[RawCustomsDesigns]

Hello everyone
First time posting here, hope i am in the right spot for my post

My buddy Mike has a laser machine he bought from China
The Label on it is as follows
SIHAO
Shanghai Sihao Machinery Equipment Co, LTD

Not sure if that's the brand or if its not, what the brand is.
If a model number is needed I'm sure i can find it somewhere on the machine.
Its a 4'x3' Table 150watt Laser

I have been using it all week and its been fine.
Today I was doing an engraving that was 42" long and 5" tall on a piece of rough cut live edge piece of wood.
Everything was engraving fine so I went off and did some other duties at work.
I came back about 5 min later and still was fine, again left and did some other stuff.
Again I came back but this time it was moving side to side and the laser was working but it was not moving on the Z axis. it was engraving over the same spot over and over.
So I hit the cancel button on the machine to shut it off fearing that a gear or something could ge

I went to use the arrow keys on the machine(not the computer) and it started acting funny. If i pushed up it would go up for a second then back down. So I pushed down and it worked fine. So I pushed back up and it went down again.
It is also making a terrible noise while it moves now. Where as before it was smooth and barely any sounds.

So my buddy was in the laser room tinkering trying to figure out what's going on and here are somethings that he has found

1) Least important but need to know. The image is upside down and reversed I'm sure that's just a setting in the computer so not to big a deal
2) The laser head moves fine back and forth while engraving but nothing else........UNLESS you put slight pressure on the bar the head is attached to that it rides on then it moves but you have to keep pressure on it. if you let go it stops, well it doesn't "stop" it jiggles like its trying to move but it just wont. (this machine has been used very little so I don't think its a worn belt, but I could be wrong).

Please let me know of any other information you may need to help me with my issue and I will post it
Thanks so much for your time
Bernie

[CNCMAN172]

Check the wires on the stepper motors. Power down laser and unplug each motor and plug back then do the same thing on controller board then power it back up and give it a try. Also check for loose belts or couplers or gears

Russ

[RawCustomsDesigns]

Check the wires on the stepper motors. Power down laser and unplug each motor and plug back then do the same thing on controller board then power it back up and give it a try. Also check for loose belts or couplers or gears

Russ

Which ones are the stepper connections. I am hesitant to start unplugging stuff, this isn't my machine so just a little worried.
Thanks

[CNCMAN172]

The two silver boxes on the left bottom of the machine are stepper drivers. The box above them is the CNC controller. Make sure you unplug the AC power to the machine before you do anything. The green plugs will just unplug with a small amount of pulling. As soon as they come out put them back in place. Do the same thing to the controller above. This is just to make sure you do not have a loose connection. When you have completed this you can plug the machine back into AC power and then start it up and see if anything changes. NEVER PULL THOSE PLUG OR WIRES WHILE THE MACHINE IS POWER UP... IT WILL FRY SOMETHING

[RawCustomsDesigns]

Ok I tried unplugging steppers and still nothing

We did find a what looked to be a burnt spot on the relay. Could that have anything to do with it.
The up and down stepper goes through the relay when the rotary is turned off.
What do you guys think?
Thanks
Bernie

[CNCMAN172]

Ok I tried unplugging steppers and still nothing

We did find a what looked to be a burnt spot on the relay. Could that have anything to do with it.
The up and down stepper goes through the relay when the rotary is turned off.
What do you guys think?
Thanks
Bernie

Clearly anything burnt would be suspect. The loud noise will moving seems to suggest an issue with the steppers, does X or Y axis work without unusual noise?

[RawCustomsDesigns]

Clearly anything burnt would be suspect. The loud noise will moving seems to suggest an issue with the steppers, does X or Y axis work without unusual noise?

The only movement that sounds normal is the side to side movement. The front to back is so random weather or not it moves correctly. Sometimes when you push up it moves down and vice versa but always sounds awful. Where as before it never sounded like this. I ordered a relay it should be here soon and I will repost my findings
Thanks so much for your help so far.
Bernie

[CNCMAN172]

You could run a test and swap the two drivers between the X axis and the Y axis and see if the problem moves to side to side instead of front to back. This would let you know if you have a bad stepper motor or driver.

The relay needs to be replaced but something tells me that is not causing the rough movement.

[RawCustomsDesigns]

You could run a test and swap the two drivers between the X axis and the Y axis and see if the problem moves to side to side instead of front to back. This would let you know if you have a bad stepper motor or driver.

The relay needs to be replaced but something tells me that is not causing the rough movement.

That's a great idea, thanks

[RawCustomsDesigns]

Great news!
It was indeed the relay.
Ordered another one off Amazon for around $8.00 and now its working just like it did before. (only difference between new and old relay is the new one is a 3a instead of a 5a)
I am going to order a couple to keep on hand just in case this happens again.

I didn't change the steppers as a test because I wanted to check the relay first.
Next step if the relay didn't work would have been the swapping of the steppers to see if that changed anything.

So grateful for all the help
Thank you
Bernie

[RaderSidetrack]

(only difference between new and old relay is the new one is a 3a instead of a 5a)
I am going to order a couple to keep on hand just in case this happens again.

I suggest spending some time looking for at least 5amp relays, and if you can find some with a greater amp rating that still fit, even better. Relay contacts are subject to arcing damage, and a higher current rating is likely to offer greater time between future relay problems.

[CNCMAN172]

Look at digikey.com or eBay and find a 5A relay, they sized it that way for a reason.

[RawCustomsDesigns]

Yes I will get the right amperage for it. When I ordered it I didn't realize it was a 3a and not a 5a.
Rather be a bit less then more but yes I plan on buying the correct one.
Thanks so much for all your help
Bernie

[RawCustomsDesigns]

i know with fuses its better to be a bit smaller than getting one larger.
Not sure if that's the same with relays or not
Thanks for the help
Bernie