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CNC computer controlled Hotwire heat problems

Foamworx

Jan 10, 2021
4
Joined
Jan 10, 2021
Messages
4
Hi all
Looking for a little help please....
I run large ncn industrial type polystyrene computer Hotwire cutters .
I have a major problem with my card that seems to control the heat running to my heat wire on the machine.
It runs off the motherboard which has X-Y 2 axis which works fine we just can’t get the heat to happen .
Does not blow fuses when we turn it on or off.
The company the makes the machines does not make this board no more and won’t provide a circuit diagram for it ....
Any thoughts on what components on this board what could be causing the problems wh
The controller box that runs the machine is over 10 years old.
Any help would be greatly appreciated....
Cheers
P hil
 

Bluejets

Oct 5, 2014
6,901
Joined
Oct 5, 2014
Messages
6,901
Show some photos of the innards and what you use to control the heat.
 

Foamworx

Jan 10, 2021
4
Joined
Jan 10, 2021
Messages
4
3C1D0EA7-6346-468D-858C-4D2E3B9AD810.jpeg
Hi all
Looking for a little help please....
I run large ncn industrial type polystyrene computer Hotwire cutters .
I have a major problem with my card that seems to control the heat running to my heat wire on the machine.
It runs off the motherboard which has X-Y 2 axis which works fine we just can’t get the heat to happen .
Does not blow fuses when we turn it on or off.
The company the makes the machines does not make this board no more and won’t provide a circuit diagram for it ....
Any thoughts on what components on this board what could be causing the problems wh
The controller box that runs the machine is over 10 years old.
Any help would be greatly appreciated....
Cheers
Phil
 

Bluejets

Oct 5, 2014
6,901
Joined
Oct 5, 2014
Messages
6,901
mmm..that's old alright,,,,,

Have you tested board components..?
They are all discretes and fairly easy to test even if you have to look up how to on Google.
Any experience with electronics at all..??
Would have to wonder what the blue tape is supposed to do.

Any power coming in /out of to the transformer...?

What are numbers on the TO220 device...perhaps some form of thyristor ...??

What is black device upper left...cannot make it out.

Any shots of other side of pc board.

Have you checked continuity of wiring leading from the board to the heating wire..?? or the heater wire itself.
With a wire cutter that moves in any way I'd be leaning towards broken wiring somewhere.
Other wiring continuity while you are at it..??
 
Last edited:

ratstar

Aug 20, 2018
485
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Aug 20, 2018
Messages
485
if you dont mind the wire constantly hot, you can just connect it up yourself.
 

73's de Edd

Aug 21, 2015
3,613
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Aug 21, 2015
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3,613
Sir Foamworx . . . . . . . . . . .

Looks like Cromas '84 design scheme . . . . . is STILL in use.
I need better photo lighting and adjunct accompanying definition of the left half of the photo.

NOW . . .

From what I can seem to make out ?
I see . . . . AC line power coming in at the RED circle for powering up the boards rudimentary low voltage supply, using he GREEN transformer outputting into the
BLACK FWB rectifier aside it, with it then being DC filtered with the BLUE E-filter cap.

Just above it is being a WHITE 1204DM SPST reed relay . . . that's why I need better visual info . . . assumed to be related to the CNC conttrol aspect.
NOW . . . concentrate on the right side VIOLET circle and its inputting of a somewhat hefty power transformer isolsted ...for anti shock safety . . . on the hot wire .
Note its/ the HEAVIER foil board traces . .. ('mo current) . . . . on the board for it, and then my heavier mark up which . . .best as I can see . . . seems to pass straight thru to one terminal of the VIOLET square connector at the other side of the board.
(The gauge if the pins on these connectors somewhat limit current capacity, so the VIOLET square might have yet another wire power source being very close to the hot wire. )
The smaller VIOLET mark up is for the other pin of the connector which flows to the left and has to then connect into and then come out of the T1-T2 terminals of the POWER TRIAC controller on the large heat sink. Its control is via the input to its gate via the oval YELLOW and their path . ..need better pic of . . . . but, logically seeming to be the the 6 pin CNC mama controller board .

The BLUE tape ? probably a connection marking safety net for a novice . . . . not yet fully knowing their CNC / ELECTRONIC A,B,C's.

ORANGE dot connector . . . . looks like its a 2-3 pin mini female jack . . . . . ? possibly connecting for a current sampling of one end of the hot wire 1 inch from an end for feed back. ? )
(But, myself, I would always have such, being hard wired direct . . .NO connectors.)

ALSO a pic of the foil side of the board is being needed to make ANYTHING out of the 6 pin CNC connector . . . . . as well as MUCH-MUCH more..
That will also let me see if marked BLUE X toroid has more than a single winding . . . . . I currently suspicion it as just an EMF / RFI supression choke. Since the BLUE circle plug seems to just come in and grab a diode and then route direct to that toroid units area.

Have no power connected to the unit and the hot wire plug unconnected and then ohm out and see if one line is conneting between the VIOLET round and square connectors ?
Meaure for ohms across the unplugged connector that goes to the hot wire.

With what info you now have, you need plug up the unit and measure / to see if you have AC line power at RED circle when turned on.
Then see what AC voltage level is at VIOLET circle. ( And suspicioning none at the VIOLET square, on a faulty unit. ).

Stopping for further needed pictures, testing feedback and any clarifications that you might need to give me. . . . . .and my wee-wee break.

Und likes der Bleu Jetster sez . . . .
What are numbers on the TO220 device ( mounted on the HEAT sink )

AN ILLUSTRIOUS STRATION . . . . . redraw
CRONOS-Hot-wire-heater.png




73's de Edd . . . . .


Typically, teamwork is being somewhat advantageous ; since it then allows you to blame someone else.




.
ADD ON . . . .
if you dont mind the wire constantly hot, you can just connect it up yourself.


Maybe you just need to see one of those CNC based CRONOS units in action . . . it wasn't exactly $ 69.99 on sale at Wally World for his kiddo to play with or for mama to make xmas tree ornaments.



.
 

Minder

Apr 24, 2015
3,478
Joined
Apr 24, 2015
Messages
3,478
Appears to be a typical SCR/Triac phase angle controller, have you tested the large white ceramic covered resistor, these tend to give out after years of use.
I suspect the hot wire has nothing to do with the positioning/CNC side of things.
M.
 

Frankchie

Nov 14, 2017
149
Joined
Nov 14, 2017
Messages
149
As already mentioned, checking the individual components would be a good first step. In most cases that can be done with a simple multimeter. Google can help you there. The semiconductor on the heatsink seems to show slight discoloration and that could be a sign of overheating.

It looks like there are a lot of connections to the mother board suggesting fairly complex signaling and i'm wondering how you decided that the mother board is not the problem?

Also it might be helpful if you can identify the mfr and model number of the equipment.
 
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