Adding to the above the smell is usually from the shellac insulation on the armature windings getting hot and melting. From the sound of it you've melted through that insulation somewhere hence the reduction in available torque
Using drill as screwdriver
- Thread starter DiyNutJob
- Start date
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Yes, I have an electric impact gun with 450Nm max torque. It's too fast and powerful for this application. I have now ordered a lidl corded screwdriver with 40Nm. I expect it to work. Right this minute I am doing hand cranking. It's not hard but very tedious.
Does the current draw increase when the motor stops? Does the heat degrade the windings? This is what I am seeing, the drill is not dead but has reduced torque compared to initially.
Could be. But I don't see much insulation in the windings, just coils of wires. Is it possible the heat modified the wires and cause it to have greater resistance?
The wire in the windings has a very thin coating of varnish - that is the insulation.
If the wire didn't have the insulation, the electricity wouldn't pass through the windings at all - it would skip over the surface of the windings, from one brush to the other.
If the motor over heats, some parts of the varnish could melt (and smell!), causing localised shorts between windings.
Again, instead of the electricity travelling through the entire winding, it could skip through these short circuits, avoiding parts of the windings; the drill consequently loses power.
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Definitely a possibility!
A screw loose?
Definitely a possibility!
You might be better with a cordless rattlegun rather than a screwdriver.
2 reasons;
1 you can't stall a rattlegun.
2 a rattlegun won't snap your wrist if the required torque increases suddenly.
Lidl have a cordless rattler (says on the box 400Nm but that's apack of lies) optimistic with adjustable torque and variable speed (soft trigger), might do quite well
2 reasons;
1 you can't stall a rattlegun.
2 a rattlegun won't snap your wrist if the required torque increases suddenly.
Lidl have a cordless rattler (says on the box 400Nm but that's a
I don't need something with too much power. The hammering action could break my tool attachment. After careful selection, I chose this for the best estimated cost & function combination: Parkside 2 -speed Corded Power Drill
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Your original drill is now damaged beyond economical repair by the damage you have caused to the windings. It may, at the moment, still function as a drill, but it is not functioning as efficiently as it should do. It will burn out completely before too long, (unless you are drilling through thin balsa wood).
The YT test is worthless by the way. It can give you a rough idea if it's damaged, but to test it properly you need to do what is called a 'drop-test' using ELV DC supply and a milliamp meter, not a multimeter. The third test he did, (short from windings to core pack), must be done with an insulation tester, (again, not with a multmeter), because a multimeter will not pass enough current to perform a proper NDT. You say you used a 'traditional hammer drill', by which I presume you mean a 230/240v mains corded drill. To test it correctly you need to pass twice the voltage through the windings to test for earth faults.
Testing armatures/stators/coil packs is a skilled job that requires specialist test equipment, not just a multimeter. You also need the experience to judge if the resistance readings are within an acceptable range.
The YT test is worthless by the way. It can give you a rough idea if it's damaged, but to test it properly you need to do what is called a 'drop-test' using ELV DC supply and a milliamp meter, not a multimeter. The third test he did, (short from windings to core pack), must be done with an insulation tester, (again, not with a multmeter), because a multimeter will not pass enough current to perform a proper NDT. You say you used a 'traditional hammer drill', by which I presume you mean a 230/240v mains corded drill. To test it correctly you need to pass twice the voltage through the windings to test for earth faults.
Testing armatures/stators/coil packs is a skilled job that requires specialist test equipment, not just a multimeter. You also need the experience to judge if the resistance readings are within an acceptable range.
Like the man above said, measuring the armature is highly complex. You can't just be making random assertions about increased consumption. The increase could be quite minor. With the money I saved from very careful buying, I can afford to splash out on some wastage in any case.
The man above, (i.e. me), is a highly skilled armature/stator winder/tester and what I and others have said is true. It may seem to be working at the moment, but the time will soon come when you try to apply a bit more pressure to drill something and it will fail. It may be just a puff of smoke and then stop, or it could be a flash with a loud bang without any warning. If you are up a ladder or balanced on something when that happens, you could end up injured or flash blinded for a short while. It's simply not worth holding on to it and definitely not worth paying out for spares without knowing the exact damage that has been caused. I've known people to buy a new armature, (the costlier of the two compared to the fields), only to discover it was the fields. Without the correct test procedure, you cannot know which part has failed so will be wasting money, as well as time, trying to repair it.
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