Well the trigger on my old miter saw has quit working. The tool shop says the trigger is obsolete, and every source i know of on the web says it's obsolete.
My questions are, what exactly goes out in a trigger? Is it possible to rebuild or modify the old trigger to make it work again?
I can't seem to find any info on maybe finding another trigger from something else or another brand that may work. Anyone got any ideas?
The saw is a Black and Decker miter saw Type 1 cat. # 1701
The trigger/switch number is 151953-00
Here is a picture of the trigger.

http://www.ereplacementparts.com/switch-p-95085.html

 

I woulde take the info off the switch and google it. Maybe you can get one direct from the manufacturer. Or maybe he can tell you what to do.

 

You could also mod it with a treadle switch (do use a guard over the pedal).

 

It's just a pair of contacts and a spring to hold the switch normally open.

Oftentimes a trigger will just get packed full of sawdust to the point the trigger can't close the contacts.
Sometimes the little brass tabs will break off internally.

How does it act?
Do you have full pull of the trigger?
Does it feel 'crunchy' when you do pull the trigger?

When was this saw manufactured?
Does it have a side safety interlock button?
I have some older Black & Decker Professional tools that I keep for parts.
This is from when they first bought DeWalt because they had ruined their reputation.
Maybe the trigger was common among some of them.

 

The saw is old. I can't find a date on it, but I bought it used maybe 17 years ago for 10.00. So I got my money out of it. I just hate throwing away something that is perfectly useable if it weren't for a single part.

How does it act, wellI can make 3 or5 cuts, then it won't work anymore. sometimes, I'd just put it away til the next time I need to make some precise cuts and I pull the old saw out to see if it will work. It will work 3 or 5 cuts, then nothing again.
I took the saw to the local tool store, and they put in new brushes and a new cord. The saw worked great. I got all my cuts done on 4 jobs. The fifth job I used the saw, I got about 7 cuts out of it, and it stopped working.
As far as I can tell, the trigger feels normal when pulling it. I don't feel any binding or crunching. I can squeeze the trigger all the way to it's stop.

I checked radio Shack's web site to see if they had any switches that might work. The only one I saw that looked like it would be comfortable on the finger when used, is a momentary switch, but it's only rated for 3 amps. My saw is 10 amps, so that switch won't last long.

I didn't know they had anything to do with Dewalt, so I'm going to check their website. Every other site I checked, including Black and Decker's, doesn't show any replacement, just that the switch is obsolete.

 

I would get some dimensions off it and look at generic switches. I'm going through the same thing now with a Global Machinery grinder that's about six years old. It's a variable speed 4.5" grinder that worked great until the switch fried, and the shop I took it to just said parts weren't available.

 

Maybe try removing the switch from the unit and blowing compressed air into any available openings/crevasses in the switch body?
Then spray some electrical contact cleaner in it and work the action a bit.

If you can feel it "click" when you pull the switch into operating position, then the mechanism should be ok. It might just be debris/corrosion on the contacts.

 

There is a very fine dusting inside the handle. So I used a can of compressed air to blow through the very few and tiny openings in the trigger housing. There's still no change.
I don't have any contact cleaner, but the trigger clicks just fine, so now I'm wondering if it is the trigger causing the problem.
Maybe it's something else. I have a volt meter, but haven't any idea how to use it.
Perhaps someone can tell me what to set the meter to, so I can check a few things.

 

Set the meter to Ohms and look for continuity across the trigger when depressed.

 

It could be a loose connection somewhere--like at the wires to the switch, or elsewhere in the handle--which you can troubleshoot with a VOM or continuity tester. What kind of "volt meter" do you have? Ideally you need one which will test resistance (ohms) or continuity, rather than testing with line voltage, especially if you're not familiar with electrical testing.

I'd particularly suspect the wires going into the switch, which are just held in place by a little spring tab.

Otherwise, it's most likely dirty or damaged contacts inside the switch, or a damaged link between the trigger and the contact arm.

The switch shown in the link you posted isn't really that old (at least not by my standards), but it's typical of Black & Decker that it's not available anymore. They want you to buy new tools, not fix old ones.

You might try this place for a replacement:

Mike's Tools - Woodworking Tools, Metalworking Tools, Power Tools, Cordless Tools, Used Tools - Mike's Tools

They're pretty good sometimes for having stocks of obsolete parts. You may have to call them directly rather than simply using their web-based search.

While those switches aren't as easy to disassemble as older ones were (which actually came apart for easy service), some of them can still be opened up so you can clean the contacts and add a little grease to the cam or tumbler which moves the contact arm. See if there's a tab on the outer cover where you can spread the cover a little so the inner (black) section can be removed. Or, that hole in the side might have a rivet or screw inside it, which can be removed or drilled out so the switch will come apart.

Word of caution though, if you get to the taking apart stage--work over the top of a table or your workbench, with a towel or sheet down to catch loose or flying parts as the case is opened, so you don't end up trying to find them on the floor.


Joe

 

I agree with not throwing it out if it can be fixed. I've got a 1960 vintage Rockwell sawsall I'd like to fix as well as my snap-on IM-5 Air impact. Check with local hardware stores - not the box stores- they might have something.

 

The switch has a little rivet I'm goin gto drill out. I've studied it for a way to open it up. but I see none.
I've tugged on all 4 wires coming into and out of the switch and all appear tight, so I doubt a loose connection. Plus I fiddled with them all while the saw is plugged in and squeezing the trigger.

I'll call that place tomorrow and see what they have to say. I didn't see anything Black and Decker listed on the site.

I have a multi function meter. I just don't know what to set the dial on to test different things. So now iknow I put it on ohms and poke the wires across the switch.
Thanks guys for all your help, It's all greatly appreciated. And keep it coming.

 

Use the DeWalt number listed on the link you posted. They carry DeWalt parts.

Before you "poke the wire across the switch," put the dial on ohms, and hold the two leads together so the meter goes to full scale. If it doesn't there should be a small dial you adjust to get the meter to full scale. If it still doesn't, the meter needs new batteries. If it's a digital meter instead, hold the leads together and the display should read 0.0 or very nearly so. Or it may say "cont" on the display. All of that is done so you'll know you're getting a true continuity reading.

Then put the meter leads across the plug blades (with the tool unplugged) and pull the trigger. You should get a full scale reading on the meter, or a 0.0 or "cont" on the digital display. That saves you having to poke around the insulation on the switch wires, which are probably covered all the way inside the switch housing.

Joe

 

I just rebuilt mine.
Drilled out rivet and pulled it apart.
Watch out,2 small springs load the toggle contacts.
the L shaped contacts on the black wires were burned thru.
I made new ones from hammered #12 wire.
had to get a 2mm screw to replace the rivet.

Works like a dream.

Closest replacement part I found was this:
Poulan 530071533 - POULAN SWITCH ASSY KIT

I am going to order one since the contact I made is real soft and will probably burn out.

retired Ford engineer strikes again.

Ben

 

Thanks for that reply Ben. Right now this project is on hold til I can get a job and get all these money hounds off my back.
I had a thought while I was probing the wires with the multi meter which the ohms showed all zeros thats a good thing.
I thought why don't I just splice the wires together and see if it the trigger at fault here? As of yet i haven't done it though. but I will.