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drill switch

Posted by cavell (My Page) on
Thu, Jul 5, 12 at 9:53

got a free 24v cordless drill. no name brand. guy said battery was dead. turns out battery is fine. the forward/reverse switch is just touchy. you have to adjust it easy. push it too far and drill does not work. the brand is "tornado". made in china. no ID on trigger switch. any sites that may sell odd bits like this part?


Follow-Up Postings:

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RE: drill switch

No tellin what that switch is.
Ya gotta get it out of the drill
and then try to identify it.
Chances are there are other
makes that use the same switch.
Google is your friend on these
occasions.


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RE: drill switch

You might be able to find some sort of labeling on the switch and find it in a Google search. Even if you do, you might have trouble finding someone that will sell them to you in quantities of less than hundreds or thousands.

As an example, I had a broken internal control switch on a luminometer at one time. The equipment manufacturer wanted over a hundred bucks for a replacement, and I would have gladly paid it, but the part was out of stock and we needed the machine. I found the manufacturer of the switch. The cost for the part was less than a buck, but they only sell to manufacturers and distributors. When I explained my problem, the nice man stuffed 5 in an envelope and sent them to me using our express delivery account.

You might also get lucky and find some on a surplus equipment seller's web site.


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RE: drill switch

A lot of El Cheapo Chinese junk---er---tools are an exact copy of a name brand tool. So close the name brand parts will fit.

It is just a matter of finding which brand they copied and go from there.


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RE: drill switch

Go ahead and take it apart. You may get lucky and find a loose wire.


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RE: drill switch

Ya gotta take it apart, if you're going to replace
the switch. Regardess of whether you can find an
exact replacement, or not. If you can't find a switch, then you've got to cobble up something else that will work.
That's what DYI is all about, (makin it work, all by
yourself).


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RE: drill switch

I had an old sabre saw (portable jig saw) with failed trigger switch. Saw would not run with the switch, but would run if the switch was bypassed. Parts for it unavailable. Found switches at the link below and found one that looked the same in the photos and it fit with minor modifications to the tool housing. But the cost (including shipping) was about as much as the saw was worth-- about like buying a complete used one. But I do have a new (Made in China) switch in it.
A variable speed switch for battery-powered tools and for 120V AC tools probably is a very different part. Never replaced one on a battery-powered tool.

Here is a link that might be useful: Eurton


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RE: drill switch

Cheap switches often use copper on copper contacts.

At 120 V they can have a decent life, but at lower voltage (like 12 V) the larger starting currents quickly pit and damage the contact surfaces.

Actual switch contacts are far more expensive than just bare copper, so they are omitted from 'price point' tools.

The manufacturer does not expect the tool to ever see enough use for the low quality contacts to fail (especially within any warranty period).


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RE: drill switch

Brick,in all due respect, the variable trigger
switches in todays power tools, use electronics
to control the tool. There is very little, if any,
large amperage load on the switch contacts. Of course, you
are going to come back and show that I am wrong,
as you do with every other poster who ever ventures
anywhere near your 'last word'.


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RE: drill switch

No one said the tool had variable speed.

The variable speed units get a good amount of relief on contact current, but many still have a full on position at the end of the variable range.

Variable speeds on low voltage units are another problem.
The currents are already very high on the low voltage side, and the gate drive to the thyristor is not insignificant.


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RE: drill switch

YOU DA MAN BRICK(head).


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RE: drill switch

Agreed that no one, including myself, claimed that the switch is variable speed. But it is highly probable that it is so. A single speed switch will work, for a time, with virtually any voltage or power type. But I suppose that 120 volts AC and battery DC switches for variable speed are quite different and not at all interchangeable. I am not an expert on the inner workings of such switches.


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RE: drill switch

If the tool is very cheap and low voltage (DC) it may be using plain old resistance for speed control.

A ceramic bar (for heat resistance) wrapped with some relatively high resistance wire.
When the trigger is pulled a contact slides across an uninsulated portion of the wire.

Cheap DC speed control.

You have to take it apart and look at the switch.


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