Thursday, 26 May 2016

Yes, people really do 3D CAD on Mobile devices!

I've been using OnShape as my primary 3D modelling package for some time now - both for designing parts for my hobby 3D printing and laser cutting, and also for general work (engineering) applications.

You can check out my early quick review here: - and the more I've used it, the more impressed I've been.

I use OnShape primarily via Chrome browser on a Windows laptop (work or home) or a Windows tablet or a Chromebook, but I also use it on my Android tablet (and it is also available for iPads). What surprises many people is that OnShape can truly be used for full-featured 3D modelling (not just viewing) on mobile devices.

OnShape have just released a blog post "YES, PEOPLE REALLY DO CAD ON MOBILE!" which gives some actual statistics which demonstrate that people really are using OnShape Mobile for modelling and design, not just viewing. While browser use is an order of magnitude bigger than mobile use (as you would expect), it is interesting to note that the usage patterns mimic each other on both platforms, except on weekends and holiday periods, where mobile use sees proportionately less of a dip than browser use - indicating it is the "platform of choice" for many users when you are away from the office.

If you are looking for a capable low-cost (free!) 3D modelling package for your hobby use, you really need to check out OnShape, if you have not done so already!

Thursday, 14 April 2016

Some reasonable planetary images with my ZWO ASI120MC camera

While seeing wasn't great from my home in inner-western Brisbane last night (13 April), it was nice and dark and clear, so I set up my Meade 200 mm LX90 (GoTo Alt-Az mount) with ZWO ASI120MC (one-shot colour camera), and fired off a few 30-second video captures with FireCapture, and then stacked and sharpened in AutoStakkert to get the best images that I could.

Jupiter was nice and high in the sky:

And the Great Red Spot came into view nicely later in the evening:

Mars and Saturn were fairly low in the sky, sitting in the sky-glow of Brisbane City to the east (and directly over my roof), so while I'm fairly happy with these shots, I hope to get some better images in a couple of months when they're a bit higher as well.

My best videos were taken without a Barlow - I just couldn't seem to get quite as sharp focus with my 2x Barlow. Maybe I need to try focussing with a Bahtinov mask on a nearby star before pointing at my target?

These are the best of last night's efforts - they may not rival Hubble, but I'm pretty happy with them.

Thursday, 31 March 2016

Use your phone / tablet as a 3D printer?!

This 3D Printer concept uses your smartphone or tablet as the light source to cure photo-resins.

Virtually silent, runs off 4 x AA batteries.

And the best bit?

It's only $99 for the printer (build volume: 76 mm x 128 mm x 52 mm; vertical build rate of about 10 mm/hour or so), and $15 for a 100 mL bottle of resin (a range of hard and flexible resins available); prints with virtually no waste.

I want one!

It sounds too good to be true - I'll believe this is a real thing when I see one actually working.

(But to quote “The X-Files”: I want to believe!)

Thursday, 17 December 2015

Netflix Socks - automatically pause your binge-watching if you fall asleep!

So the Paris Climate Conference went well, and we have apparently solved the problem of global warming - what's the next major problem humanity should tackle?

Well, it's obvious really:

You're binge-watching your favourite TV series on Netflix, you fall asleep, and you wake up two hours later having missed a couple of key episodes.

The good people at Netflix have a simple solution that you can make for yourself:

Netflix Socks

These amazing socks detect when you have dozed off, and send a pause signal to your TV / set-top box. A bright LED flashes a warning, so that you can press the over-ride button if you are awake and just happen to be sitting very still.

You can install the Netflix Socks adapter into your favourite pair of comfortable TV-watching socks, or you can download the knitting patterns to theme with your favourite Netflix shows, including Bloodline, Unbreakable Kimmy Schmidt, BoJack Horseman or House of Cards.

The parts list is pretty simple:
You should be able to make yourself the adapter for a few dollars, or you may even already have most of the parts if you have tinkered with Arduino before.


Friday, 27 November 2015

Survey results: "Color Vision and the Efficacy of EnChroma Glasses"

Blake Porter has published the results of his on-line survey into the efficacy of EnChroma sunglasses as an aid for compensating for colour blindness. He previously published a fantastic piece entitled "What is color? Enchroma glasses, neuroscience, and the mystery of color", which I mentioned in an earlier post - do take a look at this article, if you have not already done so - it is a fascinating read and very thought-provoking.

A total of 406 people responded to the survey, so it is a useful sample size. A significant majority of respondents were males in their twenties, which is not really surprising - males are more commonly affected by colour blindness than females, and the poll was conducted as an on-line survey, so some internet-savvy was required to even be aware of the poll, and then to complete it.

And the results of the survey?

In a nutshell - they really do work, for the majority of users.

You really need to read the whole article to get the full picture, but the Conclusion sums it up pretty well:


What we may conclude with some certainty is that people who have a language full of color words, are color blind, and then use corrective means to aid their color blindness, new conscious color perceptions are near instantaneous, possibly due to the broad processing capacity of the visual system, and there seems to be an intuition present, possibly due to knowledge from language, allowing these people to correctly assign their new colors with language. Overtime, their processing of new colors and their ability to discriminate across colors will be improved and the time course of this may be age dependent.

The work by Blake Porter is licensed under a Creative Commons Attribution-Non Commercial-ShareAlike 4.0 International License

Thursday, 26 November 2015

Ultrascope - Open-Source Automated Robotic Observatory

Here's one for the Geeks and Makers:

Ultrascope - an open-source Automated Robotic Observatory:

The Ultrascope project (currently in pre-Beta) aims to develop a kit-set robot telescope (or ARO - Automated Robotic Observatory), that will allow amateur astronomers to contribute to citizen science projects for a radically reduced cost - e.g. asteroid hunting, etc.

The first project is the Explorer Series Ultrascope, which is a 90 mm (3.5 inch) reflector ARO that is able to conduct celestial photography and photometry. The kit will be released as open-source plans for 3D printing or laser cutting, paired with an Arduino controller and a high-pixel smartphone (eg Lumia 1020 with 41 Megapixel CCD).

They are also working on a 200 mm (8") version, the Odyssey.

Tuesday, 27 October 2015

Things I wish somebody had told me when I started building a RepRap 3D Printer

Or to be more accurate:

Things people told me which I wish I had listened to more attentively when I started building a RepRap 3D Printer

My RepRap is a 1st-generation Prusa Mendel which was pretty much the bee's knees in affordable DIY 3D printing back in August 2011

I bought a kit of plastic bits and "vitamins " (nuts and bolts etc) on eBay, and self-sourced all of the other components (stepper motors, electronics, etc). The buy-and-build process was itself instructional (and fun!), and about two months after construction commenced, I had a workable 3D printer in operation.

The Prusa Mendel and its predecessors truly embodied one of the core philosophies of the RepRap Project: RepRap is short for Replicating Rapid-Prototyper; that is, the 3D printer can (almost) build itself. To this end, the maximum possible number of components were made from 3D-printed plastics, right down to the z-axis couplers and axis bushes.

These days, if you start a similar adventure, you are more likely to try building a 3rd-generation Prusa i3 or similar. To the uninitiated, it is hard to see how the Prusa i3 is directly related by just two generations from the Prusa Mendel, but for those of us "in the know", the family heritage is obvious.

1st-Generation Prusa Mendel (Ref: )

Current-generation (October 2015) Prusa i3 (Ref: )

The Prusa i3 (and other current-generation 3D printers) embody the accumulated learnings of both the originators of the RepRap Project, and thousands of RepRappers. The kits are cheaper than ever, but use a variety of materials and forms of construction, with less of an emphasis on using 3D printed materials for all components, for reduced cost and increased reliability / performance. (Steel or aluminium are just better at some jobs than plastic!)

Some may argue that this somehow "dilutes" the essence of RepRap, but for me, it makes the goal of ownership of an affordable and reliable 3D printer far more attainable, while still allowing freedom for experimentation and development/. (One of the great advantages of going down the open-source path, rather than buying a proprietary model, is that you can modify and upgrade your machine as often as you like, sharing your experience with that of many other like-minded individuals, so your humble beginnings can evolve into something better and better.)

In no particular order, here are my main learnings over the past few years:

  1. You NEED proper mechanical linear bearings on all axes - 3D-printed PLA bushings are a nice philosophical concept, but realistically, the motion will be MUCH smoother and jitter-free if you install linear bearings (LM8UU or similar). Do yourself a favour, and buy a kit which uses them (most modern kits do), of else, print yourself some replacement carriage parts which are designed for LM8UU bearings instead of PLA bushings, and install them as soon as possible.
  2. You NEED a heated print-bed. Yes, it is possible to print on painter's tape etc, but life is MUCH easier when you have a heated print-bed. And this leads us to ...
  3. You need a power supply with heaps of capacity. I started off with a hacked ATX power-supply which I thought had enough capacity (16 amps @ 12 volts), and while it did work, it turned out that it had trouble maintaining full supply voltage under heavy load. I have replaced it with a more robust true 15-amp sustained (18-amp peak) power supply , and it runs much better now.
  4. Get rid of the 3D-printed Z-axis couplers, and replace them with engineered metal shaft couplers. You can pick up 5 mm x 8 mm aluminium couplers for a couple of dollars on eBay, and I have found that they grip the smooth stepper motor shafts much better than a plastic clamp - of which, I printed and installed quite a few design variants (This is particularly important for a machine like the 1st-gen Prusa Mendel where the X-Axis is suspended from the Z-Axis motors; possibly less of an issue on the Prusa i3, where the motors are at the bottom, so the couplers are in compression, not tension.) They also run MUCH smoother, as they are able to take up the angular and offset errors between the motor and the threaded rod with a more reliable spring stiffness than the plastic clamp couplers.
  5. Get yourself an LCD Controller, like the RepRapDiscount Smart Controller - this will allow you to print without a computer attached, freeing up desk-space, and also removing one link from the failure chain. These can be bought very cheaply on eBay - highly recommended.
  6. If you are running an old-generation plastic-bodied print-head (PTFE and / or PEEK), replace it with an all-metal print-head with a heat-sink and fan. These run MUCH more reliably than the old PTFE-bodied print heads, and are also much more physically robust, and are able to withstand the occasional (and inevitable) print-head crash.

My 1st-generation Prusa Mendel has had all of the above upgrades applied to it - it is still physically the same arrangement as it stared life, but it now prints much more reliably and smoothly (and faster) than it did before. Dare I think that the "tinker and upgrade" phase has ended, and my RepRap will now enter a long mature life of production printing without significant additional upgrades?

(Naaah! Who am I kidding?! Of course I'll keep upgrading it - just watch this space!)

(As in all matters of opinion, some of these points may be controversial - for example, I am sure that some people have printed very successfully with 3D-printed PLA bushings, and continue to do so, but in my opinion, you are more likely to print successfully, and much more quickly, if you use linear bearings on all axes.)