Problems with raft becoming unstuck on Replicator

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Bill Pugh

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Apr 6, 2012, 2:43:00 PM4/6/12
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I just got my replicator, and I've been having problems with my initial prints. A few times, I had problems with my raft not initially sticking to the build platform. But after re-leveling the build platform very carefully, that doesn't seem to be a problem.

But now the problem I seem to keep on hitting is that after getting about 1/4" of build height, the raft (and the entire piece) become unstuck from the build platform, and I just wind up building a hair ball.

Any suggestions? I've been cleaning the platform with rubbing alcohol between builds. I could try leveling it again and reducing the clearence between the platform and the extruder heads even further.

Another issues I've noticed is that sometimes the extruder doesn't start early enough, and I get a loose or uneven thread at the beginning of my raft. That almost always leads to the raft becoming unstuck. It seems like the best builds are when the extruder starts nice and early, and starts with a thread dangling off the platform that lead to the raft. Is this what works for people?

If it matters, I have a dual extruder model, but so far I've just been trying to build single extruder models. I get the problem with both extruders.

Bill

Zip Zap

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Apr 6, 2012, 6:04:15 PM4/6/12
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The platform has to be hot enough for ABS to stick.  As I remember, 120C should be the minimum.  Maybe try using some blue painters tape or buff sand the surface of your Kapton tape to allow more adhesion.


From: Bill Pugh <bill...@gmail.com>
To: make...@googlegroups.com
Sent: Friday, April 6, 2012 11:43 AM
Subject: [MakerBot] Problems with raft becoming unstuck on Replicator

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Dan Newman

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Apr 6, 2012, 6:07:29 PM4/6/12
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On 6 Apr 2012 , at 3:04 PM, Zip Zap wrote:

> The platform has to be hot enough for ABS to stick. As I remember, 120C should be the minimum.

110 C works fine for me with my ToM. 120 C is actually a bit high from my experience. I believe
the MBI default is 100 C.

Dan

Chris

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Apr 6, 2012, 6:22:57 PM4/6/12
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Setting the platform to 110 has pretty much solved this problem for me on my replicator.  If I notice the extruder leaking during heat up I try to remove as much dangling plastic as possible, because otherwise the leaked plastic ends up sticking up from the board and can catch on the extruder as it passes by.  Others have suggested rubbing acetone on the platform between builds, and covering the sides and front with some kind of plastic to prevent drafts from coming in.  I bet the latter would help quite a bit if you're in an area that can have drafts come in from AC/etc.

Greg Thorstad

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Apr 6, 2012, 7:15:37 PM4/6/12
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Assuming your bed it true and consistant when you try to level it my guess would be you are not starting low enough so the plastic binds to the platform well.  If you want to relevel the platform you can do so with a thinner piece of paper.  Or you can go into the machine settings and increase the z home offset.  Normally it should be zero because home on the replicator is at the top but you can put a positive number in there to raise the bed height.   My suggestion would be to increase it by .05 millimeters increments and see what happens.  You dont wont to go too high or you will have the extruder dragging across the bed which is bad news.
 
Cleaning with Acetone is probably better than alchohol,  If you want a safe version then you can use a acetone base fingernail polish remover.
 
 
Greg Thorstad, B. Comm.
Thorstad Computer/Thor3d.ca/Canadian Makerbot Distributor
Box 268
Outlook, SK
S0L 2N0
306 867-9596
----- Original Message -----
From: Bill Pugh
Sent: Friday, April 06, 2012 12:43 PM
Subject: [MakerBot] Problems with raft becoming unstuck on Replicator

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Bill Pugh

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Apr 7, 2012, 7:39:20 AM4/7/12
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Thanks everyone.

I've been looking for where the controls are to change the platform and extruder temperatures. I see where to change them in the preheat settings on the replicator, but I don't see, either in ReplicatorG or the replicator, how to change the temperatures used during the build.

Bill

akr...@yahoo.com

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Apr 7, 2012, 4:33:56 PM4/7/12
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It's under Gcode/ Edit Profiles. When the edit dialog pops up click
Edit. When Skeinforge pops up choose Temperature.

Bill Pugh

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Apr 8, 2012, 9:32:12 AM4/8/12
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OK, I'm now sure where in this dialog I'm supposed to set the build platform temperature. See picture below. There is an entry for Base Temperature, but that is initialized to 225C. Am I supposed to check the temperature setting if I want to control the temperature?

The entire edit profile is a bit of a mess and insanely complicated. Is there a guide as to the common things you'd want to tweak. 

Bill

bigjosh

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Apr 8, 2012, 11:48:51 PM4/8/12
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Tried everything else, but the blue painter's tape on the platform
trick finally solved this problem for me. Thanks!

-josh

On Apr 6, 6:04 pm, Zip Zap <zzap...@yahoo.com> wrote:
> The platform has to be hot enough for ABS to stick.  As I remember, 120C should be the minimum.  Maybe try using some blue painters tape or buff sand the surface of your Kapton tape to allow more adhesion.
>
> ________________________________
>  From: Bill Pugh <bill.p...@gmail.com>
> To: make...@googlegroups.com
> Sent: Friday, April 6, 2012 11:43 AM
> Subject: [MakerBot] Problems with raft becoming unstuck on Replicator
>
> I just got my replicator, and I've been having problems with my initial prints. A few times, I had problems with my raft not initially sticking to the build platform. But after re-leveling the build platform very carefully, that doesn't seem to be a problem.
>
> But now the problem I seem to keep on hitting is that after getting about 1/4" of build height, the raft (and the entire piece) become unstuck from the build platform, and I just wind up building a hair ball.
>
> Any suggestions? I've been cleaning the platform with rubbing alcohol between builds. I could try leveling it again and reducing the clearence between the platform and the extruder heads even further.
>
> Another issues I've noticed is that sometimes the extruder doesn't start early enough, and I get a loose or uneven thread at the beginning of my raft. That almost always leads to the raft becoming unstuck. It seems like the best builds are when the extruder starts nice and early, and starts with a thread dangling off the platform that lead to the raft. Is this what works for people?
>
> If it matters, I have a dual extruder model, but so far I've just been trying to build single extruder models. I get the problem with both extruders.
>
> Bill
> --
> You received this message because you are subscribed to the Google Groups "MakerBot Operators" group.
> To view this discussion on the web visithttps://groups.google.com/d/msg/makerbot/-/QDvU4ccEfnsJ.

Threeethan

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Apr 9, 2012, 2:36:16 PM4/9/12
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Ethan here from MakerBot Support.

If you're using the Replicator with the default settings (Skeinforge
47 and "Replicator slicing defaults") you actually don't want to go
into the Skeinforge settings and edit there.

You really want to click over to the gcode tab in ReplicatorG and find
this line:

M109 S100 T0 (set HBP temperature)

It should be in the first screen of data. To change the temperature,
edit the number after the S -- I'd start off moving it up to 110.

I think this is actually a lot easier than dealing with Skeinforge.
Btw, getting temperature into Print-O-Matic is a feature request that
I keep bugging the devs about, but they tell me that's trickier than
it seems.

-Ethan

Dan Newman

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Apr 9, 2012, 2:41:24 PM4/9/12
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On 9 Apr 2012 , at 11:36 AM, Threeethan wrote:

> Ethan here from MakerBot Support.
>
> If you're using the Replicator with the default settings (Skeinforge
> 47 and "Replicator slicing defaults") you actually don't want to go
> into the Skeinforge settings and edit there.
>
> You really want to click over to the gcode tab in ReplicatorG and find
> this line:
>
> M109 S100 T0 (set HBP temperature)
>
> It should be in the first screen of data. To change the temperature,
> edit the number after the S -- I'd start off moving it up to 110.

And presumably once/if you find a magic temp. that makes things work better,
then you can edit the underlying start.gcode file to have the magic temp in
it so that you don't need to manually edit every gcode file you generate.
(That line of gcode which Ethan pointed you at is coming from the start.gcode
file.)

Dan

Dan Newman

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Apr 9, 2012, 2:48:48 PM4/9/12
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> Any suggestions? I've been cleaning the platform with rubbing alcohol
> between builds.

You'll get better results if you use acetone. Note that nail polish
remover may not have acetone. And the ones which do have it quite
diluted. But even the diluted ones are better than using isopropyl
alcohol. (Or are you using scotch? ;)

As Greg mentioned, increasing your Z offset may help. The raft needs
to be slightly squished into the platform for good adhesion. So, first
try at a temp of 110 C. If that doesn't do the job, try increasing the
Z offset by 0.05 mm. See if that helps. You may need to increase it
several times. Just don't go so far as to put the platform into the
nozzle.

Another cause of poor adhesion is drafts. I once had poor adhesion on
one side of my ToM when building a 8 cm x 8 cm object. Then I noticed
that my wife had opened a window just 5 feet away from that side of the
bot and a gentle breeze was coming in….

And, in colder weather many folks have found they need to enclose the
sides of their bot. Even alumninum foil held up with masking tape
helps in that situation.

Dan

Zip Zap

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Apr 9, 2012, 2:52:55 PM4/9/12
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Are there two temp settings for the HBP as for the extruder?  The extruder for example has a temp setting in the start code.  Then there are temp options  in the edit profile screen for various parameters during printing.  In other words, the start temp may not be the final printing temp.


From: Dan Newman <dan.n...@mtbaldy.us>
To: make...@googlegroups.com
Sent: Monday, April 9, 2012 11:41 AM
Subject: Re: [MakerBot] Re: Problems with raft becoming unstuck on Replicator
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Dan Newman

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Apr 9, 2012, 3:10:44 PM4/9/12
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On 9 Apr 2012 , at 11:52 AM, Zip Zap wrote:

> Are there two temp settings for the HBP as for the extruder? The extruder for example has a temp setting in the start code. Then there are temp options in the edit profile screen for various parameters during printing.

I believe you're referring to SF profiles? First, as Ethan suggested, leave those alone.
And second, SF knows nothing about heated build platforms. The temp setting which shows
up in your gcode for the HBP comes from the static start.gcode file which was provided
with RepG, not with SF.

Dan

Aaron Double

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Apr 9, 2012, 3:43:52 PM4/9/12
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If you set your start gcode to

M104 S#<baseTemperature> T0 (set extruder temperature)
M109 S#<bedTemperature> T0 (set heated-build-platform temperature)

to set the temps, the gecode will reflect what is set in tempurature for the hot end and will reflect the bed temp in the chamber plugin in skeinforge. Change skeinforge and they will change for you.

Aaron

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Aljosa

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Apr 9, 2012, 11:50:12 PM4/9/12
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I did a lot of testing before I landed on 100C as it worked for pretty much everything except really large objects. That being said there is some diligence that is probably required at this temp. Acetoning the surface well, and insuring that there is no oily residue is definitely one. The other problem is Z height. I'm willing to bet that 99% of people that are having a problem at 100C, and using a raft just don't have the Z height correct so that the raft is actually being extruded higher then it should be. When this happens the plastic just doesn't stick as well and you get the peeling people are seeing.

 

My logic for 100 degrees was that it was enough heat for probably 80% of things. Problem is that too much heat can adversely affect your print. This is especially true when it comes to smaller more delicate object's. If you start pumping more heat into the print, you can start to see sagging, curling or drooping of your layers. However when you start getting into larger prints (and I mean generally 70% or more build volume) you will need more heat. Especially when your objects get larger and the forces of ABS shrinking are pretty big.


Here are two examples that show this very clearly that Nick took awhile ago, they show how too much heat can negatively affect your print.

http://www.flickr.com/photos/nickstarno/5530216311/in/photostream 

http://www.flickr.com/photos/nickstarno/5530215845/in/photostream 

 

That being said pumping more heat into the plate can overcome some of the above problems but at the expense of print quality. All in all I have looked at the situation, and with some of the plate problems (which are being rectified new ones are being tested)  one of the solutions is to increase the temp to 110C. For a future release of RepG I will consider increasing the temperature slightly.

 

However before going and increasing your temperature I would recommend loosening the leveling thumb screws just a bit more. The beauty of the system is that you can actually adjust leveling while the first layer or raft is happening, and see how it actually affects the layer. What you want to aim for is a slightly squished appearance. If the raft looks more circular there is a good chance it wont stick. Also like mentioned above if you have acetone (nail polish remover is a quick substitute) insuring that the build plate is nice and clean definitely helps a lot, and please make sure the build plate is cool when cleaning it with any solvent! 

Zip Zap

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Apr 10, 2012, 2:25:13 AM4/10/12
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PLA!, PLA!, PLA! ...


From: Aljosa <anom...@gmail.com>
To: make...@googlegroups.com
Sent: Monday, April 9, 2012 8:50 PM
Subject: [MakerBot] Re: Problems with raft becoming unstuck on Replicator

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PrettySmallThings

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Apr 10, 2012, 11:18:59 AM4/10/12
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Aljosa -

I'm currently running a print with my (replicator's) bed at 100c.
When I first got my thingomatic in the fall, turning the temp up to
110c (and printing a bed leveling system) was the turning point in
transition from multitudes of failed prints to success. Reading
through this forum, the topic comes up over and over. So today, I
resisted the urge to up the bed temp to 110 on my new machine, and
what do you know, it works just fine. But the Kapton is new, freshly
cleaned, I have a really good understanding of what a good Z height
looks like, and that spending time leveling is crucial. I will
consider using 100c more often now.

But I wonder if many new users would have a more successful out-of-the-
box experience if the default bed temp on the test prints were turned
up. In the online guide, the assumption at the end of the "First Run
Experience" is that the print was successful. Mine wasn't, and I feel
that I sort of know what I'm doing. The topic of failed prints is
covered in the troubleshooting section, but it really needs a whole
page dedicated to it, prominently linked at the end of the FRE. A
Step by step of how to get a first successful print - re-leveling,
decreasing the distance between extruder and platform, and increasing
temp. Maybe followed by a short discussion of temp, and why 100c is a
good goal as a user's printing finesse grows.

My 2 cents :)

Aljosa

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Apr 10, 2012, 1:05:13 PM4/10/12
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I totally agree, and the likely outcome for the next version of RepG will have the bed set slightly higher or to 110C. There's definitely a certain finessing that sometimes needs to be done with this stuff in order to make everything work nice and smoothly. However Id like that to be as little of a requirement as possible so that new users who have zero experience on a printer can get great results. Like you said tho for an out of the box experience It might be better to go with more heat to overcome certain issues.

Past practice has always been to pump more heat into everything, and that will fix the problems. Trying to break old habits is hard but I figured a new platform to start with was as good a place as any to start breaking this habit.

All in all I'm not taking any of the feedback lightly and I'm already looking into a few minor changes for the next release based of what I'm hearing from users. The more input I get the better!

Joseph Chiu

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Apr 10, 2012, 1:12:47 PM4/10/12
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I've read somewhere an idea of using a heater blanket to warm up an
acrylic bed just prior to printing, to get the first layers to stick
and settle in; and that higher layers do not care much about the bed
temperature. Perhaps changing the temperature setting so that it
starts at 110, but once the job starts, to set it to 100 would work to
get that initial stick, but lessen sagging?

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Achilles Boiser

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Apr 10, 2012, 8:53:12 PM4/10/12
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I don't know if this is a figment of my imagination, but I do recall
awhile back seeing a youtube vid on a heated bed platform that had an
orange acryclic plate on top of a metal heated bed. In other words,
the acrylic plate would be directly heated while an object was printed
on top. I thought to myself that the heat should melt the acrylic
plate. However, it didn't.

Herón Ordóñez Guillén

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Apr 11, 2012, 1:55:54 AM4/11/12
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I think the acrylic ends up warping after a while, also the legend says the ABS sticks too good to hot acrylic and it's impossible to remove.... or so they say

Gary Crowell

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Apr 11, 2012, 1:01:00 PM4/11/12
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I've seen lots of comments generally equating 'nail polish remover' with acetone.  There are often oils and alcohol in nail polish remover.  The very same applies when people incorrectly equate 'rubbing alcohol' with with isopropyl alcohol.  I bought a couple bottles of this:  http://www.amazon.com/gp/product/B000EGZ3KM/ref=oh_o05_s00_i00_details   which looks to be pretty much what it says.  $3/16oz bottle, but the shipping was another ~$5.  The same could probably be found at a local beauty supply.

On Mon, Apr 9, 2012 at 12:48 PM, Dan Newman <dan.n...@mtbaldy.us> wrote:

> Any suggestions? I've been cleaning the platform with rubbing alcohol
> between builds.

You'll get better results if you use acetone.  Note that nail polish
remover may not have acetone.  And the ones which do have it quite
diluted. But even the diluted ones are better than using isopropyl
alcohol.  (Or are you using scotch? ;)

...

Dan


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W. Craig Trader

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Apr 11, 2012, 3:55:33 PM4/11/12
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CVS actually carries 100% Acetone, no additives.  Look for it near the nail polish removers.

Gary Crowell

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Apr 11, 2012, 5:56:54 PM4/11/12
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Yeah, I see it on their website:  http://www.cvs.com/CVSApp/catalog/shop_product_detail.jsp?filterBy=&skuId=272389&productId=272389&navAction=jump&navCount=3 
, but no CVS here.  Other pharmacies should have something like it tho.

Gary Crowell

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Apr 11, 2012, 5:58:31 PM4/11/12
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And, I just got notice a few minutes ago that my Replicator has shipped/ yay!

Rob Giseburt

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Apr 11, 2012, 6:00:03 PM4/11/12
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Worst case, any hardware store will have Acetone in the paint section.

Keep the stuff away from your kids. I understand it can be fatal if swallowed...

  -Rob

Peter Leppik

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Apr 11, 2012, 6:48:27 PM4/11/12
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Your local hardware/home improvement store will also carry acetone by the gallon.

Gary Crowell

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Apr 12, 2012, 4:28:08 PM4/12/12
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On Wed, Apr 11, 2012 at 4:48 PM, Peter Leppik <peter....@gmail.com> wrote:
Your local hardware/home improvement store will also carry acetone by the gallon.


... and that shows how clear I'm thinking; I probably have a quart of acetone on the paint shelf in the garage.

 
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