[Imaginer]

It is
150115
33SC B

Would I need to remove the sticker to see more information?

[CNCMAN172]

You might need to use a razor to carefully remove the label. You can also check and see if you have 34v on one of the three pins to ground. Pretty sure this is the 24v regulator

Russ

[Imaginer]

Here is more pictures of what is presumably the regulator. On the pin that is closest to the white connectors at the edge of the board, I measured 33.5VDC. On the center, that is 0V, I think GND. The other pin measured 4.9VDC.


This is what I did to measure the 24VDC at that last connector. I measured 0V for the red wire/yellow wire. So I think we are closer to the culprit. I remeasured again and found it to output 3mV.

I don't want to risk peeling the sticker, So I am giving the labels that I found on the chip on the other side and what is inked on the PCB

On the PCB:
5302-01972-0 Rev B. SPB

On the larger IC:
MP2467DN
C9720457
MPSC47

And the other markings I can make out to the side of the IC:
B36
31

[CNCMAN172]

The small regulator with a label at U10 is actually a small switching power supply module. This module takes the 34VDC input and outputs 5V at 2.5 amps. They used a switching supply module for this much current because the input voltage is so much higher so it does not get hot. This is the main 5V supply for the breakout board and the KFLOP board. We still need to find the 24V regulator, let me study all the pictures again. By the way you don't need to remove the label, and even if you did who would care, since K2CNC is out of business and they don't service anything. LOL. We will get you fixed.

Russ

[CNCMAN172]

Please carefully remove the heat shrink and take a photo of this module, I am almost certain this is a switching supply module for 24VDC.

Attachment 285430

This contains an small device and a small transformer used in switching supply modules. As soon as I see the parts I can tell you for sure. Thanks

Russ

[CNCMAN172]

The more I study all the photos you zipped together the more confident I am that switching module partially covered in Heat Shrink is the 24V supply. If you look carefully there are two red wires and one black wire solder to the board that go to this module. One of the red leads provide 34VDC as an input voltage to the DC/DC converter. The other RED is the 24VDC output. They only needed one black wire as that is common side of the power source on both the input and output. My guess is originally they planned on having a separate 24VDC supply that plugged onto the connector at J34. To save cost they decided to go with a DC/DC converter for 24 volts using the same 34VDC supply that is used for the motors. This is why they kind of jury rigged the wires from the K2CNC breakout board instead of having a designated connector. You might find it cheaper to go with a separate 24V supply which will take a little more wiring back to the AC incoming power. We will cross that bridge after the photos confirm what I am telling you.

Russ

[Imaginer]

Well ****. This IS the culprit. As soon as I took off the heatshrink wrap, a piece fell off from the IC. And the underside of the board is burned. I am attaching a zip that has more pictures.

Visible damage for sure. Don't even need to measure anything. I definitely need to replace this unit.

I first heard about K2CNC years ago, but hesitated since they are still using controllers running a parallel port. The minute I heard them using a USB PC connection, I have gotten a hold of Mike Loken and decided to order their servo gantry line, they are one of the few that produced such a machine with reasonable costs. But now, like others have noted, went down and became unresponsive. Hell, I liked their upgrade options of a higher z and the spindle and the servo driven feedback.

I am irked that I paid for a dust hood option, that when I called they are still "designing it" and their engineer from what I gathered is swamped. That is the thing that burns me is I paid for a part that never came about and no support, after numerous calls and emails. I had to prod them several times by email and phone to even have my unit shipped out at all.

I want this beast of a machine operating and singing. I am now closer to such now.

[CNCMAN172]

As expected that is your 24V converter.

Now there are a few ways to fix this issue, but a burnt board is might be safer to replace this with something similar.

Ebay has something similar that will probably work.

DC-DC 8-40V to 3-30V 8A Step Down Converter Module HRD12008 PSU 8A 150w Car USA $19.75
http://www.ebay.com/itm/DC-DC-8-40V-...item19e2eee0c2

However, my recommendation would be to go with the following unit.

Omron S82J-15024D Power Supply 24VDC 150W $20.00

Omron S82J 15024D Power Supply 24VDC 150W | eBay

Why? My guess is the reason the current 24V DC/DC converter went bad was pulling too much current. The Spindle FAN which could pull 2-3 AMPs, also when you press the button to change the tool holders that activates a solenoid to open up the pneumatic chuck, which is more current for a short duration of time. The second unit will need to be wired into the AC coming into the current power supply and the output will enter plug J34.

Yeah, I know what you mean it sucks you paid for something from K2CNC who had a good name in the business and now you are out. I read online some guy just ordered an entire 5x10 machine from them one month before closing and he is working to get his money back via PAYPAL. Replacing this power supply should get you up and going. If you need info on how to wire in either unit let me know and I can get you going.

Russ

[Imaginer]

That could explain why when I initially tested the machine, dry run, the spindle was unable to engage the tool collet holders. I may need to put a dedicated 24V supply to the spindle for that function, as the small board is unable to engage the chuck. That explains things a lot. This makes perfect sense since they have told me that I am one of the first customers that ordered the ELTE tool changing spindle and they had to design the dust shroud for it, meaning they don't have experience with the ELTE product, just the basic knowledge from such a limited manual.

More than likely, Kevin (the engineer that I have been told working with my unit) possibly didn't fully figure out the 24V aspects. Well, I may pick up the dedicated power supply, and fish wires to the board. The traces on the mian breakout board doesn't have any damage that I can tell, from the front or the back, and thus I am confident that the board is able to handle the given current I think. It may just be this specific component.

[CNCMAN172]

Yup, while the spindle engagement unit is using air the solenoid will pull several amps, this might actually be listed in your manual for the spindle. I do think the dedicated power supply will resolve your issues. All the rest of the wiring to the transformer and full bridge rectifier is fine or you would not have the 34VDC which is being used to generate the 5V power on board. Keep in mind you do need to supply the 24V to the breakout board because you have yet another DC/DC converter on the board that takes the 24V and turns it into 12VDC.

Yeah the engineer probably did not realize the sudden current pull when changing tool holders. The fan is probably less than 2A, but again check the spindle manual these might actually be listed.

Russ

[Imaginer]

Just ordered the Ebay listed item. Probably enough room in the box to mount the unit, possibly. Will let this thread know of my progress.

I can't express enough gratitude for your help through this troubleshooting process Russ. You have been helpful as a guide of assistance.

Next things on my list would be to design my own dust collection adapter for the ELTE spindle. Maybe I can machine this or print this shroud out.

[CNCMAN172]

Imaginer,

You are very welcome, as you gain more and more knowledge, be willing to help out someone else in need. I have been on CNCZONE for a long time and it is a great group of people.

As far as dust collection is concerning, you might want to consider the solution by KentCNC, his dust shoe is very popular. I have built my own and ultimately purchased his shoe. He has them for most spindle diameters even custom ones and his prices are extremely reasonable. Check out his site, think you will either get an idea or save yourself a bunch of time and have a quick solution.

KentCNC, LLC. Dust Shoes & Accessories

To make this thread complete, please update everyone on your progress with the new power supply.

Also for others who have the K2CNC control box here are a few more pieces of information you might find useful.

The K2CNC breakout box supports four DC servo motor drivers. The key components on these drivers are as follows:

Allegro ACS7147 - Hall Effect-based linear current sensor
Allegro A3941KLPT - MOSFET full bridge driver for DC brushed motors
Infineon QNO407 T-Power Transistors

The base board in the K2CNC breakout board contains an ATXMEGA32A4 16-bit AVR microcontroller, the firmware in that controller is what actually controls the parts on the servo driver boards. Since K2CNC is out of business and they have no support channel if you every blow a driver never throw it away as normally the bridge driver or the power transistor would normally be the item that gets blown, so the driver board would be repairable.

One other item you might want to provide was the part numbers for Q1 to Q6, I am certain the first five are all the same, but this might be useful for someone in the future.

Send us all a picture or video when you get your machine up and running and let me now if you have any further questions.

Russ

[Imaginer]

Here is the picture of the Q1.


This is the one at the other end of the board.


I have received and hooked up the 24V power supply in place of the 24V converter at the wire leads on the board. Good news, once I turned on by the button at the emergency stop switch, the spindle fan turned on and it for a time being operated normal, but recognition of the gantry servos were but for a second before Kmotion saw them as being disconnected. But the spindle fan still operated.

I turned off the controller box, for fear that damage may occured, and then ran the controller box without the 24V power supply to make sure that there wasn't any damage done and inspected the board for smell or visible damage. The gantry did operate as usual, and was able to move and home itself. Directly connecting the 24V power supply to the wires from the 24V jumper still had my machine behave as before, the fan didn't turn on, but the gantry worked. I am missing something somewhere, which I took the time to remove the soldiered wires that lead to the 24V converter, and planned to fit a fan header connector pins to it, one of the wires seemed frayed contacting the soldiered part of the board, that I think isn't quite "kosher".

I also only connected the 24V out wire to the 24V power supply. I think I may need to ground the -IN black wire of the former 24V converter module. But I will do that once I put in the fan header in place of the soldiered wires of the board.

Not at my machine at the moment, but will post pictures of what I had done with the 24V power supply, mounting, and wiring.

From the look at these pictures:



There are three places for the 24V to go to. One of them is to the green connector that drives the spindle as well? There is a trace to the J23 seems, I could be wrong. And of course, there is a trace to the white header.

[Imaginer]

Everything works now! I had to attach DC ground to the -IN wire of the old 24V converter and have the +OUT of the old 24V converter be now connected to the 24V power supply at the + terminal.

Here is the final pictures of what I have done.



I electrical taped over the yellow+black wires to the connector wire leading to the board. I used the soldier-less crimp connectors for leading the AC power from the switch and split it to the coil and the mounted 24V power supply unit that I sheet metal screwed to the back of the box. I drilled a hole leading the wires to the terminals.

Even the tool change operation issue that I had before, now works properly. The spindle is able to release and take in the tool holders well unlike before.

I may add small heatsinks to the ICs on the four servo motor drives, as something to increase reliability and add an exhaust fan. The box got a bit warm during operation.


This worked out cleanly. Now time to work with my machine. (and not work on my machine..)

[CNCMAN172]

Congratulations, a working machine. Yup you always have to attach the common to provide reference. Glad it all works great now.

Russ

[TomKerekes]

Russ,

Thanks for helping Imaginer out of a jam with all the knowledgeable pro bono help. I'd recommend any K2CNC owner with problems to seek your professional help.

Regards

[CNCMAN172]

Tom,

Thanks for the comment. I have never owned a K2CNC machine myself but have built four CNC machines and worked on several friends machines. The K2CNC company made some nice machines and had a great reputation, it is surprising to see them go out of business. Many owners want to scrap their controls with the lack of support but the control on the KG4925 was based on the KFLOP which I have found to be a solid controller and KmotionCNC is a solid program. When I first purchased the FLOP and KANALOG I setup the machine to use the MACH3 plugin, however the delayed responses and the strange things that MACH would do from time to time, pushed me to the point where I tried KmotionCNC. I have been very happy with how repeatable and solid the KFLOP and KmotionCNC work as a pair. Your effort to get everyone up and running is in no small part of why the Kflop is so successful.

The K2CNC breakout board and servo driver is not documented anywhere, and I could not find schematics anywhere, but looking up the parts and having 30 years experience in electronics it was not to difficult to figure out how it all worked. Thanks again for you kind comments.

Russ Larson

[Imaginer]

I decided to add some heatsinks and a outtake fan to increase cooling to the box. The box got quite warm during operation. I attached what I have done, and with that, I am dome with the modifications.




Not shown is the two 160mm cooling exhaust fans for the back of the drawer of the bench the machine is on.

[CNCMAN172]

Imaginer,

The heat sinks and fans will certainly not hurt, especially on the Servo Drivers, they do get hot and carry a good deal of current. Nice Job.

Russ

[CNCMAN172]

Imaginer,

For completeness of this thread the transistors Q1 to Q5 are 5867NLG which are 20A Power MOSFETs. With current ratings this high these are probably being used similar to relay. My guess is Q1 to Q4 is being used to enable each Servo Drive for the axises X,Y,Z, & A. The fifth one is probably enabling the Spindle, just a guess without direct access to the boards.

Russ