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Protecting from static discharge  

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Ricksey007
(@ricksey007)
Active Member
Protecting from static discharge

I have been getting static discharge to the printer when I touch it due to the dry environment I use it in.  Are there any solutions to this?  I have already destroyed one SD card because of this.  I am getting serious about eleiminating it before I damage the printer.

Respondido : 31/01/2023 9:26 pm
Hello
(@hello)
Noble Member
RE: Protecting from static discharge

If you have mk3 or higher I believe touching the top screw of the PSU will discharge you

Please help me out by downloading a model it's free and easy but really helps me out https://www.printables.com/@Hello_474427/models

Respondido : 01/02/2023 2:01 am
Diem
 Diem
(@diem)
Illustrious Member

Run an earth wire to an earthing point, eg a metal plate or even a bolt head, close to the printer and touch it first.

Cheerio,

Respondido : 01/02/2023 5:05 am
Ricksey007 me gusta
Spencermiller
(@spencermiller)
New Member
RE: Protecting from static discharge

Use anti-static wristbands or ground the printer to prevent static discharge. 

 

 

Respondido : 03/02/2023 11:05 am
Ricksey007
(@ricksey007)
Active Member
Topic starter answered:
RE: Protecting from static discharge

Thanks for the reply. My first attempt was to put a copper plate in front of the printer which I would touch each time I came up to the printer. I grounded this plate to the power supply outer case. I was thinking the case was grounded to the electrical ground coming to the power supply. While this did eliminate the static spark, it was still causing the printer to go blank screen or worse. I think the power supply must be design with a floating ground. My second attempt was to run a heavy copper cable from the electrical ground at the main breaker panel out to the printer and connect to the copper plate and not the power supply. So far this seems to work, but seems overkill. Do you know if I could connect a Capacitor, Resistor to the power supply case to absorb the static energy and drain the cap in a controlled way at much lower voltage?

Respondido : 03/02/2023 8:51 pm
Ricksey007
(@ricksey007)
Active Member
Topic starter answered:
RE: Protecting from static discharge

Yes, I have a MK3S+.  By PSU do you mean the Power Supply?  Or the frame to the Printer?

Respondido : 03/02/2023 8:57 pm
richnormand
(@richnormand)
Estimable Member
RE: Protecting from static discharge

Have a look at this for more ideas on the subject:

https://forum.prusa3d.com/forum/english-forum-general-discussion-announcements-and-releases/static-shocks-when-touching-the-build-sheet/

What did help for me was an antistatic dissipative floor mat and mat under the printer, as used in electronics (properly grounded).

The PSU case should be properly grounded via the third ground pin on your outlet (in most countries). However during the assembly of my MK3S I found out the paint or coating on the frame parts was preventing contact so I scraped a bit of paint at each screw locations to make sure.

Also in the postings in the link above  I ended up putting a wire and 100 kohm resistor on the extruder head via the umbilical wires  as it was not grounded at all and accumulated large static charges (pospings on page 2 near the end). Discharge would go directly to the control board when jumping via the thermocouple or heater cartridge. Problem when away since then.  Ender made a retrofit along those lines since the static discharge would cause resets and slipped lines at random intervals during print.

 

REPAIR, RENEW, REUSE, RECYCLE, REBUILD, REDUCE, RECOVER, REPURPOSE, RESTORE

Respondido : 03/02/2023 11:06 pm
Diem
 Diem
(@diem)
Illustrious Member

The ground should not float.  It's easy to check with a multimeter and a wander lead.  With a few metres of wire connected to a known good ground check the resistance to the printer (and to the socket ground, the fault might not be on the printer) - expect no more than one or two ohms.   If there is a higher resistance begin at the power connector and work forwards checking the connections until the whole is grounded.

A resistor to your touch plate will reduce the spark and the shock to you, just touch it for a fraction of a second longer; you are, in effect, one plate of the capacitor in an R-C circuit.

Cheerio,

Respondido : 04/02/2023 3:19 am
Ricksey007
(@ricksey007)
Active Member
Topic starter answered:
RE: Protecting from static discharge

A lot of good info here, thanks.  I will do some checking.

Respondido : 04/02/2023 6:08 pm
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