I’m an #privacy, #opensource, #opendata and #openstandards advocate. I’m holding a grudge against Big Tech, big IP holders and authoritharian governments. Furthermore I’m a #3Ddesigner, #3Dprinter, #webdesigner and overall #DIY guy.
We first need to create a involute of a circle in Solvespace to get a better understanding of an involute gear. This video will be followed by another where we create an involute gear and a third where we adjust the gear in Solvespace.
I’ve used version 2.3 in this video but v3.0 should work fine too for this tutorial. This is a series in progress. I will at least make one more video to demonstrate how one gear drives another in Solvespace.
First video tutorial: Involute of a Circle in Solvespace. Before creating an involute gear we first need to understand how to create an involute of a circle.
Second video tutorial: To create an involute gear we only need three parameters, the module which determines the length of the teeth, the number of teeth and the pressure angle. With these parameters we can determine the Pitch Circle, Addendum Circle or Top Circle, Dedendum Circle or Root Circle and the Base Circle. With these circles and the pressure angle the shape of the teeth can easily be created in Solvespace.
Third video tutorial: This is the third video in a series about creating an involute gear in Solvespace. If we want to adjust the module, number of teeth or pressure angle of an existing gear in Solvespace we don’t have to start from scratch. We can take an existing gear and change one of the three parameters. This will save us a lot of time. However this change must be done following a procedure that I’ll demonstrate. Other wise Solvespace will give us the error message ‘unsolved constraint’.
Solvespace is an open source, parametric, 3D CAD program that is lightweight and easy to use. It is available for GNU/Linux, OSX and Windows. In Solvespace the user applies geometrical constraints to a sketch and the program’s solver calculates the result (comparable to the FreeCAD part design workbench).
Solvespace is open source (GPLv3 license) and is available for Window, OSX and Linux. Originally developed by Jonathan Westhues and currently maintained by Paul Kahler and others. It can be downloaded here: http://solvespace.com/download.pl
OpenSCAD allows the user to create complex shapes with the polygon function for 2D and polyhedron for 3D. Polygon and polyhedron both accept a list of 2D and 3D coordinates (points) respectively as parameters. A functions can generate a list of points eliminating the need to manually created these lists. This property can be used to create shapes that are impossible with the 2D and 3D shapes that are build-in in OpenSCAD. In this blog post I’ll show how to create functions for some simple 2D shapes and explain how to manipulate the functions make more complex shapes with them.
Creating a 2D shape
To create a circle with a radius of 20 in OpenSCAD we just have to type
However OpenSCAD doesn’t allow us to reshape this build-in function to for instance an ellipse. Alternatively we can write a function that generates a list of points needed for a circle and then use polygon with the points as parameter to draw the circle. The function uses the trigonometric formulas, x = r cos φ and y = sin φ, to convert polarcoordinates to Cartesian coordinates.
When F5 is pressed a circle is drawn however the x,y coordinates of this circle are available to us. By adding echo(circle(20)); to our script the list of points is printed in the console. The circle function can easily be altered thus gaining a new shape. An example is shown below.
Now let’s take a look at the syntax of the function. Every function generates a value and in this case it is a list of points. In OpenSCAD a list of points in a two-dimensional space is represented by [[x1,y1],[x2,y2],[x3,y3],…] where all x’s and y’s are numbers. In this case of the circle function the point are generated in a for loop. The loop begin at 0 and ends at 720 with a step of 1. The radius * cos(phi/2) and radius * sin(phi) calculate each x,y coordinate for every given phi.
The ellipse, a generalization of the circle, can now easily be created by slightly changing our function.
a second parameter is added. r1 is the radius in the x-direction and r2 is the radius in the y-direction. If r1 is equal to r2 a circle is drawn.
OpenSCAD allows the user to create complex 2D shapes using functions that generate lists of points This list is used as the argument in the polygon function of OpenSCAD. Every shape can be generated as long as the mathematical expressions are known and can be translated to OpenSCAD script. This opens up a world of possibilities. The same is true for 3D shapes but instead of polygon the polyhedron function of OpenSCAD should be used. This however is a topic for a future blog entry.
Caveat: List comprehensions as shown in the functions of this article are only possible with OpenSCAD v2015.03 and above.
OpenSCAD is open source (GPLv2 license) and is well maintained by Marius Kintel et al. Besides the stable releases for Windows, OSX and Linux, developmentsnapshotsare available. I recommend using these development snapshots since they have all the latest features.
A special thanks to Xavier Faraudo who explained the advantages of functions in OpenSCAD to me.
Last May I received a new Terms of Service request from YouTube. In this request I had to grant YouTube the right to monetize my videos. In other words when I agree, YouTube can insert ads in the videos. This is the final straw for me with YouTube and Google.
I’ve created this YouTube channel with tutorials about open source 3D CAD programs and never had any intention to monetize the channel. So I definitely don’t want YT to monetize it for me.
My goal has been to inspire people to use open source software instead of proprietary software and judging by the number of views and reactions I’ve been mildly successful with that. I had over 200.000 views with my tutorials and more than 1100 subscribers. Not much for YouTube of course but keep in mind that the channel was about open source 3D CAD. Very much a niche market
I’ve put up with all YouTube’s privacy invading policy and data mining because of the popularity of YouTube. YouTube has a near monopoly when it comes to video sharing and has a huge worldwide audience. So to reach my audience with my video tutorials it made sense to use YouTube.
However where does one draw the line. I’ve created the video tutorials believe it or not with a lot a sweat and blood. And it’s important that I keep sovereignty over these videos. So whether ads will be part of the video is up to me and not YouTube. This leaves me no other alternative than to delete all my videos (except this one).
Luckily I’ve already had found an alternative home for my tutorials. It’s called PeerTube. PeerTube is video sharing software but contrary to YouTube, it is open source. In addition it’s also decentralized and federated.
This means that anyone can create a PeerTube server and host videos. These servers can connect to each other and share the videos between them (federation). As a result there is no single owner of the network. If the server that I joined fails or I don’t like the policy on that server I can either upload my videos to another server or even start my own.
I already have some content on PeerTube and I’ll upload new videos to PeerTube. However it’s unlikely that I’ll upload my older videos to it. I figure that they are less relevant anyway. I’ll put a link in the description to the new home of my videos and I hope to see you there.
I hope to see you on PeerTube and keep using open source software.
It’s more than two years ago that I started using the social network #Movim after a tip from an acquaintance. I had left G+ and never wanted to use a centralized social media platform again. I tried the Fediverse (Mastodon and Friendica), Diaspora and Movim but eventually I kept using Movim and Mastodon. The secret of Movim is tranquillity. After logging in for the first time the news stream is empty, much like Diaspora, and it only gets filled with post from people that you follow, communities that you subscribe to and rss feeds. This in combination with an easy to use chat option that gives access to whole #XMPP network makes Movim very powerful.
It’s also incredibly easy to create a community in Movim, although I think community isn’t the most appropriate description here. It’s more a blog from one or more persons where other users can subscribe to, like and comment in a linear fashion.
I recently introduced my wife to Movim and the first thing that surprised her is that, contrary to FB, the news stream contained articles worth reading instead of ads and other bs. She also liked the fact that she could use any XMPP-client for chat. Time will tell if she’ll keep using it but her initial enthusiasm was very encouraging.
Although, I’m pretty psyched about Movim I would like to see some features. First, coming back to the tranquillity, when in the news stream on the right side five posts of other Movim users appear. I suppose that this is meant for discovery and that’s great but in some of the posts I’m less interested but I can’t block or hide these posts.
Also there is no way to block or hide a person entirely. This may become a problem since Movim appears to be becoming more and more popular and with that the interaction between people grows exponentially.
Currently I’m lazily using the European server of Movim but I (or anyone else) can deploy a self-hosted instance and I’m tempted to experiment with that. I’ll probably get back to that.
Finally, I want to thank Timothée Jaussoin and other contributors for developing Movim and making it available to all of us. It’s awesome. And if you read this please consider donating to the Movim project.
I watched the famous speech ‘Freedom in the Cloud’ of Eben Moglen in 2010 at the ISOC-NY. Again if I might add. That speech had a great influence on me. It was the first time that I realised that client-server infrastructure of the internet is a huge problem. This very infrastructure ensured that all the data were aggregated and used (or abused) by the ones that owned the servers. At the same time the clients were being deprived of power. And that with the accumulation of servers in a data centre and he virtualisation of the servers (cloud) these owners were getting even more powerful.
I wasn’t the only one that was influenced by this speech of Eben. It also marked the beginning of the development of Diaspora social network. As it happens some of the initial developers of Diaspora were present at that Friday night at ISOC-NY and it inspired them to build the Diaspora software.
A lot has changed the last eleven years, and I will get to that, but what hasn’t changed is the client-server infrastructure, the source of evil. If anything the power of ones that own the servers like Facebook, Amazon, Google, Apple and even Twitter has increased greatly in the last 10 years. And as a consequence the ones working on the client side have become even more powerless. Snowden (2013) and Cambridge Analytica (2016) are just a few examples that demonstrate that this abuse of the ‘architecture of the catastrophe’ took directions that we couldn’t have envisioned.
On the plus side since 2010 a lot of developments have started to halt this catastrophe. Some were more successful than other but it’s undeniable that if someone is looking for a free (as in freedom) alternative right now a lot more options are available than 10 years ago. Also these options seem to be sustainable and rather successful. The Fediverse with Mastodon, Pleroma, PeerTube, Funkwhale, Pixelfed, Lemmy and others have made great progress since the introduction of the ActivityPub protocol. XMPP has made great progress with the introduction of advanced clients like Conversations, Movim and Gajim.
The Freedombox hasn’t lived up to it’s expectations though. The development of Freedombox was initiated by Eben and allows to set up a simple private server in your home. The last time I checked even Diaspora was not supported by Freedombox making social networking with it impossible. Luckily other initiatives have taken flight such as Yunohost. They make it easy to self-host a server and install software for blog, chat, social networking, online storage and file sharing. Yunohost and others bring the dream of Eben closer of a peer-to-peer network instead of a client-server network.
Another noteworthy development is Scuttlebutt, a client-based peer-to-peer application for encrypted social network. Just install the app on your PC or phone (Manyverse) and communicate directly with others that installed the app.
Or Briar, a client for messaging that uses Bluetooth, WiFi and the Tor network to communicate. The need to host your own server has been replaced by simply installing an app that doesn’t rely on a central server. Even if the internet is down the information keeps flowing over WiFi and Bluetooth.
Although we still live in the catastrophe that Eben spoke about eleven years ago there are more possibilities to escape and it appears that more and more people are discovering this. With every scandal, every update of the term of service a wave of new users appears on the networks that I mentioned above and that’s something to be grateful about but it should also motivate us to keep fighting for a free (as in freedom) internet.
My laptop is a Thinkpad T40 from 2003 with 1GB of RAM and a 30GB HDD (Yes, you can laugh now). I bought it second hand many years ago, it had Windows installed and it was slow as molasses. It was also a time that I got interested in FLOSS. So I looked for a suitable Linux distro and I found Puppy Linux (Slacko and later the TahrPup release). It turned my unusable laptop into a fast and very capable computer. I’ll never forget the amazement when I booted Puppy for the first time and saw how fast it was.
I’m not much of a distro hopper but last year I switched to AntiX because I felt that development of Puppy had slowed down. AntiX does more or less the same as Puppy in that it brings life to an old computer. Both are very lightweight but at this moment I find AntiX definitely more polished with JWM, FluxBox and IceWM as window managers to choose from.
Both Puppy and AntiX contain, as do most of the other Linux Distros, proprietary bits and pieces (e.g drivers and it’s possible to install proprietary programs from the Snap store or PPM) but are mostly FLOSS and are available thanks to many volunteers that dedicate so much of their time to these operating systems. So I think it’s fair to contribute back e.g by donating to the developers that make this possible.
I’ve got a confession to make. Since I left Google+ and Reddit two years ago I always missed the community approach of both social networks. Don’t get me wrong I love XMPP (or Movim, which is based on XMPP, in my case) and Mastodon, the Twitter alternative. I love their ease of use and the possibilities to communicate without a large tech company preying on my data. I love the ease to set up a chatroom or a microblog in Movim. And I love that they are federated. However both on Movim and Mastodon it’s hard for me to have a structured conversation about one single topic (e.g. cycling or 3dprinting). It’s for that reason that lately I’ve spend time on Lemmy.
Lemmy is easiest described as a federated Reddit alternative. This means that with Lemmy members can send text posts, links and images that can be up- or down voted by other members. Lemmy already consists of tens of instances and thousands of communities. Communities (the equivalent of subreddits) are the cornerstones of Lemmy. Popular topics like Linux, open source and privacy already have their own community. If a community doesn’t exist the user can easily create one. Just click Create Community, fill in a form and press Create and you’re done. Every post has to be posted in one of the communities. A huge advantage is that posts don’t get buried by hundreds of other posts in the timeline. As a consequences discussion threads are easy to follow.
The UI of Lemmy is minimalistic but very effective. The user is presented with a list of comments that are ordered by popularity. The comments can easily be filtered e.g to only show the new comments. Via a menu selection all the communities are shown and can be searched. Overall search is very well implemented. I use it a lot to learn about topics of interest to me that were discussed earlier.
Lemmy comes with a built in slur filter which I believe is a very good idea if you want to have civil discussions. Perhaps not everyone does agree with this filter but Lemmy is free and open source software so one can always create his own fork.
I’m currently on lemmy.ml which appears to be the most general purpose and the largest server in terms of subscribers but you can run your own server if you want to. The number of instances of Lemmy is growing (currently 29) and so are the number of users but only time will tell what portion of users remain active.
Besides the slur filter mentioned above the lemmy.ml instance comes with a Code of Conduct that is enforced by a team of moderators. Again a good idea for the above mentioned civil discussion. It’s worth mentioning that the moderators keep a public Modlog where one can keep track of all the actions taken by the moderators. A gesture of transparency that I haven’t seen on any social platform.
Speaking of discussion, although Lemmy is still pretty small in size, the discussions are excellent. Most of the times the comments are to the point, well informed and criticism is constructive. This makes Lemmy a vibrant community even though it’s relatively small.
The beauty is that Movim, Mastodon and Lemmy (and all other federated social networks) serve different purposes so I don’t have to choose. They can co-exist and enable people to optimize their online social needs all with free and open source software and all federated.
EDIT: This post was rewritten on 17th August of 2021 to include my experience with Lemmy over the last half year.
Framasoft the non-profit organisation behind PeerTube (and other free software) has started a fundraiser for version 3 of PeerTube. They published a roadmap accompanied by a progressive fundraiser over a period of 6 month. The current roadmap looks very promising and is divided into four main steps. Each of these steps can be fulfilled if a specific financial target has been reached. New features and improvements are among others: global search through the Fediverse, moderation improvements and features, playlists and finally live streaming.
Global search within PeerTube is a much needed feature to enable the user to find videos that are outside the instance-bubble. The PeerTube instance that I’m using (linuxrocks) only federates with a couple of other instances making it difficult for my videos to be found while I can’t find much when searching for content.
Moderation. An online video sharing platform isn’t without problems like copyright violations or not safe for work material. PeerTube already has some moderation tools like a report tool but more tools certainly won’t hurt and the roadmap show a long list of new moderation tools.
Playlists. e.g allow clips of the same video in a playlist thus making this a remix tool.
Live streaming is already big and according to market research it will grow rapidly in the coming years. For PeerTube to keep up this is therefore a necessary feature.
At the moment of this writing over half of the required amount of funds and two of the four main steps in the roadmap has been reached but Framasoft will surely appreciate more donations to be able to fulfil the complete roadmap. So either contribute financially or at least share the news!
It’s been 1.5 years since Google+ closed and I started dipping my toes into the Fediverse and other distributed social networks. It also kicked off my search to get rid of everything Google. To DeGoogle is easier said than done because Google is everywhere from search to fonts, from the video platform YouTube to the file storage and synchronisation service Google Drive, and from blog publishing service Blogger to the Google mobile operating system Android. And the list goes on. So chances are you’re using a lot of these services and most of them require a Google account, a devious move from Google. It’s for this reason that it’s very hard to get rid of this o so convenient account.
To get a more comprehensive view take a look at this article. Below I’ve compiled a list of the most important Google services and products that I replaced with something else.
Search was perhaps the easiest to replace (or is it). While Google search is by far the largest search engine in the world DuckDuckGo (DDG) is becoming increasingly popular. I’ve used DDG to great satisfaction and only had to use Google search a couple of times. The only gripe that I have is that DDG isn’t free and open source software (FLOSS) let alone distributed. In that respect I’ve read some good things about Searx and I may give that a try in the future.
The Chrome browser of Google has become very popular with an estimated market share of approximately 70%. A large portion of the Chrome’s source code is based on Chromium, the open source browser project from Google, however Chrome is proprietary freeware because it contains large blobs of proprietary code. The Spyware Watchdog considers Chrome’s Spyware level extremely high this due to multiple spyware features that are built-in such as Google Account and Navigation Assistance. Another threat comes from the earlier mentioned market share. This gets even worse when we include the other browsers that are based on Chromium such as Microsoft Edge, Opera and Vivaldi. I currently use Firefox. It’s perhaps not the most privacy minded browser around but it’s FLOSS, it has a reasonable market share which is important for support of web developers and development of Firefox is very active.
Next is YouTube which BTW is becoming more and more annoying with all these ads and the recommendations with the sole purpose to keep the user as long as possible on YouTube (and serve even more ads). I invested a lot in YouTube in the past with over 70 video made about 3D CAD, 3D printing and electronics so replacing it is not easy. The solution that I found is two-fold. I remastered (part) of my existing videos and uploaded them to both PeerTube. If I want to watch YouTube videos I use Invidious in the browser of NewPipe on my Smartphone (still Android sadly).
Over the years I got dependant on Google Drive e.g to store the CAD files that I wanted to share after I published a project either in blog or a video. I want readers and viewers to be able to reproduce the project. Since I didn’t want to self-host a solution such as Nextcloud(see edit below), I started looking for a paid service. I currently have a contract with Strato, a German hosting company that also hosts my websites. Strato offers HiDrive, it’s not FLOSS unfortunately but it offers 100% storage in the EU and (paid) end-to-end encryption is possible although only in the HiDrive desktop program for Windows (which is a bummer but I don’t need encryption for this purpose anyway).
Instead of Google maps I started using OpenStreetMap and products based on OpenStreetMap such as OsmAnd (on Android) and Komoot both on Android and the web browser. Komoot is excellent for hiking and cycling but unfortunately it isn’t FLOSS. These alternatives have proven to be good enough for me since I haven’t used Google Maps any more.
I somehow started using Gmail. I don’t know exactly why because I already had very good email services. I also fail to understand why it’s so popular because every other email service does about the same. My own ISP comes with a very good email service and so is the web hosting company that I’m using. To stop using Gmail takes some preparation most importantly to list and notify all the people and organisations that send you email to your Gmail address. Also list all online services that use your Gmail address. Now replace this Gmail address with another email address.
You may want to delete your Gmail completely but it’s possible that it’s linked to your Google account. If this is the case you can either use a different email address for this account or more radical delete your Google account completely. In case you choose the latter remember that lots of Google services are couples to your Google account and can’t be accessed any more. Having said that if you start to purge Google from your life the Google account becomes less and less important with every Google service that you delete. So at a certain point deleting the Google account will be painless.
Although Android is Free and Open Source software most Android phones come with proprietary software and services that prevent users from using the phone the way they seem fit. The easy way to free the software on your phone is to install FDroid. For most users the Google Play Store is the only way to install software on their phone. FDroid is an alternative software store that enables the user to easily install and maintain Free and Open Source software on their Android device. BTW installing FDroid and replacing proprietary apps is what I have done thus far and it’s a good start.
Even better is to replace the Google infested Android with a free version of Android like LineageOS. LineageOS is a FLOSS version of Android that can be used without a Google account and that comes without the proprietary Google apps (and perhaps other junk from the phone manufacturer). Make sure to check if your phone is supported before trying to install in on your phone.
Yes I know, I have Google fonts in my blog. That came with the choice of the WordPress theme and I didn’t realize that at the time. That’s just another example how Google infested the web and how difficult it is to DeGoogle my life but rest assured fonts will be next.
To get Google out of your digital life is hard, very hard. This tells us how much Google is integrated into our lives and probably for the most part without being aware of it. Luckily we still have choice (other than just say goodbye to the web), choice that gives us freedom to use the web without being used. The freedom to control our data and not being exploited.
Edit: As someone on Mastodon pointed out it’s not necessary to self-host NextCloud. Examples of cloud service providers running Nextcloud are Disroot, OwnCube and Operationtulip.com (currently in beta).
The Covid-19 virus has locked us into our house most of the time. Luckily my son can keep exercising with this DIY device. Some time ago I built a climbing board for my son who is an avid climber and boulderer. He wanted to be able to train at home so I thought I’d build a wooden climbing board myself. I wanted the board to be cheap, versatile and build with materials that are easily obtainable. Lastly we have solid walls in our house so I wanted to build something that I could attach to these walls.
I created a design in Solvespace, which is a great 3D CAD program. This design enables me to play with the dimensions before actually buying the materials and building the board.
The backplate and front-plate are made of 12 mm (1/2″) plywood while the beams and support beams are made of 30mm (1 1/4″) scaffolding wood. The rails are of pine wood of various thickness, 1 1/4″ being the thickest and 18mm (3/4″) the thinnest. The support beams strengthen the construction considerably.
Here are the parts that are needed for this build:
1 x backplate 90 x 61 cm (3′ x 2′) plywood (12mm or 1/2″)
1 x frontplate 90 x 31 cm (3′ x 1′) plywood (12mm or 1/2″)
2 x beam 30 x 19 cm (12″x 7.5″) scaffolding wood (30mm or 1 1/4″)
2 x support beam 41.5 x 6.2 cm (14″ x 2″) scaffolding wood (30mm or 1 1/4″)
2 x rails 90 x 5 cm (3′ x 2″) pinewood of various thickness
8 x carriage bolts 6mm (1/2″)
8 x wingnut 6mm (1/2″)
4 x lag screws 7 x 60mm (5/16″ x 2.5″)
4 x wall plug fisher 10 mm (3/8″)
18 x twin-fast screw 4.5 x 40mm (3/16″ x 1 1/2″)
How to make it
Building the board is straight forward. First I’d cut the plywood to the plates with the size indicated above. Next I’d cut the scaffolding wood for the beams. I used a simple Dremel DSM20 for this but any circular saw will do. Lastly I’d cut the pinewood beams. I used a router to make a radius on one side of the beams. This radius ensures that the beams are easier on the hands.
With all the pieces cut, I drilled the holes in the backplate, frontplate and rails. Next I assembled all the parts. Starting with the backplate and the beams. I used a 3mm drill before fastening the beams and the plywood with the twinfast screws. This avoids that the wood splits open. The beam and supportbeam were fastened with a single twinfast screw. Next I fastened the frontplate to the beams again using twinfast screws. To finish the hangboard I fastened the beams to the frontplate using the carriage bolts and wingnuts. Lastly I applied a transparent oil to the hangboard to provide protection It’s more pleasing to look at too.
Fastening the hangboard to the wall may differ from situation to situation but since we have concrete walls I used four large wall plugs (Fisher brand). The board was then attached to the wall using the lag screws with washers to protect the wood.
The hangboard proves to be strong enough for my son (he weights approximately 57kg). I tried it myself (I’m 80kg) but my fingers just aren’t strong enough to keep my weight. Nevertheless I’m confident that the construction is more than enough to keep a weight well over 65kg. As for aesthetics the board looks pretty good (for a hangboard that is).