Hey – the polar vortex may be winding down, but we need time to recover from it. No open houses tonight (Jan 31). See you next week!
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.
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
We’ve been playing with the etching of metals with our laser cutter at Workshop 88. One of our members discovered a mustard-etching method and tested it out last night during the weekly open house.
The results are pretty great for a first attempt! Expect more detail to come in future posts – but if you want to know more, please come to our open house meetings every Thursday night!
Prusa i3 MK2S 3D printer kit assembly time lapse videos
20170323 GoPro Prusa i3 MK2 assembly and print (600x time lapse)
Link to 300x time lapse video (longer, more detail, different background music):
20170323 GoPro Prusa i3 MK2 assembly and print (300x time lapse)
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.
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.
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)
- Auto mesh bed leveling
- Part cooling fan (for PLA)
- Heated bed (for ABS and other materials)
- … and as an added bonus it has a 4 color upgrade coming later this year.
The Prusa i3 MK2
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”.
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.
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)
- Prusa i3 MK2 live assembly: p1, Y-axis
- Prusa i3 MK2 3D printer clone live assembly: p2, X & Z Motion
- Prusa i3 MK2 3D printer clone live assembly: p3, X & Y Motion
- Prusa i3 MK2 3D printer clone live assembly: p4, Wiring and Printbed (mechanics finished!)
- Prusa i3 MK2 3D printer clone live assembly: p5, Electronics and Firmware!
- 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 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…
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
Check out what went on last night at Workshop 88, and while you’re there like us on Facebook:
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.
There are 5 main types of machine operations
- Engrave (follow path): The tool tip will follow the 3D path provided.
- Profile: The tool edge will follow either the inside or outside contour of a path down to the specified depth.
- Pocket: The tool will remove all the material within a contour down to the specified depth.
- Drill: A drill routine will be executed at each point location. Drill routines come in 2 flavors:
- “Peck” used with drill bits, drills to successively deeper depths liftig the bit out of the work regularly to clear chips from the flutes.
- “Spiral” used with endmills that are a smaller diameter than the finished hole.
- 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:
- “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.
- “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.
This tutorial will demonstrate Engrave, Profile, and Pocket operations, which are the most popular.
There are 4 steps to this tutorial:
- Create a .svg file containing paths needed for machine operations
- Create machine operations
- Export Gcode
- Simulate, visualize and validate
This past Thursday night gathering at the Workshop, Rick Stuart showed up all smiles- though I’m not sure if this was due to his enthusiasm to show off his new gadget or in anticipation of Rachel’s shortbread which had been announced earlier via email.
Rick has built a personal entertainment center which has the capacity to display high-defintion videos and music through an upcycled touch-screen LCD. Rick had recovered some of these screens from his previous workplace and had decided to put them to use in a new project. He has created a running loop for the system to operate: he utilized a Raspberry Pi running OpenELEC in order to run XBMC (a media center) and connected an HMDI cord to a LVDS adapter board. The adapter runs to the LCD, which is connected by USB to the Raspberry Pi. For sound, the system will be attached to speakers. Files are stored on an SD card inserted into the Raspberry Pi, and streamed files are accessible through connecting an ethernet cord.
By using HDMI instead of the normal video output connection, Rick was able to make his display high-definition. Rick said that a great advantage about his system is that he was able to essentially create his own media center out of materials he already had on hand plus the low cost of a Raspberry Pi.
Meanwhile, Zach showed me how to create very intricate origami elephants using printer paper. While there’s no hope of me recreating one on my own, I thought it was important to highlight how awesome they turned out.
Two of the questions we often get at Workshop 88 are: “How many people show up to your public meeetings?” and “What usually goes on at your public meetings?”
If you’ve been wondering the same things about Workshop 88, take a look at what was going on during our last meeting:
If you’ve never been to Workshop 88 before, the video gives a sense of how the makerspace is laid out. We have four areas from front to back: meeting room, wood/metal shop, electronics/rapid prototype lab, and multimedia room. All the rooms get a lot of use; it just happened that when the video was shot there were not many people in the back rooms.
Come out some night and make something with us!
Have you been coming to Workshop 88 public meetings on Thursday nights? If you haven’t been yet, or it’s been awhile since you’ve been in, you may be surprised to see all the stuff that is going on at the meetings each week. Thanks to Workshop 88 member Bill Paulson for snapping the photos last week!
Workshop88 is happy to announce a new meeting schedule staring February 2012. Meetings will be at 7 pm Thursday evenings every week, and the open hack night will be Monday nights. Class schedules and the meetup schedule will be updated to reflect these changes. Board meetings will be scheduled once a month.
We look forward to seeing you at our new weekly meetings.