wiring help on pro-mendel - hot end assembly
Posted by RcBazaar
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wiring help on pro-mendel - hot end assembly November 26, 2012 04:03PM |
Registered: 13 years ago Posts: 5 |
Guys..
can someone have a look at the attached pic and help me here on which wire goes where as i am a bit lost on the build done here reprap pro mendel hot end assembly... in the build on wikipedia it states as
"Use two adjacent wires from the ribbon cable for each end of the heater resistor - four in all. This is to increase the current capacity.
The wires across the ribbon cable in order go like this:
Wire with the colour stripe: Thermistor
Thermistor
Fan + volts
Fan Ground
Heater resistor Wire 1
Heater resistor Wire 1
Heater resistor Wire 2
Heater resistor Wire 2"
I am a bit lost here and any direction / help would be appreciated... and if any here can just state where the wires (numbered) would go into the parts (alphabetically stated)
Finally how does the filament melt in the nozzle??? does the bed heat up or the nozzle heats up??
can someone have a look at the attached pic and help me here on which wire goes where as i am a bit lost on the build done here reprap pro mendel hot end assembly... in the build on wikipedia it states as
"Use two adjacent wires from the ribbon cable for each end of the heater resistor - four in all. This is to increase the current capacity.
The wires across the ribbon cable in order go like this:
Wire with the colour stripe: Thermistor
Thermistor
Fan + volts
Fan Ground
Heater resistor Wire 1
Heater resistor Wire 1
Heater resistor Wire 2
Heater resistor Wire 2"
I am a bit lost here and any direction / help would be appreciated... and if any here can just state where the wires (numbered) would go into the parts (alphabetically stated)
Finally how does the filament melt in the nozzle??? does the bed heat up or the nozzle heats up??
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Re: wiring help on pro-mendel - hot end assembly December 01, 2012 03:13PM |
Registered: 13 years ago Posts: 12 |
Start by counting the wires on the ribbon cable. You need 8 wires. If like mine, your cable is wider, split the extra wires off. You want the red stripe on the 8 wire ribbon. Keep the rest for connecting end stops and stuff.
And remember to slide the heat shrink on before connecting the wires.
It's easiest to work with one component at a time, and do all the hot end connections first. Then connect the board end using the same numbers.
Wire with the colour stripe: Thermistor --wire 1
Thermistor other end --wire 2
Thermistor is not polarised, so either end connects to either terminal on the electronics board. One to each leg, and one to each terminal on the board. There is no backwards.
Fan + volts --wire 3
Fan Ground --wire 4
Fan IS polarised, so make sure the + terminal of the fan goes to the + terminal on the board and Gnd goes to Gnd. If wrong, the fan will not spin. Bad thing. The fan is important, and needs to be going at all times.
To find out which is which, connect a 9 volt battery to the fan. and when it spins, note which wire goes to which connection on the battery. The third wire is not used. So you are safe to cut that off, and use a scrap of heatshrink to stop it shorting anything.
Heater resistor Wire 1 --wire 5
Heater resistor Wire 1 --wire 6
Heater resistor Wire 2 --wire 7
Heater resistor Wire 2 --wire 8
This seems confusing at first. The idea is to double the wires. so the resistor has got double the thickness of wire to feed it more current. So you connect two wires to each leg of the resistor.
One pair for each leg of the resistor, and the same pairs connected to the two terminals on the board.
Twist 5 and 6 together, and join them to one leg of the resistor.
Twist 5 and 6 and plug into one terminal of the board.
Twist 7 and 8 together, and join them to the other leg of the resistor.
Twist 7 and 8 and plug into the other terminal of the board.
It is very important that you make sure the same pairs are used at both ends. Which pair in which terminal does not matter Resistors are not polarised, so you can't connect it backwards.
Take your time, and go step by step, and you will get it right.
And make sure to check the wiring and the stepper contol pot voltage before your first power on. Then check it again.
As to the heating question.. Both heat up.
The bed heats to make the plastic stick to it. And takes a few minutes to heat up, because it is heating a great big plate of aluminium and a pane of glass. It must be very clean though. No finger grease. Use a little bit of nail polish remover on a bit of kitchen towel to wipe the glass surface clean while it is heating, and you will get rid of any grease. Then it will stick well. After your print has finished, let it cool down to room tempriature, and the print will just pop right off, or you might need to give it a gentle twist. No brute force needed. Sometimes, you can hear a faint creaking sound as the glass and plastic contract at different rates.
The head heats up (much faster) and melts the tip of the plastic. This is what the heater resistor is for. But just the tip. This is why the hot end fan is there. To stop the rest of the plastic melting. Too hot, and too much plastic is melted, and it jams. Too cold, and the hobbed bolt will dig into the plastic, and stop feeding it.
What you are looking for when you start extruding into open space, is a long string of plastic flowing down from the nozzle. If it curls up and sticks to the nozzle as soon as it comes out, it is too hot. It will print, but badly, and you will quickly get a jam. My head temprature is set to 187 degrees. You will need to experiment to find the right temprature..
And remember to slide the heat shrink on before connecting the wires.
It's easiest to work with one component at a time, and do all the hot end connections first. Then connect the board end using the same numbers.
Wire with the colour stripe: Thermistor --wire 1
Thermistor other end --wire 2
Thermistor is not polarised, so either end connects to either terminal on the electronics board. One to each leg, and one to each terminal on the board. There is no backwards.
Fan + volts --wire 3
Fan Ground --wire 4
Fan IS polarised, so make sure the + terminal of the fan goes to the + terminal on the board and Gnd goes to Gnd. If wrong, the fan will not spin. Bad thing. The fan is important, and needs to be going at all times.
To find out which is which, connect a 9 volt battery to the fan. and when it spins, note which wire goes to which connection on the battery. The third wire is not used. So you are safe to cut that off, and use a scrap of heatshrink to stop it shorting anything.
Heater resistor Wire 1 --wire 5
Heater resistor Wire 1 --wire 6
Heater resistor Wire 2 --wire 7
Heater resistor Wire 2 --wire 8
This seems confusing at first. The idea is to double the wires. so the resistor has got double the thickness of wire to feed it more current. So you connect two wires to each leg of the resistor.
One pair for each leg of the resistor, and the same pairs connected to the two terminals on the board.
Twist 5 and 6 together, and join them to one leg of the resistor.
Twist 5 and 6 and plug into one terminal of the board.
Twist 7 and 8 together, and join them to the other leg of the resistor.
Twist 7 and 8 and plug into the other terminal of the board.
It is very important that you make sure the same pairs are used at both ends. Which pair in which terminal does not matter Resistors are not polarised, so you can't connect it backwards.
Take your time, and go step by step, and you will get it right.
And make sure to check the wiring and the stepper contol pot voltage before your first power on. Then check it again.
As to the heating question.. Both heat up.
The bed heats to make the plastic stick to it. And takes a few minutes to heat up, because it is heating a great big plate of aluminium and a pane of glass. It must be very clean though. No finger grease. Use a little bit of nail polish remover on a bit of kitchen towel to wipe the glass surface clean while it is heating, and you will get rid of any grease. Then it will stick well. After your print has finished, let it cool down to room tempriature, and the print will just pop right off, or you might need to give it a gentle twist. No brute force needed. Sometimes, you can hear a faint creaking sound as the glass and plastic contract at different rates.
The head heats up (much faster) and melts the tip of the plastic. This is what the heater resistor is for. But just the tip. This is why the hot end fan is there. To stop the rest of the plastic melting. Too hot, and too much plastic is melted, and it jams. Too cold, and the hobbed bolt will dig into the plastic, and stop feeding it.
What you are looking for when you start extruding into open space, is a long string of plastic flowing down from the nozzle. If it curls up and sticks to the nozzle as soon as it comes out, it is too hot. It will print, but badly, and you will quickly get a jam. My head temprature is set to 187 degrees. You will need to experiment to find the right temprature..
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