Power Tool Electrics Help
- Thread starter Mark A
- Start date
Help Support UKworkshop.co.uk:
Eric The Viking
Established Member
- Joined
- 19 Jan 2010
- Messages
- 6,599
- Reaction score
- 76
What were the symptoms, Mark? Is is possible you could restore the switch you have?
From the pics it looks like a broken wire spring or clip - is that so? Can you make one from heavy gauge (0.8) MIG welding wire - it's really springy and I often use it for small coil springs. It might not do for this, but a paperclip might...
Obviously safety is paramount. Whatever you do, check everything electrically afterwards and test it a lot (with a resistance meter or continuity tester) before putting mains on it again. If you don't feel absolutely confident with the result, don't re-use it.
. . .
It looks like it might be an old-style microswitch that's been adapted to fit (microswitches were intended for that - nowadays you commonly find small ones as safety interlocks on bandsaw covers, etc.).
They rarely go completely wrong although the contact surfaces do pit, from the spark when they switch off. If it's old enough, you might get away with gently cleaning the surfaces with fine emery cloth or wet+dry, or even Brasso. More recent ones tend to have plated contacts, but older ones had solid pads which can be cleaned up if you're gentle.
Putting therm together is a horrible task mind, as they were factory-assembled using jigs. It can be done with a bit of patience and ingenuity.
They're a really good application for the plastic bag trick: find a big clear plastic bag, and put everything in it, including your forearms, before re-assembly. That way when a "ping-foo-kit"* makes a bid for freedom, it is usually unsuccessful. Also do it on the dining room table as things don't bounce as far on a carpet as on concrete or vinyl.
Also have a torch handy ("flashlight" in the colonies). If you do lose something small, holding it at floor level, with the beam sweeping across the carpet usually makes a tiny screw visible because of its shadow.
Spark suppressors are usually a rectangular component with two leads in the mains wiring near the switch (there's usually a capacitor and resistor in series inside, if memory serves). They do die of old age, and will cause much more switch arcing if not replaced (they also stop interference from the motor getting back into the mains. Somethign that old might not have one, but might have a disc capacitor instead (nobody bothered about mains interference back then as there was nothing to interfere with in the main!). So if you can mend the switch, do the suppressor at the same time.
If all else fails, you might hide a modern microswitch inside the handle, although they tend to be single-pole these days (i.e. only switch one wire, not both live and neutral as this one seems to do).
HTH,
E.
PS: If that rubber-covered cable is showing any cracks, I'd change it at the same time. If you can't get rubber easily, "arctic cable" will be similarly flexible. The colour doesn't matter, obviously, but it needs to be heavier gauge than normal flex, as it's for 110V (higher current use). Match the thickness of the copper in the original cable roughly with what you buy, and you should be OK. It limits your choice of switch too (also needs to be chunky).
From the pics it looks like a broken wire spring or clip - is that so? Can you make one from heavy gauge (0.8) MIG welding wire - it's really springy and I often use it for small coil springs. It might not do for this, but a paperclip might...
Obviously safety is paramount. Whatever you do, check everything electrically afterwards and test it a lot (with a resistance meter or continuity tester) before putting mains on it again. If you don't feel absolutely confident with the result, don't re-use it.
. . .
It looks like it might be an old-style microswitch that's been adapted to fit (microswitches were intended for that - nowadays you commonly find small ones as safety interlocks on bandsaw covers, etc.).
They rarely go completely wrong although the contact surfaces do pit, from the spark when they switch off. If it's old enough, you might get away with gently cleaning the surfaces with fine emery cloth or wet+dry, or even Brasso. More recent ones tend to have plated contacts, but older ones had solid pads which can be cleaned up if you're gentle.
Putting therm together is a horrible task mind, as they were factory-assembled using jigs. It can be done with a bit of patience and ingenuity.
They're a really good application for the plastic bag trick: find a big clear plastic bag, and put everything in it, including your forearms, before re-assembly. That way when a "ping-foo-kit"* makes a bid for freedom, it is usually unsuccessful. Also do it on the dining room table as things don't bounce as far on a carpet as on concrete or vinyl.
Also have a torch handy ("flashlight" in the colonies). If you do lose something small, holding it at floor level, with the beam sweeping across the carpet usually makes a tiny screw visible because of its shadow.
Spark suppressors are usually a rectangular component with two leads in the mains wiring near the switch (there's usually a capacitor and resistor in series inside, if memory serves). They do die of old age, and will cause much more switch arcing if not replaced (they also stop interference from the motor getting back into the mains. Somethign that old might not have one, but might have a disc capacitor instead (nobody bothered about mains interference back then as there was nothing to interfere with in the main!). So if you can mend the switch, do the suppressor at the same time.
If all else fails, you might hide a modern microswitch inside the handle, although they tend to be single-pole these days (i.e. only switch one wire, not both live and neutral as this one seems to do).
HTH,
E.
PS: If that rubber-covered cable is showing any cracks, I'd change it at the same time. If you can't get rubber easily, "arctic cable" will be similarly flexible. The colour doesn't matter, obviously, but it needs to be heavier gauge than normal flex, as it's for 110V (higher current use). Match the thickness of the copper in the original cable roughly with what you buy, and you should be OK. It limits your choice of switch too (also needs to be chunky).
Can't work out from the pics what the switch looks like when assembled, but I've got a whole load of appliance switches that came in a parts cabinet from an electrical shop's service department. Some of the stuff is of the same vintage as the Tarpnen, so it's just possible there's one like it in there. Or at least something that would do instead.
Wish I'd kept my 110V Tarpen trimmer - made current strimmers look like toys.
Wish I'd kept my 110V Tarpen trimmer - made current strimmers look like toys.
wizard
Established Member
I am looking for a switch for a ELU MOF 112 Router at a reasonable price
Mark A
Established Member
Hi chaps,
Apologies for the delay in replying - it's been a long day!
Eric: Many thanks for your detailed post, it was very informative. The copper contacts (correct terminology?) were bent out of position, so will take some trial and error to move them back into the right location. The wire clip was already broken inside the switch when I took it apart, though I've worked out how to put it back together if I can make a new one. My van is currently in a garage being repaired so I'll ask for a short length of welding wire when I pick it up next week.
I'm sure you've mentioned the plastic bag tip in the past because that's exactly what I did when I disassembled the switch. The flex is in good condition and I bought a multimeter to ensure my wiring is safe, but thanks for mentioning it - far too many people take risks with electricity.
As for spark suppressors and disc capacitors? There's neither wired to the switch so I can only assume if there is either then they're inside the casing of the tool.
Dick: I'll assemble the switch tomorrow and post a photo. If you do come across something similar that would be fantastic!
I'm getting into this vintage powertool stuff - apart from the Tarpen planer and a Skil wormdrive saw, just this week I took delivery of a Black and Decker Ripsnorter to add to my collection!
Cheers,
Mark
Apologies for the delay in replying - it's been a long day!
Eric: Many thanks for your detailed post, it was very informative. The copper contacts (correct terminology?) were bent out of position, so will take some trial and error to move them back into the right location. The wire clip was already broken inside the switch when I took it apart, though I've worked out how to put it back together if I can make a new one. My van is currently in a garage being repaired so I'll ask for a short length of welding wire when I pick it up next week.
I'm sure you've mentioned the plastic bag tip in the past because that's exactly what I did when I disassembled the switch. The flex is in good condition and I bought a multimeter to ensure my wiring is safe, but thanks for mentioning it - far too many people take risks with electricity.
As for spark suppressors and disc capacitors? There's neither wired to the switch so I can only assume if there is either then they're inside the casing of the tool.
Dick: I'll assemble the switch tomorrow and post a photo. If you do come across something similar that would be fantastic!
I'm getting into this vintage powertool stuff - apart from the Tarpen planer and a Skil wormdrive saw, just this week I took delivery of a Black and Decker Ripsnorter to add to my collection!
Cheers,
Mark
Ah, yes, the B&D Ripsnorter. In the village where I was born, the joiner/wheelwright/carpenter finally bought a power tool some time in the early 1950s, and it was one of those. It was still in use certainly into the 1970s; shows that B&D could once make decent tools.
wizard
Established Member
Got the Tarpen planer and the Black and Decker Ripsnorter plus loads of others and still looking
Mark A
Established Member
Hi Dick,
Here's some more photos of the switch assembled.
[attachment=-1]uploadfromtaptalk1414351849884.jpg[attachment]
[attachment=-1]uploadfromtaptalk1414351895263.jpg[/attachment]
Wizard - How do you find your Tarplaner?
Cheers,
Mark
Here's some more photos of the switch assembled.
[attachment=-1]uploadfromtaptalk1414351849884.jpg[attachment]
[attachment=-1]uploadfromtaptalk1414351895263.jpg[/attachment]
Wizard - How do you find your Tarplaner?
Cheers,
Mark
Attachments
wizard
Established Member
Sits on the shelf with all of the other old tools
Mark A
Established Member
You're saying you don't use them? :shock:
Eric The Viking
Established Member
- Joined
- 19 Jan 2010
- Messages
- 6,599
- Reaction score
- 76
That does look like a fairly conventional old-style microswitch. Did it have a single 'pimple' near one end, that was pushed in* by the metal plate to turn it on?
They used to be very common, although the few I had of that type went decades ago, literally.
You could replace it with a modern one, with a little ingenuity. The modern ones usually have two mounting holes on diagonally opposite corners, and you can stack them to give multi-pole switching, etc. You just need one (or a pair) in roughly the same place with the same amount of movement to activate it. a piece of aluminium angle suitably fettled would make something that attaches to the existing mountings (or fits in the space).
E.
*or allowed to pop out - they can work either way.
They used to be very common, although the few I had of that type went decades ago, literally.
You could replace it with a modern one, with a little ingenuity. The modern ones usually have two mounting holes on diagonally opposite corners, and you can stack them to give multi-pole switching, etc. You just need one (or a pair) in roughly the same place with the same amount of movement to activate it. a piece of aluminium angle suitably fettled would make something that attaches to the existing mountings (or fits in the space).
E.
*or allowed to pop out - they can work either way.
Mark A":3ktty6vj said:
Hmm. Well, I've certainly got at least one switch which looks SIMILAR to that, but not sure if it would fit. Pretty sure the one in my box is fo a Black and Decker drill, but can't be sure. Will have a closer look at pic and switch and get back to you.
Mark A
Established Member
Hi chaps
I tried to show how the switch operates in a drawing, but I'm not much of an artist so gave up on that! I'll use words instead, but please excuse my poor description and dodgy terminology!
The metal strip (for want of a better word) inside the main body of the switch has a small hook on the end, and onto that is placed the little metal cup. The flared tips of the wire spring/clip (which is currently broken) are positioned into the holes behind the tip of the metal strip (marked with "x"). One end of the coiled spring is placed onto the metal cup and the other is inserted into the wire spring/clip component.
When the trigger is pulled the metal strip retracts. At that same moment the coiled spring compresses while the wire spring/clip pivots around with it. Once the moving parts reach 90° the fully compressed spring snaps the wire spring/clip forcibly in the opposite direction, which should then act on the rocker and make the electrical connection.
I managed to obtain some MIG welding wire but I think it's too thin and bendy for the job - quite a lot of force is applied to it when the trigger's pulled. dickm has suggested piano wire or spring wire, which might just work.
However, there's one point I haven't mentioned yet which may change things: the plastic (Bakelite?) component which houses the electrical contacts has become very brittle with age and the contacts no longer stay in place even after the switch is fully assembled. For sake of the photos I stuck them down with a spot of superglue, but I'd prefer a more permanent solution than just that.
Eric: Do you think the microswitch approach would still work?
Cheers,
Mark
I tried to show how the switch operates in a drawing, but I'm not much of an artist so gave up on that! I'll use words instead, but please excuse my poor description and dodgy terminology!
The metal strip (for want of a better word) inside the main body of the switch has a small hook on the end, and onto that is placed the little metal cup. The flared tips of the wire spring/clip (which is currently broken) are positioned into the holes behind the tip of the metal strip (marked with "x"). One end of the coiled spring is placed onto the metal cup and the other is inserted into the wire spring/clip component.
When the trigger is pulled the metal strip retracts. At that same moment the coiled spring compresses while the wire spring/clip pivots around with it. Once the moving parts reach 90° the fully compressed spring snaps the wire spring/clip forcibly in the opposite direction, which should then act on the rocker and make the electrical connection.
I managed to obtain some MIG welding wire but I think it's too thin and bendy for the job - quite a lot of force is applied to it when the trigger's pulled. dickm has suggested piano wire or spring wire, which might just work.
However, there's one point I haven't mentioned yet which may change things: the plastic (Bakelite?) component which houses the electrical contacts has become very brittle with age and the contacts no longer stay in place even after the switch is fully assembled. For sake of the photos I stuck them down with a spot of superglue, but I'd prefer a more permanent solution than just that.
Eric: Do you think the microswitch approach would still work?
Cheers,
Mark
Attachments
Eric The Viking
Established Member
- Joined
- 19 Jan 2010
- Messages
- 6,599
- Reaction score
- 76
As long as you have the depth in the handle. Here are some variations. They're all about 1" long, 3/8" thick and 3/4" tall. The basic operating component is the little, often red, 'pip'. All the levers and rollers do is adapt that tiny movement (the 'micro-' bit), to do something more practical in most cases. The holes on the corners are for mounting bolts. They are changeover switches, so you only need two of the three contacts, depending whether you want the switch to close when the pip moves in, or out.
The one bottom right above is the basic switch (the 'pip' is obvious although it's black). These are all 5A at 240V, which ought to be fine as it's AC (check the current rating of the motor). If it's a brushed motor it should be OK, but a higher-current switch will do no harm.
This one seems to be dual pole (like your switch), but that's not essential for this purpose:
You need do need one if the sorts shown above, with spade terminals or screws (not advisable because of the vibration in use). Googling threw up some wrongly-labelled miniature switches, intended for soldering onto circuit boards. If they are small and square and with four little 'legs' they're the wrong type.
Assemble your trigger again, and see if you can get an idea of how much the metal bit moves. The manufacturers specify the movement of their microswitches, either by distance or by angle, so you should find one that's suitable (they're all pretty similar as they are supposed to be interchangeable in industrial applications). You can also bemd those metal levers to shape if necessary, but the roller type will wear less in this application.
They should be cheap, so get some (eBay?) and experiment! You don't need to power the thing up - you can hear the click as they operate. There's a bit of hysteresis though - the movement to 'off' won't be exactly the same as the movement to 'on' your trigger's lever has to move further than the minimum distance to make the switch operate - you'll see if you play about with it.
Personally, I'd get some switches, and some aluminium strip (from a DIY shop) drill+tap for two small bolts to hold the switch (prob M3 or M2.5, non-countersink machine screws - Maplins used to sell suitable bolts). You then have a mounting plate, which you can glue into the handle with Araldite.
If you want to be really clever, you could make it adjustable by sandwiching two plates together with a rivet at one end so they can pivot, and a bolt at the other end so they can be locked together in the right position, giving you a range of movement for the microswitch lever. You'll need threadlock liquid (Loctite, etc.) because of the vibration.
Scrappy picture to follow if that doesn't make sense.
E.
The one bottom right above is the basic switch (the 'pip' is obvious although it's black). These are all 5A at 240V, which ought to be fine as it's AC (check the current rating of the motor). If it's a brushed motor it should be OK, but a higher-current switch will do no harm.
This one seems to be dual pole (like your switch), but that's not essential for this purpose:
You need do need one if the sorts shown above, with spade terminals or screws (not advisable because of the vibration in use). Googling threw up some wrongly-labelled miniature switches, intended for soldering onto circuit boards. If they are small and square and with four little 'legs' they're the wrong type.
Assemble your trigger again, and see if you can get an idea of how much the metal bit moves. The manufacturers specify the movement of their microswitches, either by distance or by angle, so you should find one that's suitable (they're all pretty similar as they are supposed to be interchangeable in industrial applications). You can also bemd those metal levers to shape if necessary, but the roller type will wear less in this application.
They should be cheap, so get some (eBay?) and experiment! You don't need to power the thing up - you can hear the click as they operate. There's a bit of hysteresis though - the movement to 'off' won't be exactly the same as the movement to 'on' your trigger's lever has to move further than the minimum distance to make the switch operate - you'll see if you play about with it.
Personally, I'd get some switches, and some aluminium strip (from a DIY shop) drill+tap for two small bolts to hold the switch (prob M3 or M2.5, non-countersink machine screws - Maplins used to sell suitable bolts). You then have a mounting plate, which you can glue into the handle with Araldite.
If you want to be really clever, you could make it adjustable by sandwiching two plates together with a rivet at one end so they can pivot, and a bolt at the other end so they can be locked together in the right position, giving you a range of movement for the microswitch lever. You'll need threadlock liquid (Loctite, etc.) because of the vibration.
Scrappy picture to follow if that doesn't make sense.
E.
Racers
Established Member
- Joined
- 22 Apr 2005
- Messages
- 9,172
- Reaction score
- 136
We used to use a bigger flatter one with all the connections on each end which might be better, but I can't find it to give you the type number.
The V3 aren't all that good with higher powers these ones are heavy duty.
Pete
Found them http://uk.farnell.com/c-k-components/as ... 0-00002068 they do a DPDT one as well but 2 side by side would work.
The V3 aren't all that good with higher powers these ones are heavy duty.
Pete
Found them http://uk.farnell.com/c-k-components/as ... 0-00002068 they do a DPDT one as well but 2 side by side would work.
Eric The Viking
Established Member
- Joined
- 19 Jan 2010
- Messages
- 6,599
- Reaction score
- 76
Pete Maddex":308dz39g said:
Agreed - that's a much better idea long term, but could still be fitted in a very smilar way.
Mark A
Established Member
Eric - my planer's motor is rated at 9.6A/110V, so I presume the current is too high for those little switches?
If so the switch Pete linked to looks good. Thanks for that.
One point I'm not sure about is how many switches do I need? The examples in the pictures have three terminals (?) but I need to connect the live and neutral from the flex to the two wires leading to the motor.
****************************************************************************************************************
Another question not directly connected to this, but I prefer not starting a new thread for a simple yes or no...
I bought a cheap 40W soldering iron to replace the switch of my impact driver last night. The iron is hot enough to melt solder but when it's held against the wires I wanted to solder together it takes so long for them to heat up the insulation surrounding the wires is melting. Surely the iron is faulty?
Cheers,
Mark
If so the switch Pete linked to looks good. Thanks for that.
One point I'm not sure about is how many switches do I need? The examples in the pictures have three terminals (?) but I need to connect the live and neutral from the flex to the two wires leading to the motor.
****************************************************************************************************************
Another question not directly connected to this, but I prefer not starting a new thread for a simple yes or no...
I bought a cheap 40W soldering iron to replace the switch of my impact driver last night. The iron is hot enough to melt solder but when it's held against the wires I wanted to solder together it takes so long for them to heat up the insulation surrounding the wires is melting. Surely the iron is faulty?
Cheers,
Mark
Eric The Viking
Established Member
- Joined
- 19 Jan 2010
- Messages
- 6,599
- Reaction score
- 76
On the first question: almost every microswitch I've ever seen is a changeover switch. It has three contacts, but you only use two at a time in this application. You can just switch the live connection, or both (you'll need a different switch for both).
Yes the little microswitches I suggested are probably too small - go with Pete's suggestion.
The soldering iron probably isn't faulty, but either it doesn't have a big enough tip, or, isn't hot enough for unleaded solder, which has a higher melting point than the old leaded stuff. Check that it's compatible with lead free solder. Lead free doesn't solder well outside a factory environment. Using leaded will work better generally (don't breathe the fumes!). Do you have a solder-sucker? Clean off the wires (of old lead-free solder) as much as you can before trying again. If you really get stuck, use a tiny smear of plumbing flux to help (if you have some) - dip the wire ends.
Also, let the soldering iron heat up for ages first, clean the tip on a wet/damp cloth then quickly tin it with solder and try the joint. Personally I always use leaded solder, but it doesn't play nicely with lead-free sometimes - you need to clean the wire carefully.
It might be easier to snip off the bare ends, strip back a bit further and start again.
Also, the wire insulation may not be intended to cope with the heat of soldering. Most power tool connections are crimped rather than soldered as it's a more reliable manufacturing process. So they can also use cheaper insulation as it doesn't have to resist soldering temperatures. If you get melt-back, you can just put a sleeve of heatshrink over the wire, slide it along out of the way, make the joint and then slide it back into place and shrink it on.
Hope that helps a bit.
PS: I'll draw you a wiring diagram when I get a moment later tonight.
Yes the little microswitches I suggested are probably too small - go with Pete's suggestion.
The soldering iron probably isn't faulty, but either it doesn't have a big enough tip, or, isn't hot enough for unleaded solder, which has a higher melting point than the old leaded stuff. Check that it's compatible with lead free solder. Lead free doesn't solder well outside a factory environment. Using leaded will work better generally (don't breathe the fumes!). Do you have a solder-sucker? Clean off the wires (of old lead-free solder) as much as you can before trying again. If you really get stuck, use a tiny smear of plumbing flux to help (if you have some) - dip the wire ends.
Also, let the soldering iron heat up for ages first, clean the tip on a wet/damp cloth then quickly tin it with solder and try the joint. Personally I always use leaded solder, but it doesn't play nicely with lead-free sometimes - you need to clean the wire carefully.
It might be easier to snip off the bare ends, strip back a bit further and start again.
Also, the wire insulation may not be intended to cope with the heat of soldering. Most power tool connections are crimped rather than soldered as it's a more reliable manufacturing process. So they can also use cheaper insulation as it doesn't have to resist soldering temperatures. If you get melt-back, you can just put a sleeve of heatshrink over the wire, slide it along out of the way, make the joint and then slide it back into place and shrink it on.
Hope that helps a bit.
PS: I'll draw you a wiring diagram when I get a moment later tonight.
Mark A
Established Member
Hi Eric,
A wiring diagram would be excellent, thanks!
I've been practicing soldering on spare wire before attempting the real thing - I don't want to bugger up a new £20 switch if I can help it.
The iron melts the solder on direct contact just fine, but it doesn't seem to transfer the heat to the wires efficiently enough, so the wire's insulation starts to melt before it's reached the required temperature for soldering.
I'll buy some more tips and try again. If I can find leaded solder all the better.
Cheers,
Mark
Sent from my GT-I9505 using Tapatalk
A wiring diagram would be excellent, thanks!
I've been practicing soldering on spare wire before attempting the real thing - I don't want to bugger up a new £20 switch if I can help it.
The iron melts the solder on direct contact just fine, but it doesn't seem to transfer the heat to the wires efficiently enough, so the wire's insulation starts to melt before it's reached the required temperature for soldering.
I'll buy some more tips and try again. If I can find leaded solder all the better.
Cheers,
Mark
Sent from my GT-I9505 using Tapatalk
Eric The Viking
Established Member
- Joined
- 19 Jan 2010
- Messages
- 6,599
- Reaction score
- 76
First off look at these diagrams of switches, and the page they're from (click the picture):
Your planer had a double-pole, single-throw, normally-open switch. That means it was normally off ("open") and, when you squeezed the trigger, it connected both live and neutral connections to the motor at the same time. When you let go, both were disconnected.
So, as far as I can see from your pictures, your switch was one of these:
It's electrically the same as a pushbutton, but I'll stick with the actual switch symbol as it's easier to work out. The dashed line in the symbol means that both "poles" of the switch operate together - the "wipers" are mechanically connected together (but not electrically!). You really need something similar as a replacement. The planer will work with a single-pole switch like this:
But it won't be completely safe. This is because, in the UK, 110V tools are used with a centre-tapped isolating transformer. The unswitched wire, which would be a 'neutral' if it was a 240V tool, is always at 55V potential with the metal case of the tool. So when the planer is 'off' there would still be 55V on BOTH wires to and from the motor. It would make you jump if your finger got between one of those wires and the metal case.
It wouldn't kill you unless you really work at it, probably, but it's not a safe situation. People have been killed by lorry batteries (24V). It's very, very unusual - they do more damage if you drop one on your foot mainly- but that's not the point: 55V can just about be fatal! So you should have a double-pole switch as before, to isolate the innards from the mains unless/until you push the trigger (what happens next is entirely your fault
).
. . .
You have two wires coming from the motor to the switch, probably both the same colour (doesn't matter), and three wires from the cable (flex) coming into the planer.
IF IT IS AN AMERICAN TOOL the cable/flex colours will be these:
Black = live
White = neutral
Green = earth
Notice that, using the OLD colour scheme in the UK, black should be NEUTRAL**, not live. That confuses people in the UK who see American stuff for the first time!
For your planer, basically, BLACK and WHITE go to one side of the switch, and the two wires from the motor go to the other, so that when you press the switch, black goes to one wire of the motor and white goes to the other wire of the motor.
If Black and white connect to each other (when you press the switch), this is what's technically known as an EPIC FAIL (or more boringly a short circuit), and may result in smoke, hot sparks, and a spoiled switch and 110V transformer.*
So check which connections are which - usually on long thin things, the switching is on the long axis. Check with a torch bulb and battery, or a meter on a low resistance (Ohms) range - they often have handy beepers so you don't need to actually look at the thing. DO NOT test it with mains.
You may only find a double-pole double-throw switch when you shop for one. This will have six connections, because each pole of the switch is changeover: when you push the switch, two contacts go 'off' and two go 'on' at the same time (look at the diagram to see how it's wired). These are fine for your task, but you need to know which contacts are which. If it's not written on the switch, you WILL need to test it before you fit it..
Hope all that helps,
E.
*It shouldn't, but don't take the risk.
**When using a 110V yellow site transformer in the UK, technically speaking, there isn't a neutral on the 110V side, only TWO 55V live wires (giving you the 110V the tool needs). It's a little complex. The system is safer than our ordinary mains in many ways, but it needs a double-pole switch to isolate the tool completely. In the USA, tools also use 110V, but it's a live + neutral arrangement similar to our 240V one here. The motors don't care, but the human-safety arrangements for the two systems are subtly different.
Your planer had a double-pole, single-throw, normally-open switch. That means it was normally off ("open") and, when you squeezed the trigger, it connected both live and neutral connections to the motor at the same time. When you let go, both were disconnected.
So, as far as I can see from your pictures, your switch was one of these:
It's electrically the same as a pushbutton, but I'll stick with the actual switch symbol as it's easier to work out. The dashed line in the symbol means that both "poles" of the switch operate together - the "wipers" are mechanically connected together (but not electrically!). You really need something similar as a replacement. The planer will work with a single-pole switch like this:
But it won't be completely safe. This is because, in the UK, 110V tools are used with a centre-tapped isolating transformer. The unswitched wire, which would be a 'neutral' if it was a 240V tool, is always at 55V potential with the metal case of the tool. So when the planer is 'off' there would still be 55V on BOTH wires to and from the motor. It would make you jump if your finger got between one of those wires and the metal case.
It wouldn't kill you unless you really work at it, probably, but it's not a safe situation. People have been killed by lorry batteries (24V). It's very, very unusual - they do more damage if you drop one on your foot mainly- but that's not the point: 55V can just about be fatal! So you should have a double-pole switch as before, to isolate the innards from the mains unless/until you push the trigger (what happens next is entirely your fault
).. . .
You have two wires coming from the motor to the switch, probably both the same colour (doesn't matter), and three wires from the cable (flex) coming into the planer.
IF IT IS AN AMERICAN TOOL the cable/flex colours will be these:
Black = live
White = neutral
Green = earth
Notice that, using the OLD colour scheme in the UK, black should be NEUTRAL**, not live. That confuses people in the UK who see American stuff for the first time!
For your planer, basically, BLACK and WHITE go to one side of the switch, and the two wires from the motor go to the other, so that when you press the switch, black goes to one wire of the motor and white goes to the other wire of the motor.
If Black and white connect to each other (when you press the switch), this is what's technically known as an EPIC FAIL (or more boringly a short circuit), and may result in smoke, hot sparks, and a spoiled switch and 110V transformer.*
So check which connections are which - usually on long thin things, the switching is on the long axis. Check with a torch bulb and battery, or a meter on a low resistance (Ohms) range - they often have handy beepers so you don't need to actually look at the thing. DO NOT test it with mains.
You may only find a double-pole double-throw switch when you shop for one. This will have six connections, because each pole of the switch is changeover: when you push the switch, two contacts go 'off' and two go 'on' at the same time (look at the diagram to see how it's wired). These are fine for your task, but you need to know which contacts are which. If it's not written on the switch, you WILL need to test it before you fit it..
Hope all that helps,
E.
*It shouldn't, but don't take the risk.
**When using a 110V yellow site transformer in the UK, technically speaking, there isn't a neutral on the 110V side, only TWO 55V live wires (giving you the 110V the tool needs). It's a little complex. The system is safer than our ordinary mains in many ways, but it needs a double-pole switch to isolate the tool completely. In the USA, tools also use 110V, but it's a live + neutral arrangement similar to our 240V one here. The motors don't care, but the human-safety arrangements for the two systems are subtly different.
