This weekend just gone I visited the Powerhouse Museum in Sydney. Currently, there is an exhibit of several Egyptian Mummies from the British Museum’s collection. The exhibition wasn’t too bad and there were plenty of amazing bits and pieces on display. (The British Museum has “acquired” quite a collection of Egyptian antiquities).
Personally, I don’t quite get the appeal or understand the need to know such excruciating detail about how these people lived and died 3000 years ago, but its not everyday you get to see something that old. (Will people in 3000 years really care so much about how we are currently living?) Anyway, entry into the exhibit also gave access to the rest of the Museum.
If you’ve never been to the Powerhouse Museum, its Sydney’s museum dedicated to technology and applied science. I’d recommend visiting the museum if you’re ever in Sydney. If you’ve stumbled across this website, then I’m sure you’d be interested in the museum’s exhibits. Continue reading →
So far its been almost two weeks since I started using PETG and I’ve resolved a lot of the problems I was experiencing in my last update.
Bed Adhesion Perfected
My prints are no longer becoming completely stuck to the print bed. Now, I can easily peel the completed print from the bed once it has cooled to about 45°C. Removing the print is almost trivial in how easy it is to do.
To achieve this, the first layer settings are very different to that of ABS. Smearing the filament into the bed is the wrong approach. It leads to nozzle jams and adhesion that causes the print to break. Instead, I have found that a first layer height of 105% of first layer thickness is needed. The extruded filament literally is laid down onto the bed. It looks as if it has no chance of adhering, however it is working perfectly.
Return of the Jam
After waxing lyrical previously how I’d fixed my nozzle jams by increasing the first layer height and reducing print speed, nozzle jams returned. They became quite significant. I was about 50% of the way into a print when they began occurring and I tried to salvage the print. Each time a jam occurred, I’d pause, remove the filament, cut the damaged filament off and insert it again and continue on. Continue reading →
I haven’t done a teardown in a while so I thought I’d share the insides of panel meter I recently found at a Sunday morning junk market for $5.
Below is a panel meter that has been used in some sort of industrial process. It was manufactured in 1980 by Kuwano. I’m not quite sure who the manufacturer was – the company’s logo is not easy to read but it might say, “Aumano”. What caught my attention with it was that it includes high and low needles as well as indicators and relay outputs for the high and low limits.
I have just begun printing from a brand new roll of PETG filament on my Da Vinci 1.0. Several reviews suggest that PETG is almost a hybrid of ABS and PLA.
I’ve used ABS for the vast majority of prints and whilst I have my printer printing ABS well, some of its properties frustrate me. They are; smell, poor bed adherence and warping.
PETG is meant to address the issues of warping and bed adherence.
My first print with PETG has been somewhat successful. Bed adherence was excellent; the filament printed straight to a clean glass surface that was heated to 80°C (the nozzle to bed clearance is 0.25mm). There was no warping or lifting of the print at the edges and the smell was not noticeable (I’m sure just because I can’t smell anything doesn’t meant there are emissions that are not good to be breathing).
Last week, Aldi was selling a torque wrench with 1/2 inch drive for $29.99. I was a bit shocked when I saw the price because that’s not a lot of money for a torque wrench.
Honestly, I was a bit skeptical of its performance and a bit hesitant to part with $29.99 for what could be a dud. However, I did go and check it out in-store before completely dismissing it. The wrench came in a durable molded plastic case and came with an extension bar, 17mm, 19mm and 21mm sockets. I was sold, so I shelled out $30 and brought the thing home.
First impressions are that its not too bad. I’m no torque wrench expert however the quality seems pretty reasonable for its price. The ratchet works, the ratchet is reversible and the whole device feels pretty substantial. Its stated specifications are; adjustable range of 28-210Nm with an accuracy of ±4%. The measuring scale is a bit difficult to read because of the bright chrome finish, but I think this can be fixed by rubbing a paint marker over the indentations and wiping of the excess paint to emphasise the scale markings.
However, is it accurate? There’s not much point tightening bolts to a required specification if the wrench itself is way off the mark.
Apologies for the long wait between drinks folks, however a few things have been taking up my time; supervising 2 construction projects at work, then starting a new job, as well as buying and selling an apartment.
To sell my apartment, I’ve had to pack up my 2nd bedroom that doubles as a workshop to prepare for all the house inspections. People who don’t spend their time building, making or tinkering with stuff wouldn’t have a workshop as a high priority on their list of “Pros”. A friend agreed that I needed to pack up my workshop, he politely noted, “It would be hard to visualise that room ever being a nursery”.
So, I’ve been without a means to build, break, print or experiment with stuff for about 8 weeks now and it has been frustrating. To fill the void, I’ve spent a lot of time learning some new things from YouTube and reading other’s blogs. Below are some of the more interesting or less well known content I’ve found. Continue reading →
Happy New Year everyone. A quick post to get the new year started and I recently scored a few HP5082-7340 hexadecimal LED display chips. These are cool looking integrated hexadecimal LED displays measuring 10mm wide and 14mm high with standard 2.54mm pin spacing.
A great feature of these displays is that each chip contains all the decoder and driver logic internal to the device. Unlike a Texas Instruments TIL302 which requires a BCD to 7-segment display driver chip such as a SN74LS47, the HP5082-7340 requires 5V, 4x pins for a BCD representation of the character, an enable signal and an optional display blanking signal.
Additionally, there is no need for current limiting resistors, this is handled on-chip.
To demonstrate how the display looks, a quick breakout was made, a schematic of the circuit shows the simplicity of interfacing one of these display chips to a microcontroller.