We had a new member join us on Saturday, Alex. He’s fifteen, but has already built his own robot:
It’s powerful, capable of roaming around paddocks and the countryside on all terrain tyres, has a speech synthesis engine on board, loads of LED lights to come in handy with debugging, and some powerful headlights for night driving.
We spent a while going through what’s involved with obstacle avoidance, and different strategies for slowing down and dealing with data.
Loads of fun, and fantastic to see workmanship like that. Congrats, Alex!
Hi All, Gav here. Just wanted to share this post from our new member, Rob D. Looks like the start of a fun project.
Had a great night at the space Saturday night and kicked off a project. Plan is to build a robot with tank tracks. Cut and printed some sprockets which I’m very happy with. I want to use the Pitsco TETRIX tank tracks but I will need to scale up the drive sprocket from 65mm diameter to about 120mm while keeping a consistent tooth profile and also making sure the first and last cut teeth line up. I made a part model in Solidworks and I’ll use a design table to scale up the sprocket to the larger size. Saturday was the first time I’ve worked with a 3D printer and a laser cutter.
Bottom right was the first print. Gav showed me how to scale it to 80% and also to shorten it in the z axis as a test run. Top right is 100%. It’s about 65mm diameter. On the left is the one cut on the laser. The key take-home was that in both cases the tooth profile looks (as far as I can tell) consistent for all teeth. I can see a faint line where the laser started and finished it’s run along the teeth but it’s so minor it looks inconsequential.
Thanks guys for showing me the ropes!
Another beautiful lasercut project from Max:
I (Gav) started playing around with lasercut Penrose tiles, mathematically very cool since they never repeat, even on an infinite plane. The downside is they are pretty fiddly to use and assemble since you have to follow the ‘rules’ about how they can join.
We then started trying out Girih Tiles, which are used in traditional Islamic architecture. Max made this beautiful layered set by using paper on acrylic as a mask for spraying the paint:
They’re astoundingly fun to play with, and I can see we’ll be making a lot more soon.
You can also see some other lasercut Girih tiles here:
Max just finished a wonderful project for his Niece, Zara:
“This is a castle with 300mm high floors to suit most dolls and doll house furniture. It packs up flat except for the corner braces and you can make as many walls and floors as you like for a larger castle. ”
The design is up on Thingiverse for people that want to make their own:
The big CNC is starting to work pretty nicely. There’s some backlash issues, and it’s not going to make a perfect jigsaw anytime soon, but good enough for a lot of stuff.
Cutting the parts carefully. This is a long and noisy process. Basically you’re putting a chunk of wood in there and removing everything that’s not the part you’ve designed:
Test fitting the parts together. Gluing was done with a jig to hold everything flat and screwed in place:
Voila! A completed part for Nick’s Sand Table:
The wood is Merbau, a nice hardwood which is cheap and pretty easy to work with.
Some specs and info on our wiki here, for people that want to know how to use it:
Special thanks to Kean, Ada, Nick and everyone that helped get the big CNC running again last night.
The results came out pretty nicely (very rough cut of some text):
Specs and some instructions on the wiki for people that are interested.
And on SundayI had a crack at making a box to hold a wax tablet to practice cuneiform:
On Wednesday a few of us went out to view the last transit of Venus for the 21st Century. Venus was passing in front of the sun, and we were determined to catch a glimpse of it!
I was hoping to use this as my ‘Science Tripod’ for the day, with batteries, motorised movement and inverter for charging the laptop, but sadly it had a mechanical failure about an hour before we were due to leave. Grabbing duct tape, we improvised!
Fortunately everyone else came well prepared too:
The night before, when it looked as if the weather in Sydney would be terrible, we’d headed over the Blue Mountains to Bathurst and spent the night. Getting up early we headed to Mt Canobolas, on the grounds that higher was better. When we got to the summit it didn’t look too good. In fact we couldn’t even see the top of the radio tower we’d parked at!
Fortunately moving down the mountain a bit worked well, and we were able to get some good shots of the transit starting. Everyone was eventually able to see the transit with their own eyes, and also get some shots with their cameras. Success! From this point on anything else was a bonus.
We eventually jumped back in the car and started to head down to Yass, in the hopes that it was clearer out there. It started to get bright in patches on the road, so we got into a routine of pulling over for a few minutes, frantically setting up tripods and cameras, snapping for a bit, then packing everything down and running off to the next patch of sunlight when the clouds moved in.
We were lucky enough to get a few more good shots in, before the clock told us that Venus was well and truly gone, even if the clouds opened up now.
Here’s some of our images:
More images can be found here:
and Tim made a time-lapse of the day here:
Everyone had a fantastic time, and we’d highly recommend doing something like this in the future. Keep your eyes out for the next major eclipse, Nov 14th 2012 in Carins!
You might have seen an unusual plastic called polycaprolactone, which also goes by the name of Polymorph, Polycap or Plastimake. It’s small white pellets of plastic that will melt in hot water and can be shaped like plasticine. When it cools, it’s rock hard and perfect for engineering applications.
The trouble up till now is that it’s quite hard to get a hold of decent quantities of it in Australia. But it turns out there’s now a local supplier, called Plastimake:
If you’ve used polycaprolatane before, you should check them out. In addition to being local and quite cheap, they’ve spent a lot of time making tutorials on what you can do with it. The roses are my favourite: (Pic shamelessly stolen from their site)
and there are loads more examples here: http://www.plastimake.com/examples
So, we put in an order for a bunch of plastic, and in addition to being very prompt, inside the box a freebie sample of colouring material, and also this drawing:
How awesome is that?
The image was made by the very talented Alice Caroll, who’s website is here: