Now that the frame is complete and ready to print, as seen in Part 2, it’s time to do the moving parts. This is a very good place to show you the Blender 3D Cursor in operation, because I will not be designing with exact dimensions, but rather with exact locations and approximate dimensions.
The 3D cursor is the thing that moves around the screen, when you click the left mouse button. You can place it with nice precision, when you use the views that are flat, ie. Top, Left, or Right, because then the cursor moves in only two dimensions. Placing the cursor in the User Perspective view is really hard, unless you snap the cursor onto something – most of the time it is not even possible. I’ll show you what I mean.
I will now try to take you through the design of the trebuchet which has been shown in Part I of this post. This description that follows is actually aimed at showing you how in Blender all design is based on very simple starting points. The trebuchet frame is based on a single circle, the hole in which the main axis will eventually be placed, with a diameter of one Blender unit. Around this circle I based an octagon with the same center, but with a diameter of three.
This blog entry comes from Copenhagen. Our university, Haaga-Helia, has for ten years been involved in an international IT seminar for students, and this year’s seminar is #9 in the series (2013 was such a messy year for all participating universities that we decided to skip it that year). The other schools are Cphbusiness in Copenhagen, Universidad Europea de Madrid from Spain, and a new entry this year, HES-SO from Switzerland.
The structure of the seminar is always the same, as is the theme, “How to be an IT professional”. The seminar runs for a week, with every school hosting a day. Usually there is a lecture in the morning, and then a workshop before lunch to be continued into the afternoon. Many times we have had social events and a business visit, for example last year in Helsinki we took the Spårakoff beer tram and went to Remedy Entertainment to see how games are made. Continue reading Greetings from Denmark→
The weather kept up but there was a brisk breeze as we headed out to the Messe for the final visit. By now we had been to all the halls and seen all that was available, and the purpose of this day was to go and check out some things again.
I spent two hours checking the multitude of Chinese thingamajigs and whatchamacallits, most with Bluetooth if not gigabit LAN. It’s amazing what they have come up with, and were I in the market for importing USB connectors or cabling or selfie sticks, I’d have been in heaven. It was interesting as it was, don’t get me wrong. Like this Taiwanese window washing robot.
For some time now, I have been thinking of printing a trebuchet. On Youtube you see massive trebuchets capable of hurling a flaming piano (!) to a distance of 200 meters, or trailer-based versions used in pumpkin-throwing contests. This sort of machinery is clearly beyond my MiniFactories and even the Print-Rite model I was handed the other week, but a small one should be within reason.
As always I first tried an unstable one before hitting on the right design. The first version seemed fine in Blender, and I was thinking of creating a system with many separate parts to maximize size. The first version looks like this in Blender:
Gears are an interesting set of things to print. With gears you can make all kinds of things, and if you run an Arduino or a Raspberry Pi, you can significantly extend the toolbox when you can design custom gears. Of course, on Thingiverse, you have literally thousands of gears to pick and print from, but surely you want to make your own?
Blender itself has a Gears add-on, which you can install merely by downloading it and using the Install Add-on feature in the User Preferences. It adds a new type of meshes to the Add Mesh menu, namely Gears. In it you have Gear and Worm Gear, of which I will leave the Worm Gear for later.