Good Grounding = less unknown error & less trouble

[Tech_Marco]

It's more clear to see that good GROUNDing is very important to deal with for a DSP and for a laser machine. Beside the missing step issue caused by an improperly grounding, the blinking LCD is also the 'victim' of the bad grounding. I believe that many of you folks encountered LCD screen blinking or fade out and came back with "Reseting..." while laser was firing. All of those problems were caused by the poor grounding.

I have mentioned a couple time that the K40 may have a "fake" grounding. Actually it's not just happened on the K40, there are so many bigger laser machine have the same problem, including the 60W 6080 machine Imported a couple years ago from the same company who make the K40. Even the AC plug with 3 prong was there at the back of the machine but it isn't really connected to nothing. Thank you for the louzy and lazy worker there is China!

Here is a to do list that may help you to prevent the bad thing or 'unknown' issue' from happening.
1) Make sure the AC outlet on the machine having the Ground pin, the green wire attached firmly to the chassis.
2) Make sure that the the AC outlet on the wall is having 'real' grounding. You may not know that some old houses do not have Ground!
3)Make sure that there is a physical wire connecting the Laser Power Supply GND to the AC Ground
4)Make sure that the DSP case is grounded.
5)Make sure that the power supply for the stepping motor is grounded

How do you know if it's grounded? Simple: Just use a DVM with AC 200V range, check voltage between the AC oulet "L" and the chaisis. You should read something like 110V to 120V. Same thing to the N against "L", you should get AC 120V (Look,I'm assuming you're using 110V machine and PS here. If you're using 220V version, you will read 220V instead) The voltage appear on the Ground and the "N" should have very low voltage, I'll say 1~2V at most. Now, check the voltage in between the laser power supply case against the netutral while laser is firing. If you see voltage over those two point having 10V or higher on your DVM meter, it means that you don't have good grounding. You should get less than 1~2V. I'll check with mine tomorrow.

When I mean Ground, I really mean that it's a good Ground! A lot of "unkown" issue can be avoided.
I gurantee you that a lot of folks eitehr don't know or under estimated the impact it cased by the bad grounding.

I posted a picture of basic AC outlet found from the Interent.



Marco

[waltfl]

Hi all
yes it is very importand to have a real ground because some house wiring especially of older homes dont even have a real ground at all some have connected them to a valve on the water pipes even if this water pipe has some plastic pipes in it or the have connected the ground of the plugs to the neutral etc. I have seen this all.
I have a totally seperate real ground what means I have driven a 8 foot grounding rod ( at Homedepot) outside the house in the ground and from there a seperate wire # 10 to the machine body and from there to a central point where all grounding wire s( points) come together. thats the only way to be sure
this way I have not probleme with the ground
greetings
walt

[Myke]

I'm a little bit confused what is the proper way to ground the chassis.

My K40 laser has Ground Wire Joint which is connected to E(arth) prong of AC plug. First I thought this Ground Wire Joint is connected to chassis but NOT. Both side has plastic insulation, the screw NOT connected with chassis. Earth wire goes from this Ground Wire Joint to laser supply, PS, etc, and they are screwed to chassis.

I think the best way is to connect E prong of AC plug to chassis directly as short as possible, so I don't know why Ground Wire Joint is insulated from chassis?

[Tech_Marco]

If that was a surprise to you then you expect a 'lot' of surprise from other engraving machine imported from China. I've been to this K40 manufacturer (pretty big factory) three times for visiting and ordering. I ordered 40x K40, four D340 and one 8060 from them. For each of machines I bought, I have to send my man to stay there to re-work before allowing the factory to let it shipped. Their quality control was bad and technically speaking, they have no "common sense". So, I gave up and never ordered machine from them. Remember that if you want to buy a laser machine, do not buy from the city "Jinan" , the ShanDong province!! Price is cheap but the quality is very low. Stay away from it even though you find a lot junk mail sent from those manufactures or you will be expecting 'trouble'

Marco