Elna SP foot pedal went bang

Elna SP foot pedal to the metal

On the back of a previous article about a repair I did on the rather wonderful Elna SP sewing machine, a reader got in touch.  She was a genuine sewing aficionado and had several top of the range current machines, but she used the trusty Elna SP for many smaller jobs, where the other machines didn’t quite cut it.

All Elna SP machines are getting on a bit and parts are either re-manufactured, scarce or secondhand, if you can find them.  Having said all that, a well-maintained Elna will run for many years and last much longer than new metal on sale now.

IMG-1971
FixItWorkshop, Worthing, November’18, Elna SP Special, in action

The foot pedal on this machine had gone pop, bang, finito.  It smelled terminal.

Knowing that parts for this machine are rarer than hens teeth and I do like a challenge, I took on the job.  I’m based in Worthing, West Sussex and the machine was located in Scotland, so after a short wait, the knackered pedal arrived in the post.

The pedal is held together with four small self-tapping screws and came apart easily.  The reason for failure was two-fold.  The copper leaf contacts had arced excessively and caused major pitting in the contact strip (see slide show) and the probably ensuing resistance had caused the main resistor to overheat, causing the winding to fail.

This slideshow requires JavaScript.

The contact surfaces were easy-ish to fix, or rather breathe new life into as all they needed was cleaning and re-shaping.  The resistor was a bit trickier to mend.  Getting hold of a replacement was going to be near impossible, so the only thing to do was to try and repair it.  Without that particular style of resistor, of that value, it wouldn’t work again.  Luckily, there was some excess resistance wire on the thing and I managed to twist it in to the broken section.  Soldering was not an option, since the wire was an alloy that wouldn’t take to solder and in any case, these things get hot in normal service.  I twisted both ends of the break to form a new section, while maintaining the same length of windings on the resistor, essential if I was to match or get close to the original specification.  Difficult.  Luckily, after a few goes, I managed it and the applied a little heat-conducting (and therefore dissipating) paste to the join.

With the pedal reassembled, I was only able to test it with my meter, since the sewing machine was far too heavy to post.  The pedal tested as a closed circuit (OK), which was a result.  I then had to wait for the pedal to be collected, taken back to Scotland and tested.  Fortunately, my fix worked and the machine sprang in to life, without a hitch or missed stitch.

Now, a word of caution with this one.  This is NOT the best way of mending something like this and all I’ve probably done is prolong it’s life a little longer.  There are generic sewing machine pedals that would work with this machine and will be fine, when this one fails in future, but that’s not the point.  The main thing is that something that was broken is now working and even if it’s not the best fix, at least it will run for a bit longer.  Happy days.

Cost of replacement: (generic part) £15-30.  Cost of repair, my time, a bit of solder and several cups of tea.

Very quiet Bauhn DAB Radio from Aldi

A little DAB radio, repaired at the workshop.

A colleague of mine brought this cool little DAB radio in to the workshop as it’s once crisp DAB tones were now no more and all life from the little device, had seemed to have ceased.  It was, very much, a dead radio.  When working, it picked up every station available, really clearly and seemed to out-perform the much more expensive devices my colleague also owned.  However, after a few months in the hands of his son, the radio would no longer turn on when plugged in.

IMG_20180515_153713.jpg
FixItWorkshop, May’18, Aldi Bauhn Radio, in for repair.

It was brought from Aldi for under £10, which seemed like a bit of a bargain to me.  It’s amazing just how much DAB radios have fallen in price in the last 5 years or so.

IMG_20180515_153836
FixItWorkshop, May’18, Aldi Bauhn Radio, in for repair, back of the radio.

The Bauhn UDABR-0197 (catchy name) is a compact, portable radio and is capable of being used with either a plug-in adaptor (supplied) or 4 x ‘AA’ batteries.  When powering this radio using either plug-in adaptor or batteries, the little radio refused to do anything.  Very sad.

I always start with the basics, so I checked the power from the plug-in adaptor first, which seemed to be delivering its 5.9VDC, pretty much spot-on. As a side note, I always check the condition of plug-in adaptor leads and plugs as they seem to almost always be made of the thinnest wire available in the Far East and prone to cracking causing poor connections.  This one was fine.

Opening up the radio was really easy, just 4 cross-head screws and the two halves of the radio came apart without any major dramas.

The first thing you notice about (cheaper) small appliances like this, is the ‘lack’ of anything inside.  The circuit boards in new small devices can sometimes be multi layered affairs, using micro components, making repair with normal workshop tools very difficult or impossible.

Luckily for this little radio, the designers have had the foresight to keep the power distribution board separate from the main ‘radio’ gubbins and this seemed to be of conventional construction.

On closer inspection of the power distribution board, it revealed a break in two of the pins from the ‘power-in’ jack socket meaning that power would not get through to the main circuit board.  The two pins were also shorting together, causing a local loop connection.  This meant than neither mains adaptor supply nor battery would power the radio.  Problem realised.

I was then able re-make the connection using a soldering iron on the board, reconnecting the pins to a spare section of copper detail on the power distribution printed circuit board.  Very satisfying.

Once the radio was back together, all screws back in place, power supply connected, the radio burst in to life, just in time for me to listen to my favourite station.  Happy days.

IMG_20180515_155029
FixItWorkshop, May’18, Aldi Bauhn Radio, in for repair, all fixed.

Cost of a new radio; £10.  Cost of repair; A bit of soldering and a cuppa plus gingernut biscuit.

Ultimate Speed Battery Charger from Lidl, on standby

Battery charger repaired at the workshop

My in-laws have an ornament on their drive, in the shape of a 2001 MGF roadster.  I say ornament because it’s fairly stationery, all of the time.  Even so, it’s battery gets topped up once in a while and the engine turned over when the urge presents itself.  Because the car isn’t used, the battery’s only means of charge is via a plug-in charger, my father-in-law occasionally hooks up.

IMG_5316.JPG
FixItWorkshop, March’18, Ultimate Speed (Lidl) Battery Charger.

The battery charger in question is an Ultimate Speed (Lidl brand) universal battery charger.  They’ve been on sale in the UK for a number of years at the £15 (approx.) mark.  They’re really good value as they allow ‘smart charging’ of car and motorcycle batteries without the risk of damage at a fraction of the price of the ‘big brands’ or a replacement battery.

However, this charger decided that it wasn’t playing anymore and refused to offer it’s charging services when recently connected to the MG’s flat battery.  On it’s way to the great bin in the sky, I managed to divert the charger via the workshop.

Once connected to the mains, the standby light illuminated, indicating something was actually happening, but upon connecting the low voltage side to a battery, making a charge selection via the single push-button switch, nothing changed and the whole unit remained on standby.  Pretty annoying.

Luckily, I have the triangular screwdriver required to undo the six screws that hold the (IP) ingress protected casing together.  Triangular screw heads are annoying and pointless as they prevent, in my opinion, people with a basic tool set having a go at a repair like this.  If you do fancy getting one of these tools, they are easily available on Amazon and eBay.

On with the fix.  With the casing opened up, my first port of call was with the switch itself.  Past experience has taught me to 1; start with the easy stuff and 2; these push to make switches fail all the time.  They’re in everything from door bells to cookers at the moment and when faulty, make the most expensive item and expensive paper weight in the blink of an eye.

To test the switch, I connected the charger to the mains and hooked up the low voltage end to a battery and simulated the button push switch by shorting out the switches connections on the circuit board.  Hey presto, the charger worked perfectly, every time.  The switch either needed repairing or replacing.

Because I’m a skin-flint, I opted to see what could be done with the present switch.  With care, these switches can be prised apart, using a sharp knife and the insides cleaned.  I took the switch apart which revealed nothing more than slightly corroded switch surfaces.  I can only assume that the product’s bold IP rated claim is a little over exaggerated and that some damp had wriggled its way to the switch and mucked it up.  With a cotton bud and switch cleaner, the switch surfaces scrubbed up like new and I re-assembled the switch lever and securing plat using a soldering iron to re-melt the plastic nubs holding the switch together.  No one would ever know it had been in bits.

With the circuit board returned to the housing, all six screws done up, the charger was back to rude health once more and ready to tend to the stranded MGF.

Vedette Wall Clock ne marche pas

A little repair on a French wall clock

This lovely wall clock had been running perfectly fine until a friend of mine decided to move it temporarily from the wall, during a recent bout of home decorating.  Now, I’m no expert on French wall clocks, but we think this one is circa 1920s or 30s, but either way, it’s a lovely thing to have in the house.  This one is also fitted with Westminster chimes, so one assumes it was made for the English market as an export item, all those years ago.

IMG_20180122_202319
FixItWorkshop, Jan’18, Vedette Wall Clock (French)

Once the paint had dried, the owner decided to re-fit the clock to its hook on the wall, but it simply didn’t run, even when fully wound-up.  Strange, what had happened?

Having a quick look at the front of the clock revealed nothing much.  The pendulum was where it should be and appeared to swing freely, as a pendulum should, but there was a slightly strange ‘double-click’ tick-tock, indicating something wasn’t right.  Clocks of this type should emit a definite even tick – tock -tick-tock.  This one wasn’t. Hmm.

Before going to see the clock, I had already decided that the small spring that suspends the pendulum could have been broken, so I packed a few spares I happened to have, just in case.  Opening up the mechanism revealed that the spring was actually intact, not bent or warped and therefore perfectly serviceable.  It was fairly obvious almost immediately that the small clasp which secures the pendulum to the escapement lever was bent and the probably cause of the problem.  All that was needed was a small amount of tinker-time to fix that with a small pair of pliers.  However, that wasn’t the end of the story.  Having undergone a ham-fisted removal from the wall, the escapement pendulum lever was now in a slightly different position and some more fettling was required to get the clock back ‘in-beat’, a common requirement on this mechanism type and often the reason why a clock won’t run, even when fully wound.

As the clock mechanism was out of the main casing (see photo) I decided to prop-up the mechanism on two tins of beans to allow the pendulum to hang over the side of a level table.  This allowed me to access to the clock’s mechanism and hear what was going on clearly.  A slight adjustment on the main pendulum lever to the right on this mechanism and the clock was back ‘in beat’, keeping good time.

After giving the case a general clean up and polish, I refitted the clock mechanism back inside it and hung the whole thing back on its hook, back where it belonged, on the wall.

Cost of a replacement: Sky’s the limit. Cost of repair; 1 cup of tea and 1 chocolate digestive.

Poorly Scalextric Sport Digital Lap Counter (C8215)…

Scalextric C8215 lap counter repaired in the workshop…

First off, I must confess, that this is part of my own Scalextric collection, not part of someone else’s.  I’ve always enjoyed slot car racing and a lap counter is an essential addition to anyone who wants to prove that they’re the fastest around the track!  Trust me, it can be very addictive, especially when racing against one’s better half.

IMG_4854
FixItWorkshop, Dec’17, Scalextric Lap Counter C8215

Anyway, I wanted to share this little repair in the hope that others might benefit.

My once reliable lap counter started to miss laps on lane two at very crucial stages of a race.  It started by only happening occasionally before completely missing several laps in a row, forcing a stewards’ enquiry to settle the race finish times.  Lane one was fine.

Time to get out the screw driver and delve in to the workings of the timer.  Once removed from the main track layout, the back of the unit has a cover which is held in place with six small self-tapping screws.  These come undone easily and removing the back reveals two sets of electrical switch contacts, operated by a lever on each track, just under the slot car rails.  The idea here is that the slot on the slot car operates the lever as the car passes the lap counter track piece, operating the switches contacts, completing a circuit, thus counting the laps.

Comparing the switch contact clearances, lane one’s was considerably closer than lane two’s.  This means that the ‘dwell’ time on lane two’s switch would be less that the switch on lane one, which was working ok, meaning a possible cause of the problem.  To anyone who’s adjusted contact breaker points on an old car, you’ll know what I mean here.

I had no idea what the correct clearance should be, so took an educated guess and closed the gap to about 0.5mm, done by eyesight alone.  I made sure that both sets of switches were the same (see photos).  While I had the counter in pieces, I cleaned the contact surfaces with a little electrical contact cleaner, just for good measure.

After re-assembly and re-fitting to the track, a few test laps with my fastest race Mini, proved that the counter was working as it should once again.

Cost of a replacement counter (second hand) circa £12.  Cost of the repair; 10 minutes tinker-time.

Raucous Kenwood Chef A701a

A noisy Kenwood Chef A701a gets a gearbox rebuild.

This Chef had been sleeping quietly in a kitchen cupboard for some time before being woken up to make cake mixtures once again.  The owner had owned the mixer for many years from new and was sentimentally attached to it.  I fully sympathise, they’re great machines.  It had been used many times in the past and then packed away as new machines came and went.  Having decided that there was still a place for the A701a, it was fired up.

The owner didn’t remember it being quite as noisy and wondered if something was wrong with it.  She got in touch and brought it in to the workshop.   After listening to the mixer at varying speeds, we agreed that perhaps it was a bit noisy and that further investigation was required.

 At this stage I must confess at this repair has been on the bench for a long while..!

I think the A701 is my favourite Kenwood Chef product as it’s very elegant, beautifully proportioned and almost over-engineered.  It comes from a time where built-in obsolescence was a swear word.

White removed
FixItWorkshop, Oct’17, Kenwood Chef, A701a,

On with the problem.  After disconnecting the gearbox by removing the drive belt, I checked the motor for general wear and tear, the brushes and speed control mechanism and I concluded that it all seemed OK and working smoothly.  The gearbox however did seem a bit noisy when turned manually, nothing hideously graunchy, but a little rough.  To be honest, it would have probably survived, but I wanted to open up the gearbox to make sure that it was as it should be.

Whilst removing the Chef’s casing around the gearbox, I’d noticed traces of grease around the joints and various power take-offs.  All models seem to do this to an extent, but this one seemed to be quite bad.  Closer inspection revealed that some of the grease had escaped out of the seal between the two halves of the gearbox casing.  Opening up the casing revealed that the grease that was left had been pushed to the corners of the space within the gearbox and that the gears were a bit dry, this was probably the root cause of the noise.  The planet wheel that drives the beater was also bone dry.

Luckily, there are plenty of suppliers who can supply rebuild kits for Kenwood Chef gearboxes, including new gears and grease.  The gears in this seemed serviceable, but it seemed very sensible to replace the lubricant with the correct 130g of Kenwood gearbox grease, which is food safe.  I used ‘Kenwood Chef Restore’, an eBay seller and the kit was a reasonable £10.99, including P&P.  The kit included the main gearbox grease, white grease for the planet gear and sealant for the gearbox casing.

IMG_4570
FixItWorkshop, Oct’17, Kenwood Chef A701a, repair kit from Kenwood Chef Restore, eBay.

Before replacing anything, the first job was to clean out all traces of the original grease which had gone very sticky and was contaminated with general wear.   The first pass clean involved using paper toweling, followed by water and detergent, before a final clean with brake cleaner, which removed the last few traces of grease and dirt.

With the gearbox refilled and resealed making sure the spacers were re-fitted to the correct parts, the drive belt re-fitted with just enough slack, the gears sounded much sweeter with the final parts of the casing reassembled.  One last point to note is that I used silicone sealant on the blender attachment power take-off plate in replacement to the one fitted, since the original seal was well past it (see below).

As a finishing touch, I replaced the existing machine feet which had turned to mush with replacements from Sussex Spares (eBay shop) for a very reasonable £2.70, delivered.

The Chef was now ready to prepare cake mixtures again.

Cost of new machine: £300 and up.  Cost of replacement parts: £13.69 (plus my time).

 

Lucky Voice Microphone without the X-Factor

Lucky Voice Microphone repaired.

A colleague of mine came in with a broken microphone, which is part of a Lucky Voice karaoke set and retails for about £60.00 on Amazon.  The microphone had worked pretty well, but recently had lost its ‘X-Factor’ somewhat.

The microphone is fairly standard fare and connects to a standard XLR plug and socket arrangement.  As this part is usually under the most stress as the singer moves about, it seemed sensible to have a look at that first.  Upon connection to my amp, there was a huge amount of crackling which seemed to coincide with cable movements at the microphone end.  Swapping the lead for a known good one I had proved that the microphone was fine, but the lead not so fine.

Only one screw holds the plug together and straightaway, the problem presented itself.

IMG_4519
FixItWorkshop, Oct’17, X-Factor microphone, XLR connector.

The main core had detached from the connector, as the outer cable sheathing has come away from the XLR connector body clamp.  Not ideal.

A quick strip back and solder job and the wires were connected back where they needed to be.  A little dab of hot-melt glue on the cable grip and a re-tighten and the cable was not going to move anyway.

With the plug re-assembled and the screw put back, the microphone tested perfectly on the amp, ready for karaoke once more.

Cost of a new similar lead: £10,  Cost of repair: 15 minutes, dab of glue and solder.  Nice.