Introduction: Power Tool Repair Made Easy

Picture of Power Tool Repair Made Easy

Get power tools for free and save the earth at the same time!

It's super-easy to fix power tools now. Thanks to online manuals, part searching and ordering, you can get the replacement parts you need and install them in mere minutes of labor.
Dead power tools are free in the trash if you can spot them. Get known as a scavenger and people will give them to you.

Power tools die only in certain ways. Usually it's one of these:
Drive Belt
Power cord

Here's how to fix one of each.
If you've got a tool with a dead Nicad battery pack, here's how to zap that back to life.

Tool Repair is Easier than Ever Before
The ease of finding, getting, and replacing these parts represent a whole new economic phenomenon.
In the past the economies of mass production VS. hand repair drove a trend where manufacturing got cheaper and cheaper and repair got more and more expensive. So broken devices were getting dumped and replaced instead of fixed.

But now the labor savings of e-commerce and online manuals make repair a real cheap option. Design-For-Manufacturing (DFM) practices such as snap fits and single-type fastener assemblies can speed repair as well as manufacture.

Woohoo! Could we be seeing a correction of the mass-produced trash problem?

Step 1: New Drive Belt

Picture of New Drive Belt

Any tool that has a drive belt usually dies first from that.
Planers, beltsanders, and rug-beater style vacuum cleaners for example.
The motor will still spin but nothing much else will happen. The motor will seem to have no load.

This planer had a stripped and shredded belt when I first opened it.
Take the side cover off and you'll see pieces of broken belt, or a lacking belt if someone else has opened it first. I wrote "needs belt" on the tool with sharpie to remind me.

Do an online search for your model number and "drive belt" or "belt" or "replacement parts".
Once you find the parts diagram and part number, do a search for that part number to find a good price from a good vendor. Black+Decker and Dewalt often use the same parts. This belt was a Dewalt part that listed this Black+Decker model as compatible.
Order it.
My belt cost $6.50 plus $1.99 usmail shipping, for a grand total of $8.47. When the part arrives, don't do anything with it until you need a big emotional payoff. Then,

Install it.

Your planer will also probably have chipped blades or "knives".
I've found cheap planer knives on ebay.

The knives on this unit and most are double-edged, so you can turn them around for a second life if you didn't break them.
In the future use a slow feed rate if you suspect you'll hit a nail.

Step 2: How It Used to Be

Picture of How It Used to Be

Here's my old Ryobi belt sander. It was friday evening and I was beltsanding away, excited for a long weekend of boatbuilding. Then this photo happened. No more teeth on belt. No parts suppliers would be open til tuesday. I finally found the part on the primitive interweb of the day for $30 with "allow 6 weeks" shipping.
Damn. I couldn't find any belts in my own bins with the right pitch, thanks to their weasel ways.
Aha! I thought, I'll make it a chain drive. So then I wasted a vast amount of time destroying the tool with a chain drive mechanism that never worked.

Don't do that. Get the real parts. These days it's fast and cheap. Those are quantitative improvements that have made a huge qualitative difference. Welcome to the new (but better) economic reality of tool repair.

Step 3: What Screwdriver Was That?

Picture of What Screwdriver Was That?

Here's the best kind of screwdriver to get. The blades all turn around so you get four different blades and two sizes of nut driver. They store in place so you don't lose them. These cost $4 or so at Harborfreight and are on the counter of most hardware stores for $7. Buy a big one and a little one. This is the big one. Oil it well, or when it lands in the bilge it will rust in place and will take some wiggling to get it open again.

Step 4: New Brushes

Picture of New Brushes

Body Grinders, routers, and other tools that run at high loads for a long time wear out their brushes quickest.

Brushes usually don't die suddenly.
At first you'll have to shake or twist the tool to get it to start.
Then maybe you'll have to push the wheel with a stick to get it to start.
Eventually it won't start at all.
Brushes are really easy to check on a good tool.

They're under the little "frankenstein neck bolt" plastic covers. Be careful because sometimes the springs jump and throw stuff away stuff you want.

One of these brushes is obviously messed up, looks likethe spring broke, shorted, and lost its springiness.

Don't buy a new angle grinder that costs less than $15. This one was $17 and it's fabulous. It came with spare brushes.

Step 5: New Power Switch

Picture of New Power Switch

The more powerful the motor, the more likely a bad switch is. Circle (a.k.a circular, Skil) saws almost always die from a switch failure. Body grinders pretty often also.

Feels similar to bad brushes, but spinning the motor with a stick does nothing. Messing with the switch makes the motor jump.

This switch has a rubber cover. I peeled it for visual inspection and see broken parts inside and charred contacts. A continuity test also reveals a bad switch.

I do an online search to find the parts diagram and part number. A price search, $10 (including shipping) online order, and a few days go by, and I've got the part I need.

I detach and push out the old one. I push the new one into the plastic clips and wire it up just like the old one, and Bob's my new grinder! I mean Uncle!

Step 6: New Power Cord

Picture of New Power Cord

Old tools and drills in particular tend to die from power cords. Here's how I put one on a Bosch jigsaw.

Power cords can be tricky to diagnose. Which is a good thing, because you'll get tools for free and they're easy to fix with random power cords.

I used to do a continuity test by shoving needles into the cable and hooking my meter's clips to those. That way I could find out just where the break was without messing up the insulation.
If it's just the plug at the end you'll want to replace that.
It's also easy to cut the cord and splice a new one on halfway.

Vincent gave me this one with no cord at all so the decision was already made.
I had a scavenged power cord, probably from a computer with the computer end cut off.
I wired it in. This tool had a clamp for keeping the cord from pulling out. If there isn't one of those you can improvise with wire ties or tying a knot in the cord.

Once I looked inside I saw it was an insulated case with no place for a ground attachment. So I cut the green ground wire off my cord. Then I broke off the ground pin from the connector so no one would get confused.

Older tools sometimes have a metal case that is grounded through the third pin. The theory there is that if any wires get loose and short inside, they'll short to the case and blow a fuse instead of electrocuting you.

Step 7: Zap NiCad Batteries Back to Life

Picture of Zap NiCad Batteries Back to Life
Battery powered tools usually get thrown away when the battery no longer holds a charge.
If it's a NiCad battery pack, you can usually make it work again by zapping it as shown here.
There's usually nothing else wrong with the tool. Thank you "Garbage Santa"!

If your battery pack doesn't come back to life you can take it apart and zap or replace individual cells.

If your battery pack is made of something other than NiCads, don't despair.
You can take them apart , replace individual cells, or empty your dead pack and wire that connector to a different battery pack that is good. Laptop computers are a good source of battery packs also! All you have to do is make sure you assemble a pack with a voltage close to what your tool needs, and the charger is intended for the battery chemistry you end up using.
Be careful with the wiring. A reverse voltage will burn out the speed controller of your tool.

WARNING: Read about the dangers of the type of battery you are using. Ignorance is no defense against anything.

Watch the video and see how zapping is done.


Dave999999 (author)2016-11-17

I have a faulty trigger switch in a Ferm Jigsaw (JSV-600P), the parts don't seem to be availble. Can anyone help me with this please. Looks like I will have to bypass the switch if I can't get a replacement. Thanks in advance.

ArifB12 (author)2016-04-02

What makes the carbon brushes in my mini grinder worn out faster after several usage.

ShaneW34 (author)2016-02-13

I have a concord 6" bench grinder with 2 blue wires and 2 white wires coming from the motor and 2 white wires on a relay. Needing to know how to wire a new 3 wire power cord to it.

Christine Utomo (author)2015-12-07

I have a mini grinder and Ive used it the night before...but in the morning it wont start at all...can anyone help? I havent check the power cord though

gibBo550 (author)2015-11-15

how can I find the Part Number the brushes for a Metabo AG 550 angle grinder. Metabo's web site does not list it

GavinK2 (author)2015-08-06


I've got an old B&D router ive restored (mid 70's) and it runs beautifully... however... the bit assembly is totally different. It uses a small allan key screw to tighten it (which is stripped) and you cant get the bits for those routers anymore. Any ideas of how I could convert it to the new system or use it for something else maybe?

Thanks in advance.

GETITR (author)2015-01-03

got a dewalt d25404 and it is turning slow and makes an unhealthy noise,brushes have been changed still the same.any ideas please whit the fault here is?

t0mm0t (author)GETITR2015-04-09

maybe a bearing is broken. they make terrible sounds when the are done...

Jeff Mazur (author)GETITR2015-01-20

Can't say for sure without examining the tool, but as often as not that sort of thing is due to bad bearings.

stuffdone (author)2014-11-03

How do you fix the trigger switch? It is a reversible 120 Volt variable speed B&D but the factory switch is no longer available.

My only options appear to be to try to repair the existing switch or find a switch from some other model that I can substitute. Obviously purchasing a bunch of random switches at $15 - 20 each just to try them is not an option.

It is a B&D Holgun 1180-09 Type 2 and was made in USA. It has been a great drill for 30+ years and all the new stuff is Chines crap now. This has more power than many 1/2" drills sold today. I really want to save it.

tom.thomson.9 (author)2014-11-02


My son in law has asked me to fix his finishing sander for him and I would appreciate advice please.

It is a P Pro CLM260TS. I plugged it in, switched on and it lasted about 2 seconds then nothing. Took the cover off, switched on again and tested it. There is power reading from all the wires to and from the switch, including neutral, also at the brushes, which are like new and seating well.

Tried spinning the motor while power turned on but nothing.

Any advice will be appreciated whether it is economically repairable or a scrapper.



nicola.frame.7 made it! (author)2014-10-26

if you need any carbon brush I found the best international site in Scotland you can chat with friendly staff with their chat app pay with paypal or credit debit card and they stock everything you need for your power tool carbon brush needs

jayson.choi.14 (author)2014-10-03

how do we fix grouded electrical jackhammer?what are the steps to do?

jayson.choi.14 (author)2014-10-03

how do we fix grouded electrical jackhammer?what are the steps to do?

gronan1 (author)2014-05-11

A good "old fashioned hardware store" many times, will have A section of drawers that contain an assortment of bit's that are used to repair electric tool's. Brushes,switches, nut's and bolt's.
Unfortunately, they are headed into the scrap heap of history. Only A few more weeks remain for 7 Corners Hardware in St.Paul MN. The owner has decided to close up instead of selling out as the kid's have no interest in the hardware business.
R.I.P 7 Corners.

Alan Liefting (author)2014-02-26

Other common failures are armatures and feild coils.

ponentesincausa (author)2013-12-16

Are brushes a one-size-fits-all (except for dremels, obviously)? or do I have to search the part by model number too?

No, they vary in size.

paul1101 (author)2013-01-11

Veru INFORMATIVE and just FANTASTIC! I was looking for the related information. Thanks a lot it is very useful for me. would love to read some pieces on the topic.

yoyology (author)2012-05-09

Our local ReTool store has a pallet bin of "as-is" power tools for $4.99. Armed with your instructable, I'm goin' shopping! :-)

The 4th Doctor (author)2011-12-04

i got that grinder for less then 15 dollars

retrotimelord (author)2011-12-03

not the best welder off the block

charlieb000 (author)2011-10-09

mmmm $15 angle grinder... i got a way to destroy the gearbox on the more expensive ones.. wonder how much the cheapies take? i figured out that using a grinder upside down (edge of disk makes contact only) removes more steel quickly because there is less surface area contacting than if a larger area of the disk is contacting (just like with drop saws) which makes plenty of heat, smearing the metal. the (now) upward pressure does something bad inside the gearbox and the little gear gets eaten out and the larger gear gets a bald spot... this might be due to the bearings not being wide enough. once the gears start to wear out they will self destruct over time even if you have stopped due to vibration because the teeth are no longer meeting tightly. hitachis lasted over a year, metabo lasted only a few months....

other positives of upside down grinding are you are less likely to slip and miss what you really want to hit (because you are pulling it towards you rather than pushing). you dont have to lift the grinder so high (great if you are using one of those massive ones!), you can grind aluminium with a steel grinding wheel (less smearing) easily, and finally, the disk will never come apart because you made it thin.

dont say i never warned you.

jdarrington (author)2011-06-30

I just followed the link you listed to how to bring nicad batteries back to life with a welder and I tried it and it worked! I've got four different drills and about 7 (formerly) dead batteries that are now alive and well again. It's like Christmas morning because I've got some of my favorite electric power tools back again.

coppeis (author)2010-10-21

Where can I get these said free power tools?

toolrepair (author)2010-10-05

You could try for the replacement battery and charger. Depends on the brand though, they have most and are continually adding more.

*Tool Repair Guru*

flamesami (author)2010-05-18

What make is the knife in the 1st picture? or is it a custom one? I would appreciate it very much if you could tell me.
P.S. Is it good? It looks really nice, but I'm an ignoramus compared to many people on here.

Bascom Smith (author)2010-03-19

Need Drill Chuck for 1/2 in. Shop Mate number 520 t1 with taper 1/2 to 5/8

bertnorris-123 (author)2010-02-02

I have a Richmond 6v Drill Driver I want a replacement Charger and Battery where can I get them I would be ever so grateful for info 
                                                                    cheers Bert


gnasty gnork (author)2009-08-26

i have the same angle grinder and i was wondering wut that part was when i opened the box lol

DIY Dave (author)gnasty gnork2010-01-20

What brand is that angle grinder?

gnasty gnork (author)DIY Dave2010-01-20

i dont remember... it was the cheapy model i got at harbor freight

DIY Dave (author)gnasty gnork2010-01-20

OK, thanks

masterochicken (author)2009-11-24

Walmart and Lowes cut the power cords off all their display tools. I wonder if they could be convinced to sell the old ones instead of just throwing them away.

DIY Dave (author)masterochicken2009-12-02

I was wondering that same thing. I guess I should ask.

masterochicken (author)DIY Dave2009-12-03

I kind of want to, but I'm really bad at talking to people.

sharlston (author)2009-10-20

thanks for the ible tim 5 stars

IdeasFromAir (author)2009-08-10

Who knows how to change chuck on DC730KA drill? Help me please.

Goodluck (author)IdeasFromAir2009-08-18

Different chucks are removed in different ways. First start with your drill's instruction manual. If it doesn't tell you and you can find a model number and/or a manufacturer's name on the chuck itself, search that. Otherwise, you'll have to 'spearmint. Open the chuck fully and look down inside it (use a flashlight). There might be a screw down in there. If there is, it might be right or left hand threads. Try turning it both ways. Hopefully it'll break loose and come out. If there is no screw or you did manage to remove it, proceed as follows: chuck the short leg of a hex key (allen wrench) of somewhat substantial size (1/4" or larger) into the chuck. Set the drill on it's side on a strong table (or workbench or curb...) with the chuck hanging off the edge. Strike the hex key sharply with a hammer (chunk of 2X4, large rock, etc...) such that it will cause the chuck to spin in a counterclockwise direction when looking at the chuck head on (like you did to see down inside it). Hopefully the chuck will break free and thread right off.

stephenniall (author)2009-06-30

i went to a autojumble picked up a huge black and decker sander for 50p (1$) took it back to my house and it wouldnt work So i opened the handle up The live wire wasnt connected properly so i connected it up Inside the handle Soldered it Put it back together it works perfect i took the Belt bit off Wire brushed down the rust and its better than the new one ive got

leebryuk (author)2008-01-17

I liked it. Nice job of what amounts to the basics of power tools. They are simple beasts by necessity. The advent of cordless tools has made throw away seem a more viable option. Those damned batteries are expensive. However, I believe Harbor Freight does have 18v replacement batteries on sale at $10.

pfred2 (author)leebryuk2009-06-21

Yeah with maybe 15 amp minutes of current in them! Random toxic waste would hold a better charge.

Stonefeather (author)2008-03-27

I am putting a new power cord on an old bench grinder I bought at auction, since the old one looks unsafe. I know the green wire on the new cord is the ground and I see how to attach it, but the old cord isn't color coded, so I don't know which wire is equivalent to the black and which to the white. How do I figure it out, or doesn't it actually matter? BTW, the new cord is a 14 gauge/15 amp cord, which the fellow at the store told me would be good. Is he right?

pfred2 (author)Stonefeather2009-06-21

Induction motors typically consider both hot and neutral L1 and L2 and it doesn't matter which is which. Now if you transpose the starter windings then it can matter. Then the motor would run the other way.

chutamarque (author)Stonefeather2008-05-04

Hi Mate, This is bloody easy, for a 240v or 110v supply blue ,black is negative (-) and postive is brown or red (+) earth are green or a greenyellow combo. Any other colours could mean a control circut -refer to maker -.thanks -

well make a simple circuit with a battery and a led and test each wire

LinuxH4x0r (author)2008-01-17

Great job! I have the same grinder (chicago electric from harbor freight). Hopefully it will last a while, but when it goes I will be prepared. Does anyone know if the brushes from the grinder woould be compatible with the motor on a kichenaide blender?

kill-a-watt (author)LinuxH4x0r2008-01-18

I've had to replace brushes in a power window motor. Although the brushes that I got were too big, it's an easy matter to sand them down to fit.

Dodd (author)kill-a-watt2008-02-22

If you need brushes for a power tool and can't get them, any (helpful) car parts retailer will sell you brushes of a similar size. Take the old ones with you. Its easy to sand them down to any size you want.

chrisbaker (author)Dodd2008-07-18

I seem to remember my dad making brushes for his powertools from the carbon (?) rod from the inside of a C or D-size battery. Anyone here ever do that, or am I misremembering?

About This Instructable




Bio: Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founder of, manufacturers of "3D Printer" output ... More »
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