From smoking to crackling

A place for users to ask questions and search for already asked questions. "BE NICE" and helpful!

PM GeneMpls with Questions about this FAQ PM - Top Right Side by your name.
User avatar
Keith Sherwin
Site Admin
Posts: 998
Joined: Fri Jun 24, 2016 1:44 pm
Location: Okanagan Valley, B.C. Canada

Re: From smoking to crackling

Postby Keith Sherwin » Wed Dec 28, 2016 1:45 pm

Dustin, You must have missed a few of the photos. It turned out to be silicone as in RTV, so that wasn't the problem. And, 22 gauge will carry all the current you need for that tube. The insulation is the big factor. However, Fred, at this point, has not told us if he has done the other things suggested to him. It IMHO is probably humidity which he needs to clear up before adding insulation and sealing it in between the two layers.
69 Real (80)Watt Laser w/multi FL lenses. T.L.
Made 5 CNC's, Electronics, Electrical, PLC & Computer background.
:idea: Started this forum - Using RDWorks V8.01.21 on W7 Pro
Lead in creation of the RDWorksLab English Manual.
Crazy Uncle Keith!

User avatar
fred ungewitter
Posts: 221
Joined: Tue Aug 16, 2016 12:55 pm
Location: East Central FL, USA

Re: From smoking to crackling

Postby fred ungewitter » Wed Dec 28, 2016 2:27 pm

The tube gently warmed up overnight. As the tube has been shut down for nearly 24 hours, all moisture has evaporated. I plan to position a fan to keep evaporation at maximum during operation, perhaps a permanent installation of a large computer muffin fan through the housing. I realize now that the expansion cover plate would be well suited for such an installation. Easy to duplicate in any flat material and no permanent butcher jobs on my cabinet. The fan may become a permanent fixture.

I've now removed the existing tubing, exposing the silicone within. Careful shaving of the silicone results in this:
IMG_3250.JPG


The wire was easily straightened and re-wrapped:

IMG_3251.JPG


IMG_3252.JPG


My RTV silicone was only slightly clogged in the tip and is clean and flowing, applied to the HV connection and re-covered with the tubing.

IMG_3255.JPG


The sparks appeared to emanate from the side of the tube, about mid-point of the diameter, the portion pointing to the front of the machine. Considering the amount of condensation on the tube, I'm hoping that was the primary problem. The entire length of the HV wire has no burn marks, but I added some self-fusing rubber tape where it passes through the housing. A hole about 25 mm diameter with the angle of the HV wire making it enter just about in the middle, all good things so far.

I'm going to give the silicone at least overnight to cure. I have a sample squeeze of the stuff to monitor to let me know when it's cured, although the stuff on the HV connection will cure more slowly. RTV silicone cures from contact with moisture, typically from the outside in. I didn't know what would happen to the insulating properties if I added corn starch to speed up the curing, so I didn't.

I also recognize the concept that high voltage does not need large gauge wire, so the ten gauge shotgun///////wire I found is back in the junk pile. The insulation on this wire is pretty healthy and as noted earlier, in good condition.

Diverting slightly from this subject, yet applicable in general is a power question. Is there a 12v tap I could be using to drive the dryer fan? There's a fan in one of the covers and I figure I could tap into that line if it's 12v, which I can easily determine.
You do not have the required permissions to view the files attached to this post.
fred

Redsail clone 60w 700 x 500
home upper right
RDWorks 8.01.18
Windows 7

Emblaser A3 4w diode laser
BCN3D Sigma Dual Extruder 3d printer
LMS Mini-mill
Cube 3rd gen 3d printer (works great, for sale)
Under construction: OX CNC 1000x750 router - out of the box, still in baggies!

User avatar
Keith Sherwin
Site Admin
Posts: 998
Joined: Fri Jun 24, 2016 1:44 pm
Location: Okanagan Valley, B.C. Canada

Re: From smoking to crackling

Postby Keith Sherwin » Wed Dec 28, 2016 2:59 pm

Good idea to not add anything to the RTV. Did not know that moisture cured it though.

Can't guess what voltages you have available. You will need to look at the power supply and see what is available. Might be written on the case. 12 Volts is not used by the controller, but could be supplied for the fan. You will need to measure with a volt meter. If not, an AC/12VDC adapter should be pretty cheap, just make sure it has the current capability required.
69 Real (80)Watt Laser w/multi FL lenses. T.L.
Made 5 CNC's, Electronics, Electrical, PLC & Computer background.
:idea: Started this forum - Using RDWorks V8.01.21 on W7 Pro
Lead in creation of the RDWorksLab English Manual.
Crazy Uncle Keith!

John Lifer
Posts: 29
Joined: Mon Dec 05, 2016 5:02 am
Location: NorthWest Arkansas

Re: From smoking to crackling

Postby John Lifer » Wed Dec 28, 2016 6:11 pm

My machine has the high voltage line running through a silicone tubing,same as waterline, all the way from the power supply to within 3 inches of the connection at the tube. And my Efr tube has a screw connection with a silicone boot over the end. This might help with reducing the arcing
Working with a Ray Fine Chinese CO2 Laser
RF-13900 1300x900 bed, 80 Watt
Using TR and RDworks V8.01.19
John in NWA

Malcolm Ferrie
Posts: 225
Joined: Mon Aug 22, 2016 10:31 am
Location: N.E. Scotland

Re: From smoking to crackling

Postby Malcolm Ferrie » Thu Dec 29, 2016 7:06 am

I have just fitted a new 50w tube and I am having the same problem but my arcing is coming from the steel band around the tube arcing brightly down to the chassis of the laser, with the lights out I feel like Frankenstein's creator. Oh I'm sad.
Malcolm Ferrie
North East Scotland
2 x 50 x 30 50w Lasers (TL)
1 x 70 x 50 60w Laser (TR)
1 x Mini 0.5w Laser (Anywhere)
1 x 50 x 30 water cooled cnc (BL)
Corel Draw 12 & x7, Artcam, Cut 2D, PhotoGrav
If I can't make it myself, I don't need it.

User avatar
Keith Sherwin
Site Admin
Posts: 998
Joined: Fri Jun 24, 2016 1:44 pm
Location: Okanagan Valley, B.C. Canada

Re: From smoking to crackling

Postby Keith Sherwin » Thu Dec 29, 2016 7:16 am

Time to cut some plastic holders Malcolm. Look in Russ's Adventure area for DXF of clamps.
viewtopic.php?f=6&t=33
Is your cooling water clean? If not clean, water can be a conductor.
69 Real (80)Watt Laser w/multi FL lenses. T.L.
Made 5 CNC's, Electronics, Electrical, PLC & Computer background.
:idea: Started this forum - Using RDWorks V8.01.21 on W7 Pro
Lead in creation of the RDWorksLab English Manual.
Crazy Uncle Keith!

Don Flynn
Posts: 12
Joined: Sun Nov 20, 2016 9:33 am
Location: Chicago, IL

Re: From smoking to crackling

Postby Don Flynn » Thu Dec 29, 2016 9:00 am

Keith here is Link to tube that Russ has that I am using. They also bundle power supplies with them if you need one as well as other package deals.

https://www.aliexpress.com/item/1-Pcs-1 ... 0.0.e3gA0r
Chinese Laser 60 Watts. Bed Size 500mm X 300mm Home Position:TL.
RDWorks v8.01.18 on Windows 10

Don

User avatar
Keith Sherwin
Site Admin
Posts: 998
Joined: Fri Jun 24, 2016 1:44 pm
Location: Okanagan Valley, B.C. Canada

Re: From smoking to crackling

Postby Keith Sherwin » Thu Dec 29, 2016 9:15 am

That was intended for Malcolm.
But thanks for the link.
69 Real (80)Watt Laser w/multi FL lenses. T.L.
Made 5 CNC's, Electronics, Electrical, PLC & Computer background.
:idea: Started this forum - Using RDWorks V8.01.21 on W7 Pro
Lead in creation of the RDWorksLab English Manual.
Crazy Uncle Keith!

User avatar
fred ungewitter
Posts: 221
Joined: Tue Aug 16, 2016 12:55 pm
Location: East Central FL, USA

Re: From smoking to crackling

Postby fred ungewitter » Thu Dec 29, 2016 4:53 pm

Once more into the fray.

With water temperatures as low as 13 deg C and ambient running about 26 deg C, relative humidity between 45 and 55 percent, I'm certainly going to embrace the "too much moisture" aspect of my tube's recent failure. To that end, an expression in itself redundant, I've pursued a solution that has proven to be as effective as it is simple.

I ventured into my junk room, hard hat and safety glasses absent, and rummaged around in the area expected to be populated by a collection of old computer fans. A monster 120 mm fan tumbled from above, replete with rubber vibration absorbers and a wire finger chopper shield! Huzzah, huzzah!

A bit of an energy hog, at 12vdc and 1.40 amperes, but again, luck is with me. A previous project no longer in service required the power supply, only one shelf away, an equal monster at 12vdc and 15 amperes!

In the process of carving a piece of ABS plastic salvaged from the housing of a projection television, I was able to use the wire shield to trace the outline to be cut for the fan. The cover at the high voltage end of the laser provided a suitable template for the bolt holes as well. Without forethought, I planned to merely attach the removed cover above the new installation. Serendipitously, this peculiar location also served as the perfect location for the temporary power supply mounting. it's not pretty, but not particularly ugly and best of all, it works.

IMG_3257.JPG


IMG_3258.JPG


IMG_3259.JPG


The photos appear to show a much dirtier area than one observes in real life. Irrespective of that, I now will be devising a suitable particulate filter to apply to the finger chopper screen. I don't need to add more crap to the area around the high voltage end.

As a test, I closed the tube access cover and slightly opened the main body cover. Even with the cover fully open, there's a strong blast of air from the monster fan.

Condensing the account, (hard to believe, isn't it?) I fired up the water cooler and pushed the 13-15 deg C water through the tube. After 45 minutes, the tube was wonderfully dry. To be certain of these results, I powered off the fan, but left the water pump running. Fewer than ten minutes later, the hv end of the tube had frosted over with fine moisture. I have not yet cleaned the tube with alcohol, and there may be enough dust and particles there to give the water some seed particles on which to condense, but it does confirm that the fan keeps the tube dry.

Either I continue to use the heavy duty power supply or find one a little less hefty, but either way, it will eventually be wired into the same switch as the water pump.

Continued next message...
You do not have the required permissions to view the files attached to this post.
fred

Redsail clone 60w 700 x 500
home upper right
RDWorks 8.01.18
Windows 7

Emblaser A3 4w diode laser
BCN3D Sigma Dual Extruder 3d printer
LMS Mini-mill
Cube 3rd gen 3d printer (works great, for sale)
Under construction: OX CNC 1000x750 router - out of the box, still in baggies!

User avatar
fred ungewitter
Posts: 221
Joined: Tue Aug 16, 2016 12:55 pm
Location: East Central FL, USA

Re: From smoking to crackling

Postby fred ungewitter » Thu Dec 29, 2016 5:03 pm

I'm confident that the tube connection silicone is cured. The assembly on the high voltage contact is quite firm and the test blobs are solid as well. I approached the fire-up with optimism, almost immediately dashed to pieces.

With the system configured to burn a test file, the nozzle moved as expected and pretended to perform the burn, but the ammeter showed zero and there was no visible activity at the high voltage end of the tube.

The last activity was fireworks or more accurately, high voltage sparking. Nothing happening at all at the high voltage end now. I'm going to give the system a day to discharge any pent-up anger and to discharge any pent-up voltage before I return to poking around in the high voltage guts.

I can see from an extreme angle that there's a five ampere fuse in the left side of the high voltage power supply. I'll check that first, for obvious reasons. I see there is also a test button, but what does that do? What sort of test is run? What indication is presented during and after the test?

I'm going to remove my silicone cap and re-wind the pin connection, although I think that's unlikely to be the solution. My experience with high voltage is that air is the best insulation possible, which means the silicone would reduce insulation effectiveness slightly. I figure I can re-wrap the high voltage pin and perform a test firing without the silicone sealing as long as I keep my sensitive body parts away from that area. I'm sure glad I have an eight foot earthen ground only a few feet outside the wall!

If the original problem can be attributed to moisture on the tube and that problem has been solved, what is next in the home/hobbyist user test sequence?

I expect push-back from the vendor, despite the "two year warranty" in the eBay item listing. I've already been told I can buy another tube from them. Yeah, right, like I'll give them more of my money. Okay, realistically, more of my wife's money. Either way, what's the best way to pin down the problem?

Believe it or not, this message will be continued in another forum, more appropriate to the next line of reasoning.
fred

Redsail clone 60w 700 x 500
home upper right
RDWorks 8.01.18
Windows 7

Emblaser A3 4w diode laser
BCN3D Sigma Dual Extruder 3d printer
LMS Mini-mill
Cube 3rd gen 3d printer (works great, for sale)
Under construction: OX CNC 1000x750 router - out of the box, still in baggies!


Return to “User Questions and Help”

Who is online

Users browsing this forum: No registered users and 1 guest