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Hi all,

So I was trying to calibrate my extruder and made the mistake of changing the mm/step on the towers causing my nozzle to hit the paper on top of my glass. Not realizing I changed the wrong setting in the eeprom. I think I have it corrected now but it caused the nozzle to hit fairly hard and drag before I was able to shut the printer off.

The glass is ok, but it appears I damaged the nozzle because plastic is coming out in a big glob now rather than the small stream. Is it safe to assume the nozzle being brass can be damaged this way? I ordered a couple replacement nozzles as well as the .35 nozzle to see if this fixes the issue.

Also does anyone know how hard this is to change? is it simply removing the existing one and then installing the one? Also does anyone have any info on the .35 and if its worth using?

Thanks for the help
Larry.

Hard to say what's damaged without pictures. Brass is a soft metal though, so what you're saying doesn't sound implausible.

It's quite easy to change, don't worry.
If you need a spare of something, always buy 2 just in case.

Yeah I bought 2 .5 nozzles and a .35 nozzle.

I won't be caught with just 1 again. I just wanted to be sure my thought process appeared to be correct. I have done some searching about the .35 nozzle but can't figure out if it will cause me more trouble than it worth or if worth going that small for more detail.

Then the question is settings other than the nozzle size. I'm not sure if something else should be changed.

Do this: polish the top of the nozzle on leather or tshirt material (take it off the printer). Look at the orifice. Is it round or look squished. If it's round and looks correct, you probably burnished the burr off. If it still looks bad, then get a .50mm (I'm assuming this is the stock nozzle) and ream it out by hand (don't use a drill!). Or, you can use a normal sewing needle to open the nozzle too. Push in from the back side.

you may have knocked the tip out of the nozzle so that it is missing the .5mm drilled hole. If ts big blobs thats likely your problem. Not hard at all to change

I did the EXACT same thing during my setup. The nozzle broke in such a way that it broke the tip off leaving a larger hole. I purchased a new tip.

Russ

Thanks Russ,

i'm glad i'm not crazy. I ended up ordering 3 nozzles and they should arrive today.......Going through withdrawl.

Then I need to figure out why my nozzle was dragging on the prints.....eek.

A trick I use when setting up my printers and milling machine. Space it down so "zero" is just touching a known spacer, I happen to use a blank lathe tool as they're pretty precise and I have them.

Now move the head to another location and try sliding the tool under. Adjust up/down as needed but there's no fear of crashing while you're getting it dialed in.

A crash on the milling machine can be a bit more expensive so I'm careful they don't happen.

jdurand wrote:A trick I use when setting up my printers and milling machine. Space it down so "zero" is just touching a known spacer, I happen to use a blank lathe tool as they're pretty precise and I have them.

Now move the head to another location and try sliding the tool under. Adjust up/down as needed but there's no fear of crashing while you're getting it dialed in.

A crash on the milling machine can be a bit more expensive so I'm careful they don't happen.

That's a good idea. I suppose a 10mm drill bit shank would fit that purpose? Just something measurable and uniform i guess would work.

Or if you ran out of things to spend money on, there's this: http://www.ebay.com/itm/Precision-Z-Axs ... 566fc54a0f

jdurand wrote:A trick I use when setting up my printers and milling machine. Space it down so "zero" is just touching a known spacer, I happen to use a blank lathe tool as they're pretty precise and I have them.

Now move the head to another location and try sliding the tool under. Adjust up/down as needed but there's no fear of crashing while you're getting it dialed in.

A crash on the milling machine can be a bit more expensive so I'm careful they don't happen.

Can you explain this a little more for me? If you set the zero to a spacer, then how do you tell the machine what the actual zero is?

Thanks,
Darren

Your spacer is the known you add to your distance.
You could use something like a microscope slide also. Spare SD card. .etc....

Or, after you get everything flat, then just do a z-zero in the middle of the table.

You can edit the EEPROM to change the Z-height to add the known value of the spacer, although that would put you exactly at zero with no clearance at the nozzle/glass.

So the better approach until you know the exact value you want to extrude at would be to do what jdurand said, and perform a z-height calibration from the LCD and set the nozzle down on a piece of paper with decent resistance.

Just remember to home your towers first via the LCD before calibrating the Z.

I use a feeler gauge and add the known width to the value in the eeprom.
On my mill I use one of these http://www.ebay.com/itm/Precision-Z-Axs ... 566fc54a0f which I thought would be useless when I bought it, but ended up being the easiest way to set 0 for a Tool.

Along these same lines, how often do you check your zeros? Do you do it every time you print? I've found I have to do that because it seems to always be just a tiny bit off.

Darren

I usually watch the first layer go down, if it doesn't look right I stop the print set Z=0 and restart it.
In practice I rarely reset Z unless I start doing things like swapping glass sheets or fiddling with the hotend.

I'll have to check into that gauge. I'll admit I'm not 100% sure how use it. I'll have to do some research. Now that I have the nozzle fixed i'm running some calibration prints.