Jump to content
Ultimaker Community of 3D Printing Experts
AbeFM

Soluble Supports: Tower Layer Bonding

Recommended Posts

I've been trying to get a decent print with PVA orPET-G supports for PLA printing, and I've been having almost great prints with very bad extrusion about a CM up. The print is ok, the layer adhesion on the tower sucks and the tower will break there later in the print, a couple cm later.

 

I'm using a fairly new dual nozzle set up, but it seems to print dual PLA reasonable well.

ZH60DtJw4-qlwts-UdcVdqdN3H8YIYEJfkU7NGJZ

https://photos.app.goo.gl/PUTGuZspJpkdKli72

 

What can I do to improve the stability of the tower?

 

It seems it would be awesome to have a core printed in just one filament, to keep it stronger, but I'd like to know what I can do now. Thanks!

Edited by AbeFM
Update picture

Share this post


Link to post
Share on other sites
On 5/12/2018 at 7:23 AM, ultiarjan said:

I find increasing the prime tower thickness will increase it's reliability;

 

image.thumb.png.65c68337dfa29cfea2baf9a89f396886.png

This works as long as the ratio of the thickness and the size lets the individual circles touch and form a solid structure.

 

There's a density calculation which would be beneficial if it were done here. Adding a lot of "Prime Tower Purge Volume", can help here, just letting stuff get up to temp.

 

 

On 5/12/2018 at 2:45 AM, kmanstudios said:

What slicer are you talking about?

This is the definition of standby temp, which I read as the same as your original assumption: When not in use, this is the temp it is waiting at.

Standby_Temperature.jpg.dfce6078aa129bbc9ef2a6af759263f7.jpg

 

There are 3 temperatures per nozzle that are used, four counting first layer:

 

Ext#    Color    Print Standby    Lowest    Starts
A    Black    205    202    190    <=195 (Set 205)
B    Blue    192    195    177    ~188 (set 192)

 

Notes:

Support still printing at 177 setpoint
Ext B Sitting/Set at 182/182 when not printing
Sets new temp (195), immediate prints

Sets temp to 177, keeps printing.
Switches set temps, immediately prints on unheated ExtA

 

The interesting bit is the temperature is proactively set to (what I assume is) 15 degrees below "Standby".

 

I really like the idea of a "Standby" temp as well as a "start printing at" temp. But as best I can tell I can't get to those. What I CAN say is that whatever is going on, I see a lot of extruder-feeding happening when the nozzle temperature is well below extrusion temperature.

 

Most of the failed Purge Towers and Ooze Shields happen when they are printed at the Standby temperature instead of at the Print temperature. If the structures were more robust, it would likely be ok. But given they aren't, waiting for the right temps (AT the tower, not AT the part!!!!) would go a long way.

Share this post


Link to post
Share on other sites
Gcode Line#	Command	Extduer	Temp
11	M109	A	S210
12	M109	B	S189
3044	M109	B	S195
4671	M109	A	S195
4672	M104	B	S182
4678	M104	A	S205
5025	M104	A	S190
6071	M109	B	S182
6072	M104	A	S195
6077	M104	B	S192
6527	M104	B	S177
7021	M109	A	S195
7022	M104	B	S182
8168	M109	B	S182
9121	M109	A	S195
10263	M109	B	S182
10264	M104	A	S195
10269	M104	B	S192
10839	M104	B	S177
11274	M109	A	S195
11275	M104	B	S182
11280	M104	A	S205
11594	M104	A	S190
12566	M109	B	S182
12567	M104	A	S195
12572	M104	B	S192
13260	M104	B	S177
13675	M109	A	S195
13676	M104	B	S182
13681	M104	A	S205
13893	M104	A	S190
14867	M109	B	S182
14868	M104	A	S195
14873	M104	B	S192
15371	M104	B	S177
15792	M109	A	S195
15793	M104	B	S182
15797	M104	A	S205
15975	M104	A	S190
16851	M109	B	S182
16852	M104	A	S195
16861	M104	B	S192
17618	M104	B	S177
18013	M109	A	S195
18014	M104	B	S182
18023	M104	A	S205
18201	M104	A	S190
18823	M109	B	S182
18824	M104	A	S195
18833	M104	B	S192
19605	M104	B	S177
19895	M109	A	S195
19896	M104	B	S182
19906	M104	A	S205

I pulled all the temperature change lines from my g-code, which repeats:

11280	M104	A	S205
11594	M104	A	S190
12566	M109	B	S182
12567	M104	A	S195
12572	M104	B	S192
13260	M104	B	S177
13675	M109	A	S195
13676	M104	B	S182

A Print Temp

A (Print-15)

B Standby

A Standby

B Print Temp

B (Standby - 15)

A Standby Temp

B Standby Temp

 

At minimum I see a difference, ExtA uses Print-15, ExtB uses Standby-15

 

I'm going to generate some gcode with less-ambiguous temperatures and repeat this exercise. 

Share this post


Link to post
Share on other sites

Yeah, there seems to be a bit of disparity between the wording of the interface and the actual code created. That can present frustrating examples of miscommunications between people such as yourself (Can pinpoint code) and myself (Goes by interface at this time) that can create unneeded agita.

 

But, I am going to take your word for it and hope someone fromm Team UM's coding department can clarify what is going on.

 

Also, I just stopped using the priming tower just because it is a time suck and really wastes materials

 

Share this post


Link to post
Share on other sites
Gcode Line#	Command	Extduer	Temp
11	M109	A	S210
12	M109	B	S189
3044	M109	B	S195
4671	M109	A	S195
4672	M104	B	S182
4678	M104	A	S205
5025	M104	A	S190
6071	M109	B	S182
6072	M104	A	S195
6077	M104	B	S192
6527	M104	B	S177
7021	M109	A	S195
7022	M104	B	S182
8168	M109	B	S182
9121	M109	A	S195
10263	M109	B	S182
10264	M104	A	S195
10269	M104	B	S192
10839	M104	B	S177
11274	M109	A	S195
11275	M104	B	S182
11280	M104	A	S205
11594	M104	A	S190
12566	M109	B	S182
12567	M104	A	S195
12572	M104	B	S192
13260	M104	B	S177
13675	M109	A	S195
13676	M104	B	S182
13681	M104	A	S205
13893	M104	A	S190
14867	M109	B	S182
14868	M104	A	S195
14873	M104	B	S192
15371	M104	B	S177
15792	M109	A	S195
15793	M104	B	S182
15797	M104	A	S205
15975	M104	A	S190
16851	M109	B	S182
16852	M104	A	S195
16861	M104	B	S192
17618	M104	B	S177
18013	M109	A	S195
18014	M104	B	S182
18023	M104	A	S205
18201	M104	A	S190
18823	M109	B	S182
18824	M104	A	S195
18833	M104	B	S192
19605	M104	B	S177
19895	M109	A	S195
19896	M104	B	S182
19906	M104	A	S205

I pulled all the temperature change lines from my g-code, which repeats:

11280	M104	A	S205
11594	M104	A	S190
12566	M109	B	S182
12567	M104	A	S195
12572	M104	B	S192
13260	M104	B	S177
13675	M109	A	S195
13676	M104	B	S182

A Print Temp

A (Print-15)

B Standby

A Standby

B Print Temp

B (Standby - 15)

A Standby Temp

B Standby Temp

 

At minimum I see a difference, ExtA uses Print-15, ExtB uses Standby-15

 

I'm going to generate some gcode with less-ambiguous temperatures and repeat this exercise. 

--------------------------

 

Trying again: When I use extereme values (temps of 300+) to establish enough seperation between the values to tell "Print Extruder A - 15" apart from "Standby Extruder B + 10", the software changes the values (I think my "350" became "150" in g-code??.

 

With the following settings:
 

Extruder Material Material Print Material Standby Profile Print Profile First Layer Profile Standby
A My PLA 205 193 206 208 196
B My PVA 192 185 191 194 188

 

21 layers with PVA, 80 layers overall

 

I get:

Temp Times Ext State Offset
165 16 B Standby -20
175 10 B Standby -10
181 10 A Standby -10
188 4      
190 11      
194 2      
195 22      
196 6      
205 11      
208 2    

 

 

The issue is I just can't tell what's going on. I know it prints a LOT when the temps are set lower than ANY temperature I set anywhere in the program, and I know I get underextrusion from such. I can't tell (ExtA <Material Setting: Print Temp> - 10) apart from (ExtB <Material Setting: Standby Temp> + 10), by the time I have to consider offsets of +/- 20, and to get no overlap, and not hit temps too low (<160?) or too high (>250), I quickly run out of testing options. With some support I'd be happy to keep testing but I just feel I don't have enough to work with.

 

I'm a LONG time into trying to figure out what is going on, and would love some instructions on how the program works.

 

Edited by AbeFM

Share this post


Link to post
Share on other sites

This gets worse the longer I look at it.

 

I would be VERY happy to help someone knowledgeable debug this, but I feel I don't understand what it is even trying to do well enough.

 

Most of the variables seem to have hidden constraints, changes aren't always respected, and I don't even know what the behavior SHOULD be, so it's really hard to tell if it is doing what it should.

 

It SEEMS like there are settings (in the printer profile?) which are hidden, and cover things like temperature offsets, time to turn the extruder temperature down preemptively by. These settings are likely great on an UM, but not cutting it for my E3D based equipment.

Share this post


Link to post
Share on other sites

I'm wondering if it was a case of not having unhidden the options at the same time as having a definition which supported dual extruders.

 

I'm still having printing issues, but at least they make sense now. Thanks!!!!!!

Share this post


Link to post
Share on other sites

I to have been struggling with the tower also and it breaking off part way up. It seems like such a waste of material and time to increase the size and wall thickness to keep the tower from breaking apart.

 

kmanstudios I have seen you post a couple times that you do not use the tower.  Could you give us a couple hints how you do this. When I lower the temp the nozzle sometime freezes and the retracts do not seem enough.. I know i am missing something in set up or settings. Thanks in advance

Share this post


Link to post
Share on other sites

Lemme see how I can put this and see if it makes sense to you:

  1. When I get finished with a print, I do sometimes have to knock a few stringy things off with my thumbnail or every once in a while a sharp x-acto
  2. I get a bit of stringing on the PVA, but I got that with the priming tower anyway
  3. As long as the stringiness is not going inside the model, I am not worried
  4. I use pretty much defauolt settings for things like PLA, PVA, TPLA. PETG can get a bit stringy and takes a bit of getting used to setting

That is my basic operation right there. I just got tired of the waste and added time of the priming tower. Every once in a blue moon, I may use an ooze shield, but honestly, I cannot recall the last time I did so.

 

This is my latest print with no priming tower on the UM3E and after removing the PVA. I did have to remove a few PLA strings.

TinyOneOnUM3E.thumb.jpg.81c1523cd8e02e592c694498e42a231f.jpg

Front.thumb.jpg.636884e6ab99dbce369fbdb227e28b2d.jpg

 

Edit:

Oh yeah, those are a US quarter and a 2 Euro coin for size relationship. So, thems some kinda teeny fingers and toes.

Edited by kmanstudios

Share this post


Link to post
Share on other sites

I have been experimenting with not using the tower and using Cura's suggested settings. There seems to be a balance of temperature at the start and end of a print session before it switches to the other print core, this determines how much leaks out when the other head is printing. Is this your experience? In addition the length and speed of retraction also seems to make a difference and is  different for PVA and PLA. Do you ever modify them?

Share this post


Link to post
Share on other sites

Not really. I agree with the balances they have worked out. The PVA is hard to tell because it is so absorbant, it can change characteristics in a print's duration and that will affect the stringiness. But for the most part, I find the settings pretty good for most colors and materials for the ones they have included.

Share this post


Link to post
Share on other sites

Your printer has the fancy moving nozzles, right? I don't know when UM started doing that (UM3?)

 

The issue I have is the PVA "strings" end up being "PVA-row-of-holes-in-your-part" once you wash it.

 

Awesome print, BTW

Edited by AbeFM

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Our picks

    • Introducing Ultimaker Cura 3.6 | Beta
      Ultimaker Cura 3.6 | Beta is available. It comes with new features, bug fixes, and UX improvements. We would really like to have your feedback on it to make our stable release as good as it can be. As always, you can download the beta for free from our website, for Windows, MacOS, and Linux.
        • Like
      • 82 replies
    • Print Core CC | Red for Ruby
      Q: For some users, abrasive materials may be a new subject matter. Can you explain what it is that makes a material abrasive when you are not sure which print core to use?
      A: Materials which are hard in a solid piece (like metals, ceramics and carbon fibers) will generally also wear down the nozzle. In general one should assume...
        • Like
      • 28 replies
    • "Back To The Future" using Generative Design & Investment Casting
      Designing for light-weight parts is becoming more important, and I’m a firm believer in the need to produce lighter weight, less over-engineered parts for the future. This is for sustainability reasons because we need to be using less raw materials and, in things like transportation, it impacts the energy usage of the product during it’s service life.
        • Like
      • 12 replies
×

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!