(K40 Laser Cut Area Enlargement) High voltage wire and Flyback

Hey All,

I have a question about the high voltage wire and the flyback. I am enlarging the K40s cutting area within the k40s eclosure, so I removed the electronics and its being put in its own enclosure. My problem is two things.

1). The high voltage wire has some chaffing where it comes out of the back of the PSU, due to the aluminum base is real rough.
2). The high voltage wire will now be to short so I bought 6 feet of new high voltage wire with connectors from amazon.

I was originally going to splice in the wire just after the flyback and add the length I’d need, but now with the chaffing, I would like to remove the high voltage wire from the flyback.

Without removing the high voltage wire from the flyback, does anyone know how the wire is connected to the flyback? Is it just placed in and capped, is it soldered, or is it molded in?

Regards
Bill

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The High Voltage connection is potted into the HVT. I would not recommend removing it.
What supply do you have, show a picture of the problem area?
I thought the standard supply cover does not encapsulate the HV output??
Add a grommet or some plastic grommet material to the edge it is chafing against?

Just add a connector or high voltage splice to the pigtail

Hi Don,

Thanks for the reply. Adding to the pigtail was my original intention, but if It was feasible to remove it from the flyback and start new, that’s was what I’d prefer. The housing does cover it, but when opening and closing the electronics lid on the k40 enclosure, it moves the wire around causing the chaffing. It wont be an issue in the new electronics housing. They probably should have potted it with a 90° bend going to the rear but I’m sure it’s made for a universal fit…

The chaffing doesn’t look as bad at it is in the picture and is where I will do the splice. I would solder, wrap with a few pieces of shrink tubing then slip a section of the silicon water hose over that to prevent arching and any further chaffing. I could easily replace the hose if needed.

Here are a few pictures.

Regards
Bill

I would put this on the edge of the LPS:
https://amzn.to/2Fwn7kq
… and then add the connector to the HV wire making a pigtail as far away from the enclosure as is practical.

… if you make a splice also do it as far away from the enclosure as you can. This voltage can jump up to 2".
If you splice use Permatex Blue RTV and make the tubing diameter as large as you can then fill it with the RTV. Make the tube overlap 1" past any open-wire surface.
When you solder the joint use “Ball Soldering”. You don’t want any sharp points in the soldered joint.

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Hey Don,

Do you think the length of the high voltage wire will effect the the laser output?

Regards
Bill

Not within reason … like the length of the cabinet.? The big problem with long HV wire is the e-noise & static build up that it may cause. Route it as far away from the electronics as possible.

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Hi Don,

Thanks again for your reply. I’m using the stock electronics, and both steppers will be on the left side. The laser tube’s + side is on the right, so it made sense to put the electronics housing to the left side of the laser’s enclosure to keep the stepper wires as short as possible and to use the X-axis ribbon cable. The longest wire will be the high voltage, going from left to right, and will be outside and in the back of the lasers enclosure. I was going to encase the high voltage wire in a silicon water tubing.

Regards
Bill

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Hey All,

I started tearing down the laser and repopulating the electronics in a new electronics enclosure.

There is no way to splice the high voltage wire to where it’s not going to be anywhere near the metal enclosure. It’s just too short from the factory. Either I have to splice it, and it will be next to the metal, or I remove it off the laser tube and reconnect it back onto the laser tube with a longer piece from the 2-meter selection I have. If I do that, I can then can splice it well away from any metal. I can reconnect it back onto the laser tube just as it came from the factory with silicon and a water tub section filled with silicon that came with the laser.

Any thoughts?

Regards
Bill



I think either will work as long as you make the splices correctly including the tube connection.
If you have a long enough piece, I would elect to use the single piece and make the connection at the tube.
Is the LPS staying in the laser cabinet or the electronics cabinet?

Hi Don,

Yes, all the original electronics are to be used and enclose in a separate box. Here are some pictures. I need to shorten the wires and connect them to the PSU. I placed the top on to give you an idea of what it will look like. I am amazed that the color the box comes in matches the K40 enclosure, and the three covers almost perfectly. The open rectangle hole in the front is were my digital water temperature gauge goes. I haven’t gotten to that point yet.

Regards
Bill

Is your HV cable exiting the electronics box and then entering the box with the laser?
I would be nervous about that being outside where a human can access it.
You know that that cable runs 20,000v right?
If it runs outside I would fin a way to enclose it …

I strongly urge you to add interlocks to both sets of covers, the electronics, and the laser compartment.
You also should include water flow and water temp sensor into that interlock circuit.

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Hi Don,

Yes, the HV cable will leave the electronics box and run behind the laser along the wall. It will be 100% enclosed within a silicon hose the same kind as they put on the laser tube connection points. There is no possible way it can be accessed unless you move the laser enclosure. A few things left to do, like shim the head, drill and mount #1 mirror, lengthen the stepper motor wires, mount the limit switches, connect the HV wire, and splice the - (neg) wire to the tube. Also, add a ground wire connecting the electronics housing to the laser housing, cover some of the openings in the back of the laser enclosure, adjust the tube alignment, and then fire it up to align the mirrors. I have all new mirror mounts and head, along with mirrors and a new lens.

I’m almost at the end of the tunnel.

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