At my wits end with PETG

I have a E3D V6 and by accident I was printing at 275c ( now 245c, and first layer 255c) . I didn't look at the PTFE tubing yet but it is still printing very well.
I am building a smaller lighter wade's like extruder so this weekend I will see how the PTFE looks like.

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amigob
I have a E3D V6 and by accident I was printing at 275c ( now 245c, and first layer 255c) . I didn't look at the PTFE tubing yet but it is still printing very well.
I am building a smaller lighter wade's like extruder so this weekend I will see how the PTFE looks like.

In my experience that melts the PTFE liner. For me the liner closes off and I have to use a drill bit to open it back up. But you might have been lucky

I used cooling pasta in between the heat break and the heat sink( thread ), so I have good heat conduction to the heat sink , maybe that is my luck .
BTW this is what E3D says

The E3D-v6 as sold is limited in temperature by the thermistor to 295*C but can go higher (tested up to 420*C)

Edited 1 time(s). Last edit at 03/17/2016 12:53PM by amigob.

The v6 only brings the ptfe to above the level of the heatsink. As long as the fan is running temperatures up there should be fine. The v6-lite takes the ptfe all the way to the nozzle junction and it will be subject to much higher temperatures. Like the one I was using.

Hi. I had a similar problem, read this (I found the solution today!), it might help you, petg really likes water...:

[forums.reprap.org]

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JamesK
The v6 only brings the ptfe to above the level of the heatsink. As long as the fan is running temperatures up there should be fine. The v6-lite takes the ptfe all the way to the nozzle junction and it will be subject to much higher temperatures. Like the one I was using.

Well the issue was I found that the Hotend fan was out. The wires disconnected from too much tension. So the heat creeped down into the heat barrel and melted the ptfe into the nozzle.

I found a good solution for me for the first layer of PETG
- every thing sticks direly to the bed
- no strings any more on the first layer
- sticks very well

after cool down ( used 90 degrees bed )
first experience removing the finished product, couldn't get it loss :-{ even not with a pliers.
But lifting the brim with a knife and plop it was loss :-)



I sprayed the glass plate with 3DLAC spray

one disadvantage , cleaning the glass plate is messy.

Edited 4 time(s). Last edit at 03/25/2016 05:42PM by amigob.

Quote
amigob
I found a good solution for me for the first layer of PETG
- every thing sticks direly to the bed
- no strings any more on the first layer
- sticks very well

after cool down ( used 90 degrees bed )
first experience removing the finished product, couldn't get it loss :-{ even not with a pliers.
But lifting the brim with a knife and plop it was loss :-)

[attachment 75329 WP_20160325_005.jpg]

I sprayed the glass plate with 3DLAC spray

one disadvantage , cleaning the glass plate is messy.

I dont use any spray or glue etc. I print PETG directly to the glass bed. I cant get the print off wihtout using a paint scraper blade. You just have to make sure your z height is correct. Then for me make the first layer thick. 0.4mm for a 0.4mm nozzle. My bed is at 72deg C and its nice and sticky.

I tried everything ( different heights, different temperatures ( PETG and bed ), different flow rates ), to get the PETG stick to the glass but it just didn't.
And really it doesn't stick at all.

So I gave up on that, I printed the x carrier, again last night, and really with the pray, it sticks extreme, and lifting the brim after cooldown pop and it is of.
I am so confident in this solution that I am going to try ABS now.

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amigob
I tried everything ( different heights, different temperatures ( PETG and bed ), different flow rates ), to get the PETG stick to the glass but it just didn't.
And really it doesn't stick at all.

So I gave up on that, I printed the x carrier, again last night, and really with the pray, it sticks extreme, and lifting the brim after cooldown pop and it is of.
I am so confident in this solution that I am going to try ABS now.

Well it might be your PETG you are using. When I have my z height to close to the printbed (ie around -.05 to -0.15), PETG gets smeared onto the heatbed. So much so that I peeled off parts of the tempered glass right off the glass itself. Therefore, I learned that it is more important to have it the correct height with less stickyness than too close. Also, after each print I use rubbing alcohol to clean the glass bed. This helps a lot.

Using MakerGeeks PETG
60*C bed
250*C hotend

I have verified my temps with an IR temp gun - max 3* deviation.

Sticks just fine to clean glass mirror. I have to pry up the corners a little and work around the edges of large surface area prints with a razor blade to get them to loosen. Nothing worrisome so far.

Edited 2 time(s). Last edit at 03/26/2016 04:54PM by MrBaz.

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MrBaz
Using MakerGeeks PETG
60*C bed
250*C hotend

I have verified my temps with an IR temp gun - max 3* deviation.

Sticks just fine to clean glass mirror. I have to pry up the corners a little and work around the edges of large surface area prints with a razor blade to get them to loosen. Nothing worrisome so far.

Exactly. PETG likes glass.

My settingss:
Brand: Alchement
73*C bed
238*C hotend

Would not recommend Alchement brand. I was printing a 5hr print. And checked on it every 15min. Then got comfortable with it. Checked it again at the 4hr mark, there was a non uniform bump in the filament. This plugged the extruder. The gears were grinding the filament cuz it was stuck. I would say 1 hr ago it got stuck. So the nozzle was floating in the air now laying down filament.

The problem is that getting filament from the US to here (NL) costs a lot.
So I am stuck with Real PETG filament
And the normal price ~80 dollars per kilo ????

I will make a Movie of loosening my prints now it is really ' amazing mike '

can't show the simple pop of movie,
after cool down it was already loose,

I constanly see that at the beginning and and if an extruded line I have to much filament.
So I was wondering are extruded amounts synced with the movement acceleration ?
So not only with speed.

Or should I match these movement accelerations with extrusion acceleration my self ?
I use Repetier

Edited 1 time(s). Last edit at 03/28/2016 11:23AM by amigob.

Quote
amigob
I constanly see that at the beginning and and if an extruded line I have to much filament.
So I was wondering are extruded amounts synced with the movement acceleration ?
So not only with speed.

Or should I match these movement accelerations with extrusion acceleration my self ?
I use Repetier

You might need to find the retraction rate settings. Adjust that so you do not get too much extruded filament after a print.

So today I realize why peoples PETG does not stick to the glass plate.

I bought a new hotend with a new different thermistor. I have no way of testing the settings for the thermistor. Its supposed to be a EPCOS 100K generic thermistor. But I do not know if its a 1k or 4.7k pullup. After various testing, I could not get the filament to stick to the bed. I figured out that the hotend was not hot enough. Also, I figured that the glass bed was not hot enough. So I cranked them both up higher. Now the filament sticks.

My new temps are 247 deg C for the hotend and 87 deg for the hotbed. I have tried 237, 238, 240 for the hotend with little success. I have also tried 73, 75, 77, and 80deg for the hotbed and no success. The only way I made it work was with the temps above of 247 hotend and 87 hotbed.

The hotbed is the correct temp because can check it with my IR thermomiter. But the hotened is covered by a silicon boot.

Agreed, it sticks well once you get the temps right. I bought a K-type thermometer about a week ago. I was surprised and pleased that it agrees very well with the temperatures reported by the firmware from the thermistors, to within 1 to 2C over the working range. On the glass surface I discovered my IR thermometer over-reads by about 10C.

How did you verify that your thermistor was the correct temp? I cannot figure out how? Do you aim the IR thermometer at the heatbreak?

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DRTak
How did you verify that your thermistor was the correct temp? I cannot figure out how? Do you aim the IR thermometer at the heatbreak?

I compared the thermistor readings against the K-type thermometer. I'm assuming that the K-type performs according to spec, which may be a bit of a leap, but what can you do. The hotend is too small to get reliable readings with the IR thermometer. The comparison I did was on the top surface of the glass bed, comparing the IR against the reading from the K-type. The IR thermometer appears to be the least reliable, but it's quick and convenient and gives ballpark measurements for motors and electronics.

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JamesK

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DRTak
How did you verify that your thermistor was the correct temp? I cannot figure out how? Do you aim the IR thermometer at the heatbreak?

I compared the thermistor readings against the K-type thermometer. I'm assuming that the K-type performs according to spec, which may be a bit of a leap, but what can you do. The hotend is too small to get reliable readings with the IR thermometer. The comparison I did was on the top surface of the glass bed, comparing the IR against the reading from the K-type. The IR thermometer appears to be the least reliable, but it's quick and convenient and gives ballpark measurements for motors and electronics.

I wish I would have done that before I installed it with RTV silicone into the heaterblock. You are right. I should have attached the hotened thermistor to the heated bed. Then checked the hotend thermistor temp to that of the heatbed. That would have helped me. For now I can only assume that my hotened thermistor may be off by 10-30 deg cel