A couple of weeks ago I have finished building the latest version of my CNC machine. In size, this new CNC machine is a few cm bigger than the typical small square IKEA tables. The purpose of building it, was to have a test-bed for improvements, but also to have a CNC at home for making parts for my future projects.
Some of the improvements I have in mind are the integration of more tools for my CNC machines, like laser engraver, tangential knife, etc. Currently the supported tools are Kress spindles and also those typical Chinese…DC powered…air cooled…shitty spindles for milling, as well as Mk8 extruders for 3D printing.
Another thing that needed testing was some new features and improvements I was planing for the firmware of the controller and the controller itself. One of them was to improve the communications between the PC and the controller, by implementing a command queue on the controller. This allows the CNC machine to execute g-code commands one right after the other. In previous versions of the firmware the controller was executing a command and then it was waiting for a few milliseconds for the next command to arrive.
So after implementing this command queue, I had the opportunity to also do another sub-project I had in mind for quite some time, which was to make the CNC play music. I wrote a small python script, that translates note-duration pairs into feed-rate and distance pairs and generating a g-code file that when executed makes the CNC sound like a playing music. I uploaded a small video of a little demonstration on YouTube, which you can see bellow.
Tsoureki is a traditional sweet bread we make in Greece during Xmas and Easter. It is a cousin of challah. It definitely is braided, which is something common. But we put milk instead of water and knead it with butter. A major difference is that we add some spices, which are traditionally orange zest, ground kardamon seeds and ground Mahleb seeds (in some parts of Greece they use ground resin from Mastic trees instead which is a completely different aroma).
1Tbsp Orange zest
4g Ground Kardamon seeds
4g Ground Mahleb seeds
1Tbsp oil (Sunflower or other “light” not too aromatic oil, definitely NOT olive)
1Kg Flour (Prefer a strong flour with high gluten content)
100g Fresh yeast (or the analog in dry yeast)
1 Egg yolk to brush
1. Mix sugar, orange zest, spices, salt and oil in a mixing bowl.
2. Heat the milk to lukewarm.
3. Get some of the milk and dissolve the yeast.
4. Bring the rest of the milk to simmer and then add it to your Sugar mix and stir them together. This should warm up all these ingredients.
5. Add the dissolved yeast.
6. Add the eggs and continue stirring. You should have a slurry by that time.
7. Mix in the flour gradually. This will get you to a very wet very sticky dough.
8. Melt your butter and start adding it gradually to your dough, while kneading-folding. At some point the dough will absorb all the butter and stop sticking to your hands or mixing bowl. Do 3-4 more folds after that. Don’t expect your dough to be too firm. It’s fine.
9. Cover the dough and let it sit for 2-3 hours or until it is doubled in volume. Ideally leave it overnight.
10. Form the dough into braided loaves. Brush them with egg yolk and let them rest for an hour or so. We usually put some almonds as decoration before baking (Blanch the almonds to get rid of their skin if you do that, to make them look nice). Especially for Easter some decorate them with Easter eggs.
11. Bake them at 170-180 C for about 40 minutes.
During the last 12 months I have designed and built a big CNC milling machine and 3D printer for a customer. The maximum work area of the machine is a bit more than 1m by 1m in X and Y axis and up to 30cm in Z-axis. The Z-axis carriage can accept either a spindle for milling or an extruder for 3D printing.
It was a good opportunity to consolidate things that I learned by building my small crude CNC machines and to go a step further. Currently I am designing another version with similar design, but with smaller dimensions (roughly about 40x40x20 cm travel in X-Y-Z axis respectively). So about 60% smaller than that big one. Also planed projects are improvements in my USB CNC controller and it’s software, as well as some more tools to complement the spindle and the extruder.
Bellow you can find some pictures of during the construction and the finished product, as well as a video with the device cutting some letters on corian.
A couple of days ago, I needed to cut 2 pieces of 8mm OD steel shaft, in order to make the Z-axis guides for my CNC Mk3.
I could probably cut them using the hacksaw or even by using just the dremel with a disk cutter. I indeed used the dremel with a disk cutter, but in conjunction with that, I decided to put the steel rod on my cordless drill and spin it while cutting it. Just for the fun of it and to make the cuts as straight as possible.
One of the upgrades I am making to my CNC is the change of the linear guide system, from a edge track with V-groove bearings like the one shown in Picture1, to a 8mm steel rod with LM8UU linear bearing.
The 8mm steel rods serve as the track for the LM8UU linear bearings and need to be secured to the CNC usually from their two ends. Given that the 8mm rods are have a round “profile” it is not easy (or nice) to just drill them and secure them with a screw. Instead they need some kind of a holder Like the one in Picture2, which is screwed on the frame and then the the 8mm rod is attached to them. You can buy one of these from ebay for a couple of EUR, but that has two disadvantages, first that you will have to wait several days for them to get delivered and second and most important…you loose all the fun of making them yourself. Although it is not too much fun if you don’t have the right tools (like a descent standing drill for example).
So anyway, I decided to design and build my own holders, despite the lack of any standing drill in my toolset. The initial design is shown in Picture3. In the design you can see a large 8mm hole, where the steel rod is inserted. There is a cut parallel to the 8mm hole, which allows the hole to be tightened using a screw, in order to tightly secure the steel rod. On the left side of the image you can see where that screw is fitted. The bottom half of that hole is threaded (M3 size thread). The other two holes on the right of the picture 3 are for fastening the holder on the frame.
I made the first 4 holders, which are for the 2 steel rods used for the Y-axis, but later on I decided that I could make the part a bit shorter and get rid of the one of the two holes used for fastening it on the frame.
I start making the part by cutting a 25mm long piece of 15x15mm solid aluminum profile. I use a small saw for metal to do this. Then the centers of the holes are marked with a caliper and pencil and finally with a punching tool.
I then use my improvised jig that uses a dremel and a dremel router base, in order to be able to make the holes as perpendicular as possible to the part. Unfortunately the dremel router base is not as precise as I wanted, but the result is acceptable I believe. One of the two handles of the dremel router base is a screw, which allows you to lock it to a certain depth. I noticed that it improves things a bit if you make this as tight as possible (just to the point that you can barely can plunge it down).
The holes are initially drilled to 2.5mm. After that the holes are widened to 3mm, except the hole that is used for the screw that squeeze the “jaws” of the part, which is only drilled halfway to 3mm. This is done because the other half will be taped for the M3 threads. The 3mm is the maximum I can do with my dremel. So the jig is useless from that point on and I just use a simple hand drill, to widen the big hole for the 8mm rod from 3mm to 4mm, then 5mm, then 6mm, then 7.5mm and finally to 8mm. Luckily the initial 3mm hole is a good guide and the hole remains perpendicular (at least perpendicular enough).
Next I use again the hand saw to cut the slot parallel to the 8mm hole and finally I make the M3 threads for the tightening screw.
After a final sanding and filing the holder is ready!
This is the first holder I made, using the old design with the 2 holes for fastening to the frame.
Lately I wanted to connect an external monitor to it and use it for dual display. I have already found a nice utility called “Screen Spanning Doctor” which seems to be reconfiguring something in the OSX and the Firmware(?) of the computer and allows you to use external monitors for dual display.
When you apply this configurations with the above utility, you are also able to set the resolution of the external monitor to something higher than 1024×768. Which is great also. My problem was that when I connected a monitor that supported 1280×1024 for example, I was not able to set the resolution to this setting. In spite that the iBook was giving me this option. I tried that with a Philips and also a Samsung TFT display, as also with a cheap CRT display. After some search in the net, I found that some guys where able to do that with some Dell displays. While there where too few sites referring to problems like the one I had.
Another thing I noticed was that many people where trying to work with their iBook in what is called “clamshell mode”. Working with the laptops lid closed. Any iBook user knows that when you close the lid the computer goes to sleep. And there is no option to disable that in OSX. Though there are some tricks that may work and some of them are applied from this “Screen Spanning Doctor” utility.
So here is my approach to clamshell mode:
Before a couple of months my iBook’s hard drive failed. I bought a new one and I disassembled the iBook to replace the failed HDD. Everything went OK. But as always I forgot something. What I forgot to put was a tiny magnet! Which was located under the position where the “left arrow” key is. Under the upper metal cover of the inside of the laptop. This metal cover is what you see if you lift up the iBook’s keyboard. Apple has this magnet there as a replacement for one of the screws that keep in place this metal sheet and also to activate the “sleep switch”, which is located behind the TFT screen. Indeed in this generation of the iBook, if you take a magnet and wave it in front of the TFT screen (warning don’t scratch the screen 🙂 ), you will see the iBook going to sleep :).
So my iBook is now an insomniac :D.
Anyway, DON’T TRY THIS AT HOME! YOU MAY DESTROY YOUR IBOOK. Not that I care…but…
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There is a perl script I wrote to keep some traffic stats for my home router. It is something like mrtg, but more minimalistic.
The strong point of this script is that it doesn’t need configuration like mrtg. It discovers automaticly your network interfaces every time it runs. Well at the other hand it is not as powerful as mrtg is.
Ofcourse it uses rrdtool of Tobi Oetiker (the creator of mrtg).
So I am posting it here in case someone else wants something like that. It should run in any unix like system with snmpd running. If someone has an idea for any additional features or has a patch or even needs some help with setup, feel free to mail me. Find my email in my contact section of my homepage.
Διάβασα μόλις ένα άρθρο, για το LHC (Large Hadron Collider), ο οποίος πρόκειται να ολοκληρωθεί και να μπει σε λειτουργία του χρόνου. Το LHC είναι αυτό που λέμε η τελευταία λέξη της τεχνολογίας…είναι όπως λένε η πιο μεγάλη, πιο πολύπλοκη και πιο τεχνολογικά εξελιγμένη μηχανή που έχει φτιάξει μέχρι τώρα ο άνθρωπος. Πιο συγκεκριμένα είναι ο μεγαλύτερος επιταχυντής σωματιδίων και φτιάχνεται στο CERN, εκεί παρέα με τους άλλους επιταχυντές σωματιδίων.
Φανταζόμουν λοιπόν (ίσως επηρεασμένος από μια συζήτηση με συναδέλφους στο γραφείο), άντε και φτιάχτηκε…άντε και μπήκε σε λειτουργία. Έστω ότι κάνουμε ένα πείραμα και ανακαλύπτουμε και κάτι πάει στραβά και αντί να ανακαλύψουμε την φύση κάποιου σωματιδίου, ανακαλύπτουμε πως σχηματίζονται οι μαύρες τρύπες…(εννοώ το διαπιστώνουμε πειραματικά…θεωρητικά κάτι ξέρουμε). Φανταστείτε την σκηνή…δεν θα καταλάβει κανένας τίποτα…ξαφνικά ζζζζζούπ!
Όλα αυτά βέβαια ανήκουν στην σφαίρα της επιστημονικής φαντασίας. Δεν συμβαίνουν τόσο απλά. Αλλά σαν ιστορία ακούγεται τραγικό. Τόσο παίδεμα, τόσοι πόλεμοι, τόση ταλαιπωρία, τόσος πόνος και φυσικά πού το πας το γεγονός και μόνο της έναρξης της ζωής πάνω στον πλανήτη. Όλα αυτά θα τα ρουφούσε η τρύπα σε μια στιγμή και ούτε που θα προλαβαίναμε να το συνειδητοποιήσουμε. Πολύ ωραία βάση για μυθιστόρημα επιστημονικής φαντασίας.
Για να σοβαρευτώ όμως λιγάκι…
Η συγκεκριμένη μηχανή είναι κάτι πολύ αξιόλογο. Θα βοηθήσει την ανθρωπότητα να μάθει πολλά καινούρια σωματίδια. Από ότι λένε η σχεδίασή της είχε αρχίσει από το 1950 κιόλας. Αυτό που μου έκανε εντύπωση είναι ότι είναι αποτέλεσμα συνεργασίας 80 κρατών! Για να δούμε τι γνώσεις την περιμένουν την ανθρωπότητα στο εγγύς μέλλον…
Ο server αναβαθμίστηκε. Η αλήθεια είναι ότι προσπαθούσα να κάνω αυτή την αναβάθμιση από την εποχή που ήμουν στην Λάρισα, αλλά μόλις προχθές κατάφερα να βρω driver για το DSL modem, ο οποίος να παίζει σε FreeBSD 6.0.
There is the post in the ueagle driver forum, with a link to the patch for FreeBSD 6.0.
Σκέφτηκα να το γράψω αυτό στα αγγλικά, μήπως και βοηθήσει κανέναν που ψάχνει να βρεί το ίδιο patch. :p
Μετά την αναβάθμιση του driver υπάρχουν και διορθώσεις σε προβλήματα του blog. Το blog πλέων δεν κολλάει μετά την αποστολή κάποιου comment. Επίσης κάποια comments δεν χρειάζονται πλέων έγκριση.
Επίσης…για όσους δεν το έχουν παρατηρήσει, το site έχει αλλάξει domain. Το url του blog από εδώ και πέρα είναι http://www.georgiadis.eu/~jpg.