Last Christmas I was given a nice set of drinks glasses.
In order to keep them safe, I keep them in their original
cardboard box, which keeps them safe, but isn’t aesthetically great
and keeps them hidden, so this was a quick project to create storage
for them that is better looking and more permanent, and would fit in
with the display stand I created earlier.
The
box itself is made from iroko scrap. The outer walls are simple butt
joints, and the dividers interlock each other as shown in the
animation below.
For a finish, the wood was treated with danish oil.
read on for a description of the build (and me practising my 3D skills in Blender!)
Thin foam was cut to squares as a base in each of the six segments.
Thin strips of foam were then wrapped around the glasses and they were placed into the box, where the edges of the box act to hold the circle of foam in place, and finally small triangular segments were cut and placed around the circle to pad the corners. This creates a suitable fit, and the foam has an almost velcro-like quality that holds all the bits together without needing adhesive.
This is another small part of a larger modular project.
The aim is to create a display for drinks bottles and miniatures, which will present them nicely, while at the same time securing them to protect against small amounts of movement. i.e. I'm not expecting them to be secured if the whole stand is tipped over, but they must be able to tolerate the stand being wobbled side-to-side without the bottles clinking or falling over.
There is also the need to balance the trade-off between the display aspect of the unit, and the amount of storage it provides.
After iterating over a number of designs I settled on the idea of having a central area which would display a number of larger bottles, with a frame/shelf element around the back and side edges to hold miniatures (the front would need to be left open to allow access to the bottles).
The base
The base is simple plywood, with foam to support the larger bottles. The foam is spray-glued to the plywood, with cut-outs to place the bottles, and is wrapped in fabric - also spray-glued and stapled.
The frame
The frame is oak, attached through the bottom of the plywood, and supported by the miniatures shelves and the top frame, which is mitred, and screwed to the uprights with dowels to cover the screw holes. The sides are left open, but the back is enclosed with iroko (there is a logic to this that will become apparent later). The mixture of woods creates a nice colour contrast and adds additional support.
The miniatures shelves
The basic idea behind the miniature shelf is to use a forstner bit to cut out grooves for the bottles to stand in. But this alone raises a couple of problems
If they're just sat in holes, it won't be possible to see the labels and know easily what they are.
There's no definitive standard size/shape of the bottles.
The latter question has an easy answer, just pick the smallest forstner bit that covers the most bottles that I have to hand - this turned out to be 41mm.
The solution to the first point is to cut the groove off centre, so that it has an open front, allowing the label to be seen, but again, this raises the next question - if the groove is open-fronted, then what's to stop the bottle just falling out?
I'd already planned to line the bottle slots with leather to prevent rattling. By over-sizing the corners of the leather (see below illustration), the leather also acts like a clip to hold the bottles in place, with a sturdy leather disc glued in the bottom to provide extra support.
I recently started volunteering at a local 'repair cafe'. It’s a
community environmental initiative where people in the local
community can bring in small broken consumer electronics, and the
volunteers will see if it can be repaired, at no charge, in order to
keep items out of the waste stream.
If items can’t be fixed on site, advice is given whether it’s
worth repairing, and if so what parts, etc. might be required. If
they can be fixed, they’re tested to ensure they’re safe, and
weighed so that the organisation can monitor the amount of material
kept from landfill.
The other volunteers have a wealth of experience in a number of
technical and scientific fields, so I also see it as an opportunity
to learn and improve my skill set.
I’m also going to keep a record of the repairs I do, and
document them here in the hope that it provides a DIY reference for
others who may need similar fixes but aren’t able to access a
repair cafe in their area.
So, these are the repairs I was faced with on my first day:
An automatic cat feeder – a simple mechanical clock device
turning cogs which in turn allowed a lid on a good tray to open
after the set time. The mechanism was reported as being slow.
Observation of the device over a couple of minutes didn’t really
show any sign of being off, and a test over half hour showed some
drift – about an extra minute. The device was far from being a
precision instrument though, so suggested that they observe the
amount of drift over the time period they’re after and adjust the
time they set accordingly.
An electrical beard trimmer. The mains wire was disconnected. Soldered in place and fixed.
A DAB digital radio, on which the LCD display wasn’t
functioning. Managed to disassemble and retrieve the faulty part, so
that a replacement could be found.
A toaster. The lever to push the
toast down was stiff. This seemed to be a design flaw in the
toaster, where the lever being pushed down would effectively pivot
on the rail where it’s mounted, causing it to bind.
There wasn’t
much that could be done to repair it, but was able to advise the
user how to workaround it by keeping the lever flat whilst it was
being pushed.
A halogen cooking lamp thing. The
timer and the fan would run, but the halogen lamp wouldn’t turn
on. Testing showed no power to the halogen connector. Tracing the
problem back showed that a potentiometer device (pictured) which set the
halogens temperature had broken part.
Advised the
user of the broken part so they can try and get a spare from the
manufacturer to attempt a repair next time.
This was a commissioned project that went nowhere, but could easily be re-purposed for many different use cases, so I thought I'd share it.
The aim is to create a range finder device that can be mounted and aimed at a
roll of material on an assembly line, so that the range finder can be
used to determine the amount of material left on the roll, and sound a
buzzer when the supply falls below a set amount, informing the machines
operator so that they can replace the roll and minimize downtime.
The sensor is a Sharp GP2Y0A21YK0F. The datasheet shows that the
voltage drops as the distance increases. In our particular use case,
this means that as the material runs out, the voltage will drop, so we
want to flag a warning below a set voltage.
Initially I thought about using a low battery circuit similar to the one I modified to use in the Keyboard Pedal
project. However, I later realised that would be over-complicating it,
and that the same result can be achieved using a simple comparator
circuit.
The chip used is the LM358 op-amp, and the circuit is similar to the one found on page 6 of this PDF.
The key differences being:
The voltage provided by the resistor and zener diode in their
diagram is replaced by a potentiometer in mine, so that the 'trigger'
value can be adjusted.
The potentiometer in their diagram is replaced by the IR sensor in mine.
The resistor and LED output in theirs, replaced by a buzzer.
The voltage of my circuit is 5V so it can run off a USB charger.
With all those changes taken into account, the resulting circuit looks like this.
Note that RV2 is the IR distance sensor - I didn't have the symbol
for it in KiCad so used a potentiometer symbol as that's essentially the
behaviour it exhibits.
The finished circuit, fit neatly into it's enclosure.
The case
The circuit needed to be neatly enclosed for it's purpose. Often for
electronics projects I'll end up re-purposing existing containers and
boxes as enclosures, but as it was a commissioned project something more
professional was in order.
The whole enclosure is 3D printed, based off a simple lidded box design with cut outs for controls and the IR sensor itself.
I also took the opportunity to turn the box into a simple parametric
template so I can recycle it for other projects. the SCAD source code
can be found on GitHub.
All that's needed is to supply the internal dimensions that are
required and it'll create a thin-walled box meeting those criteria,
using only stock OpenSCAD commands - no other modules required.
The lid
fits snug - on my (admittedly by this point quite old) 3D printer,
a nice unintended side effect of the rough resolution is that the
ridges create a nice friction fit, allowing the box to be closed tight,
but also popped back open with relative ease should maintenance be
required.
The controls and buzzer
The sensor - the glue-filled part was to allow flexibility in angling the sensor, but was later found to be not required
The test
As I didn't have access to the factory where this was intended to be
used, I whipped up a quick test rig using kitchen roll as the stunt
double for the actual material.
The short buzzing before the alarm fully triggers is driven by the
'wobble' of the roll on the holder. In production use the material rolls
are much more securely held, and so this effect would be minimised.
Creating a powerful linear actuator by attaching a car jack to a motor is nothing new, but a lot of the demonstrations that I've seen neglect the fact that the point where the motor needs to mount to the jack (at the end of the threaded rod), will have movement both vertically and horizontally towards/from the middle of the jack. This makes it difficult to mount the motor in a fixed position.
So while this isn't a project in itself - it's a small part of a bigger project I'm currently working on, I thought I'd share my solution to this problem in case it is of use other others attempting something similar.
I found the best method is to focus on mounting the motor in relation to the threaded rod, rather than the jack, or the other frame/other parts of the project, as this is the only bit where the position remains relative.
The frame supporting the motor in line with the jack
(Jack body not illustrated)
This frame (yellow) goes around the middle of the jack, and hooks at the end over the threaded rod (green).
At the other end, the motor (red) is attached to the rod in order to turn it and mounted securely to the frame, allowing it to move with the rise and fall of the jack.
The downside to this mechanism is that the torque of the motor will cause the whole frame to rotate. This can be overcome by building the frame as close to the jack body as possible, to minimise the amount of rotation.
In addition, springs are mounted from the underside of the elevated surface to the frame, to add additional support and reduce vibration.
Electronically, the motor is driven by a H-bridge controller. Reed switches are mounted to the base - one on the base itself, another positioned in an elevated position to line up with the frame at it's highest point. Corresponding magnets are mounted on the frame, which line up with the reed switches to create a high level limit and low limit.
Control is currently provided by an Arduino with a single button input - each button press will either raise or lower the platform.
Following on from the pen and pencil projects I figured I'd continue on with the stationery theme.
Like most people who've ever taken notes, I have a lot of half-used
notebooks gathering dust, leaving a large stockpile of perfectly good
paper not getting used simply because it's bound to some other paper
that did.
I'd been thinking about trying a book-binding type
project anyway, so figured why not save a few steps and do some
up-cycling in the process.
The candidate books are some school-exercise-book style notebooks.
These are great candidates because they are only bound by 2 staples and each book is a single stack of folded paper.
There's a detailed Instructable for this, which I used heavily for this project, so rather than reinvent the wheel, I'm only going to detail the areas where my process differed from theirs.
To start with, I removed the covers from 4 of the blue books.
To get the fabric for the binding, an old t-shirt was sacrificed.
I oversized the measurements for this bit, so that I could pin the fabric to a scrap backing board, to hold it taut while I mounted the folios.
I put clips each end of the stack of paper, painted some PVA glue onto the fabric, and then added the spines of the paper. Doing it this way around prevents the glue leaking between the pages and fixing them together.
The resulting object was surprisingly stable enough to move somewhere safe to dry.
In the meantime I started preparing the cover as per the instructables instructions. However the leather that I had for the cover was slightly too narrow to have the one inch border that it instructs, but still have enough material to wrap around, so I'd be working with narrower margins.
In addition, in order to be able to fold the leather over to create a neat edge, it needs to be thinned. I did this using a combination of skiving tool and sanding, to thin the material around the border.
After that it was just a case of following the rest of the instructable. For the lining paper I used some of the card I had left over from the Picture Frame that I did a while back.
To finish it off I added some brass corners, and that was it. Not perfect by any means, but very happy with it as a first attempt.
About a year ago, at Makers Central, I did a wood-turning tutorial and made my first pen.
Since then, I've added a mini-lathe to the workshop (purely because I lack the room for a full size one).
Just before heading back to Makers Central this year I thought it'd be good to have another go and see my progress.
Being me, I'm not really a fan of just constructing kits, and I always like to try and incorporate elements of upcycling and reclaiming into my projects.
I've had this ballpoint and mechanical pencil set for as long as I can remember - it's old to the point where you can see how faded the plastic has become. So there's the upcycling bit of the project sorted, this time I'm going to make a mechanical pencil to re-house the innards of this one.
The pencil is walnut and chrome - I wanted to try and keep the same shape as the pen I made last year, but use contrasting colours to the maple and brass that I used last time.
The metal bits came from a clicky pen kit, but were a good enough fit to work with the pencil mechanism.
So there we go. Making pens is enjoyable, but doesn't make much of a project, and I generally don't make more than one of the same item, so I don't see myself becoming a full-time pen turner any time soon, but I do have some variations of the theme that I might pursue.
