Saturday, 28 November 2020

Live-edge oak spotlight light fixture

The basic idea

The idea is that the fitting uses GU10 spotlight fittings like those typically recessed into ceilings.

However, instead of recessing them into the ceiling, they're recessed into a piece of live-edge wood, which is hung from the ceiling like a more traditional light fitting.

The woodwork

There's not much really in the way of woodwork in this project, just clean off bark and splintery bits from the live edge, preserving as much of the edge as possible.

Quite a bit of sanding was also needed to clear up the surfaces.

The end of the board I had was cleanly sawn which I thought detracted from the live edges, so I broke the corners down with a carving disc on an angle grinder.

Creating grooves for
the spotlights latches
Then measure the centre line. I started by taking the average width of the board and working from that, but there is some leeway - having both sides be live edge makes this near impossible to find a perfect centre line, but ultimately as long as it looks central to the naked eye.

The spotlight fittings are not designed to go through the thickness of the board - after all, they're intended for plasterboard ceilings. While it won't affect the functioning of the light, it means that the spring loaded clips that latch. To work around this, I used a forstner drill to thin around the edge of the spotlight holes where the latch would sit - This is easier to do before the main spotlight hole is cut out, to stop the forstner bit from slipping.

Then I cut out the holes for the spotlights by drilling a pilot hole and widening with a jigsaw.

Test fit of one of the light surrounds

Wiring the spotlights

The three spotlights are wired in parallel, split across 2 junction boxes. Having them in parallel means that if one bulb was to fail, the others could continue to function.

 

To make installing the light easier, the lead that connects from the ceiling to the wood itself included a 'kettle plug' style plug and socket, simply so that the wiring could be done on the workbench, and just plugged in at the time of installation.

 

Mounting

The ceiling roses were purchased, and have simple hooks on them for hanging the chain.

Eyelet screws were attached in the back of the wood at each corner, from which the chain was attached.

Enough leeway was given on the chains so that adjustment could be made to ensure that the light hangs flat.


Friday, 23 October 2020

Combination pinboard and cinema poster frame

Even before Covid-19, people were already starting to talk about "work-life balance", and it's effect on health.

When Covid made working from home the norm, maintaining that balance became even harder, especially for those whose homes are more open-plan, meaning the same rooms they go to relax could end up also being where they go to work.

This project is aimed at exactly this problem.

During the day, the frame can be opened up, to reveal a pin-board where all the usual work notes and paperwork can be pinned, but once the working day is done, the frame can slide closed, shutting the metaphorical door on office life, leaving just the poster visible, more in fitting with a relaxed home lounge look.

The 'front' (poster) frame

This frame is more akin to a traditional frame, but as it will be the sliding component, and so not directly mounted to the wall, keeping the weight low is important.

As with the back frame, the joints are mitred half-lap. The same oak is used, but much thinner (roughly half inch). A rebate is cut in to seat the glass, poster and backing board.

With weight limitation in mind, thin perspex was used in place of glass. The rest of the frame is pretty standard - a sandwich of the perspex, the poster, backing card, and then hardboard (in this case, up-cycled panels from a hollow core door) all held in place with some pins.

The 'back' (pinboard) frame

To start with, this is a standard mitred half-lap jointed frame, albeit deeper than a normal frame - about an inch. It also does not have any rebate or groove, as it's not needed.

The pin board that I'm re-purposing is another of the same style I used for the desk organiser. It's smaller than the poster frame, but this is by design to allow room for the sliding mechanism.

The two long sides are removed.

These are replaced with longer oak sides that attach it to the frame. On one side this is simply screwed into the larger frame, and on the other, small grooves are cut into the frame for it to fit into, similar to a tenon.

 

This second side leaves approximately 4 inches between the edge of that inner frame, and the edge of the main frame.

 

The rail mechanism

2 4x2" pieces of oak are drilled with a 20mm hole lengthways, and then glued in place at the top and bottom of the frame, filling this gap.

Then, the entire frame is cut lengthways, halfway through these pieces of oak, leaving 2" of it on either side. These will form the rails.

The 20mm hole is extended through the 'long side' part of the inner frame, at both ends.

The 'thin' part of the frame - the one without the pin board attached, is the part of the back frame that the front frame will mount to, and be the part that slides out.

16mm aluminium tubing was inserted through each of the channels. On the thin side of the frame, a screw was driven perpendicular to the 20mm hole, fixing the tube in place and adding some support to the glued in block.

These two tubes are then threaded through the 'fat' part of the frame.


Joining the two frames

Screws from the back frame are driven through into the front frame on the left hand side (the 'thin' side).

To prevent sagging when the frame is opened, leather loops are attached around the other end of the tubing and screwed into the back of the front frame.

This makes the sliding part of the frame counterbalance it's own weight.

The whole thing was finished with a coat of danish oil, 4 angle brackets were added and it was mounted to the wall.

 

 

Friday, 11 September 2020

Boosting broadband speed with satellite co-axial cable

When I moved into this house, there was a lot of extraneous wiring. Phone line extensions that went nowhere, that kinda thing, so I ripped out everything back to the master socket by the front door.

When fibre was enabled, I had a visit from an Openreach engineer, reporting a fault detected on the line - the case was the old master socket had some corrosion, so he replaced it with a new one.

However, I want to move all my network gear to the under-stairs cupboard, and branch everything from there. As I don't use a landline, this would mostly just mean Wi-fi and a few ethernet cables.

There's a not insignificant cost to have Openreach come out and move the master socket, so I'd rather avoid that. It's also not something you can really do yourself - the master socket marks the point in the connection where the providers responsibility for the wiring ends and yours begins. If you tried to move it yourself and screwed up, there's a significant charge to that too.

Just using a phone extension lead works, but slows the broadband speed noticably.

Unfortunately, due to the age of the phone system and it's various evolutions over the years, finding decent, up to date information is not as easy as it should be.
I manged to put together a DIY solution that boosted my broadband speed by approx 50% (~14 Mb download speed with regular phone extension, to ~21 Mb using my solution)

This was done by combining a few other ideas and sources of information.
This is what worked for me. Your results may vary, and usual "don't try this at home" warnings apply.

Moving the master socket without moving it

I found this guide which shows a master socket with 'A' and 'B' connections, which it states, you can run to another socket using CAT5 network cable, which will have a similar effect to moving the master socket, as it bypasses a lot of the filtering of the sockets, and CAT5, being twisted-pair cable, has better shielding qualities than regular phone extension.

But unfortunately, my master socket is the newer type 'NTE5C' socket, so it doesn't have the same connections.. It does have a similar A and B connector, but it's on the provider side of the socket, and is in use, so I don't want to mess around with that.

It give me an idea though. Even if that route is out of the question, a lot of the interference comes from the cabling used. If I were to create a phone extension lead from CAT5, it should still be an improvement to a regular phone line. 

Looking up how to install a telephone extension on the NTE5C type of master socket led me to this video which shows using the front panel to connect an extension using pins 2, 3, and 5.


Pins 2 and 5, according to the first article, are the equivalents of A & B.

So, what if I put in a telephone extension using that connector like in the video, but instead used better cable as per the article? In theory, the speed should improve due to the increase in cable quality, but would lose a bit because a microfilter would be required (because it's not been pre-filtered.)

I also thought, if CAT5 beats regular phone cable because it's twisted pair gives it some shielding, then wouldn't something more shielded so even better? I had a usable length of co-axial cable, the type used by satellite dishes and antennas.

This is a single copper core with a mesh-like shield all the way around it. These would provide the connections to pins 2 & 5 (I used the core for pin 2, the shield for 5, but I don't think it'd matter which way round).

The article does recommend solid core wire, which the core of the coaxial is, but the shielding is not, so I guess there may be some performance trade off there.

This was wired to a regular phone socket under the stairs, in which there's a microfilter and the router.

Initially the speed fluctuated a bit, but once it bedded in, it settled on a speed (as reported by the router) of approximately 21Mb, which is up from the approximately 14Mb that was achieved with the same length of regular phone extension cable.

I'd be tempted to experiment further (ideally with something with twin solid cores and shielded.), as there's still a bit of room for improvement - at the master socket directly, the router could get 26Mb - but for now it's fast enough.


Friday, 21 August 2020

Straight razor from table saw blade

So a while back I replaced the table saw blade in the workshop and got the idea in my head to try and make a straight razor out of it.

I sketched out a quick design and then cut it from some scraps of redwood (the same stuff I used in the ring box project - not sure if that's the correct species, but it's wood, and it's a red-ish colour, so close enough.) on the bandsaw. Fortunately I had two scraps the same thickness, so I needn't worry about the thickness of each of the scales (sides) being identical.

The blade itself was sketched out in marker on the old table saw blade and cut out with an angle grinder. Once the rough shape was done, a mix of bench grinder and rotary grinding tools were used to refine the shape.

The gap between the 2 scales of the handle was padded out using some brass sheet, cut to match the shape of the scales, whilst including cut out space both for the blade to fold in to, and to allow the tang to rotate into when the blade is opened.

This, and the scales were both epoxied together, and then two holes were drilled and brass pins added, for additional strength and their own aesthetic quality.

The third brass pin provides the hinge that the blade will pivot from to make the opening and closing mechanism.

Before the blade and handle were put together, it was easier to finish each part separately.

In the case of the handle, this meant sanding to round off the edges and make it more comfortable to hold, and a wipe out with danish oil.

In the case of the blade this meant a lot of grinding, sharpening and honing to get it to a sharp enough edge to cut hairs. With hindsight although it probably isn't the best steel to use for a blade, it is sharp enough to shave with - it just requires frequent honing.

But, at the end of the day it works, I'm pleased with how it's turned out, and I learnt a bit more about blade making and the dark arts of sharpening and honing along the way. I also now totally get why some people fall into this particular niche rather than just more general metalworking... I'm actually quite tempted to go find some better steel and make another already.

Saturday, 8 August 2020

Tattoo Machine for Leatherwork

This is the fifth of my 'Lockdown Projects' - Projects made during the Coronavirus lockdown, which I limited to one week, and only using materials I had to hand.
 
Before I start this write up I just want to emphasize this tattoo gun is not intended for use on anything other than leather. Using it for anything else risks a number of heath issues.
 
With that out of the way, I’ve been intrigued by the idea of using tattooing as a way of patterning it. A quick search shows that it’s not an uncommon practice – particularly it would seem, for leather boots.
 
The theory goes that given that leather is essentially just skin, it would tattoo in the similar way to a person.
 
After seeing a home-made tattoo gun in an episode of Orange is the New Black years ago, I’ve had the idea in the back of my head to build one and try it.
 
During lockdown, it seemed like a thematic fit to finally hack one together.
The body of the machine is from a mechanical pencil. 
 
The main needle mechanism is a sewing needle, with an empty metal pen refill, and a hook made of a bent paperclip. These bits are epoxied together for sturdiness.
The motor was taken from a handheld fan. A button provided the connection between the needle mechanism and the motor.
 
The bracket was a small bit of metal from the junk bin - that was probably once part of a printer or something similar I’d previously dismantled.
 
The motor and bracket were fixed together with cable ties and a final cable tie tensions the mechanism so that there’s less rattle and wobble in the needle.
 
 
Initially I used 2xAA batteries for a power supply, but after a bit of testing, it needed more power, so I replaced that with a USB connector.
 
Obviously I didn’t have any tattoo ink to hand, so I just used leather dye to test.
 


Monday, 22 June 2020

Context-sensitive macro keypad

I've been doing quite a bit of 3D work recently for both 3D printing and VR software development.

The main software that I use for 3D work are OpenSCAD and Blender.

One annoyance I have is that the short cut keys each use for standard things such as scale, rotate, move, etc. are all different, which makes switching between applications more awkward than it need be.

So my latest electronics project is to create universal short cut keys - a physical keypad that has single button presses for those functions, but then translates them into the relevant keyboard/mouse presses dependent on which application has focus at the time.

The hardware
As we're still under lockdown due to COVID-19, I'm restricted to using only components and tools I have got at home, like with the USB Switch project.

The keypad itself is this mechanical key switch tester.



Unfortunately the eighth switch was lost some time ago. I'll leave the gap there as potential room for expansion in future though.

The controller is an Arduino Pro Micro. I thought about using a different microcontroller, however the real sticking point was my lack of a spare USB to serial adapter.

The Pro Micro helps keep the overall form factor nice and compact, whilst keeping the programming side of things straightforward.

I picked out some LEDs to backlight the keys as there was spacing for them, and the keycaps are translucent. I tried to find all different colours, but my inventory didn't allow for that, so there's a couple of duplications.

The rest of the hardware is just some diodes and resistors, a bit of perfboard and some scavenged wires.

The hardware is wired up like so:
Quite simply, there's two matrices, one for the switches, and one for the LEDs. Because of the missing key, one column in each only has three connections.


The case is just some plastic container that would otherwise have been trash. It wasn't a perfect fit so required some Dremel-based customisation.

The Firmware

The Arduino will stay set up as a USB to Serial device rather than as a keyboard because there needs to be bi-directional communication - the Arduino needs to also receive input from the application in order to control the lights.

This post was a useful resource when putting together the matrices.

The full source is available in the project on GitHub.

The Software
The software is a java desktop app that communicates with the Arduino using jSerialComm. It controls which keys are 'set' and indicates this with the LEDs.

The interfacing with the other applications comes from a thread that uses system calls to the 'xdotool' linux command, reading in the output of that command which is the name of the current window that has focus. There's room here to make the application multi-platform, by implementing a similar Windows command in something like AutoHotKey.

If the window matches the defined rule set, the relevant keys are highlighted and a thread monitors serial input. If that key is pressed, java built-in Robot class sends the relevant commands to the application.

As with the firmware, the source is available on GitHub. It's in a pretty simplistic state at the moment due to the one-week time limit I've placed on these lockdown projects, but there's room to expand and improve in future.

Tuesday, 26 May 2020

Tray Stand / Foldable Table

While lockdown has prevented me from being able to get back to many woodworking projects this year, I did manage to cut a few offcuts to size and sand them in order to fashion a stand for a bamboo tray. The idea being for it to be a temporary table or drinks stand in our small patch of outside space.

The construction is a simple X-frame, with horizontal bars at each of the four points - 2 to support the tray, 2 to act as feet. These are joined to the X-frame using a 3D-printed bracket - the SCAD file for this is up on GitHub.

In order to stop the frame from spreading out and collapsing under the weight of the tray and it's contents, the feet were joined with some denim fabric, courtesy of an old pair of jeans. This allows the stand to be folded up, but providing plenty of rigidity during use.

Sewing things other than leather is a pretty new thing to me, my only prior sewing-related project being the lanyard I made a while back. So I'm the first to admit it's not the neatest work, but it does the job, so can't complain.

With the benefit of hindsight, the hinges allowed a bit too much flexibility, allowing the cross-bars to roll. The fabric on the feet alleviates this at the bottom. On the top, the base of the tray has a small lip which helps latch onto the cross-bars - whilst they still roll, it's impact is minimised and the tray/table works fine.