple emails).
  3. Open email on your phone and open your email
  4. Long press on each attachment to bring up the action menu
  5. Select Save To Files
  6. Save the file to GarageBand / GarageBand File Transfer
    • Click GarageBand to expand it
    • Click GarageBand File Transfer
    • Click Add in the upper right corner
  7. Launch GarageBand
  8. Click Create Document
  9. Click Tracks at the top of the screen
  10. Swipe left or right until you get to the Audio Recorder and click the screen
  11. Click the Tracks icon (Third from the left at the top off the screen, looks like a brick wall)
  12. Click Loops icon (second from right at the top, looks like a loop, next to the wrench)
  13. Click Audio Files at the top center of the window
  14. You should now see your file(s) you saved from your email.  Click them to hear them, drag one onto the workspace next to the microphone on the left.
  15. Click Save (Down arrow at upper left of the screen)
  16. Click My Songs
  17. Long click on your saved file to bring up menu
  18. Click Share
  19. Click Ringtone
  20. Type name
  21. Click Export in the upper right corner
  22. Done!

Now look for your new ringtone in Settings Notifications or Sounds.
This process can also be used to create songs, just select Song instead of Ringtone.

To Delete a ringtone

  1. Launch GarageBand
  2. Long press in shared folder on any track
  3. Click Share
  4. Click Ringtone
  5. Click Your Ringtones
  6. Click Edit
  7. Select and delete files as needed
  8. Back out of menus or close the app

This was fun!  I hope you were able to follow these directions to get interesting new free ringtones into your iPhone while discovering powerful open source tools along the way.

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