What? Printrbot Prep

 
   
        

What worked:

+ Kickstarter. The Printrbot story is quite interesting, as Brook Drum set up a kickstarter campaign to fund an initial run of ~20 3d printers @ $500. but managed to sell over 1500 in 1 month! I actually bought a Printrbot+ 'reward' from a 'backer' (Matt), via the printrbottalk forum, about 3 months after the kickstarter 'funding' round ended, thinking that delivery was just around the corner. That was over 5 months ago, and I've only just received it!
+ Digital calipers from Ebay, £20 inc postage (description was: 'Gemred Large Display 6in 150mm Veriner Calipers with Case'). They appear to be good quality, they feel solid and are all metal. On the downside they have imperial divisions.
+ 880g of loose multi-coloured PLA from Faberdashery, £36 inc postage. (£41/kg!). It measured 2.83-2.91mm across 10 random samples and appears very consistent. It ,might be expensive but the whole package appears very high quality, from the nice box, red tissue paper, ziploc bags and desiccant to the neat cable tying into bundles.

 + 2.3kg of spooled Natural PLA from RepRap Kit, £63 inc postage (£27/kg). It measures 2.81 - 2.9mm across a few measurements of the outer layer of the coil. The spool seams nice but the packaging's not great.
+ LED strip from Ebay, £1.40 inc postage (unbelievable price, description was: 'New White 30cm 18 SMD LED Flexible Strip Light Car Van 12V custom lighting' in case the link breaks
+ Power supply from Ebay, £21 inc postage (description was:'12V 30A 360W Switching Power Supply Driver For LED Strip Light Display 220V/110V'. I haven't powered it up yet but the size, price and form suit this project well. Hopefully it's reliable enough.
+ Matt driving an over 4 hour round trip to hand deliver the parcel (taking it out of Parcel Force's unreliable hands) Thanks Matt!

What didn’t:

- Power supply packaging - it arrived damaged but should work ok.

- Printrbot taking 8 months to ship their product, and repeatedly making unrealistic estimations

- Printrbot posting to the incorrect address, leading to:

- Parcel Force not listening to my redirection requests, and continuing to try to delivery to the incorrect address, despite me paying two redirection fees.

What's next: 
Check parcel contents, put it together

What? Firebox balancing robot

 

What worked:
+ The combination of Arduino, Sparkfun 5DoF, screwshield and Sabertooth 2 x 25A worked beautifully for the electronics.
 + To calibrate the 5DoF outputs, I put together a simple calibration rig using an old servo for its potentiometer, bearings and servo horn. This allowed me to log the actual angle of the sensor board whilst also recording it's accelerometer and gyro outputs.
+ The ride on jeep motors and wheels were perfect for driving Firebox along
 + I initially used Pulsein on the arduino to read the RC signals. Later I Implemented interrupts which, significantly speeded up the loop rate.
 + I found Firebox balanced very well on carpet, but really struggled on hard floors (i couldn't tune the control constants to damp the oscillations). Adding soft tyres made of soft pipe insulation foam added the required damping, regardless of the floor it was running on.
 + As usual, I hadn't left enough time to get polished bodywork finished before Derby Maker Faire, so the next best thing was some cute cardboard body work. The kids love it!
+ The animated head and led eyes also went down well. More degrees of freedom to play with is always better :-)

What didn’t:
- Tuning over wired usb/serial
- Using an Adafruit data logger was a mixed experience. Getting it to work seperately to the robot was very straight forward. Unfortunately every IO it required clashed in with something already in use. I'd use one again though, just considering its requirements earlier in the design. It also didn't provide much useful data as there was no absolute reference to 'ground' or 'up'
- No independent measurement of up
- Not mathematically modelling it
- Screw shield/protoboard
- Offset pins on 5DoF breakout board

What's next: 
Ride on balancing robot

What? Maker Faire Derby

        

   

   

    

I recently exhibited at Derby’s first maker faire, joining my mate Simon Jelley to show off a few of our projects. First challenge was what should we take? Simon and I both had many unfinished projects on the go when we first heard about the Faire (mid March), so it served as good motivation to focus on a few of them and get them finished. When we filled in the entry form in April, we had settled on, for me: my PrintrBot, (ordered in February) and my balancing robot (balancing, but no body work (youtube video)), from Simon: Peggy based station clock (working but didn’t show the right time), live magic eye on an old tv using data from a Kinect (roughly working on a pc at the time), high performance night vision (working but shoddily housed) and a Nixie clock (unstarted). In the end my printer didn’t arrive in time (and still hasn’t arrived), I barely got the balancing robot finished, Simon managed to make a stand for the Peggy but didn’t fix the timing error, got the magic eye working on an 80s tv (youtube video), didn’t manage to rehouse the night vision and couldn’t get his clock working, although he did get a cool Nixie tube name badge working. To replace the Printrbot and add a bit of interest to our stand we built a Kelvin’s Thunderstorm over a couple of evenings at work (youtube video of it working) (wikipedia explanation).

Overall event:

What worked:

+ The behind the scenes tour and was an interesting addition for exhibiting makers

+ The old Silk mill was a pleasant, stimulating space to display in

+ Derby city centre was a good location with the canal, shops and grassy area

+ The event staff were cheery and helpful

What didn’t:

- It was a shame the event was so small, it didn’t take long to look at all the exhibits

- There was no café/food available on site (other than crisps/muffins)

Our stand

What worked:

+ The moving/cute robot was a great attraction for kids

+ The small labels we added to each exhibit looked good and helped people get them

+ We had a wide variety of stuff on show

+ We had an average quality of finish compared to other projects on display

+ having 3 people supporting the stand helped enormously

+ Having a bowl of jelly and marshmallows J

What didn’t:

-  Generally our projects required too much explanation for the general public to understand

- Some of them were quite high maintenance, requiring constant supervision (robot & thunderstorm)

- In general they were not very interactive (other than the robot turning to face people

- Not having everything working was disappointing for us but most people didn’t get what any of it was for anyway!

- The hardworking, late night, last minute push was very demanding and left me exhausted

What’s next:

We’ve applied for Brighton Maker Faire

Finish/refine the projects

Get the PrintrBot working, once it arrives

What? 2011

    

    

    

    
    

What? Blog
What worked:
I like the look of my template but its a bit cumbersome to use. 
Its definitely helped me focus and driven me to do projects to a higher standard, and finish them.
What didn't:
I've only published 4 posts. I've actually drafted many more but not published them for a variety of reasons.
What's next:
Keep going and post more. I'm going to lower my mental threshold of what justifies a post to encourage more posting.
Streamline the template. I'll look into making a formal template.
As posts build, expose the blog to a wider audience.


What? Photography
What worked:
I've really got into using flash, particularly off camera flash. 
I've got into the habit of taking the camera everywhere I go, taking pictures when I can.
My Sigma 35mm F1.4 & my flash cable were both great purchases
I've taken some great pet and baby photos this year, generally with flash. 
What didn't:
Not taking enough considered photos, particularly of family.
What next:
Take time to take more quality family photos
Practice techniques, particularly off camera flash




What? House (decorating)
What worked:
Decorating our box room as an office has helped increase my productivity and it looks good
Laminate flooring in the living room looks good and has been practical, contrary to our fears.
What didn't:
Not finishing all the decorating through not prioritizing
What next:
Finish it off. (Hall, kitchen, detailing)


What? Projects
What worked:
The power tool dragster, despite not having any published posts was the focus of most of my project work last year. It was a great project and we had a good time at the event. It taught me that I can work 40+hrs a week on a project outside of work if I put my mind to it, and doing 20hrs a week is fairly sustainable.  
What didn't:
Other than little bits of work on my Int Moth, I haven't done much other practical work
What next:
Finish what I intended to finish last year
Buy a 3D printer


New projects:Indoor wind vane, 3D scanner, 3D Colour printer

Argos 'walk-in' Greenhouse review

Project: garden

What: Argos aluminium walk in greenhouse

    
    

    

    



 




What worked:

The size is perfect for what we wanted. 

The Aluminium extrusion and corrugated polycarbonate panels are much more substantial. than the standard cheap steel tube with plastic fittings and plastic film greenhouses that are now common. It should last much longer, stand up to the wind better and the polycarbonate shouldn't be too expensive to replace when it eventually succumbs to UV degradation. 

The opening window is a nice addition too. One of the problems we've previously found the the tent like greenhouses is that you need to keep the door open on hot days. This means that if you go away either you leave the door open and run the risk with cool nights or leave it closed and risk the green house overheating on hot days. We are planning to fit an 'automatic' window opener to remove both risks.

The cost wasn't too bad. given the limitations I think I paid too much (£150 from Argos) but if I'd bought it on Ebay for ~£90 I wouldn't feel so bad.

What didn't work

The instructions were particularly bad. some of the images where incorrect but the most annoying part was the last instruction was to push the plastic end caps onto the ends of the aluminium extrusion. This is impossible once assembled but could have been done first, making the difficult assemble process safer.

The clips for holding the polycarbonate panels are not too bad, but they need to fit into grooves which are only present on two sides for most of the panels. We decided to add double sided tape so that the panels won't get blown off.

The basic door design is ok with rollers at the top and guide 'nubs' at the bottom. the assemble tolerances are so low though that the nubs easily fall out of their track, so the door freely swings around. the door end stop is also insubstantial (its just the plastic end cap weakly push into the end of the aluminium extrusion) I will be adding my own, bolted on, door stop..

The included spanners were often unsuitable for the job. They were weak and ill fitting yet oversize so couldn't fit into many of the gaps they needed to.

what next

fill with plants

add automatic vent

add door stop

new projects: infra sound generator

Malta

What? Malta Holiday


    

    

    

    

    
I've just gotten back from a 1 week holiday in a very hot Malta. This was the first holiday in 5 years where I've flown to a single destination (other holidays have been touring around and/or travelling by car/train).
What worked:
Google Maps caching saved us from getting lost on the slightly nuts Maltese roads. I managed to find some free open wifi at the airport when we landed and I quickly downloaded all of malta's roads (it's only 120 sq miles). It didn't managed to capture the 1 way system very well though.
Like wise, having GPS on my phone was a saviour. It's now impossible to get lost, even in a foreign country.
Google reader was excellent for quickly syncing content whenever I could get a network connection, for me to read later. Who needs books? 
My new Sigma 30mm F1.4 prime was just what I wanted for capturing the festivities in the low light, both inside churches and outside at night. I'm still getting used to it. 2 of my favorites above were taken with it but half of them could have been taken with it if I'd got the confidence to keep it on my 40D whilst roaming. The rest were taken with my ever faithful 15-85mm f/3.5-5.6 IS. 
I've recently discovered the benefits of wearing headphones on flights, even when not listening to music. Just blocking out some of the flight noise/screaming kids makes the flight a lot more relaxing. I need to invest in some noise cancelling headphones next.


What didn't work:
Not having wifi in the hotel cost us a lot of time, Especially since I didn't have roaming data connection. It's easy to get used to checking if places will be open when you've got always on internet, so it was a real pain not having it in our room. And I'm not paying £5/hour to access the hotel's paid service when there's a free, open WIFI spot just outside the hotel. Even if I need to stand in the middle of the street in the blazing sun to pick it up.
Android's Browser not caching was therefore even more annoying. Several times I went out of the hotel to pick up the wifi, found the contact details of a few places I needed to call, then went back inside to make the call. At the slightest twitch the browser would stop displaying the page because there was no network connection. I know there's no connection, just show me what you've downloaded so far!
Air Malta's food was particularly bad on the way out. I might take a packed lunch next time.
Our hire car, a Chevrolet whatever (Cruze?), in black, was not a good choice for the twisty, surprisingly hilly, predictably hot, Maltese driving. The aircon could not keep up and the engine appeared gutless. As I'm used to driving a diesel, having to work the gears and use high revs to make the most of the engine was a bit of a shock. 
My wife's Kindle didn't like me lying on it. Even though it was in a padded, reinforced case, after I accidentally lay on it the screen only responds in one corner :-(  
On camera flash for taking pictures of buildings at night did a surprisingly good job of illuminating the building but a predictably poor job of revealing its shape/texture.


What's next:
Buy/Fix Kindle
Buy/make a remote flash cable
Experiment with my Hama flash slave adapter more