3d brush off

Tidy up those tooth brushes

I recently had to replace the battery on our faithful Braun OralB 3d electric toothbrush. That was a simple and mundane process but it did trigger me to find a solution on housing the brush heads. Family of 4 and with a few different brush heads we have gone through a few different variations on trying to keep them tidy. Always on the lookout for 3d print jobs to help hone my skills on Solidworks and our 3d printers, I figured this would be a perfect project.


Rotating Oralb brushhead organiser

Clearance Clarence 

One of the tripups on 3d printing is getting tolerance levels right. Especially moving parts, interference tolerances and friction fit. So I planned to work on those a little bit with this project. Tolerance one, was the fit of the brushhead on the posts. The brushhead has an interesting shaped and tapered cavity that locks onto the handle and motor housing. I measured the base up and subtracted .5mm. I was not going to taper the posts but I did put in the indent and provided plenty of “fillet” to help support the post on the wheel. The second “sliding fit” tolerance was between the wheel and the base. The idea was lazy susanish. It would allow me to spin the wheel around to select the brushhead. I could just have a central post but lets up the ante a bit. I decided on a post and ring. This meant two interference fit surfaces and double the xp points.


the base with its centre “axle” and spin ring


Come in spinner

Obviously the extruded boss size and shape had to mate with the wheels extruded cut. This is no biggie for Solidworks. I added .5 mm height on the boss so the bottom of the wheel (the flat) did not rest on the bases top surface. The surfaces that touch are only the top lip of the ring and the sidewall of the axis.


wheel plate bottom view

Lots or 1 and 2mm fillets everywhere to avoid edges and it gives it a manufactured/professional  polished look.

Easy peasy lemon peely

This particular 3d printer boasts an ezy peel setting. That’s the foundation layer it uses to build the part on. Basically a cross hatch of sacrificial thin plastic. Easy is not always the word I would use but with a handy mini chisel scalpel, the job gets done fairly quickly. Watch those fingers, wear gloves. DON’T use the mini chisel to leaver off the plastic! Slice the plastic away between the part and the foundation layer. Leaver if you have to, only  with a screwdriver. Good old packing foam  creates a quick protective holder. I gave the flat surfaces a quick sand to clean up any leftovers.


Peeling off the foundation

Thats all folks

The base can either be screwed or glued or mounted in numerous ways to something in the bathroom. Being all plastic and with plenty of water run off edges, the design will allow good access and keep things neat and be easy to clean away that toothpaste plaque that seems to build up on anything the heads touch. Or is that just because the kids don’t flush the heads after use?


A Roland mystery goop

Whats brown and corrosive?

Initial thought was coffee spill. But it didn’t have that typical sweet coffee smell. It was certainly very sticky and the dried areas of the substance were very stubborn to removal. Hey this sort of gear is used in pubs so who knows, right? Moving right along.


The fabulous Roland KC880 is a majestic stereo 5ch input combo amp.Well worth the attention it was getting. It was fine except for mic input, ch1. Any amount of gain and it popped, fizzed, crackled, glitched and incessantly faltered. As with most amps, to get to the PCB we have to remove 500..or so.. knobs n front panel nuts. This revealed the PCB and the problem. Also like many amps you can’t work on it opened up because the wire harnesses are too short. This is a big amp btw, it has its own wheels. Welcome to my world of pain.

Of interest is where the goop pooled. Its obvious it had to come down the potentiometer shaft(above right). This pot was ch2 gain but the goop was pooled around the mic preamp section of ch1, bingo.


The pot had to be removed for cleaning too but it was interesting the goop had migrated almost without trace from the pot to this final resting place. After much scrubbing I had removed the goop. It was an almost unbeatable match for my tool of warfare the optic fibre(fibreglass bristle) brush. Indicators gave away the fact the goop was once a very thin liquid as it had indeed slithered its way under the SMD components. I also found traces of it  much further away on various parts and especially the switches protruding through to the front panel… this indicated bio hazard like chemical warfare type spillage. Someone must have a had a real good party, probably the type “respectable physicists” or in this case chemists wouldn’t be found at. Lots of careful cleaning and almost a can of contact cleaner went into the ozone. Sometimes you just have to keep going, pursue to the end. Like a dog with chew toy don’t let it go or defeat you. Such a small percentage fault of a much bigger and complex device. I couldn’t turn away from this one, the hours ticked by but progress was forthcoming.


Almost cleaned, at least we can see components now

It still burped and carried on

A good clean solves 80% of problems but not this time. It still whistled and whinged. I went in search of corroded parts. First to fall  victim was the missing collector pin of Q16. Followed by high resistive values for R147, R146. Closer tests revealed, R149 and well that 1k in the middle was dead. D4 and D5 were still gooped underneath so everything, one at a time so I didn’t misplace something, was removed cleaned and returned. Q16 was a problem, no collector. It did however have the same LG text as Q15.. A net search indicated this could be anything but deduction kept bringing me back to a typical NPN transistor.  I found a possible same SOT elsewhere (which was driving a LED) so did a transplant and then replaced the LED one with a BCW72 I had in my parts bin. Less chance of incurring the wrath of parameter missmatch this way.

After the cleaning, re soldering and buzzing out of signal paths it was time to hook it up again.

Well what do you know, surgery par excellence

Nice quiet mic preamp. Ran it thru its paces and gain figures matched. Tested the line input switchover and concluded the transplant was a winner. Back to work for you boyo.


While I didn’t take photos 😦 I can state the main amp, as is the transformer, is located in the speaker cab. Access is by removing the grill and then the speaker/s. I checked in here spillage or anything untoward. All looked good and the whole amp had that great solid and dependable Roland quality of build about it.

If you incite chemical warfare at your next party and things spill over, do have the nous to tip smothered device onto an edge that might drain nasty substances away from precious electrons. Oh and contact your doctor immediately for a flush. The spill is not the problem, the slowly corroding goop it might turn into tho, is the beginning of your financial nightmare.

It went off like a fire cracker

It spewed forth like a party popper

So I’m testing a system that has a tendency to run away and thus destroying the carbon filament feeder motor on a rather large robotic carbon part “printer”.
I joined this scenario after the second motor, now a charcoal remnant of its former self was brought to my desk.
So I think Ill emulate the load with a resistor instead of just replacing the dead unit with the new $500 device. .. Estimated(according to the manual) power delivered was 60W.
So I opted for a 100W emulated load.
System was stable for a while, readings as expected in fact on the low side.

Then it suddenly did its thing


Readings in the last nano second, recorded ratings of 900W. My poor 100W rated load disembowelled itself after loosing the watt war. The blue croc clip pictured right was found 20m away. The bus wires that paralleled the gold resistors were never found. The coiled black wire you see, is the resistive wire that is normally wound around the “black” former which should be inside the gold aluminium cladding, potted. The putrid smell of dead electrons still inhabit my nostrils.

So yes we have a problem

Further inspection. I traced the estimated 2amp wires back to a very large man height cabinet on the wall. On opening. The 3 phase fuses on this thing look like sticks of dynamite. But hey its a big robot..  I traced the motor feed wires to their control board. This PCB was feed by a 20amp 48v transformer….WT? The motor is rated at 30v max at 2 amps. This defies Spock logic.


Currently waiting response from manufacturer for a host of questions I now have..

Cable Identification Tip/Hack


Cable haze be gone

There are many instances in this day and age of  escalating cable count where things just get out of hand. The maze of wires becomes untraceable. Whether its behind the home theatre system, the collection of computer leads at work or in my case on the stage keeping track of mic an guitar feeds.

There are many accessories available, sticky labels(eww the left over residue tho) , velcro, cable ties etc but my hack was born from quick thinking on site. Its cheap, removable and simple.

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Plumbers tape PTFE

PTFE also known as; teflon, plumbers tape, pipe seal tape, thread seal tape is the way. Thin and sticks to itself with no sticky residue. Does not bulk up the cable. White so it marks clearly and easily with various pens and sharpies. Simply wrap the teflon around the cable and write on it. I have also foregone the writing part and just put a series of rings in some instances(ie 3 rings is microphone 3 etc). The tape loves a sharpie and depending on how you wind it will yield long or short label space. It holds very well to the lead even if you are feeding the cable thru things but I tend to wrap it just before I connect it to its source or destination.

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Flat wraps are the best

Application and Removal tip

As mentioned the stuff sticks to itself rather well. The first wrap is probably the hardest but youtube for instructions and once you get the hang of it its quick to apply. I tend to wrap around 5 or so times and break and break it with my fingers rather than stretching till snap on the cable. This provides a cleaner edge with which to unpeel later on.

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To remove, find that edge! and roll it the opposite way with your finger or thumb. If it starts to tear it can get a bit tricky. Again a bit of practice. Once that first lip is up its easy street.

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Armoured for life

If you really want it to last, give it an armoured coating with a quick cheap wrap of clear spiral cable wrap.

What brought this on?

I was looking for a quick way to label a stack of guitar and microphone leads whilst on set bumping in a band. There is nothing worse than having dozens of cables hooked to various things and in the chaos of a bump in someone patches it to the wrong thing. Trying to trace where its come from or going to later can waste precious time. Not all the leads are mine so I can’t just go permanently marking them. I hate having to clean up sticky residue from labels or masking tape etc so I wouldn’t do that to someone else either. I kept thinking cling wrap would do then the brain took a leap, plumbers tape! I always have some in the tool kit and away we went.

I did some further , longevity, testing after the gig and it lasted remarkably well.


10m of teflon plumbers tape is a few $$ and available anywhere.

Spiral wrap should be available at electronics store or hardware, about $5 for 25m


Shining like a National

ukulele !

I’m not a great uke fan to be honest. I prefer my tones a little lower but when  friend mentioned  a “resonator uke” my interests were captured. Immediate thoughts turned to Graceland.

“The Mississippi Delta is shining like a national guitar”

~Paul Simon

And I was not disappointed. This was indeed a mini National resonator with even the famous diamond pattern cover plate. All housed onto and into a cigar box.

Again my disclaimer, this is not a buildalong or howto but a collection of experiences. There are many websites with great buildalongs and in depth information. I would encourage builders to do your research as there are so many ways to skin this cat and all lots of fun.

Do I have tools?

So my muso friend Chantelle loves a uke but was looking for a bluesy sound. She did some reading and was hooked on a resonator style uke idea. Lots of people out there building cigar box ukes with resonators. Lots of kits and suppliers of parts available too but she was in need of some basic tools. This is where I drop into the story. So after most of the components arrived, a date was arranged to hangout in my shed and build. Chantelle is thorough in her research and her attention to detail and willingness to tool up is great, so we worked together well.



So over a cuppa we did a quick pre assemble of the parts and went thru some ideas on how we were going to complete the project. We went thru the various bits n pieces and kit parts she had purchased. All looked of reasonable quality.

Things were going to be tight around the resonator end. But it would all fit in there.

Using the cover plate for reference we drew our centre lines, marked out the box and cut the resonator hole and sound holes.boxholescut


The real question was ..

How do we mount the cone?

The cone sits inside a “soundwell” so that the string saddle(bridge biscuit) sits above the surface of the top and provides us with the string action height. Chantelle was quick with the maths and measures and we decided the simplest solution was to build an inner box to house and support the cone.

The construction was straight forward. A bottom plate of ply to stop the cone from falling thru was glued to a second plate which helped position and centre the cone. My Delta scroll saw continued the link to the Mississippi and we took that as a good omen.. After scrolling out 3 holes Chantelle was getting better at scroll work 😉 A little shaping on the oscillating spindle sander to true up the inner circles and we were good. The cone drops in from the top. Being a cigar box the back is hinged and not much good to mount things so the soundwell would have to mount from the front. We could and may yet, glue the  well to the inside front but for now we created a top plate that would grab the shiny chrome cover plate screws, securing it rather well to the top. It meant for now we could disassemble and thus ease potential problems and pitfalls we might come across later. Four posts space the top plate from the cone holder and thus sets the bulk of the action height. The inner box is a snug fit inside the cigar box.


Using the centre lines and paper template we drilled ans screwed the neck in place. Taped the fretboard to the neck and screwed the tuning pegs onto the headstock.headstocktuningpegs

The biggest problem to slow us down from first sound was how to mount the strings at the tail end. The cover plate was intended to be used with beaded strings, which was not what we had. So grabbing a scrap of hardwood I set about making tailpiece. Not so easy as its a compounded curved surface. I drilled 4 small holes thru the tail to accommodate the strings and used the two outer “bead” holes and two screws with washers to mount the tailpiece to the plate.


Using only 4 of the cover plate screws we mounted the cover plate and made sure to capture the soundwell/inner box. Getting a little excited now we whipped the strings on for our first sound test and proof of concept.


First sounding


As expected the tuning does not hold well with new strings we also found the tuning pegs were decentering from the headstock holes with the string tension. The pegs did not come with proper bushes so we will have to look at that later. Other than that it sounded great and had a very distinct metallic ring to it.


With the initial success proven, we broke it back down and continued our build. Sanding parts back and properly gluing the fretboard and neck. Do note the use of bicycle inner tubing as the best woodworkers clamp ever discovered.



Thinking to the future, we made a small block that glued into the inner box to provide a little more meat for the strap button screw.

Additional tuning peg bushes from a local music shop.


After the gluing set over night Chantelle returned to pick it all up and whisk it home for the restring and a decent play before we commence part two of the build which will involve the cosmetics.


Next up.. paint

see you in part 2

*Photographs, Chantelle Riordan and Mark Symonds

What do five blokes and X32 have in common?

Wifi!- the perfect foldback

For those of you who have wished and searched for the perfect stage foldback, look no further. Tech is coming of age. Foldback to a musician or any performer is very important and when it starts requiring multiple sends for various performers, all on the same stage, things can start to heat up. A purist would enforce no audio leakage from the stage to the audience. What the audience (Front Of House) hears should be cleaner than the usual mud of sound the musos on stage have to wade thru. So perhaps headphones but then thats not the best look for a rock band. As a bassist I have to be honest and I’m sure many would agree with me that “you kind of need to feel it a bit too” to kick the adrenaline in and play to your best.

Sound is a little bit harder to “focus” than light is, so giving each individual on stage the sound mix they want to hear can be daunting and time consuming. Bumping into a new venue with limited time the last thing you want is to waste it on foldback. Well not any more..


x32 what a beast!


X32 gets wolf whistle

Behringer have a known rep for good value for money..Its not the best gear in the land but bang for buck its a happy medium, especially for those with a budget. X32 is a digital mixer with lots of bells and whistles, but this is not a review of the beast, plenty of those elsewhere. It would take many a blog to show off the cue trigger system, built in  effects rack, signal routing abilities, EQ, preamps, DCAs, matrix mix, Midi control(yep sync or trigger lighting(DMX) and or instrument patches) and the “offline/online” network ability of PC, MAC and linux editing software. What I’d like to flag is the control aspect and more specifically the foldback/monitor side of things.


Smartphone mixer view(image grabbed from the net)

Typical 5man band

While Tillerman is not a typical 5 man band, the five of us provide the core. We have a string section and brass as well but for now lets go with the core. Vocals, guitars, drums and keys. All have to hear a little bit of each other and all have to hear themselves to aid playing well.

In days of old each individual had his own instrument amp stack behind him. The additional vocals go out to FOH PA and returned to some front foldback wedges for the singers. I wont elaborate but we know how hard it is to balance that. Both for the audience and the members on stage.


Image of android tablet screen (image grabbed from the net)

One man, one amp, my mix

What if an individual member, has his own wedge and the audio to that wedge is exactly and only what he wants to hear. For eg. I am not interested in hearing the violin or the backing singers so much, I get my cues from the lead guitarist and drummer. X32 allows just this. Each member has a wedge and they are in control of what they hear. This is all done by wifi using ipads,tablets or smartphones. I can personally choose what I want to hear and how loud or soft I want to hear it , using my tablet, on my music stand, with real time adjustment. The x32 delivers this mix via one of the many internal mix busses. Any of which can be routed to Aux or xlr outputs and thus into a monitor speaker.

The tablet app is simple and looks just like a mixer bank of faders, all nicely labelled (if you have taken the time to enter the scribble strips) and can be recalled for different sessions, stages or even pre-programmed to change per song. Such is the flexibility. All of course can be pre-programmed or adjusted real time.


ipad mixer view

See it in action!

Want to see this puppy in action? Come and watch Tillerman the show, the Cat Stevens songbook. Don’t forget to say gday to the bass player 😉


Darktable, synced on 2PCs

Can two PCs, running Darktable with photos and library/styles ie configuration files synced over the internet work? YES

I work on my photos in two main locations and it was important for me to establish a system that allowed me to do this seamlessly.  I could use a cloud but call me old fashioned or cheap or simple, whatever floats your boat. For a number of reasons I chose to do it this way along time ago and its been working ever since even after a few software and hardware upgrades.

What is Darktable

For those uninitiated Darktable is a magic bit of free software written for Linux (Ubuntu etc) which allows editing of RAW photos. It includes cataloguing, application of styles etc Go check it out. The main point I want to draw your attention to here is that its non destructive editing/manipulation of the original file. It keeps those changes in a separate .XMP which is extremely small. It is that file, the RAW image and the configuration files which must be seen as the same form both PCs. I didn’t want one location. RAW are large files speed is important. Also two locations gives me that security of an off site backup.

Syncing Photos

I’m going to get to the trickier stuff further down but for now the simpler moves in our game of photo chess. As mentioned we have large RAW files, the .XMP definition file and our output printable, web or JPG files. As the RAW files are large I generally tend to move them either on the SD card or USB sticks from location to location. Especially after a large photo session incorporating 100s of images. Once the RAW files are in both locations tho they dont change so never add to the bandwidth or internet burden. Only the XMP or output files change and these are small so zip along the net highway.


Via an SSH tunnel linking both machines across the net I use Rsync or the gui version Grsync to keep both HDs looking the same. Keeps all the photos up to date. No matter what machine I am on it all looks the same. Any style I create, any edit can be done on either machine. This also means no matter where I am in the world I could via the SSH access the photos.

Syncing Library, styles etc

The one thing I was lacking was the configuration setup the library database used by Darktable to keep track of where things are, tags, styles, the last thing I was editing , history and that sort of thing. Luckily Rsyncing the /home/user/.config/darktable folder works perfectly. All your styles, presets, watermarks and the current configuration of the Darktable view is seamless across machines. Again a rsync command takes care of this.

Using external HDs

My Photos are stored on removable drives. In one location I have extended the SATA cables outside the box and the drive just sits on the top. Prior to that the drive was kept inside but I do lots of different things and was often disk swapping. In location 2 I have a SATA to USB dock where I plug the HD in. Ubuntu changed the way it mounted things a while back and also due to HD updates (you always need more or bigger HDs when playing with images) so naming started to become an issue. That is the darktable (DT) library stores the location of each image so it can cross reference tags etc. This is great when searching thousands of images for a faint memory. Of course this relies on you diligently tagging your photos on the initial import..but that’s for another post.

Linux makes this easy we can make any location  “look” the same to DT. Ubuntu now mounts drives in /media/user/ so what I did was create a symbolic link in /media/ to point to whatever the name of the drive was .


Here is the PHOTOS HD as mounted by Ubuntu. /media/user/

Links can break if the HD is not physically there but thats not a problem It will re link as soon as the HD becomes available. Just don’t use DT when its not there.

To create the symbolic link I found it best to set it up in sudo or super user mode. you can either do it manually or run your file manager sudo nautilus or sudo thunar etc from. I wont go into the nitty grit here because doing stuff sudo can create havoc. Not a beginners thing. This post is more conceptual than an exact how to.


sudo nautilus

Ctrl shift Click drag to create link in /media/

Broken but not busted

To prove all this works well, I broke it. It was that time again to upgrade to a bigger HD on both machines. I noticed in the copy process that one of the drives was running under NTFS. Not sure how that happened but it was time to set it all to FAT32, making it all a little bit more compatible.

Naming labels.

Everbody loves FAT32, or so the internet says. Its the most compatible across platforms. As we are using Linux but may want to jaunt over to a WinPC or even a MAC, logic would suggest we format our drives in FAT32. Problem is by default FAT32 labels its drives in uppercase only. There are ways around this but why make things tricky. That sort of thing bites you in the bum later on, normally when you are under pressure.

So I formatted the two new drives as FAT32, copied the terabytes of data across to both of them(yes this took a while) and installed the drives in their PCs. All booted , all photos were viewable…then I invoked DT and it was all broken.

Darktable had the wrong address

If you look at the library.DB in .config/darktable/ with say SQlite manager you will see in table film_rolls a field  called folder. This is where the image address records are stored. Straight away I noticed the problem. My library was looking for /media/Photos due to the NTFS hangover. I could have fixed this with the symbolic link, I could have forced the label to be lowercase but lets try and clean it up so it always works and it matches the default scenario. I had also in the past moved drives around and new that other locations in the library were kind of broken. Time to fix this all up once and for all.

SQliteman-modifying the Library.db

I am not  an SQL guy, in fact its the first time I have used it. I find the syntax and online help messy and confusing. Creating a “query” to search or find the problem was easy enough. replacing the address too was easy.

select folder,
from film_rolls

But saving the db, with the changes took me a while to work out. I bobbled my way thru examples online and finally came up with this.

UPDATE film_rolls set folder =replace(folder,’/media/Photos/’,’/media/PHOTOS/’);

Using this new found info you could “touchup” or modify any weird things in the DT library.db. WARNING applies of course. backup first.