Taz 4.1 Ground issues?

Found an interesting article on preventing ESD i figured i’d share with everybody who has the time to read it.

http://www.dbicorporation.com/esd-art1.htm

Dredging this up…

I have a KITTAZ (TAZ 4) that has been having problems no that winter and dry air is upon me here in New England. If I walk across my office (Berber carpet) and touch the Taz, I get a static zap and the RAMBo resets itself. Of course the print stops. If I discharge myself first, this does not happen but every so often I must have a bit of residual static because all of a sudden my Z position gets out of whack by anything from 1mm up to about 10mm. By this I mean, at some point (I’ve not been ale to isolate how or when) I see the nozzle is printing above where it should be by a mm up to 10mm . It’s the darnedest thing and I’ve never seen this in the summer when there is no static charge issue.

The other thing I’ll add, I’ve used RAMBos in the past on Mini Kossel and Rostock Max delta printers. I’ve touched the metal frames of them with a good static zap and not had a single problem! I use Mean Well supplies. Perhaps the external supply with the Taz is not sufficiently grounded? Has anyone found a solution to this issue? It is driving me crazy, especially since even with a discharge, I get this odd Z lift issue.

I am not 100% sure, but I think it is a floating supply.

2 things. First you could get you a ground plug adapter that they sell for static mats or static wrist straps and use it to force the case to be grounded, run a wire from it to the case. (first get a tester to be sure the plug in your house is wired correctly, this is a big must).

Next, you can also take a spray bottle and put about an ounce of Downy fabric softener in it then fill it the rest of the way with water and liberally spray the carpet all around the printer. We use to do this in arcades in the winter to keep people from zapping improperly made machines with static.

The first option is the most permanent of course but the second is a quick and easy fix though you need to re apply it every few weeks.

Thanks guys.

Ground plug adapter is a great idea. I know what you mean about trusting house wiring. I’ve checked all my outlets after the house was built and at least 10 of them were wired reversed and a few had bad grounds.

So I finished the large print finally but I literally did not get closer than 2’ to the printer table while it ran (6 hours). The print looks flawless EXCEPT there is a “part line” at about 8mm up. It is not filament starving, it literally looks like the Z raised a few 10ths of a mm and continued to print that layer. This is similar to what I have observed quite a few times when I touch the filament or printer after supposedly discharging static. I print on a PEI surface on glass. I wonder if the printer itself is building up a charge too.

Just a note for people: That LCD knob is just sitting out attached to a part on the LCD panel, so any static you have built up walking to the printer or just crossing your arms will travel from you into that part that is not grounded at all. Even if you ground the frame that knob is not grounded, since it does not touch the frame in any way.

Good point. We should be able to ground that reasonably well I think. I’ll wire it up and post photos when I get back home later this week.

Ok, I seem to have a solution to my issue. Here is what I did:

I attached a 22 gauge wire to the screw that holds the faceplate onto the outlet my Taz is plugged in to (I used an eyelet for good contact). I wrapped this wire loosely around the power cord, over the supply and then loosely around the cord to the Taz. At that end, I installed another eyelet and fixed it with one of the cap screws to the rear frame assembly. I also made a short 6" jumper with eyelets at each end and connected the front frame to the grounded back frame because, it turns out, they are electrically isolated from each other!

Now, I can drag my feet to work up a big static charge and touch any part of the frame, aluminum bed and carriage. I get a zap but the RAMBo does not reset. I did not ground the LCD panel yet but I intend to add a jumper to it as well.

Sounds good.

I would recommend getting some metal corner braces if you can to replace the plastic ones. Otherwise you may get intermittent grounding

Although that is a good solution it is more work and expense than needed. The jumpers are secure and even if one failed it would not be a problem since I tested with one successfully.

The 8020 corner gussets and drop in t nuts to add those are only about $10 total and it really does stiffen the frame.

I like stiff frames. Do you have a link to the braces? As for grounding, I don’t have an issue with the cross pieces and verticals on one face (front or back) of the frame. The issue was that he front frame is isolated from the back frame. These are separated by printed parts so no metal-to-metal contact at all. The jumper I added connects them electrically.

These ones are the ones I used, not sure if this is the best price for them, but you can see the type: http://www.ebay.com/itm/8020-TSlot-Zinc-2-Hole-Slotted-Inside-Corner-Bracket-w-Tabs-20-Series-14053-N-/330293540113?hash=item4ce7077511:g:v~8AAOSwT4lWSfYP

You can use standard T-nuts to fit them. I found the drop in after installation ones were worth the extra expense in my case. I know these ones will fit: http://store.makerstoolworks.com/hardware/m5-t-slot-nuts-post-install/ and I know half the ones on ebay don’t fit.

You’ll be able to fit 7 of the 8 corners. THe LCD connection cable is in the way to fit the top left one, but the LCD frame itself is stiffer than the stock corner anyways and it’s metal.

Doesn’t the control box itslef connect the front and back frames on the 4/5? It does on the Taz 3. Maybe that explains why the 3 doesn’t seem to have the issue others describe.

Thanks. I use the same t nuts. I added my display so it isn’t the lulzbot version so I can get all 8 corners.

I believe the taz 4 case is plastic but I’m not home so I can’t check.

Looks like you can get the corner pieces at the same place. http://store.makerstoolworks.com/90-degree-extrusion-bracket/?_ga=1.119213889.93255225.1454871753

Taz 4/5 have a plastic spacer between the frame and control box.

Huh. Is the bolt inside the frame at least in contact with the control box via the T nut, or is the whole thing isolated?

The 20mm bed extrusion should be connecting the frame sides, but I suppose the anodizing might be too thick there. Might be worth removing the finish at that point on all 4 extrusion surfaces.

No, there is a plastic brace that it bolts into on the frame. As for the bed it many times is just sitting above the frame due to the Y table frame holders.

I suppose you could slide a set of washers in there?