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I bought a Makita table saw ( https://makitauk.com/news/makitas-new-site-saw-has-85mm-depth-of-cut) from a guy on eBay and it has been faultless, right up to this morning when I went to cut some wood for a picture frame - no great load on the motor - when the blew.
Basically, the saw was plugged in and powered on for a few minutes and was fine. I pressed the big green go button and the blade just started to spin when everything just stopped. I checked the power trip at the consumer unit in the garage and nothing had tripped. I then realised that the light on the gang plug* that the saw was plugged into was not on. I changed the 13amp fuse on this and the saw restarted just fine so I cut the two lengths of wood I needed. About 10 minutes later I went to saw something else and the same thing happened. I had to go elsewhere so haven't investigated further but hints and tips for tomorrow would be welcome.
On a side note, I thought the RCD was meant to trip quicker than the old 13amp fuses but clearly not in this setup
*Probably not advisable to plug the saw into a gang plug extension but it is convenient and has been fine in the past.
Have you tried repeating this without the gang plug?
RCD is earth fault, 13 fuse is over current and speed of fusing depends on fuse installed spec.
If it's only as start up it could be inrush current. Install a slow time delay fuse and try that.
Not tried anything yet as I was in a rush this morning and just left it for tomorrow when I have time to investigate. Yes, try without the gang plug is step 1. Actually it is step 2, step 1 is to make sure the blade is free spinning without and sawdust or general crap adding to the load.
Not sure what a 'time delay fuse' is. I can guess but I have never heard of, or seen one. I guess it will allow a little extra load while the blade spins up before kicking in. This makes sense and I assume that most effort is when it first starts, first starts to cut and first starts to bind if you twist the wood while cutting (I never do that of course). I am hoping that cleaning and lubing everything will reduce that problem althoug it was tripping as the blade started and before any actual cutting.
Both suggestion welcome and kind of mirror my thinking.
Silly question, but is anything else plugged into the extension? If the saw is designed to pull 13A peak and there's a heater or something plugged into the extension as well, it's going to pop.
Direct drive motor?
Overloaded capacitor if the motor has one might be pulling too many amps on start up.
Basics first
New plug
New extension rated to 16amp Sniff test of the motor.
Oh yeah unplugged when tinkering
Nothing else was plugged into th gang plug.
Not sure about motor type.
No funny smells.
Will investigate carefully in the morning.
I actually suspect there is something that is binding against the blade/motor spindle with ramps up the current when it starts. Moving it around when I ended up replacing the fuse the first time possibly dislodged it but then it slipped back which tripped it the second time.
I will start with a thorough clean and inspection inside the main casing, then work along the elctrics from the plug.
Cheers guys. Looks like I wasn't missing anything too obvious.
Some extension leads are effectively made out of tin foil inside, it's amazing some of them work at all. If that's good...
I'd open the tool up and chop out the first 20cm of cable and reterminate it incase of stress damage. Annoyingly I'd already opened up the rest of the tool thinking the brushes were shorting out on the motor (armature) before realising it was the flex.
[i]/Some extension leads are effectively made out of tin foil inside, [/i]
Seen that before too. Hopefully Makita will be a little better
Can you plug it in somewhere else with a standard on the wall socket ?. Kitchen maybe.
I was going to suggest the capacitor, they have a habit of going, and its nearly always starts, then stops, like for a better term, 'can't catch it's breath'
Install a slow time delay fuse and try that.
Don't do this. Something has changed, most likely in the saw/extension lead
Basically as suggested by various people above. Start simple, unplug the saw and check for dust and slivers of wood slowing the blade and go from there.
Get the garage circuit extended to reach the saw without an extension lead, trip hazards aren't great near to a working saw 🙂
My dust extractor used to do this. Was annoying as hell.
I changed various bits, checked/cleaned everything several times, changed the capacitor and it still did it.
I actually had a big bag of fuses like a bag of sweets that I needed as it would blow them randomly and very often.
We have a 16amp connection and we changed the plug to that and its been very well behaved ever since.
I know nothing about electrics and have no confidence with it so needed help on it but it works well.
We already had a 16amp outlet in the workshop but I guess you might need to have one installed.
This bloke had similar problems with his welder but unlike me, seems to know what he's talking about with electrics.
sounds like it's just pulling too many amps for the circuit you have it plugged into. depending on your set up there might be other things on the loop using power too
try it directly into an outlet where you know nothing else is drawing power on the loop.
might be you need to upgrade a circuit. to the garage
personally I wouldn't go taking things apart and invalidating warranties
ah have I misread? it's secondhand and been working fine for sometime and then suddenly doesn't? unlikely to be the circuit then unless you've changed or added any appliances, missus wasn't using a blender or something at the same time?
.
Cleaned out the case witht he shop vac and air fromt he compressor. Amazing how much was in there. I found the nut I dropped a couple of weeks back stuck in the rubber foot of the table when I turned in upside down for better access. Cleaned and greased the blade lifting mechanism and tightened a couple of loose bolts. Put it all back together and it works just fine when plugged directly into the socket. When I first used a different extension cable that was fine too for the first couple of attempts and then tripped. Plugging directly into the socket continues to be fine. The sockets are mounted on the rafters so the cables go upwards rather than across the floor so as long as I keep the saw under the socket I am fine. I was using the extension to position it neared the big door to get rid of dust more easily.
I noticed when I was measuring some wood I was cutting the the blade is about 4mm offset from the zero marker on the built in scale as if it is now closer to the motor. I had the blade off while cleaning and tightening stuff but don't remember moving anything that much. I guess it could always have been offset and I had never noticed before but I will have another look when it is a bit warmer. For now it works.
Maybe fate is trying to look after you, what with your reputation!
Good progress 👍
The sockets are mounted on the rafters so the cables go upwards rather than across the floor so as long as I keep the saw under the socket I am fine.
Is it worth trying the extension up on the rafter to see if that works?
Because it sounds like the flex on the saw needs to be replaced.
What’s the motor rated wattage wise? And have you got a way of accurately measuring the voltage at the socket you’re plugging into? A bit of volt drop plus some load on the blade or start up current could be enough to tip it over the fuse rating
Problem Solvers.