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Big warping problem

Posted by tikkis 
Big warping problem
September 16, 2015 06:15PM
Hello.

i have had my Sunhokey purse i3 for a while now, and hate it so mutch.
i have calibrated XZY and the platform to the best of my abillity .
the bed is calibrated with a feeler gauge to 0.1mm distance from bed to nozzle, and z offset is set to -0,1 in slicer (repeater host). for the have worked on this machine for 4 month but i can't get it to print properly.
No mather what i do the print is warping in one or more corners. have tried
glue on 3m blue painters tape.
i use 10% infill
brim and skirt
slow speed set to 50.

printing at 250c measured the nozzel with IR Thermometer to 200C
bed at 60c measured 55c

please some help here.
ALL prints are warping.
there is no draft in the living room.
Re: Big warping problem
September 16, 2015 07:30PM
Don't trust laser thermos, use a Multimeter with a thermistor. What type of plastic is that? ABS or PLA? PLA should print with a nozzle temp about 180 and should stick fine to a 60 degree bed. However ABS will need about 210 at the nozzle to print and a bed of 100. Do you by any chance have a fan blowing on the print/or bed? Some hotend fans end up hitting the bed leading to warping/loose prints. I have also learned no fans on abs prints!! someone said that was common knowledge but if your new (like I am) it is not.

If you're pushing 250 on a hotend with a liner it's cooked by now I would think.
Re: Big warping problem
September 17, 2015 05:58AM
Switch to PETG filament, and your warping will stop:
[forums.reprap.org]
Re: Big warping problem
September 17, 2015 06:02AM
Hi,

I agree with jason.
You experience 3d printer's calibration
is a long journey full of disapointments for the lonesome man.
Be patient, and walk step by step. It'll be ok.
Don't start with ABS, prefer PLA for first calibration.

Extreme temperatures brings problems.
You'd rather use average temperatures.

250°C is probably too high for PLA
usualy it's 190-200°C
with 65°C for the bed, part's fan on.
some ABS needs 250°C,
but mostly it's rather around 220-235°C
with105°C for the bed, part's fan off.

Now, bed preparation.

To prevent wrapping, you want a good bounding.
if you have a rough surface, like printerbot's powder coating,
sanded aluminium, painter's tape or buildtak,
you probably don't need any bounding agent for PLA,
just clean any geasy layer after each print with alcool (IPA),
becausse plastic will always release kinda grease.

On glass and/or with ABS, you need definitely a bounding agent.
Some uses ABS juice, it works but it's a messy stuff.
I prefer hairspray : strong with no shine agent.
It's translucent, it don't affect part's look,
easy to cleanup and less messy than glue sticks.
Wolfbite, Dimafix are airsprays (spray or liquid).
ABS wraps easily anyways. You realy need a warm bed 105-110°C.
An enclosure can reduce ABS wrapping drasticaly.
It can be realy simple, like a carboard box all over the printer.

The overall shape of your part can make it warp a lot.
Some damned parts can't stay flat because
the shape release a lot of internal tensions.
Sometimes you must redesign your part,
or lay it on another side to get good print results.
Long contact side wraps more than repeated small ones.
Consider using the raft and squirt options when slicing too.

++JM
Re: Big warping problem
September 17, 2015 10:46AM
thanks for input.

i am using pla the type that came with the printer. i have read that this is no good. so i would try to get some PETG then.
I have a multimeter with temp so i will try that also.


due to the high temperatures i use. is that i used a IR meter to measure the temp direct on the nozzle and it is 50C wrong. but i will check again with a multimeter..
Re: Big warping problem
September 17, 2015 12:48PM
Do they warp during printing or when cooling? You can try a couple sheets of kitchen towel over the print and let it cool until below 30 degrees. I do this with HIPS and it seems to half the amount of warping.
Re: Big warping problem
September 17, 2015 12:49PM
Hi,

Try a print with PLA around 195°C with bed @65°C.

++JM
Re: Big warping problem
September 19, 2015 11:16PM
DON'T TRUST AN IR THERMOMETER! Trust the thermistor in your hotend and set it to 185. You're burning the crap out of the PLA! I also use the cheapest hairspray I could find and I use a tempered glass plate I found on Amazon.
I also set my nozzle at 0.1mm but what are you using a Z offset for? That, besides the grossly overheated plastic, could be leading to poor adhesion by not putting down a good first layer. You should also be running the speed for the first layer about 50% of normal speed, from what I've been reading. I'm a noob too but learning fast.

You said you are using blue painter's tape but that looks like masking tape!

Edited 1 time(s). Last edit at 09/19/2015 11:18PM by tjnamtiw.
Re: Big warping problem
September 20, 2015 12:40AM
My IR thermometer does not even want to give me a number for the nozzle or bed. So I ordered a K-type thermocouple probe meter.
Re: Big warping problem
September 20, 2015 09:23AM
Quote
RRuser
My IR thermometer does not even want to give me a number for the nozzle or bed. So I ordered a K-type thermocouple probe meter.

IR thermometers give vastly different readings on black vs shiny surfaces. The better ones have a selector switch for the type of surface you're shooing but, in my experience using them at work, they are really only good at giving RELATIVE temps when shooting the exact same spot. For instance, in maintenance you may have spots defined on various motor bearings and once a week you shoot those spots and record the readings. You're looking for the possibility that they are getting hotter. You're looking for trends and not accurate temperatures.

End of lesson. spinning smiley sticking its tongue out
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