ABS+PLA flashforge

Hi,I tried to print in both PLA+ABS with my flashforge creator pro but without any success.did someone experience the same issue and can help please ?I tried with simplify3d and replicatorG and got the same result. the PLA filament is blocked between the PET tube and the "MK8" extruder and I have to umount this part in order to remove the plastic.I also tried different PLA filament and also reverse PLA and ABS extruder side and always got the same issue...the first layer of PLA is ok, then when it switch from ABS to PLA again, the problem is present everytime (even on different models)thanks in advance for your help !Sebastien

Umm.
sounds like you are doing something really weird or just not using the right extrusion temperatures.

What settings are you using ?
ie:
bed temp
extruder temp
print speed

And are you using pla and abs at the same time in different nozzles ?

Also are you using the latest version of simplify 3d ? version 3.0 Because the flashforge profiles are weird. So far I haven't got it to print anything from version 3. So I'm still using the last version of 2. because I've got that down to a fine art.

They really didn't need to bugger up the profiles the way they did.

Thanks for your quick attention :)so the bed temp : 60° (tried also 90°)extruder temp : PLA:200° ABS:230°print speed :2200mm/minAnd are you using pla and abs at the same time in different nozzles ? yes, pla and abs at the same time in different nozzlesAlso are you using the latest version of simplify 3d ? version 3.0 Because the flashforge profiles are weird. So far I haven't got it to print anything from version 3. So I'm still using the last version of 2. because I've got that down to a fine art.I've tried with replicatorG which exactly gives me the same issue even if it does not work in the same manner. I did use simplify 3d v2 for a long time, but never tried to pint with both extruder. I've upgraded to v3 last week, and tried to print with dual extruder for the 1st time...

Did you calibrate your extruder? Sounds to me like you're over extruding and causing a jam inside your nozzle and PTFE tube.

Quote:

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Originally Posted by Sebastian Finke

Did you calibrate your extruder? Sounds to me like you're over extruding and causing a jam inside your nozzle and PTFE tube.

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hi,
there's no jam for sure in the Nozzle, but yes, it appears to be jammed in the tube. what does it mean calibration ? is it an option in simplify3d depending of the filament ? or is it through the flashforge console ? I use to change retracation parameters for PLA but not the rest. I didn't change any parameters and use the default simplify3d value for extrusion (and also on replicatorG)

thanks

Read Section 5.1.4 in this link to learn how to calibrate your extruder. Read the rest too, it'll help you get the most out of your printer.

:)

And for interests sake here is the Sailfish manual. Read it, it is your FFCP bible.

A manual !
Hot diggity, didn't know such things still existed :-)


Hmm, so 36mm/s - slow enough. Temps look good.

But if you're using abs and pla at the same time you'll probably need to keep the bed at 60. You can't set different bed temps for each filament type if you're doing a dual print.
Well i suppose you could, but it'd be a real pita as it heated up aand cooled down.

It actually sounds like the extruders aren't holding temp.

What I used to get originally with s3d was it would heat the right extruder to temp and then stop heating it so it would start to cool down. You'd get the first layer and then it'd be too cool to extrude any more and stop.
Never had that with the left extruder.

My first (and currently only) attempt to print with s3d v3.0 Resulted in everything looking like it was behaving correctly. Bed temp fine, left extruder temp fine. As far as I could see left extruder selected for everything. Starts to print, and was trying to use the right extruder.

At which point I went back to version 2 lol
Cursing the people who decided to mess with something that worked.

Might have a go today. I need the new infill settings so I have to get it working. Just wish the simplify3d would check their profiles.
On the klic-n-print the standard s3d profile had wrong size bed and dropped the z axis about 1mm every single time it adjusted for the next layer. You could hear it go clunk as it dropped.
I did get that sorted by loading a flashforge creator profile and modifying the gcode and bed size.

But yep the profile side of s3d is the worst part - from my point of view anyway.

thanks for your links Sebastian, this is really interesting :) I will try that today !

Sebastien

yep, this new simplify v3 is more user friendly from my point of view, but I'm not sure the profile is good enough for PLA, although it works fine for me with ABS. good luck with your new attempt aardvark ;)

this is where I get really confused lol
PLA is just so easy to use and totally forgiving on temps, things it'll stick too etc.

Whereas abs was alway a pain. Could never print anything without a raft, dimensions were never quite right, warped, cracked, smelt and forced you to always have acetone fumes around.

Both abs and the pla I like best, are made by same people: reprapper tech.

The reprapper pla is tougher than the abs, totally not-brittle, not quite as flexible as the abs - but certainly flexible enough for everything I've tried it with. And prints at the dimensions I design the models to.
Only smells of maple syrup, doesn't need acetone.
Abs parts I've made for a really tight fit generally crak where pla parts with same settings give enough to snapfit.

It really is weird I seem to have totally different experiences to everybody else.

Have never drilled pla - or abs - always put any holes in the designs.
So can't comment on that.

As pictures are better than words, you will find some screenshots here.
apparently, there's no convex issue, but all the PLA prints have holes on top of them although this is not the case for ABS print.
it's probably normal as simplify3d PLA profile is different than ABS one (in the screenshot also)
for info, in the screenshots,
D means "right extruder" and G means "left extruder".
the white box is ABS. orange and red are PLA (diameter is perfectly 1.75mm for both of them)

https://goo.gl/photos/wbdwUib9xKLSsVe19



Seb

You should not be getting gaps like that!

I can't say much about S3D as I use Makerware but something's not right. What speeds are you printing at?

Quote:

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Originally Posted by Sebastian Finke

You should not be getting gaps like that!

I can't say much about S3D as I use Makerware but something's not right. What speeds are you printing at?

---

I print by default at 2200mm/min and tried to reduce to 70% of this value without any change. maybe there's not enough filament (pla extrusion multiplier is 10%less than original value in the screenshot. I don't know what does it mean exactly)

The extrusion multiplier is determined by the effective diameter of the filament drive gear. For example: if your extruder stepper is running at 30r/min and your filament drive gear has a diameter of, say, 20mm and you are using 1.75mm filament then your peripheral speed is

π x d x r

= 3.142 x (20 + 1.75) x 30

= 2050.155mm/min.

This peripheral speed is equal to the speed that the filament is fed into the nozzle. The extrusion multiplier is a factor/percentage of this speed. In a perfect world this should be 1 but several factors can affect it:

1) the filament is pressed into the filament drive gear thus reducing the effective diameter. And since all plastic have different densities they pressed into the gear to varying degrees resulting in different values for each plastic.

2) The filament drive gears can vary in diameter. Treat each gear as an unknown until calibrated.

3) Filament diameters vary, also varying the effective diameter.

4) Nozzle back pressure causing miniscule slipping

5) Friction (in filament guide tube, spool on spool holder, etc) causing miniscule slipping.

You can measure the filament diameter and the filament drive gear diameter. Determining how much of the filament is pressed into the gear is a bit of a shot in the dark, same goes for determining slippage due to back pressure due to slippage and friction. Hence the calibration process.

The extrusion multiplier allows you to adjust for all these factors. The calibration box is a visual test but serves its purpose well enough. A more scientific approach would be to do an immersion test of several items to determine the true volumetric output of the extruder.

thanks a lot for this complete explanation Sebastian.
I find it really interesting, and think can help to limit the issue I get on the top of the box, but I'm still wondering why my print still stucks when printing in dual extrusion. I found a new menu in simplify 3d (dual extrusion wizard), and I will have a look today. maybe it will solve this problem.

thanks

You can't print PLA on top of ABS and vice versa, if that's what you're trying. From your description "the first layer of PLA is ok, then when it switch from ABS to PLA again, ..."
If instead you mean you always have trouble when changing from ABS filament to PLA filament, likely you have a small amount of ABS still in the extruder and the PLA temperature is not hot enough to push it through. Preheat extruder to ABS temp and push through PLA to push through any leftover ABS, then back down temp to appropriate PLA temp. If extruder is blocked by ABS, pushing melted PLA into the blockage will cause it to back up into the PET.

Also, when you say filament is blocked between PET and extruder, I can tell you on my FlashForge, the two extruders are not perfectly level. So, if you're running both extruders and one is putting down a higher level of plastic than the other, quite possibly the plastic in the lowest extruder is right up against the higher layer of plastic from the higher extruder, and with no where to go, the plastic is backing out into the PET. I haven't dual extruded yet, but I can tell you I have to relevel the bed when switching from left to right extruder use and vice versa.