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

Last minute gift ideas for makers!

Here’s some ideas for the maker, tinkerer, builder on your Christmas list. (Following these links and buying from Amazon will support Workshop 88.) Most of these items are still available to be shipped before Christmas!

Hard to go wrong with an arduino uno – even if your maker already has one, it’s always nice to have a spare.
This kit comes with all the parts needed to get started making with arduino.
10 NRF24L01+ 2.4GHz Wireless RF Transceiver Modules compatible with arduinos. Very cool way to quickly experiment with wireless communication between arduino projects.
This book is a great introduction to learning how to make with the arduino microcontrollers.
This kit includes everything needed to get going with the Raspberry Pi.
Have a Raspberry Pi already? Here’s a handy case to help protect it.
Add a camera to your Raspberry Pi!
Every maker doing electronics needs a multimeter. Here’s a fully featured one at a decent price.
If your maker is new to 3D printing, you may want to consider this accessory kit.
A fun filament to print with is glow-in-the dark plastic. This might be a filament that someone may not choose to buy on their own, making it a nice gift. 

Recently at Workshop 88!

Last Thursday evening we had the pleasure of having a group from the Society Of Women Engineers tour our makerspace and ask questions on the many aspects of being a maker and what we were working on. They were a mix of female Engineers from different fields of engineering; chemical engineers, mechanical engineers, electrical engineers,and civil engineers. Really great night having them here with us. Are you, or do you have a group of people interested in makerspaces or hackerspaces? Come visit us on any Thursday evenings from 7-10 pm @ workshop88.

from Workshop 88’s Facebook page

Last Thursday night @ Workshop 88

biff-setting-up-the-radio-jim-working-andrew-watching-scaled
Last Thursday we had quite a bit going on at the weekly open house:

Ray connected the chassis of a motorized wheelchair to a remote control unit and was able to drive it around the front room.  Here’s a video:

The laser cutter was being used extensively to cut out some tesselating lizards and geckos, as well as to make stencils for an ammo box intended to hold plastic eggs. The project is called “Hen Grenades”.

Later in the evening Rachel came in and showed off her new LEGO compatible circuit boards – they are really awesome!  We were having so much fun playing with them that no one remembered to take photos.  Come in next week and ask her about them!

Mathematica on the raspberry-pi – a library class

I really like teaching classes through Workshop 88 at the libraries.  Over the summer, I had a chance to teach a few of the classes Workshop 88 offers at some of the local libraries. One library that we like going to wanted a class to introduce their teens and preteens to the Raspberry Pi.

I recruited a few helpers and we gathered up several Raspberry Pis, keyboards, mouses, and power supplies to have enough supplies that the kids would be working in pairs or at their own Raspberry Pi.  We set up before the kids arrived and had everything ready to go. At the start of class we talked about the idea of the Raspberry Pi as a low-cost single board computer and we pointed out all the hardware features of the Pi.  Then we showed off all of the distributions that we had brought examples of.

That took all of 25 minutes for a 90 minute class. Oops.

So, I asked how many of the kids were familar with Scratch, and it turned out that more than half of them had already used Scratch in school.  I decided that they should get a chance to work with Mathematica, so that they would be exposed to something new.

There is a pretty good introduction to Mathematica for the Raspberry Pi on the Raspberry Pi Foundation website. (The actual Mathematica tutorial starts here.)

We did a bunch of things that I think worked really well:

1.) Showed basic math operations
2.) Showed how to make graphs
(One of the kids said at this point that Mathematica is basically just a less powerful calculator. That’s when we kicked it up a notch.)
3.) Kids explored how many digits of pi they could get out of Mathematica.
4.) Kids played with displaying 3D shapes using the Graphics3D function. Examples: Graphics3D[{PolyhedronData[{Antiprism, 4}, “Faces”]}]
Graphics3D[{Opacity[.4], Glow[RGBColor[1, 0, .5]],
PolyhedronData[“JessensOrthogonalIcosahedron”, “Faces”]}]
5.) Kids played with 2D shapes.  Examples: Graphics[Polygon[{pentagon, 1 + .5 pentagon, 1.5 + .2 pentagon}]]
hexagon = Table[{Sin[2 Pi n/6], Cos[2 Pi n/6]}, {n, 6}]
Graphics[Polygon[hexagon]]

Lastly, we tried to generate some sound files with Mathematica, but it didn’t seem to work too well on the Raspberry Pis.

Overall, I think the kids had a great time playing with Mathematica and trying out a bunch of things that they had no idea a $35 computer could do.