Very hot Flex XC 3401

psnt1ol said:
746 divided by 120 volts will equate to 6.2 amps but if that same motor was supplied by 100 volts it would be; 746 divided by 100 which would equate to 7.46 amps or an increase in current of about 20%.

Again.... I could be wrong. If I am then please accept my apology.
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Sorry, Power (watts) = VA, so in your example the power would be the same, the heat would be the same. That example is for constant horsepower. But in the real world you will not draw more current in your circuit, by using a thin extension cord you have increased the resistance of the circuit, and by Ohm's law, the circuit will now draw less amps (but the actual difference in resistance between, say, 12 ga and 16 ga wire is very small, so this will be a minimal current reduction). The reason to use a heavy-gauge extension cord with a tool like this is to make sure the power is being dissipated in the tool, not the cord (as well as not setting your extension cord on fire). Also if you are heating up the cord, the resistance of the conductor goes up, further reducing the power available at the tool.

I think I got that all right.

I'm sure it gets a little more complicated inside the power tool, where there is a cooling fan attached to the moving parts that may be less efficient at different speeds, etc.

Here's another argument about it: A very very basic motor amps question - RC Groups which is kind of about power windows in your car, but does make the point that refrigerators and compressors may have start windings which are for, duh, starting (intermittent use), and if you drop the voltage really low you may never get out of the "start" speed which would put those windings into continuous duty and overheat them.
 
Setec Astronomy said:
Sorry, Power (watts) = VA, so in your example the power would be the same, the heat would be the same. That example is for constant horsepower. But in the real world you will not draw more current in your circuit, by using a thin extension cord you have increased the resistance of the circuit, and by Ohm's law, the circuit will now draw less amps (but the actual difference in resistance between, say, 12 ga and 16 ga wire is very small, so this will be a minimal current reduction). The reason to use a heavy-gauge extension cord with a tool like this is to make sure the power is being dissipated in the tool, not the cord (as well as not setting your extension cord on fire). Also if you are heating up the cord, the resistance of the conductor goes up, further reducing the power available at the tool.

I think I got that all right.

I'm sure it gets a little more complicated inside the power tool, where there is a cooling fan attached to the moving parts that may be less efficient at different speeds, etc.

Here's another argument about it: A very very basic motor amps question - RC Groups which is kind of about power windows in your car, but does make the point that refrigerators and compressors may have start windings which are for, duh, starting (intermittent use), and if you drop the voltage really low you may never get out of the "start" speed which would put those windings into continuous duty and overheat them.
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Thanks for the link. Apparently, this is a hotly debated issue. I never realized.

Again....I am not a electrician or an engineer. I based my information from my basic schooling and life experiences. I noticed that some power tools do run hotter with a cord that is both undersized and too long. I did burn out a compressor as a kid by using several regular household extension cords. I also witnessed smoke coming out of a saw under load and the same saw was fine later when paired with a heavy gauge cord. I can't explain why it did what it did but I am open to learn.

I guess OP can easily finds out if the cord was the issue by plugging the Flex to the outlet directly and see what happens.
 
psnt1ol said:
Thanks for the link. Apparently, this is a hotly debated issue. I never realized.
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Yeah, well, I'm trying to find the mechanism buy which this "burning out" works. I understand the refrigeration scenario (and other motors which use a start capacitor), but the power tool one doesn't make sense to me. And the fact that I can't easily find an explanation for it on the internet tells me that it's an old wive's tale. However, I am not discounting your personal experiences.
 
Setec Astronomy said:
How can you burn off a snap ring (which is made out of metal)? Are you talking about part of the backing plate?
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Sorry, apparently I got the 2 confused. The gear ring is what Im talking about not the snap ring. My flex was burning off pieces of the felt ring, which at first i thought was the polish dusting & the gear ring as well.
 
JHL88 said:
Sorry, apparently I got the 2 confused. The gear ring is what Im talking about not the snap ring. My flex was burning off pieces of the felt ring, which at first i thought was the polish dusting & the gear ring as well.
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Ok, now I understand, sorry.
 
Hey guys I brought a 50ft 12gauge cord and some 3 in 1 oil, I opened up my Flex and this is what it looks like. Looks kinda dry to me?
 
Jet Black said:
Hey guys I brought a 50ft 12gauge cord and some 3 in 1 oil, I opened up my Flex and this is what it looks like. Looks kinda dry to me?
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The grease goes down in the right-angle gearbox which is below what you are looking at.
 
Whoa...that backing plate has definitely seen some heat generated. You can see where the felt ring has been making contact and what looks like melting the backing plate. I'm not saying this is the problem, just asking, but how much downward pressure are you applying?
 
Jet Black said:
It doesn't go on the ring
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I'm sorry, yes, it looks like you overheated the backing plate against the felt ring. I was talking about if you were going to grease the gears which is what I thought some of the other users had been talking about, about the head of the machine getting hot from the right-angle gearset.
 
Setec Astronomy said:
I'm sorry, yes, it looks like you overheated the backing plate against the felt ring. I was talking about if you were going to grease the gears which is what I thought some of the other users had been talking about, about the head of the machine getting hot from the right-angle gearset.
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Ok good here it looks like it may rain but I may fire it up to see what happens.
 
Setec Astronomy said:
I'm sorry, yes, it looks like you overheated the backing plate against the felt ring. I was talking about if you were going to grease the gears which is what I thought some of the other users had been talking about, about the head of the machine getting hot from the right-angle gearset.
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:agree:

Mine may need greased inside the head of the machine, but doing it yourself isn't recommended as, among other things, it will void your warranty.

It used to be advisable to lubricate the felt ring with air tool oil, but that's no longer the case. It looks like grease pad put on the felt ring...
 
02xtreme07SS said:
Whoa...that backing plate has definitely seen some heat generated. You can see where the felt ring has been making contact and what looks like melting the backing plate. I'm not saying this is the problem, just asking, but how much downward pressure are you applying?
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About 15lbs of pressure, maybe because I'm a big guy I could have put a little too much I'll pay attention next time for shore

erichaley said:
Umm, yeah, good ol' autocorrect...

I meant to say it looks like grease was put on the felt ring.
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No when I first got it I skipped oiling anything.
 
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