Robotics on Sunday
Robotics blogger, Per Sjoborg, from flexibilityenvelope, is coming to visit us on Sunday the 20th. He is bringing the coolest pieces of consumer modular technology yet, Modrobotic’s Cubelets. I’ll be down from 2pm onwards if you would like to join us, or do any other kind of robotic hacking.
Tom
Laser Cutter
Edinburgh Hacklab is pleased to announce the arrival of a rather special bit of equipment, a laser cutter.
So what does one do with a laser cutter? It enables high resolution (0.0254mm/1000dpi) engraving and/or cutting of a wide range of materials including Acrylic, Crystal, Bamboo, Cloth, Fabric/Denim, Fiberglass, Glass, Laminated Plastic, Leather, Marble, Plastic, Paper, Rubber, Wood, MDF, Marble, Anodized Aluminum and Coated Metal.
Af
ter the initial setup was complete little time was wasted before lasering began!
Training for members will be taking place over the coming days and weeks, so expect to see some great stuff being made.
Enjoy the full installation process taking place in a time lapse video below.
CNC Milling ABS plastic (and outstanding issues)
Sacrificial wood clamps the piece so the cutter doesn't hit the steel vice. We have a new cutting lubricant in the bottom of the photo. A bottle of red helps the time pass.
Maria and I were working last week fabricating four identical complex pieces out of ABS plastic. Initially we though a lowish feed rate combined with a fast cutting speed would give the best results but actually that’s not true. ABS suffers from the material melting and reattaching tangental to the circular cutter, so the effect is that when you cut, you end up drawing frayed lines over the surface. This is particularly noticeable on 90 degree corners and in deep pockets (concave regions). The first fix we tried was running the same program a second time. This did improve the situation but not enough to give it a finished look.
CNC working again
New Oldham couplings for the Z and Y axis have been fitted. The X axis has not been replaced but it has also never been broken. We have the bits to fit the X axis, we can do it next round of breakages :p Slop and backlash have been greatly reduced, and the machine sounds smoother now.
I think we should not use the previous vice for gripping and instead get a new precision one. The old vice was too big, heavy and did not have parallel jaws when tightened. Recommended milling vices seem to use a totally different mechanism to ensure the jaws stay parallel under pressure, for example http://www.arceurotrade.co.uk/Catalogue/Workholding/Machine-Vices
Raft Race Report
It was Saturday morning, following a late night of raft assembly and a tight fit into the transport the Edinburgh Hacklab raft was at the canal ready for racing. During some pre-race testing there was a capsize with the two occupants going for a swim.
We went in the first heat against a very impressive raft built of thick plastic pipes and plastic containers. After an unsuccessful attempt to get 6 people on our raft, the crew was reduced to 4 (Gandolf, Martin, Tom D & Ceava). The raft made it to the finish at a steady pace with no mishaps, unfortunately behind the competition. 
As runners up we were to take up a place in the “plate race”. By this time the rain was chucking it down, and with spectators rapidly leaving a decision was made by organisers to merge the plate race & final.
After a crowded and splashy start the hacklab raft started
to fall behind. Whilst attempting some repositioning of the 3 crew there were “stability issues” resulting in a capsize. After a slightly “interesting” escape from under the capsized raft Peter requiring the services of the rescue boat, leaving Martin and Bart to continue. Unable to right the vessel they used it “upside down” and found it worked quite well!
Jane & Ceava took up an offer to crew a beautifully made raft using milk cartons for floatation as the original young Milk Carton Crew wanted a rest. They finished 4th whilst
the hacklab built raft finished 5th. Smiling faces all round, despite being cold and wet.
Great to see lots of us getting involved in the design, collection/donation of materials, build and paddling.
Photos on Flickr
We are already talking about next years design….
RepRap pen test
Here’s the machine from March’s RepRap build party, still lacking its extruder but joining our collection of robotic devices writing ‘hacklab’ at the lab. The machine belongs to Edinburgh University, but we’re helping to get it up and running so it can print a set of parts for the Hacklab’s own RepRap Mendel.
First CNC-controlled cuts on the mill
For those of you not following on the mailing list, this was the first live cutting done by our CNC mill conversion a couple of weeks back. Now we just need to complete the automation of the Z-axis, which is in progress.
Speaker Cabinet Progress
Made good progress on the speaker cabinet at the Hacklab last night, ably assisted by @tinyblob. Unfortunately, the screws I bought for the back panel are a few mm too short so I need to do some shopping. Getting close now, though.
I still need to chisel out pockets for handles on the accompanying 4U rack box but that shouldn’t take long.
Mill->CNC project
Martin and I worked more on the Mill->CNC project.
“We tried to get the Linux-based CNC software EMC2 running with the mill. The initial idea had been to use Jay’s ITX machine for this, but it turns out this won’t run the necessary realtime kernel due to not having a working local APIC. We had a dig through the cupboard for other machines but didn’t find anything usable.
Does anyone have something spare that could fill this role? It needs a parallel port (a real one, not USB), a working local APIC under Linux, and ability to run a recent distribution.
Alternatively there’s an older release of EMC2 based on Ubuntu 8.04 that might work on the ITX, I’ll try tomorrow night.” – Martin
Milling to 3 axis CNC project
This project has been a long term project nearly since Edinburgh Hacklab’s formation. The goal was to take the broken RepRap, and use its 3 axis stepper motors and electronic and fit them to a basic milling machine (Clarke CMD10 Micro Milling Machine). So far we have successfully made new motor mounts for the X and Y axis and fitted the NEMA 23 steppers to it. The stepper motors can now move the workpiece from electronic instruction.
We have postponed automating the Z axis. Many useful things can still be machined without an automatic Z, e.g. PCBs, sheet profiling. Also it does not make much sense investing more time into the machine until we know the X and Y axis will work as desired. While we know that the X and Y turn, we do not know whether they occasionally skip steps which would lead to loss of accuracy in the machine.
Our focus currently is building the tool chain which turns graphical representations of objects (CAD) into lists of machine instructions (G-Code). This process of instructing a machine to cut according to a technical drawing is known as computer aided machining (CAM). The installed RepRap Arduino electronic controller is already a G-code interpreter. So we are looking for an affordable CAD and CAM software solution (preferably open source). Gareth has suggested http://www.heeks.net/ which seems to tick the right boxes.
There are still some more minor issues to resolve before we can try out heeks. Martin found a laptop for use to use with the machine, but the wi-fi does not seem to work. Before we can install any software on the machining laptop, we need an Internet connection. The machine, to minimize dust contamination, is located as far away from our computers as possible, thus complicating setting up a network connection.
Tom Larkworthy
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Hacklab status: Closed :(
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- @SkyscannerJobs sorry to disappoint, but we're now doing software night on Thursdays.
- New blog post Can’t wait for the Raspberry Pi? Hack a router!, read it here: edinburghhacklab.com/?p=861
- eggfriedrice One repaired scope at @edinhacklab. No more magic smoke/smell! twitpic.com/9lgsl0
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