Retire.IT – Rest in peace – Black & Decker GL570 Line Trimmer

There comes a time in any machine’s life, that unless it is capable of self-repair that eventually the law of diminishing returns kicks in. Sadly this has now happened to my Black & Decker GL570 Line Trimmer that I have been steadfastly maintaining to this day. The actuator that enables the line to be extended began to have trouble soon after its repair the second time – due to the hole in which the actuator rotates that was getting enlarged, hence the actuator was not rotating freely and was not doing its job. Today I was trying to trim the edges after a hiatus of a month or more, the growth was a bit too much – the motor was getting hot from the heavy cutting and threw its bearing. When the bearing came off, the motor ground to a halt, and the actuator pin snapped off.

After opening it up, even after 10 minutes, the motor was hot to the touch. Perhaps this is now the time for this faithful line trimmer to rest in peace. Shall I “Retire.IT“? I.e. allow it to rest in peace or perhaps look to see what can be done with its component parts.

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Here is the motor with the bearing that has come off – that is the little brass piece. I could put the bearing back in, but due to the nature of the motor and its housing, there isn’t anything to stop it coming back out – unless I make a stopper to block the bearing from sliding off.

Now this might be a good time to see about removing the line spool housing from the motor spindle. If this can be done without damage to the spindle shaft, I might be able to use or repurpose one of the after-market cutting heads. If I can do this, then this line trimmer could live again with perhaps a Little Juey head.

We don’t usually rush in as we also might need to work out the economics of the situation. A replacement cutting head would cost about $32 but a cheap new line trimmer like the Ozito 550W is only $50.  If I go for a new line trimmer, it will most likely be in fine working condition and will generally work within its guarantee period.  After it goes out of warranty, I might eventually end up in the same situation with having a line trimmer that isn’t working well.

Maybe the solution is to attempt to remove the line spool housing from the motor.  If it could be done without damage, then perhaps design and make a new trimmer head for it that is either similar to the commercial heads where it is easy to replace the line.  Failing this, then buy a new line trimmer, and think of a use for the motor from the Black & Decker.

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Reassemble.IT – Black & Decker GL570 Line Trimmer

…continued from yesterday…

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I put the actuator into the vise on my milling machine, then milled the worn pin off it.

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Then I used a 2mm drill and drilled the initial hole for the pin to go into. I do this so that if the first hole is not centred, I can still adjust the position when I drill for the final size.

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I drilled the final 2.5mm hole into the actuator. The pin that I made is just over 2.5mm in diameter so it should press in and be reasonably firm.

I inserted the pin into the actuator, then milled to the appropriate height.  Here is a photo of the repaired actuator.

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Now some of you might not have a line trimmer, so I have a photo of it installed into the line trimmer head.

SONY DSCSo the question in everyone’s mind is “Does it work and do the job?”.  A very good question – since the pin is slightly longer, it will be a little heavier.  My scales can only measure to the gram, and it shows the weight of the entire actuator is 2g.  Anyway, the acid test is to try it out.

I have to say that the this was an oustanding success.  I trimmed more than 10m of edge and the line did not break.  It would advance the line from time to time – I inspected the actuator afterwards, and I can see no real wear.  Not bad what a couple of thousand dollars worth of machinery can do!

The nylon material I used is from a kitchen cutting board – I bought one some time ago as a source of cheap nylon.  I put it in the lathe to turn it down to size, 2.5mm and 3.9mm, then the rest was on the milling machine today.

[Edit]  When turning soft materials like nylon and other plastics on a lathe, it is best to turn down the diameter in stages.  I wanted a final 3.9mm diameter so elected to first turn to a 5mm diameter first, then I turned a section to 2.5mm.  This is because plastics are not as rigid as metals, so will move away from the cutting bit, hence turn down to 2.5mm in small sections until the length of that section is correct, before turning the 3.9mm section.

Recycle.IT, Repair.IT – Black & Decker GL570 Line Trimmer

Our local councils have regular clean-up days for disposal of household goods – that can often be good working items or be just plain rubbish. Anyway, I scrounge around for interesting things that can be recycled – and sometime last year, I came across a Black & Decker GL570 electric line trimmer. Knowing that electric line trimmers like this basically consist of a switch and motor – chances are that they can be easily fixed, as long as the motor itself hasn’t failed. The motor can also be reused for other purposes – this would allow me to “recycle.it“.

I grabbed it and once I was home, I checked it – it would spin very slowly but with a loud rattling noise – ok, not good. Anyway, it was put aside for a while, and when I had some time, I opened up the motor housing – the end bearing of the motor had come adrift and was loose inside the housing. That explained the slow spinning – it was a matter of a minute to push the bearing back on, then reassemble the motor housing. Testing it again, gave a good spinning line – fantastic – another item saved from the trash heap. Do you know that households generate tons and tons of rubbish that include lots of things that can be fixed, just like this?

Ok – this is not the end of this post, far from it. The line trimmer would work and would cut well, and then sometimes the line would not advance. This occurred occasionally then more frequently until a few days ago when the line would break after cutting a foot or so of lawn edge. Not good! I took the spool out, then saw that the actuator has a pin that allows the spool to advance the line – this pin was worn, such that it was likely to be the cause of the problem. You can see the end of it which should have this round pin but is very flattened.

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So, what to do? Buy a new one, of course – checking the manufacturer spare parts gave me a part number – 806474 – good. I rang the nearest service agent at Clyde, ring ring, ring ring – no answer. Ok, try the next one at Lidcombe – they answered, and was put through to spare parts. Are you sure that is the part number? – I am asked, it should have a dash 01 or something similar. I explained that the part number came from Black & Decker’s website from the parts listing for this line trimmer. Anyway, they got my mobile number so will get back to me. By the way, eBay shows that I could get a pair of these from the UK for about $14 – and if I order now, it should arrive by January 2, 2015.

Now what? I have a machine shop in my garage, so maybe I should just “repair.it“? I could cut the pin out, drill a small hole then make another piece that would fit in place. I have some nylon sitting around and some HDPE – anyway, I made a pin out of nylon – it is slightly longer so that it will engage with the spool a bit better, which will help with the wear, but it it will be slightly heavier.

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The extra weight might cause problems, but it is worth a try. All I need to do now, is to mill the pin off, then drill a 2.5mm hole dead centre of where it should be and just push the new pin in. I could glue it, but it would be best to try it out first.