Glowforge just announced a referral program that provides a coupon for up to $500 off a Glowforge machine. I obtained my Glowforge Basic as part of their crowdfunding campaign. Patience was rewarded – my machine has been an awesome addition to the shop. And don’t purchase a referral from you know who bay or some other auction site – I offer this freely because if you do use it I’ll get a matching store credit for materials and supplies at no cost to you. So here you go – the needed link:
As I mention in my “About Me” page I’m a long-time amateur radio operator. Ham radio for many might be thought of as an anachronism in the times of cell phones and internet. If you picture modern ham radio as just two operators “ragchewing” on a weird sounding single sideband transmission, you have hardly scratched the surface.
For plenty of reasons, I have largely worked on digital modes and what is known as QRP. Which in layman’s terms means low transmitting power (and to some extent inexpensive) equipment. While around as an operating option since about 2009, Weak Signal Propagation Reporting (WSPR) finally made it into the news last year in a big way, and it is one of the digital ham modes I operate. I’ll explain why in a bit.
What is WSPR? It is a narrow band, slow speed digital mode that is a transmission consisting of a call sign of the sender, the station’s Maidenhead grid location on earth and the transmitter power. This is a beacon sent out only to see where it might be received – there is no “2-way” communication but for the aggregated reception reports created by receiving stations published on the web.
WSPR was produced by Joe Taylor, a ham operator (K1JT) and Nobel Physics prize winner. In the past, he’s developed other transmission and reception methods to help with moonbounce and meteor scatter radio work.
My beacon transmits sporadically day and night using 200 milliwatts – on 40, 30 and 20 meters (essentially a spot on the 7MHz, 10MHz and 14 MHz ham bands). Your typical Class 2 bluetooth devices use 2.5 milliwatts of transmitter power, going at best 30′. But my 40 meter WSPR transmission can make it across the Atlantic depending on conditions! Here is a map of my 40m beacon one recent evening.
A you can see, my signal was heard to the mid-west and all the way to Europe! As I’m sending several different amateur radio band beacons here is what my map looked like on Friday evening, January 14:
So what purpose does this serve besides some bragging rights for operating a QRP digital mode? For one thing, this mode provides valuable radio wave propagation testing on a real time basis on shortwave bands. But another use is what made the headlines: predicting where a lost airliner might be found!
Think of each brief beacon “hop” as a digital tripwire. If something passed through its path the propagation would be “disturbed.” This disturbance along with some others in the same general region could be used to track locations of the object that made the changes in signal. All of the beacons are stored in a database, so a researcher can go back and recreate conditions that existed in the region at the time of interest. And an aerospace engineer in Germany did just that for the missing Indonesian MH340 plane: https://hackaday.com/2021/04/24/wspr-may-hold-the-key-to-mh370-final-position/
Will it be where he predicted? Stay tuned (sorry about the pun) – perhaps we will find out in 2022!
Now that is a loaded question! The end of the COVID thing? Self-driving cars that actually work? A $20,000 electric vehicle with 450 mile range? [I’d go for a Mr. Fusion like Doc in Back to the Future]
No doubt 2022 will continue to bring some new innovations to meet the challenges of these days. How about the focus of much of this blog: Additive Manufacturing?
I suspect that 2022 will be more incremental improvements, especially in novel materials. I don’t expect a $500 3D metal printer for home use, but I do expect that prices of 3D metal printing will continue to become more affordable from vendors such as Shapeways and Xometry. New novel polymeric materials could also be an important aspect of even home-based equipment.
Anyway, I’d suggest looking past the news of pandemic problems to stories of problems solved in 2022!
So this is not additive manufacturing per se, although it was used to prototype the device early on by the developers.
In 2018 I backed a project on Kickstarter for a metal detector that showed a lot of promise – Air Metal Detector – which used a smartphone app to run the system through a Bluetooth connection. The basic idea was to reduce the cost to just the active components in the coil and support structure while providing the option for more sophistication with the application. OTA updates of application and embedded coil software would permit fixes and improvements. Along with this was the potential to reduce weight but the final weight of course depends on the choice of phone. Promised delivery was for November 2019.
Fast forward to June 2021 – just as I was going on our first out-of-town vacation to a New Jersey beach resort, I got an email from FedEx stating that a package was being delivered the following day that required a direct signature. Thankfully FedEx now has package hold options at DollarGeneral stores, so I picked the one that was going to be on my return trip path home! But the sender listed made no sense to me and I had no direct notice that this was going to be the long awaited Air MD unit, though some weeks earlier I got a request to confirm my shipping address from the project.
In going back to the Kickstarter project page I soon realized I was in a very unique position at least for now – apparently I’m one of 3 or 4 to receive this out of 299 or so folks who pledged for it. Thus this hasty post (with more details to come) to prove I’m not making this up!
It did connect to the app on my iPhone and a quick test with a 25c piece worked as expected, but this is just a quick “all systems go” outcome. I’ll be working on more extensive tests and collecting some user experiences to share in the next day or so. If you have questions you’d like answered in all that, leave it in the comments. Two quick things from me already – the charging port is magnetic like Apple products and is unprotected from the elements. And there is no changing out an eventually defective battery – the head is sealed to IP65 standards they say, and I see no way to service anything inside.
Stay tuned for updates! I plan on comparing this to a Nokta Makro Simplex, which is my current favorite detector.
A bit of an update – I was waiting for the Android app to become available as it was not on the Play store or downloadable through their web site. But I continued to check. It did get out recently. I had some connectivity problems with Bluetooth – it would try to connect then shortly lose the connection with a cryptic error message. This did not happen on my iOS device – an iPhone 5. I am inclined to use the Android option because of a much bigger screen. My first test was on an LG G3 Stylus. However, after trying it on another Android phone I got the same response. The app installed on both Android platforms without any error or warning messages.
Weather here in the last 2 weeks has been lousy and wet, and whenever I’ve had an opening for a test I’ve been discouraged by all that. But I’ve turned on comments for this post, so please suggest things for me to try. I was out to a very rural wooded site using the Nokta Simplex to find old iron pins for a property survey – not exactly treasure hunting, but still valuable to the owner. I found all of them in quick succession, except for one that by rough measurement was under a large snowplow blade! Too much iron for sure.
And one more impression – I had occasion to try some comparisons with my Nokta unit at the end of the summer, in between rain and other chores needed when it wasn’t! If I had to choose one or the other I’d pick the Nokta. Both were pretty reliable in the simple stuff like coins thrown into my yard tests but I found the Air MD unit a bit “fussier.” While I want to do some “calibrated” tests at depth, time for that has eluded me so far. I have not found any of the major commercial vendors of metal detectors selling or reviewing it as of November 2021, but I’ll add any I find here. Plus, sooner or later I’ll probably find a more specific use for testing – or if you are reading this, please suggest one!
Or how my personal additive manufacturing lab was turned into a PPE manufacturing facility.
It was the second week of March 2020 as we closed out the first half of our Spring semester and sent the students home for their traditional week of Spring Break. Lurking already in the background was the spread of the COVID-19 infection. Situated as we are in a largely rural area, such a threat seemed at best a distant problem. But at the end of spring break we extended the students’ return out one more week. And then we were on a permanent hold until May. Maybe we could get in one last week of labs and teaching during our normal finals period, but that was quashed too. Thankfully 93% of our courses were able to complete online, in some fashion or another, but from my own experience not in an ideal manner. But these are not ideal times. And as of this post there are still about 10% of the student body left waiting to know how to complete incomplete Spring semester courses perhaps this summer.
Switching immediately to an online format for a materials science class and a class in additive manufacturing — both with “hands-on” lab components — meant doing some serious modifications. Thankfully I was somewhat already into the technology of video production for teaching. And then the “fun” began.
We do teach our manufacturing students in the 4-year program all sorts of logistics, planning tools, productivity concepts, and more. The strain on the supply chains from panic buying (“where’s the toilet paper??”) honed some of our points often seen as unimportant – but these students were living it. And as for me, seeing the need for personal protective equipment (PPE) was crucial to the safety of healthcare workers and others, the shortages were unacceptable.
So what has been the output? I’ve honestly lost count, but somewhere around 300 face shields, 800 “ear savers” and several hundred other adaptive items (door handle grabbers, key chain sanitizers, cloth mask clips etc.). Among the PPE were some odd items for class. Everything was donated to the recipients – including visiting nurses, nursing homes, dentists, child care centers, etc.
And while it has slowed down, I’m not completely out of the business. I’m sure my work has helped in a small way to contain the spread.
If you’d like to help me pay for my personal materials and wear and tear on my equipment (besides supplies, my MakerBot Replicator+ needed a new extruder and my Flashforge Adventurer crashed a nozzle and build plate) just use the PayPal donation button on the left menu! Even a dollar or two would be a wonderful acknowledgement.
Talk about being totally distracted! This past year professionally and personally was filled with all sorts of new things. To catch up with everything will be difficult, but from the last post, yes, I did get the new Prusa SL1 last fall (but still under construction, however). Our new college Makerspace is fully up and running, and I’m the faculty-in-residence this year to assist with all sorts of things maker. Because my teaching schedule is now reduced, there is much more time for adding to this blog – hopefully things of value that somebody will tap my “Donate” button! 😉 Feeding me caffeinated drinks is the best way to ensure more technical content here!
As is obvious from date of this post and the last one I was not doing much blogging here – and for a good reason. I was still very immersed in additive manufacturing problems and solutions, but my own personal life was so overloaded with family needs that blogging just didn’t happen.
Well, I hope to fix this several ways. I have some neat project information to share involving additive manufacturing in the restoration of several antique automobiles. This will definitely be the year of the liquid SLA printer – just take a look at Josef Prusa’s first UV/LCD unit the SL1:
Expected to be shipped end of January 2019, and yes I do have one on order. I will also be posting a review of the Anycubic Photon too – it is a very nice unit that works well for me. And I picked up a used Formlabs Form 1 – main issue dirty mirrors (that seems to be a common issue) and Formlabs nicely sent me a replacement set even though I was able to restore the ones in the unit. Plus an upgrade to the SparkMaker’s system to increase resolution through a parts kit and a test run of T3D’s phone / tablet unit. Maybe OLO / ONO (the much late phone based 3D printer) could appear!
I also expect to see some new breakthroughs in scanning. I’ll be posting a review of Qlone (tablet / phone app) that recently got upgraded to 4K.
And as my college has opened a new Makerspace, I’ll devote one post to showing you how our design team of faculty and students created a unique facililty.
Last week the box with my R2 came after a long 6 month wait from pre-order. And I was not disappointed, but for one weird thing. First, it is quite a massive machine, larger than an Ultimaker 2. The 5″ touchscreen is half the front lower panel. There is a front door with a magnetic latch, unlike the C2 which has no door at all. Mechanically the R2 shares the general design layout and setup of the C2, but there are some differences. For one, there is a webcam installed on the left inner panel (looking from the front of the unit). And the heated build plate is magnetically attached but leveling screws are present which must be manually adjusted, though there is a guided process from the menu.
Unpacking was routine, and the dreaded inner door scratches people reported in early shipments were not present because there was a nice piece of plastic film protecting it.
As I completed unpacking it, I noticed that at the top of the Z screw a bearing was missing. I checked the packaging for it and could not find it. To be sure, I even searched in the electronics compartment. Thankfully this is just a press-in-place 608 skate bearing and I happen to have plenty of those around of good quality. Its purpose is to fix the end of the Z screw so it will not wobble. If you read my review of the C2 you will recall that I discovered the same bearing there to be dislodged after several hours of use.
Powering it up and after connecting to my WiFi it reported a firmware update was available so I immediately did that and waited for the process to complete. I then did the bed level adjustment and the Z height offset. Eager to get it going, I loaded the blue PLA filament it came with and started printing. And remarkably, everything worked as it should have!
So straight out of the box, plus one firmware update and it worked perfectly. I’ll get some close up pictures of the machine itself as well as some prints to show you how it does, but the default settings in Cura for PLA give fantastic results.
So now that it is several months later, how did it go? The main thing was as I started making new prints it became obvious that the Z screw had been bent in shipping or perhaps even at the factory. Long story short, Robo3D replaced the Z screw fairly quickly once I put a ticket in for warranty issues…. initially wanting me to sent it back (quite a chore) or as I suggested, just send me the part and I’ll return the dud if necessary. Well, not necessary to return it so I got it in 2 weeks and replaced it in about 1 hour’s work. Did that get things fixed? Yes, the Z banding disappeared! And it has continued to be a reliable machine though for the moment it is offline for the time being… other machines being evaluated and so forth – details to follow!
I purchased a Robo C2 from Amazon 6 weeks ago, and figured it was time to collect my experiences to date. It came packed very well for shipping, lots of accessories and a small reel of filament. There apparently are not many out there yet. Let me start with the good: it has WiFi remote control with over-the-air updates using Octoprint (I’ve had at least 6 updates since I started using it), but it also has a USB front port for direct load of jobs, a color touch screen (though more on that later), automatic leveling (but some say not fully implemented yet), a nice aesthetic for design, and a fairly large build envelope for its overall size. There is a smartphone app to control it too. In general, mine seems very well built but there have been some problems out of the box. On the good side, I’ve gotten some fantastic prints out of it, but also some nasty failures.
This truly should have been a machine that would knock the competition out of the park. With some QC and tweaks it might eventually. But if my experience is any indication, as of now it just doesn’t. You expect a learning curve but if we are to have a reliable “appliance” there must be no points of major fail. So where does this machine fall short?
First there is no heated bed. OK, not a show stopper – without a heated bed there are still loads of filament options. I’ve tried PLA (good), TPU (limited success), PVB – Polymaker’s new alcohol polished filament -(OK but not consistent). Obviously ABS is out. There are grades of enhanced PLA (Polymaker PolyMAX PLA) which also have worked well. For now though my best machine for TPU has been my Monoprice Makerselect.
I’ll start with a minor annoyance. The first thing you notice after you turn it on is the head cooling fan. And by the way, my power switch is “backwards.” The machine turns on when the circle is depressed but the convention is for the line to be “on.” In IEC 5007 standard, the power on (line) symbol, appears on one end of a toggle switch that the control places the equipment into a fully powered state. It comes from the binary system (1 or | means on) – thus “0” means off… The electronics are neatly out of the way in the base of the machine. There is a Raspberry Pi board on the left side and a Robo control board on the right.
So, that extruder fan runs at full blast all the time even if the extruder is cold… I have not checked but either the fan is a sleeve bearing design or maybe just noisier that others of its type, but that has not been the biggest issue. Now you might ask “why is fan noise an issue?” Answer: this is meant to live in a room like a classroom or other living space and who wants a thresher running at all times? Somewhere I thought there was a control for that fan but I have not found it in the C2’s menus just yet…
But a much bigger concern is this: If you look at the various support boards you’ll see that getting the Z offset right has been a big gap in this machine (sorry for the bad pun…). The build plate has 4 magnets that stick it to 4 acorn nuts. Two of my magnets were loose (clearly they were force fit at the factory, but with time the plastic creeped – so with a little superglue I got them fixed. On first use you manually level the bed by using the “Wizard” for leveling. So far so good. It calls for a piece of paper to be the gapping tool. However, if you use a single sheet of copy paper (at least for my unit) the head will go crashing into the build plate. What works for a gap tool is the heavy, single-layer cardboard you find backing a 9V battery package. Yes, that is many times thicker than a piece of copy paper… but for me it works. I destroyed several sheets of the black painter tape pads that cover the plastic bed before landing on that solution. To date I’ve not seen this addressed, and I also gouged out the build plate too. You can adjust the temperature, feed rate and fan % on the fly but not the Z offset. I would like to be able to dial in a change to the Z offset from the front panel, but if there is an option for that I did not find it. And in a recent update, the Z offset values after calibration have shifted from around 5mm to 14mm with no explanation as to why. As you might suspect, getting the Z offset exactly right is critical to getting a successful print.
Which takes me to the next issue. The Z stage design is typical – supported by two large rods with the Z screw in the middle of them. There is a bearing at the top of the Z screw to stabilize the end. That bearing came loose – again just force fitted like the build plate magnets and over time it popped out of the hole. There is nothing to positively keep it in place. Thankfully that is a trivial fix. Gently pushing on the front of the aluminum plate that attaches to the Z axis mechanics, you find that there is considerable mechanical “slop” or twist. It is as if the linear bearings are not correct for the shafts or the mount is not firmly attached to them. The play is at least 1-2mm at the front and you can clearly see the shift at the rods. Try this with a Wanhao D6 and you’ll get nowhere (these machines are the same price and incredibly rigid).
As for the touch screen, it is resistive – meaning the response is a bit slow. You can’t expect it to behave like your capacitive screen on your smart phone or tablet. I’ve adjusted to it but sometimes you want fast response – like when you are in a hurry cancelling a job when the head crashes into the build plate. The interface is full of features, they are logically arranged, but here and there one is left with some puzzling options. You can remove filament and reload through the Filament Change wizard. But if all you want to do is unload, there is not a direct option. So I ran the wizard up to getting the filament unloaded, then tried to use the “back arrow” to return to the main menu – nope – crash goes the interface and all I could do was shut it off and reboot.
Another thing I’ve noticed is the WiFi connection seems to get lost after a job starts. Restarting the Cura software (a customized version for Robo) usually seems to fix that. I have other 3D printers on my network (MakerBot, Mod-T) that never have this issue. Perhaps this is more a bug with the version of Cura that Robo supplies for this machine (2.3.1).
So I plan to continue testing this machine (of course with filament that does not require a heated bed). On wonders why not a glass plate instead of painter’s tape? If the IR sensor for leveling needs black, surely black glass might work?? Or how about BuildTak(tm)? I’ve created a CAD model of the build plate and will try BuildTak(tm) on it instead of black tape. If it works, look for it on Thingiverse! Thankfully Robo is sending me a new original one on warranty, but at the moment you can’t purchase them for extras.
More details to come and pictures as I get some time in the next few weeks.
UPDATE 5/08/17: I made a request to customer service concerning my crashed build plate and not too long after someone got back to me with a form to submit for a replacement. And a few days later I received not one but two new plates! This time, the magnets were glued in place (a bit of fog on the plastic from the cyanoacrylic glue was evident). In the mean time, I had replaced the tape on my original with BuildTak(tm) custom trimmed to fit. After resetting the gap, it works really well. Because the BuildTak is stiffer and a bit thicker than the painter’s tape pads it comes with, the craters in the top of the surface don’t matter. So I’m saving the new plates for later. I’ve lost count of updates, but things keep getting better. Print quality is great at the default (100 micron) layer thickness and the WiFi connection is not lost as much, though it still does. So it looks like they are serious about perfecting this machine, and I’m getting much more consistent prints. I still need to post some pictures – soon!
UPDATE 7/11/17: Wow, things have come a long way since the release. I lost track of the updates but the most recent one was quite a refresh of the user interface and one that makes sense to me. And the older customized Cura 2.3 client has been replaced with Cura 2.5 customized for the 2 series machines. What a difference! No more dropped WiFi connections for one. And the prints are outstanding at the “default” 100 microns.
So clearly Robo made a huge effort to get this into shape and with all of the updates I can fully recommend this model, and the R2 unit too (just got it and a review is being written this week).