View Full Version : Laser Welder Gloat

06-09-2013, 02:58 AM
Got another new toy on the way, a 4 axis CNC laser welder!

The laser itself is a Nd:YAG made by JK Laser in England. It is rated at 55J per pulse, .5ms to 20ms pulse length, up to 100Hz pulse rep, 400W average power. The manual says it can be used for laser welding, drilling and cutting up to 5mm metal. Fun! Great for welding odd-ball metals.

Bad thing is it sucks power, at 240 3 phase it wants 66 amps peak. Ouch! The power supply is Two 19" rack cabinets bolted side by side about 4-1/2 feet tall and weighs in at about 880lbs (400kg). It also wants about 5 gal/min water cooling.

It was originally bought by Tektronix in 1985 for the display division. A friend who used to work down there said when he was there they used a ruby laser to zap tabs inside evacuated CRTs. The machine has sat for about 10-12 years now. About that time the original Anorad control died and they decided to upgrade the control to something more modern. They used MDSI OpenCNC with Yaskawa Sigma II brushless servos. After spending a LOT of money on the software, drives, and I/O the management decided this was costing too much and wanted to get out of the laser welding side of things so the project was dropped. The machine has sat ever since.

This is the software, yeah, $11,000 for the 4 axis version: http://www.mdsi2.com/Solutions/CNC_Controls/default.aspx

The machine has an amazing amount of documentation including copies of the original correspondence between Tek and the machine integrator, Lumonics. There are two filing cabinet drawers of complete schematics and blueprints for the laser and the machine it was integrated into. Every custom part used to put it together seems to have a print.

I am hoping I can modify it to run off of single phase. According to the schematics the power comes in and is routed to three places, a single phase transformer which supplies the DC for the control electronics, a three phase pump for the head cooling loop and two main three phase transformers in parallel. The first two are easy to deal with, a small VFD on the pump. What I am hoping is since the transformer is tapped for voltage selection I can rewire the windings for single phase operation. The output does not matter so much, it is just rectified for a 425v DC buss to charge the capacitor banks. If this does not work I have a 15HP rotary phase converter I built for my lathe that might run it.

For the cooling I will just use a garden hose for now, it wants 2 to 6 bar at 20l/min of water. If this thing does work I will probably get a plastic 55 gal drum and use a pump to circulate from that into the power supply's heat exchanger. A thermostat would add tap water to the tank as it heated to keep the temp stable. Maybe an evaporative cooler too.

It comes with an extra set of new lamps. Bad news is it sounds like it may need to have the YAG rod repolished. I cant imagine how much this is going to cost. It is a pretty good sized rod too, 3/8" diameter and 6.25" long.

Oh yeah, $500.

http://farm8.staticflickr.com/7375/8993990666_90c082d0b3_b.jpg (http://www.flickr.com/photos/67292116@N00/8993990666/)
Lumonics laser welder (http://www.flickr.com/photos/67292116@N00/8993990666/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

http://farm9.staticflickr.com/8121/8993991530_e7c6649aa1_b.jpg (http://www.flickr.com/photos/67292116@N00/8993991530/)
Lumonics laser welder (http://www.flickr.com/photos/67292116@N00/8993991530/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

06-09-2013, 07:42 AM
DAMN that's a SCARY machine!

/Goldfinger mode;

"No Mr Bond, I expect you to die"

400w average from a laser - what's the beamwidth? I can see a long haul getting it working, when you do I might want some laser cut parts for one of my bikes... What's its work envelope? But nice score, "you suck" awarded :)

06-09-2013, 08:26 AM
Yep. You suck.

They'd have to rewire half the power grid in my little town just to turn the damned thing on.

Keep us posted. You get that bad boy running and you'll have lots of friends. :D

06-09-2013, 08:57 AM
Wow. Get yourself a shark and you'll be all set!

06-09-2013, 08:58 AM
Nice find macona - you get hold of the coolest stuff.

Diesel-generated power is relatively cheap. I'd be looking for an old genset to power that.

06-09-2013, 10:29 AM
A 20hp Phase Perfect will power that nicely :)

Nice score. Take care with YAG... you can't see it coming (I worked for a couple of years with a big lab yag used for "materials testing" - imaging the beam on CID cameras to guarantee the power characteristics - late 80's...)

06-09-2013, 01:39 PM
man you get some awesome scores!

06-09-2013, 04:54 PM
Go ahead and invest in the 55 gallon drum and a pump because its very rare for a municipal water supply to flow that kind of volume at 0 pressure, unless you have a big meter, say 1 1/2" or bigger. I would be surprised if you could get 5 gpm at 30 psi (your minimum pressure) sustained.

06-09-2013, 05:26 PM
Water around here is about 60PSI and I get about 8-9 gal/min at 0psi. It should do with trick. It was ran off city water in the past.

The machine has lots of extras including a few pairs of goggles and a IR viewer set.

Dave, I am not sure of much of anything at this point. It does use a 3/8" rod so the initial beam is at least a good chunk of that. Bit it should be a pretty tiny spot, it does have a beam expander.

06-09-2013, 05:58 PM
Looking at the power requirements and given its age, It was easier to use 3 phase rectifiers 'cause they couldn't find suitable high current rectifiers. I addition to the fact that they never envisioned that being installed in your garage... :>)

Most likely, just as with a 3 phase /1 phase welder you could just drop the peak pulse rate by 33% or so and keep on welding...sure will be fun to try.


06-09-2013, 07:31 PM
If I just went with trying single phase I think it would be limited to about 1/3 output, if it worked at all. It does have undervoltage detection. Using single phase you would be only using 1/3 of each transformer.

I am probably going to have to rig up a power supply to reform the main tank caps. They have not been charged in forever.

06-10-2013, 12:15 AM
re 3 phase: I would think that the load will try to draw the same amount of current regardless of what is suppling it. While it may well be to much for the winding and the rectifier, the demand is the same. ie the load impedance... 10 ohms is 10 ohms. So the voltage won't be low if you give it long enough to charge, but as you observe the safety circuits may not like it.

The reforming would be a really good idea.
http://www.nmr.mgh.harvard.edu/~reese/electrolytics/#reform (http://www.nmr.mgh.harvard.edu/%7Ereese/electrolytics/#reform)

Wow. First four search results... and to think that I used to just hook them up to a 12v battery...


06-10-2013, 01:29 AM
Got another new toy on the way, a 4 axis CNC laser welder!

YUP! I like your methods. I didnt read all the post or replies. Some good stuff though what I did pick up on. Fun toy.

So Ill comment on why does it have a large current demand? I dont see it with a 400W tube. Lazing tubes are not too unlike RF tubes other than one likes AC and the other DC. I get that you are loosing some with the conversion from AC to DC. It is a DC tube right? I dont know. But for a 400W output Id like to know where the other power is? Almost 16kW with 66amps at 240.

I think the rotary unit will supply it. If its a DC machine it wont run like an inductive load but sure as heck wont be like a resistive load (Like a welder) which wont work. The rotary should do it. I have an old Emco lathe that was said to not like rotary 3ph. Well I just bought a large enough one so it couldnt complain. And it doesn't. Runs just fine and the big Baldor 15hp 3ph motor doesn't even know it has a load on it.

Kinda funny though my home grown 5hp rotary via Art Volz. Nice guy. We were both metal shaper fans. We talked a lil. Anyway, this lil 5hp motor kinda likes to "grind" when the bridgeport in switched from forward (4000rpm) to reverse. You know, sounds like the windings want to leave the housing LOL. I dont do it often and I actually get more chatter from the contactor switch. Other issues.

I thought about running an additional string of three 6ga lines from my 15hp unit but dont need to yet. Its serious overkill for my lil garage.

It will be nice to see you get this beast powered up. Ummm? The shades? They arent so you look cool. They are there so you can keep looking. UV is a bear :) JR

06-10-2013, 02:27 AM
Paul, thanks for the links. I got to figure out what I am going to do for a 450v power supply to reform them. Maybe a simple voltage quadrupler and a variac. Or I could put 4 of those solyndra solar cells I have in series and put it outside! That ought to bring the bank up nice and slow.

JRouche, This is a YAG laser, flash lamp pumped crystal rod. Lots of wasted energy in heat, thats why it wants 5 gallons/min of water to keep it cool. Dual flash lamps, one bank of caps for each one. About 2 ga wires to the head.

When I figure out how I am getting this thing home I will know more. I will also post some more pics of the power supply. The input rectifiers were pretty substantial though I really was not paying attention to that when I was disconnecting the power supply from the rest of the machine. I think it used some larger bolt down half bridge modules for the main rectification.

06-10-2013, 07:57 AM
Water around here is about 60PSI and I get about 8-9 gal/min at 0psi. It should do with trick. It was ran off city water in the past.

The machine has lots of extras including a few pairs of goggles and a IR viewer set.

Dave, I am not sure of much of anything at this point. It does use a 3/8" rod so the initial beam is at least a good chunk of that. Bit it should be a pretty tiny spot, it does have a beam expander.

Apart from your eyes I would also be worried about getting holes burnt through your head or body!

06-10-2013, 08:22 AM
As long as you have a variac laying around you might couple that to the 110 side of a 440 volt control transformer and either feed the existing rectifiers or just add a half wave rectifier outboard. That would make the current sensing easier I guess.

The yag isn't very efficient but it sure is fun. You could probably melt stuff with the drive pulse alone.


michigan doug
06-10-2013, 06:29 PM
You suck!

Post more pics as you get the beast to come back to life.

What might you use it for??


06-10-2013, 10:48 PM
Apart from your eyes I would also be worried about getting holes burnt through your head or body!

Nah, it takes an extreme amount of power to do something that damaging to your body. This wont do it. YAGs are a little less friendly than CO2s though.

You suck!

Post more pics as you get the beast to come back to life.

What might you use it for??


Make others jealous? Make the power company REALLY like me?

Dont know. A guy on another forum brought up Laser sintering, might try that. This has a real Z axis on it.

I was digging through some of the documentation and found the blueprints for the demo and build out for the floor at Tektronix where this was being installed. Pretty cool! (Building 48, 3rd floor)

Here is a pic of the schematic of the power side of the power supply:

http://farm4.staticflickr.com/3683/9012878260_3b7fbb1672_b.jpg (http://www.flickr.com/photos/67292116@N00/9012878260/)
Laser Welder Schematic (http://www.flickr.com/photos/67292116@N00/9012878260/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

This is the rectification section, three MDD42-12N1 half bridge per lamp, they are rated at 100A IFRMS and 64A IFAVM, whatever that means, forward current root mean squared and forward average mean. I couldnt find definitions. Either way they should be happy if I can figure out how to run it off of single phase by rewiring.

http://farm3.staticflickr.com/2806/9011653643_294c2c2560_b.jpg (http://www.flickr.com/photos/67292116@N00/9011653643/)
DC Buss Rectifiers (http://www.flickr.com/photos/67292116@N00/9011653643/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

06-11-2013, 12:04 AM
Hey Jer

Does this thing have two pump tubes? Trying to figger why they had two supplies. I took a look at the schematic... aint it always easier to read the paper than reality... Nice harness in the pic, but it's packed in there...

TB105 and TB106 look to be be a good place to install a limiting resistor if you wanted to use the existing PS to reform the caps.


06-11-2013, 12:52 AM
Yeah, it has a complete power supply, cap bank, and trigger circuit for each pump lamp.

If you click on the photo it will take you to flicker where the full size version resides. Not a bad pic for an iphone with so-so lighting.

It looks like there are D sized prints of the schematics. I hope to bring it home thursday and friday.

It comes with an extra pump that was from a chiller it used to run off of. 115/230 single phase motor, up to 20gal/min at 60' head. That should do for my cooling scheme.

06-11-2013, 01:37 AM
If you run it off single phase, you should SERIOUSLY beef up the filter capacitors or the existing ones may blow from the massive increase in ripple current, Not to mention the huge increase in ripple voltage that the load would experiance, 3 phase does not even need filter caps and will only have 33% ripple.
If you only used very short pulses and sync locked it to mains, it might work on single phase OK.

20hp rotary converter*714W = 14,280W / 240v = 59amps input. Not nearly enough to run a 66amp 3 phase supply!

06-11-2013, 02:07 AM
I have a whole bunch more 450v caps I had gotten from the Tek Country store years ago. Wonder if they might have been spares for it. That would be funny!

A friend who worked at Tek a little before they got this wrote me:

Yep, I used to work on the 3rd floor of building 48. The 2nd, 3rd floor and 1/2 of the basement were all CRT manufacturing and engineering (where I worked). The other 1/2 of the basement was devoted to IC testing of Tek made IC's. Building 46 (since demolished) was north of 48 separated by the cafeteria. Building 46 made all the traditional crt's plus all CRT gun assemblies. The more you describe this monster I sort of remember it being discussed by some friends I still had in CRT. Have fun with it!

06-11-2013, 06:56 PM
Found some more info on it going through the documentation. Travel on X is 18" and Y is 12", Z has 8" of travel.

Tektronix paid over $270,000 for it, today that is over $450k.

It weighs way more than I was expecting. The plate the X-Y stage is mounted to is a 4'x4' sheet of 1" steel reinforced underneath with a 9x5 grid of 4" x 1/2" thick flat bar on edge. The base plate alone without the rest of the machine weighs 1038lbs.

06-11-2013, 10:53 PM
Not knowing a lot about laser welding, does the actual process get done in a chamber or enclosure with inert gas, or is it shrouded with gas like tig?

06-11-2013, 11:59 PM
It depends, here the gas (argon) comes out the nozzle when welding. Some laser setups are in a glovebox where it is filled entirely with argon. For cutting I will use either nitrogen or oxygen.

06-13-2013, 12:28 AM
Brought home the first part of the pile, the power supply and the spares/manuals/etc. I am renting a trailer tomorrow to pick up and bring the main unit home.

http://farm8.staticflickr.com/7301/9028979237_83ccb8f327_b.jpg (http://www.flickr.com/photos/67292116@N00/9028979237/)
IMG_6620 (http://www.flickr.com/photos/67292116@N00/9028979237/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

http://farm8.staticflickr.com/7327/9028972255_34fdedbc8d_b.jpg (http://www.flickr.com/photos/67292116@N00/9028972255/)
IMG_6621 (http://www.flickr.com/photos/67292116@N00/9028972255/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

Black Forest
06-13-2013, 04:49 AM
What do you intend to do with this beauty when you get it running? Do you actually have a need to laser weld? Or do you have some work for it to actually generate some income? Just curious! What could you actually use it for? What type of things would one use this machine to weld? I personally thing it is worth having just for the cool factor but I do wonder what you will do with the machine.

06-13-2013, 05:48 AM
This combined with your wierd and wonderful history of purchases must put you near to the top of some agencys watch list.

Do let us know who comes knocking first :).


06-14-2013, 01:13 AM
Not sure what I am going to do with it. First I need to see if I can get it working. I got a line on a guy that can recoat the ends of the YAG rod. There were some new flash lamps from an earlier machine that came with it that I just sold to a collector, that just paid for 80% of the machine!

Rob... I dont think they will knock!

06-14-2013, 07:09 PM
Loaded up and ready to come home:

http://farm6.staticflickr.com/5333/9044013167_6d36825bf6_b.jpg (http://www.flickr.com/photos/67292116@N00/9044013167/)
Untitled (http://www.flickr.com/photos/67292116@N00/9044013167/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

http://farm4.staticflickr.com/3673/9044012273_d84c1fe8ed_b.jpg (http://www.flickr.com/photos/67292116@N00/9044012273/)
Untitled (http://www.flickr.com/photos/67292116@N00/9044012273/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

06-14-2013, 10:49 PM
I believe that those Yaskawa Sigma 2 drives can be run in Stepper mode (step/direction) and in that mode they would work with Mach3. Might not be as fancy as that MDSI software, but still very capable.

66 Amps at 240V??? that's VERY inefficient...

06-14-2013, 11:33 PM
Yes, the Sigma IIs do have step/dir inputs. I think if I do choose to ditch OpenCNC I might go to EMC on this one. But the Mechatrolink interface makes wiring so much easier.

Yeah, not very efficient. CO2 lasers are the most efficient and these old lamp pumped lasers are down there. Not much you can do about it.

06-15-2013, 12:33 AM
You know when your electric bill triples DEA will be at the door thinking you have a new pot farm, and telling them you have a $250K laser may be worse. Please post the mug shot.:rolleyes:

06-17-2013, 12:00 AM
Gut it unloaded and in the garage after about 2 hours of jockeying stuff around. I rolled it off the back of the trailer with a pallet jack and a come-a-long. Didnt fit in the garage as well in real life as it did on paper. A friend said I could put it in his shop so I loaded it back up this morning and took it over.

Took over the spares and stuff as well and went though some of it. A lot of goodies to be had, a thermometer type laser power probe, new set of laser goggle (Little sticky, old plastic), IR laser viewing plates, and lots of spare parts. Everything there to install the LD optics for drilling.

The laser has two set ups. A short cavity configuration where the laser runs at 400 watts average power in a multimode TEM state or in a longer cavity configuration that includes a intracavity telescope and a water cooled aperture. This brings the power down to 120 watts average but makes the beam single mode TEM00 which gives the smallest spot possible for drilling and cutting.

I still need to bring over the laser power supply and get that wired in. My friend has three phase in his shop so the power wont be an issue any more, well, probably. The laser is configurable to 208v, 220v, and 380v, his shop is 240v. The manual does not spec line voltage tolerances so I need to contact JK lasers and see if there will be a problem. Worst case, I have to get a three phase autotransformer to buck the voltage down. Once that is solved and I can determine the laser works I will move on to finishing the CNC portion of the machine.

http://farm3.staticflickr.com/2860/9064661200_606178fe7a_b.jpg (http://www.flickr.com/photos/67292116@N00/9064661200/)
IMG_6623 (http://www.flickr.com/photos/67292116@N00/9064661200/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

http://farm3.staticflickr.com/2808/9062435581_c358bb7e85_b.jpg (http://www.flickr.com/photos/67292116@N00/9062435581/)
IMG_6626 (http://www.flickr.com/photos/67292116@N00/9062435581/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

http://farm8.staticflickr.com/7460/9062434975_cb119ae329_b.jpg (http://www.flickr.com/photos/67292116@N00/9062434975/)
IMG_6630 (http://www.flickr.com/photos/67292116@N00/9062434975/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

http://farm4.staticflickr.com/3824/9064661822_d830c94b1d_b.jpg (http://www.flickr.com/photos/67292116@N00/9064661822/)
IMG_6632 (http://www.flickr.com/photos/67292116@N00/9064661822/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

06-17-2013, 12:38 AM
new home looks very nice

06-17-2013, 12:48 AM
220v = 240v, Just like how 110v = 120v.

That said, once you put 66amps of load on there service, Don't worry, it will be (loaded down to) 220v

06-17-2013, 01:28 AM
The line shouldnt load down to 220v, it is a full 200A 3 phase service.

I think it will probably be OK, but I want confirmation from JK first.

06-18-2013, 01:43 PM
Looks like I have +/-6% to work with. So it's a couple 1.5kw buck/boost transformers for me.

Ordered new particulate and DI filter for the internal cooling loop. Need to find some heavy 6ga SO cord for power.

06-21-2013, 11:58 PM
Last night I went over to the shop and dug through the manuals and schematics. Found some more info on what it was originally being used for, the final hermetic seal on the Tek 2467 and Tek 7707 tubes. The 2467 I can find info on, the 7707 I can't, I will head down to the Tek museum locally to see if anyone knows about this guy. The tubes used a microchannel plate to amplify the electron beam in tube to get a brighter image at very fast scan times.

I pulled the cover off the resonator to take a look. Someone in the past had taken out the intracavity telescope used in drilling and cutting as well as a beam path sealing tube. Both of these are in the drawer so they just need to be cleaned up. That will have to wait until next week, I am waiting to get some Chromatographic grade methanol to clean the optics. I pulled off the beam guards between the mirrors and the yag rod and took a peak down there. It looks pretty good, the rod is clear.

Today I hooked up some high voltage to the cap banks. The cap banks consist of 24 1000uf, 450v caps. They get charged to 425v max and the energy is dumped into the flash lamps with a giant transistor. I have a small DC/DC front end converter that gives me 380v out from 85 to 120v in. I slowly charged the banks and they seem to be happy to at least 380v.

More pics:
Down the rod:
http://farm8.staticflickr.com/7445/9099039816_779051c1b7_b.jpg (http://www.flickr.com/photos/67292116@N00/9099039816/)
IMG_2144 (http://www.flickr.com/photos/67292116@N00/9099039816/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

http://farm4.staticflickr.com/3767/9099039328_08f4272a7d_b.jpg (http://www.flickr.com/photos/67292116@N00/9099039328/)
IMG_2148 (http://www.flickr.com/photos/67292116@N00/9099039328/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

Components from left to right, beam expanding telescope (collimator), shutter and water cooled beam dump, energy monitor section, output couple mount, optical cavity, total reflector mount. After that is where the intracavity telescope mounts and the beam path cover. In this picture the laser is set up for welding, it has a very short cavity with flat mirrors on both ends. You get a powerful fat beam that is multimode, not great beam quality. This is fine for welding. For things where you need to get down much smaller they add the intracavity telescope, replace the front mirror with an etalon and the high reflector is replaced with a water cooled aperture and moved back and another mirror with a 10m curvature is installed at the far end of the rail. This gives a lower powered, high quality beam that can be focused much tighter.

http://farm4.staticflickr.com/3681/9099038860_e0cbb2d499_b.jpg (http://www.flickr.com/photos/67292116@N00/9099038860/)
IMG_2125 (http://www.flickr.com/photos/67292116@N00/9099038860/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

http://farm4.staticflickr.com/3759/9099038314_9a36d46d77_b.jpg (http://www.flickr.com/photos/67292116@N00/9099038314/)
IMG_2122 (http://www.flickr.com/photos/67292116@N00/9099038314/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

06-22-2013, 12:49 AM
macona, your posts are truly inspiring and very over my head, love em

07-13-2013, 01:48 AM
Ran 50' of 6ga wire for power and installed the two bucking transformers a couple weeks ago. The circuit breaker for the panel showed up the day before yesterday and I installed that and finally got power to the machine. The bucking transformers are doing their job dropping the 240v to 220v. I fired up the controls and the computer to be greeted with Windows NT 4.0 and a Novell login screen. I used a linux boot disk to reset the passwords and deleted Novell. I should be able to give the drives and motors a test run tomorrow.

http://farm4.staticflickr.com/3704/9272016685_51657224ed_b.jpg (http://www.flickr.com/photos/67292116@N00/9272016685/)
IMG_2181 (http://www.flickr.com/photos/67292116@N00/9272016685/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

http://farm8.staticflickr.com/7449/9274804392_17efd9d7a7_b.jpg (http://www.flickr.com/photos/67292116@N00/9274804392/)
IMG_2191 (http://www.flickr.com/photos/67292116@N00/9274804392/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

Tony Ennis
07-13-2013, 08:49 AM
The most important thing is to make "air quotes" with your fingers every time you say "lay-zur".

07-13-2013, 11:24 AM
Before you get any further, you need one of these on the shop door.


07-13-2013, 01:41 PM
Well, i do have this as my porch light:

http://farm4.staticflickr.com/3813/9031198490_e53f4f1f3d_b.jpg (http://www.flickr.com/photos/67292116@N00/9031198490/)
IMG_6622 (http://www.flickr.com/photos/67292116@N00/9031198490/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

07-14-2013, 08:40 AM
This is so cool....can't wait for the next update!

07-14-2013, 11:58 PM
I took the computer back yesterday and put it back together. I could not get it to initialize the servos. Today I went back over and messed around with it some more and it started working. I think I had an IRQ error with the Mechatrolink II card that communicates with the servo drives. I managed to get it jogging but it is pretty out of tune. The X axis oscillated so much it broke the helical coupling. Luckily I have another at home that I machined to fit.

I downloaded the latest yaskawa software to tune the drives, Ill give that I try, maybe tomorrow, I need to make some parts on the mill for a company and that kind of takes precedence.

I had figured the software commanded the position of the drives through the Mechatrolink interface but it looks like it actually sends analog speed values to the drives and takes the encoder data and completes the loop in the PC. So it is a fully closed loop system.

07-19-2013, 03:09 AM
I ended up removing all the helical couplers and replacing them with bellows type. They are much stiffer torsionally and the flex was causing wind up which resulted in very unstable operatio. After replacing them the machine acted totally different. I used the Yaskawa software to set the inertia comp settings and to find the resonant freq. It takes that data and figures out the tuning parameters from that. Worked pretty well.

Once I got the drives tuned to the machine I had to get the control software tuned to the drives. This was a pain in the rear. The software has a lot of parameters you can use but nothing that really said what applied to my drive system. When this version was released it was the first to support Mechatrolink and the set up data is rather incomplete. But after about 4-5 hours of messing with the parameters I finally got it tuned pretty well. The A axis may have to be redesigned. It is not very happy, tuning wise, the inertial mismatch is too big. I may have to use a gearbox to drive it. I will also have to retune the Z axis when I put the weld head back on. At this point I think I can reinstall the way covers, there should be nothing more to do under there.

Couple pics, one of the old coupler and one of the new ones.

http://farm8.staticflickr.com/7394/9320111844_27fd1c19ef_b.jpg (http://www.flickr.com/photos/67292116@N00/9320111844/)
IMG_2215 (http://www.flickr.com/photos/67292116@N00/9320111844/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

http://farm4.staticflickr.com/3721/9317319171_0b1d08ddbf_b.jpg (http://www.flickr.com/photos/67292116@N00/9317319171/)
IMG_2216 (http://www.flickr.com/photos/67292116@N00/9317319171/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

07-19-2013, 10:25 AM
Do you have link to a source for the bellows couplers?

07-19-2013, 12:27 PM
I used the DKN20 series couplers for this:


You probably will want to be sitting down when you see the prices. I keep a stash of them and buy them when I find them cheap surplus.

Ebay is a good place to get them too. I found some used ones I was going to buy if I couldnt bore the ones I had out to 14mm for the servo shaft. Even used they would have cost me $110 for 4.

http://www.ebay.com/sch/i.html?_odkw=bellows+couplings+-vacuum+-hose&_osacat=12576&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.Xbellows+coup ling+-vacuum+-hose&_nkw=bellows+coupling+-vacuum+-hose&_sacat=12576

07-23-2013, 07:09 PM
The sign is amusing on your house, but actually necessary on the shop...

07-23-2013, 08:35 PM
It's a bloody amazing project, to say well done sounds patronising, defiantly out of the ball park
Thanks for the ultrasonic link too, I,m trying fitting them to my parts washer!

Mark Rand
07-23-2013, 09:04 PM
Well, bugger me, JK laser used to be 1/2 a mile away.mow they're 2 miles away from me:). We've currently got two 5 axis Trumph lasers at work (transitioning from the old to the new...), but they aren't using local lasers:confused:

07-24-2013, 01:37 PM
Monday night I finally got the power supply moved over. Man, is that thing heavy. The lift gate was protesting.

Last night I wired and plumbed in the power supply. I need to fill it with distilled water next and I should be ready to see what happens.

Here is a pic of the power supply with the covers off. Top left is the "DC Chassis" It rectifies and filters power from the two main three phase transformers in the base of the supply. It also has the bleed resistors to drain the caps when it is shut down. Below that is the heat exchanger. It takes city water through a temperature control valve and passes it through a heat exchanger. The pump circulates water to the head first passing through carbon particulate and deionizing filters. Unlike many other arc lamp driven systems the electrodes are not immersed in water.

Top right is the circuit card rack. It has the logic for the power supply and handles the interfacing between the console/cnc and the power supply as well as controls the shutter and interlocks. Below that is the two flash lamp supplies, one supply per lamp. Each has twenty four 1000uf, 450v caps. A massive bipolar transistor controls the output to the lamps. The supply can control repetition rate, pulse length, and pulse intensity.

The two modules on the bottom on either side are the ignitors and simmer modules. The supply always keeps the lamp lit with a low current passing through. This makes firing more reliable and also makes it easier to time the flashes. Behind each modules is a 3 phase transformer, each one feeds on half of the DC Chassis.

http://farm4.staticflickr.com/3819/9357387177_769020dd00_b.jpg (http://www.flickr.com/photos/67292116@N00/9357387177/)
Laser PowerSupply (http://www.flickr.com/photos/67292116@N00/9357387177/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

07-25-2013, 01:56 AM
I took some distilled water over and filled it up. Hit the power button and ran into two problems. Leaky filter seal and the shaft seal on the pump leaks. It's a Lowara PB40/A pump that looks like was only sold in the UK. I think I found the shaft seal, only available in the UK, 60.90. Ouch...

Also found one of the transformer cooling fans is dead, no big deal on that one, there is a spare for it.

It does not leak too badly so I hit the power button for the power supply. I hear a click and nothing else happens. I start looking at the schematics and see I should have 48v for the main contactor and there is nothing. A bunch of tracing and I find a loose fuse holder on the power distribution board. They used an extra thick PCB and the leads on the fuse holders are not really long enough and the joint broke. I managed to shock the living hell out of myself finding this out. I am going to be sore in the morning.

Now I have 48v to the time delay relay on the DC Panel (Blue knob in above pic). The relay is not activating, it is just a snap on module on top of a more normal contactor. I disconnected it and popped it open, looked OK and then I noticed the plunger was stuck. I pulled on it a little bit and it popped loose and began to work normally. It had just sat too long and the rubber glued itself together. I proceeded to put it back together and hit the power button. The lights in the building flickered and the ready light came on. I hit the local button and the flash lamps started firing. I have not checked for emission yet.

A little video of it doing it's thing. The panel controls for pulse width and rate are not too happy. Might have to replace those as well.

Now I need to clean the collimator and the bend mirror and see if I have anything.


07-28-2013, 01:03 AM
Last thursday I cleaned the optics and got the resonator lasing. I dont think the internal power meter is quite working right. I couldn't get the shutter to open, eventually figured out I need the doors closed on the cabinet to do that. Friday night I managed to set a paper towel on fire. Good progress.

I brought the push wheel switches home last night to repair them. They have a little plastic arm inside that acts as a spring to return the buttons after they have been pressed. Over the last couple decades these cracked and are no longer spring like. I stuck a soft piece of rubber in its place and that seems to work fine.

I took them back over today and reinstalled them. They work pretty good now. While I was there I decided to install the cutting head back on the Z slide. When I did this I found it was grossly out of line with the center line of beam. I spent the next hour realigning everything. It looks like this was the way it was when it came from the machine builders.

Got everything tuned in pretty well. I just cant get it to stabilize to a stop. The motors just dither, real annoying. I am getting pretty close to ditching this software and moving to LinuxCNC.

For fun I decided to see what it could do, I put a coke can in there and brought it into focus and fired away, here is the damage, not bad for old flash lamps and hammered cavity optics:

http://farm4.staticflickr.com/3722/9382870656_4a208efb63_b.jpg (http://www.flickr.com/photos/67292116@N00/9382870656/)
IMG_2258 (http://www.flickr.com/photos/67292116@N00/9382870656/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr


08-02-2013, 12:17 AM
Last monday I took the water pump apart to see what I could do about the mechanical seal, the only sources for the OEM seal are in the UK and at probably over $100 shipped I figured it was worth a try to see if I could find a replacement. It is a pretty standard seal, Aluminum oxide on one side, graphite on the other. 12mm shaft and a 26mm bore on the casing. I found a seal that matched these dimensions on Amazon for $6.20. What do you know it worked! I also changed the motor bearings while I was at it, they were pretty dry.

I knew the output coupler was pretty toast and I had never checked the high reflector. I found a new HR for an ESI laser that I had in one of my parts bins. Right diameter, wrong thickness. I took it over a couple nights ago to see if I could get it to fit. When I pulled out the old HR I found someone installed it backwards! OOPS! The new HR fit more or less and and I got 114w on my laser power meter. Not terrible, I guess. A new HR is about $300.

I have been put in touch with a company that works with Lumonics lasers and I am going to have then redo the coatings on the rod soon now that I know this beast works.

08-02-2013, 01:17 AM
Macona, you get to play with some interesting stuff. By the way, I've found a much less expensive way to set paper on fire- something called matches. :)

08-02-2013, 09:58 AM
Macona, you get to play with some interesting stuff. By the way, I've found a much less expensive way to set paper on fire- something called matches. :)

Sure, but they ain't near as much fun! :D

09-03-2013, 02:43 PM
Ive been waiting on the guy at MDSI (OpenCNC) to help me get the darn servo loop tuned and have not heard anything from him. So at this point I am going to dump OpenCNC and go with LinuxCNC and use the internal positioning control that the drives have. This allows me to just send them step/dir signals like with a stepper motor. I am ordering a Mesa 5i25 with the 7i76 breakout today.

Found a nicer computer to replace the existing one with. It is a Advantech 19" industrial PCI/ISA backplane case with a PIII 933mhz SBC. 15" touchscreen with a membrane keybd and touchpad. Seems to work fine, with things tweaked it runs the latency app at about 21000 ns. Linux is fighting me with the monitor and the touchscreen. The monitor does not return EDID info so linux wont go past 800x600 no matter what, even after adding the modelines for it. I found a EDID emulator that goes in between the video card and display to give it the info it wants.

The touchscreen seems to just be a driver issue.

http://farm6.staticflickr.com/5508/9667142446_44fa42281e_b.jpg (http://www.flickr.com/photos/67292116@N00/9667142446/)
Advantech 19" rackmount (http://www.flickr.com/photos/67292116@N00/9667142446/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

09-03-2013, 09:05 PM
I used to get some nice stuff from Tektronics Rams warehouse.
Are they still in business?

09-04-2013, 12:56 AM
Yes, Cant remember which days. Not anything like it used to be. I did get a nice 1050mhz rf signal generator though last year. Now that I am working again I cant get down there.

09-04-2013, 09:48 AM

Once you get this thing up and running, have you considered making CRT repairs? I've got a Tek SC503 CRT that has the two heater strip attachments separated from the pins to the plug. Trying to find a replacement SC503 CRT has been like pulling hen's teeth. It's a small storage scope that plugs into the TM500/5000 mainframes.


11-04-2013, 02:19 AM
I got the board set over a month ago and ended up also getting a 7i69 board that will allow up to 48 more points of IO and will tie directly into Opto22 IO Racks via 50 pin flat cable.

Getting a working computer system together has been hell. The first setup (Pictured above) had issues, I could not connect to the mesa daughter boards. Turns out there was something strange with the PIII single board computer in the case. For some reason when set to a 133 mhz buss the 5i25 card became unhappy. Only this card though, all the other cards, USB, WiFi, and firewire were happy. This took a while to figure out and started a hunt for a board that would work. I ended up finding a P4 SBC that would fit in to the existing backplane on ebay and it is working the best out of all the motherboards I have tried, getting about 10000/10000 under the latency test after a couple days running it. It was not without problems though. The board had bulging caps which I replaced (Damn RoHS solder) and then the thing would lock up linux after about 8 hours and I was getting a SMI pulse. I reset the BIOS to fail safe settings and all the problems went away, even the SMI issue.

I was hoping I could use a firewire c-mount camera I have to add computer vision to the machine but it really kills the machine when displaying video. Linux has been a pain with that. So many little things with firewire and simpler things like the touchscreen.

So now that I know my machine will actually work I have started putting the panel together. I ended up ditching the old roll around console that the guy was using before me. I got a 2'x3' JIC cabinet to put everything in. This will hold the computer, drives, and all the IO stuff. This is pretty much everything screwed down, I need to start wiring next.

http://farm8.staticflickr.com/7383/10665123216_3b6277b1da_c.jpg (http://www.flickr.com/photos/67292116@N00/10665123216/)
Laser welder drive panel (http://www.flickr.com/photos/67292116@N00/10665123216/) by macona (http://www.flickr.com/people/67292116@N00/), on Flickr

12-03-2013, 03:22 AM
Got the drive panel wired mostly wired up short of IO for the control panel and the breakout for the laser. I ordered up a couple parallel port extension cables to tie into the laser. The laser controls terminate in generic Centronics 36 pin connectors so that makes it easy.

I took the panel and computer over to my friends place where I am keeping the laser and hooked it up. It worked. Of course all the motor directions were backwards but that was an easy parameter change. Everything homed out like it should. I need to find a better GUI for linuxcnc, the ones that come with it are awful.

The Mesa boards are working out great. The one that ties into the opto-22 rack worked out simpler than I though, any port can be input or output and it is just a matter of reading to writing to that "pin". Now I need to get a friend of mine to write some code to make up some custom M codes to control the laser.

12-03-2013, 02:09 PM
If you are DIY'ing any breakouts and need Centronics connectors let me know. I purchased a big bag of mixed connectors on eBay and it came with about a dozen Centronics types I have no use for. Yours for the price of mail to wherever you are if you want them.


12-03-2013, 03:55 PM
I was going to make some pcb breakouts for the centronics connectors. Then I found I can get 36pin extension cables for $5 shipped from Dell. No contest there. Just cut the cable and wire into the opto22 terminals.

12-03-2013, 07:27 PM
Just as well. I took a look at them and they're all IDC type. I thought they were PC board mount. Oh well, guess I'll hang on to them for 10 years like all the other junk around here ;-)

03-18-2014, 12:02 AM
Its been a while since I posted about this guy. Between the thermal cameras and the vacuum system I have been preoccupied.

So, I now have the drive and power panel assembled. Hooked it up to the servos on the machine and it all works controlled through linuxcnc. At least I can move stuff around. I have not messed with the control of the laser from linuxcnc, that can wait. Pick below of a semi finished board, it has been cleaned up with some wire molding to keep things somewhat in place.

https://farm3.staticflickr.com/2812/13234803665_235bc88e1a_b.jpg (https://flic.kr/p/mavQ36)

I went through a couple different designs for the control panel, I got a 24"x30" cabinet and had a control panel cut out for it on the laser at work as well as a bulkhead for the servo cabinet for the cables. Not cheap, about $130, but a lot easier than trying to make it myself. The left side will hold the 19" rack mount 8U PC display and the two 4U controls for the laser.

https://farm8.staticflickr.com/7212/13234738485_51220b05a1_b.jpg (https://flic.kr/p/mavuEi)

https://farm3.staticflickr.com/2812/13234932983_79bda6107e_b.jpg (https://flic.kr/p/mawutH)

I plasma cut the openings in the JIC cabinets this weekend and tried to powder coat the control panel and bulkhead plate. The powder went on thin and I am just going to have to paint it.

https://farm3.staticflickr.com/2850/13234689835_4ef44251ea_b.jpg (https://flic.kr/p/mavfcv)