Hotend Problems May 14, 2014 11:15PM |
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Re: Hotend Problems May 15, 2014 03:07AM |
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Re: Hotend Problems May 15, 2014 07:41PM |
Registered: 10 years ago Posts: 67 |
So I'm getting about 20C from my thermistor. I set it to heat and....nothing. I check D8, D9, and D10 and am getting no voltage. Whats happening? Is it in the code? Short in my RAMPS board?Quote
Cefiar
If you're feeding the board 12V, then you should get very close to that across the hotend.
If you don't have a thermistor hooked up, or Marlin reads too low a temp on the thermistor, it will not turn the hotend on.
Note: Disconnected and very low temp are pretty much the same thing for a thermistor, which is why the software disables the output if it's "too low". If the thermistor breaks or a wire falls out, your hotend will continue to heat and never turn off when at temp, as the temp reading will still be sitting at the same value. This could result in the hotend getting damaged* and possibly taking the printer (and you) with it.
[*] - PTFE burning, PEEK burning, or in the case of an all-metal hot end, the mount bending, your carriage melting/falling off, or your aluminium heatblock melting. All are possible, depending on the type of hotend and/or type of heating element.
Re: Hotend Problems May 15, 2014 09:35PM |
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Re: Hotend Problems May 15, 2014 11:42PM |
Registered: 10 years ago Posts: 67 |
Re: Hotend Problems May 16, 2014 03:59AM |
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Re: Hotend Problems May 16, 2014 07:18AM |
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Re: Hotend Problems May 16, 2014 08:36AM |
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Re: Hotend Problems May 16, 2014 05:54PM |
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Re: Hotend Problems May 17, 2014 05:15PM |
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Re: Hotend Problems May 17, 2014 08:36PM |
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Re: Hotend Problems May 18, 2014 08:44AM |
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Re: Hotend Problems May 18, 2014 10:15AM |
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Re: Hotend Problems May 18, 2014 02:52PM |
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Re: Hotend Problems May 18, 2014 04:00PM |
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Re: Hotend Problems May 18, 2014 04:55PM |
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Re: Hotend Problems May 18, 2014 05:55PM |
Registered: 10 years ago Posts: 67 |
Yes.Quote
jbernardis
Checking between ground (negative) and either leg of the fuse is the correct way to do it. There is absolutely nothing between the power supply connector and the fuse - so you should see 12 volts on at least one of them. If you're not seeing it on either, you either have a bad trace (fairly unlikely) a bad connector, or a bad power supply. Do you get voltage between the two power connectors for the 5 Amp rail?
Re: Hotend Problems May 18, 2014 07:04PM |
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Re: Hotend Problems May 19, 2014 01:38AM |
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Re: Hotend Problems May 19, 2014 08:59AM |
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Re: Hotend Problems May 19, 2014 02:51PM |
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Re: Hotend Problems May 19, 2014 04:08PM |
Registered: 10 years ago Posts: 869 |
No. Your link is for 2.5 amp polyfuses. It should be a 5 amp polyfuse which means the 5 amps is the maximum current the fuse will pass without tripping. Typically but not always the trip current, or minimum current that is guaranteed to cause a trip, will be about twice the hold current.Quote
jbernardis
Check the link I gave you earlier - I think the first fuse on the page will meet your needs.
Re: Hotend Problems May 19, 2014 08:15PM |
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Re: Hotend Problems May 19, 2014 10:27PM |
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Re: Hotend Problems May 19, 2014 10:30PM |
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Re: Hotend Problems May 20, 2014 01:02AM |
Registered: 11 years ago Posts: 1,320 |
Quote
cdru
No. Your link is for 2.5 amp polyfuses. It should be a 5 amp polyfuse which means the 5 amps is the maximum current the fuse will pass without tripping. Typically but not always the trip current, or minimum current that is guaranteed to cause a trip, will be about twice the hold current.Quote
jbernardis
Check the link I gave you earlier - I think the first fuse on the page will meet your needs.
The original specs called for a MFR500 fuse which will allow up to 5 amps to pass through all day long, start to warm over 5 amps and trip after a while, and quickly trip at 10 amps or more.
Re: Hotend Problems May 20, 2014 06:36PM |
Registered: 10 years ago Posts: 67 |
Re: Hotend Problems May 21, 2014 08:17AM |
Registered: 10 years ago Posts: 869 |
Presuming that you have the RAMPS board oriented so that the power connectors are on the left edge of the board, it's no surprise that you got nothing when measuring supply ground to the far left mosfet pin. They're directly connected. Measure to the pin farthest away from the power connectors for D10 (or all the way to the right). That pin is the gate pin and comes from the arduino. If you still have nothing, either your pins.h file is wrong and the Mega board isn't using the right pin, or your Mega board is toast somehow. If you measure ~5v but the LED still doesn't light, your MOSFET is fried. But that's easy to replace.Quote
BradStaff
No LED light when I switch the heater on. I'm getting nothing from Supply ground to D10's far left Mosfet pin. Arduino Problem?
Re: Hotend Problems May 22, 2014 07:53PM |
Registered: 10 years ago Posts: 67 |