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Polycarbonate printing

Posted by richrap 
Polycarbonate printing
July 12, 2011 07:22AM
Has anyone extruded and/or printed with PC? I really fancy having a go at using it.

Any feedback on using it or worries etc?

http://en.wikipedia.org/wiki/Polycarbonate

Cheers,

Rich.


[richrap.blogspot.com]
Re: Polycarbonate printing
July 14, 2011 08:43AM
It should certainly be possible - the high-end Fortus machines that Stratasys makes can run polycarbonate (they are built to run at higher temperatures than the Dimension series machines).

I'd start by trying a PC-ABS blend (hoping to try that myself once I investigate a few other ABS resins) before attempting straight PC, however.


[haveblue.org]
Re: Polycarbonate printing
July 18, 2011 11:20PM
Thanks, I'll give it a try.

I have one coloured ABS that needs 263 degrees C to extrude, I'm running it fast at 270 so maybe the hot end will manage 290 before meltdown.


[richrap.blogspot.com]
Re: Polycarbonate printing (UPDATED - Sep2011)
September 30, 2011 05:38AM
Hello Everyone,

I have had some PC filament made up and have also done some initial printing with Polycarbonate on a Reprap Prusa mendel.
The full details are on my Blog here
And the video's can be viewed in Hi-Def resolution on YouTube Here.



I'm more than happy to add the info to the Reprap wiki, but I really need some help on how to do it? anyone gut a few mins to show me how to make new pages?

I would like to create a new Wiki Page on Polycarbonate, based on the same sort of page as used for PLA below, can anyone guide me on how to do this on the reprap wiki please?
[objects.reprap.org]

Also maybe add a section for Polycarbonate to this page - [objects.reprap.org]

Also this section (Polymer working group) of this forum has a wiki page - [objects.reprap.org] and it's completely empty! Does anyone think a section for materials testing would be a good idea? I'm in the middle of testing quite a lot of different filament and the printed objects, it would be nice to have somewhere to put up my findings and for others to add, comment and expand on.



Rich


[richrap.blogspot.com]
Re: Polycarbonate printing
September 30, 2011 07:54AM
Congratulations.. Awesome.
I have experience in vacuumforming and extruding Polycarbonate and just can say that it is the worst material to absorb moisture...
Even when thermoforming (vacuum) it is forming bubbles. It is also only possible to bend it on a hotwire without bubbles, if the PC is fresh..
(The protective PE sheet helps only marginally, but it has to be taken off at least on one side for drying..)
When having PC profile extruded they definitely put it into a drying hopper connected to the feeder of the extruder. When I asked I was told that the pellets had to be dried in line. So a seperate dryer wouldnt work..

But considering that the free to air extruded filament is clear I dont thgink that the problem is humidity (You probably had very "fresh" PC)
My guess is that it solidifies very fast so it has not enough time to fill all gaps and you get the white effect. You could maybe try building a chamber around it and heat the printed part ...

Good luck..

For new pages on the wiki: just search for Polycarbonate, when it returns no results it will offer to create a new page... The rest is downhil...smiling smiley


www.reprapfordummies.net
IRC: #reprap on freenode.net (Action68)
[github.com]
Re: Polycarbonate printing
September 30, 2011 08:41AM
Great work Rich.

I think going white is a sign that it has become semi-crystalline rather than amorphous.


[www.hydraraptor.blogspot.com]
Re: Polycarbonate printing
September 30, 2011 11:34AM
Many thanks for the feedback,

I will have a go at the Wiki pages soon.

I think I have a lot more reading to do regarding plastic's, quick google search gives a vast number of resources for semi-crystalline and amorphous Plastic references

A reference to standard testing of thermoplastics is on the Wiki Page at the bottom.

I'm feeling more informed by the minute so I'll experiment more with PC and PC-ABS in a few weeks.

Rich


[richrap.blogspot.com]
Re: Polycarbonate printing
October 03, 2011 02:11AM
Quote

I'm more than happy to add the info to the Reprap wiki, but I really need some help on how to do it?

1. Click on the "edit" link near top of the wiki page.

2. Write.

3. Click on "Save page" button below the edit field.

If you're unsure how to write, find a page similar to what you want, then hit the edit link there and copy the raw text.

To create a new page, type the name of that new page into the search field and click the red link appearing then. Spaces in page names are allowed.


Generation 7 Electronics Teacup Firmware RepRap DIY
     
Re: Polycarbonate printing
October 05, 2011 11:12PM
Rich,
Before you print PC, bake it in your home oven at 82 to 92 degrees C for 1 to 2 hours. It will remove the moisture in the PC Filament. I've never done this with filament, but have with injection molding resin, so you will have to experiment a bit. If you bake it too long or too hot, you will warp the filament. If you do it too short or too cold, it will not remove all of the moisture. PC is quite hydroscopic, when you don't remove all of the moisture, your are creating steam bubbles in your filament which adds to the whitening of the clear PC. PC absorbs moisture from the air. Steam is why Styrofoam is white, but natural polystyrene is clear. It is also why MakerBot is now shipping their filament in HDPE bags with a dessicant pouchs to remove any moisture. No moisture = much improved prints. Too much moisture and no one is happy.

I am currently in the process of setting up my own extruder and have hundreds of KG of GE Lexan PC and a GE Cycoloy 6001 series PC/ABS (about the most expensive made because it is used in Automobile instrument panels, cell phones, and laptops) that I am planning to extrude into filament.

I am also very interested in testing different materials. Everyone seems to be making ABS filament, but no one says what type and brand of ABS they are using. I guess their open source doesn't apply to filament materials. There are thousands of types of ABS from dozens of manufacturers. Even if all filament was using the exact same material, ABS is process sensitive. If you process it wrong, you can turn it into brittle junk, but the filament can still look just as glossy as good filament. If you really process it wrong, it will not look glossy, have pits in the surface and smell REALLY bad when you try and extrude it. I am sure a lot of the black filament is recycled parts, which could have contaminants in the batch and with unknown types of ABS.

Anyway, count me in for material testing. By late November, I should have a whole lab for material's testing.

BTW, the work you have done is quite impressive, your multicolored prints are truly amazing.

Take Care,
Matt
Re: Polycarbonate printing
October 06, 2011 05:16AM
Thanks Traumflug and ahmetcemturan for the Wiki pointers.

I have started a Page on PC here - http://reprap.org/wiki/Polycarbonate

I'm still not sure how to add Photo's or video to the page, so any easy pointers on this would be great, Thanks.

Rich.


Traumflug Wrote:
-------------------------------------------------------
> I'm more than happy to add the info to the Reprap
> wiki, but I really need some help on how to do
> it?
>
> 1. Click on the "edit" link near top of the wiki
> page.
>
> 2. Write.
>
> 3. Click on "Save page" button below the edit
> field.
>
> If you're unsure how to write, find a page similar
> to what you want, then hit the edit link there and
> copy the raw text.
>
> To create a new page, type the name of that new
> page into the search field and click the red link
> appearing then. Spaces in page names are allowed.


[richrap.blogspot.com]
Re: Polycarbonate printing
October 06, 2011 05:28AM
Thanks TreaterBot,

I will certainly give that a go when I experiment again with what's remaining of the test batch.

Let us know how you get on with Lexan /PC extrusion into filament, that would be a very good achievement.

I have most of my issues around using ABS, I have a few different types and between then they are the most different and frustrating to extrude, 'low-cost' ABS from China seems very soft, often not round and sometimes produces a very off looking surface (matt, very fine fluff) looks like it's been sanded, other types work really well (Like Makerbot ABS, expensive but worth it as it actually works in 3D printer extruders)

I would like to see more testing, analysis and general understanding of ABS for 3D printing, I get the impression that Raw ABS is not often used in industry and that it's almost always blended in some form of another. That could be exactly what we need for good 3D printing.

I'm glad you like the Blog, many thanks.

Rich.


TreaterBot Wrote:
-------------------------------------------------------
> Rich,
> Before you print PC, bake it in your home oven at
> 82 to 92 degrees C for 1 to 2 hours.


> I am currently in the process of setting up my own
> extruder and have hundreds of KG of GE Lexan PC
> and a GE Cycoloy 6001 series PC/ABS (about the
> most expensive made because it is used in
> Automobile instrument panels, cell phones, and
> laptops) that I am planning to extrude into
> filament.
>
> I am also very interested in testing different
> materials. Everyone seems to be making ABS
> filament, but no one says what type and brand of
> ABS they are using. I guess their open source
> doesn't apply to filament materials. There are
> thousands of types of ABS from dozens of
> manufacturers. Even if all filament was using the
> exact same material, ABS is process sensitive. If
> you process it wrong, you can turn it into brittle
> junk, but the filament can still look just as
> glossy as good filament. If you really process it
> wrong, it will not look glossy, have pits in the
> surface and smell REALLY bad when you try and
> extrude it. I am sure a lot of the black filament
> is recycled parts, which could have contaminants
> in the batch and with unknown types of ABS.
>
> Anyway, count me in for material testing. By late
> November, I should have a whole lab for material's
> testing.
>
> BTW, the work you have done is quite impressive,
> your multicolored prints are truly amazing.
>
> Take Care,
> Matt


[richrap.blogspot.com]
Re: Polycarbonate printing
October 06, 2011 09:17AM
Rich,

I have been working on a High Heat printer head that is capable of printing PC, PC/ABS, and PET (Polyester aka Mylar, or pop bottles). It will be able to operate at and sustain temperatures of up to 326 degrees C. It's necessary in order to open up a whole lot more plastics for 3D printing. I like the improved MK7 extruder head, but it will smoke and burn if you try and take it up to the suggested temperature range for PC. PC is extremely rugged. It's what bullet resistant glass is (they laminate thin layers together instead of one thick layer).

I am also experimenting with tool steel for the nozzle tips. If you look at professional plastics equipment only use Tool Steel for nozzle tips. Brass is easy to machine, but also easier to scratch, strip, and oxidize and I'm not sure how if it will react to the higher temps. It's a work in progress.

I'll let you know when I produce a test batch of PC and PC/ABS. If anyone else wants to also test new materials, let me know and I will get you some samples too. Have you ever tried Polystyrene or High Impact Polystyrene (HIPS)? It has a melt temp similar to HDPE or PP, but has the shrink factor of ABS and PS has the clarity of PC. I've got a couple thousand lbs of Black, ABS colored Tan, and White.

Do you think I should test both 1.75mm and 3.0mm, or standardize most tests to the same filament size? If so, which one would you choose?

Take Care,
Matt
Re: Polycarbonate printing
October 06, 2011 04:07PM
Quote

I get the impression that Raw ABS is not often used in industry and that it's almost always blended in some form of another.

ABS is already a blend of three polymers so I think the variations start there with the proportions of each.


[www.hydraraptor.blogspot.com]
Re: Polycarbonate printing
October 06, 2011 10:22PM
You are fundamentally right. ABS that is used for extrusion / vacuum forming sheets generally has a much higher Styrene content and a lesser Acrylic content. Styrene is about half to 1/3 the price and it's contribution is much less in thin sheets or thin filaments, but when you try and combine the filaments into a "solid" the brittleness of styrene starts to manifest itself. I would think an injection molding grade of ABS would suit RepRap / RepStrap machines better, they have higher melt flows and generally higher impact values (like a Notched Izod Test - a good place to start when testing impact strength of various polymers you - print the "chip" and hit it).

Case in point, over a dozen years ago I worked for an aggressive skate helmet manufacturer. The local injection molding company that supplied the helmet shells also did ABS thermoformed skins for another local helmet manufacturer and had excess thermoformed ABS trimmings from their shells that they then had to sell as regrind for $0.10/lb. All our helmets were injection molded, not thermoformed. Most helmets were sent to us for painting, a percentage went to our Vacuum Metalizer (to put a mirror finish on them). All helmet shells were made out of black ABS. The injection molder didn't use the new spec'ed high impact ABS material for all of the helmets, only the ones sent to us (where they were impact tested). They processed tens of thousands of helmets using their junk thermoformed regrind ABS and sent them to the vacuum metalizer where they weren't impact tested at all. All so they could replace our $2.80 / lb material with their $0.10 junk. Once X Games skaters had their first fall, the helmets fractured in such away that it appeared to be made of hundreds of shiny serrated knives - not good. The owner's of the company I worked for refused to do a recall or even admit there was a problem so they would save face and cash, and I ended up leaving the company due to their horrible ethics. Selling a "safety" helmet that turns into knives on impact really didn't sit right with me. The point is, unscrupulous processors will pass off junk material as good and charge the same price. I think that most material suppliers are trying their best, but I believe in "Trust, but verify". I don't believe in regulation, just get the data and let the market decide what is acceptable.

ABS also has a large number of additives, like flame retardants, UV inhibitors, colorants, processing agents, etc.... I did testing at an auto factory that I used to work at, and even colorant of different colors affects the shrink factor and impact resistance of otherwise identical parts that were properly processed of new "virgin" resin.

I am going to doing a LOT of testing on the ABS resins currently available. I've got about 3,000 KG currently on my floor of GE Cycolac (AKA the most expensive) resins in about 6 types in both recycled (post industrial, not post consumer) and Virgin Material. GE makes good resins, but they also cost more than Chinese or Korean resins. Are they worth it, who knows? Can't say until all are tested and compared.

Resins are only part of the equation for good parts. Process control is equal or greater than the material you start with. Bad processing of good resin makes bad resin and bad parts. Good processing of bad resin still makes bad parts. Remember, the material that you are running has been processed at least twice (once by the compounder and once by the filament extruder) and maybe much more. If you ruin the process at any stage, you ruin your chance at success. Unfortunately, far too many filament suppliers pass off bad filament at the same price as good. Most times, I believe they don't even know the difference until it is pointed out to them. Anyway, I am going to put number to test batches of each resin source I can get a statistically significant sample from.

I love the MakerBot Thing-O-Matic, but I cringe when they say they are using the same resin that Lego blocks are made out of. True both are ABS resins, but Lego Blocks are very high impact ABS, truly great stuff. Not even the Lego knock offs like Mega Blocks et all are made out of the same resin as Lego Blocks - just hit them with a hammer and it becomes very clear. I am trying to put meaningful hard numbers to the various resins from suppliers to find out the differences. I am also trying to develop processing guidelines for each. Better resins + better processing = better parts and more satisfaction.

Take Care,
Matt
Re: Polycarbonate printing
October 07, 2011 02:23AM
Thanks Matt, That's some good info to work with.

You both make a good point, the mix of A, B and S is the first critical point to understand, then we can investigate if mixing that with other things makes them better or not for 3D printing.

And to reply to the other question about filament size, many people are moving over to 1.75mm filament as the 'standard' I'm using up my 3mm stock and buying more 1.75mm for the future. it's easier to use and it also seems to give better results as long as the diameter is well controlled.

About deviation, if you plan to process and sell filament, you will need very consistent diameter over the length of the filament (Roll). We can change settings for different batches, but it wants to stay the same over a print (roll of material) and don't go over 1.75mm or Bowden extruder setups will have other issues. I would target 1.7mm and expect to stay between 1.65 and 1.75 as the maximum range.

Also, you should register on the Forum, I'm sure many other people will want to keep in contact with you.

Cheers,

Rich.


[richrap.blogspot.com]
Re: Polycarbonate printing
October 07, 2011 07:21AM
Hi Matt, really great having someone who knows the process and materials that good as You.

Regarding filament diameter: I think the development will go into the direction of using less diameter filament (below 2mm).
I really dont know why the filament diameters are so awkward lile 1.5 ish and 2.8ish. Most probably because these diameters are commonly used for some other process... But if I was starting from scratch I would make the diameter 1.90 -1.95 so anyone who has a 2mm drill at home can make himself a quite nice quality control gauge. (You might want to pull the filament through it before trying to jam it into the extruder.)
About the bowden extruders I am not sure whether a 2 or 2.1mm ID bowden cable would be available.. (pls comment)

The advantages of 1.75 (or lets say thinner) filament is definitely that it can be extruded at higher speeds as the surface to volume (or better perimeter to x-section) ratio is much better. When Increasing filament diameter from 1.75 to 2.8mm the x-section increases 2.5 times as opposed to the perimeter that only increases 1.6 times. So the transfer of heat is definitely less effective.

On the other hand I also believe (correct me if I am wrong) that a thinner extrusion (up to a certain dimension of course) is easier to control than a thicker one.. (easier to get homogenous temperature because of above said...)

And last but not least the increased definition for extrusion with thinner filament. When extruding very thin lines this (often neglected) parameter becomes vital. Assume you are extrudimng the perimeter of a hole (d= 5mm, 0.2mm layers, 0.3mm extrusion width, split up into 18 segments) the extrusion distance between vertices would be 0.87mm and the corresponding extruded filament would roughly need a volume of about 0.042mm3. That would correlate to about 0.0022mm of raw filament with 1.75mm and 0.000869mm with 2.8mm. !!!!!
So even if your extruder has an E steps value of 1000 you still dont hit 1 step. (Lower gearing would result in even lower retraction speeds..)

And a bit off topic but strongly related : You are lucky if you are extruder is working with absolute distances as even if the distance is less than one step, it will be covered for in the next step that reaches that threshold.
If you are running relative distances with your extruder...... Well the information is lost then...


www.reprapfordummies.net
IRC: #reprap on freenode.net (Action68)
[github.com]
Re: Polycarbonate printing
October 13, 2011 01:02PM
TreaterBot Wrote:
-------------------------------------------------------
> I am also very interested in testing different
> materials. Everyone seems to be making ABS
> filament, but no one says what type and brand of
> ABS they are using. I guess their open source
> doesn't apply to filament materials.

Matt, this is precisely what has annoyed me when looking into materials - everyone says 'ABS' when we really need to be far more specific and know the precise resins in use. Chi Mei PA-747 is what Makerbot and pretty much every other US filament vendor sells as 'ABS', yet it runs much more poorly than Cycolac MG47. Both are ABS, but referring to them solely in that way causes a great deal of confusion when people expect that one ABS will run just like another (which is exactly what I thought at first before diving much deeper into researching materials). I'd love to see vendors actually note right on the product page what exact resin their filament is made from (and as long as I'm wishing, I'd like to see them note tolerances as well).

Rich, great work with the polycarbonate! So, uh, which resin was used? :-)


[haveblue.org]
Re: Polycarbonate printing
October 13, 2011 11:00PM
Ahh, the great relative/absolute filament extrusion debate.

I have extensively run both methods at this point, and have noticed absolutely no difference of quality either way.
It may seem like a big issue in theory, but in practice the ooze rates and general mechanical slop and delay appear to be much greater contributors to defects. Also, I have much more freedom to hand-alter the g-code in relative extrusion terms.

I'm not convinced the firmware doesn't deal with them properly already, though. If I send 1000 1/1000th of a step extrude commands, does the firmware round each one down to zero, or does it internally sum them up and send a pulse when appropriate? (I really don't know, but the guys writing the firmware all seem pretty sharp to me) Maybe this warrants a test.




ahmetcemturan Wrote:
-------------------------------------------------------
> Hi Matt, really great having someone who knows the
> process and materials that good as You.
>
> Regarding filament diameter: I think the
> development will go into the direction of using
> less diameter filament (below 2mm).
> I really dont know why the filament diameters are
> so awkward lile 1.5 ish and 2.8ish. Most probably
> because these diameters are commonly used for some
> other process... But if I was starting from
> scratch I would make the diameter 1.90 -1.95 so
> anyone who has a 2mm drill at home can make
> himself a quite nice quality control gauge. (You
> might want to pull the filament through it before
> trying to jam it into the extruder.)
> About the bowden extruders I am not sure whether a
> 2 or 2.1mm ID bowden cable would be available..
> (pls comment)
>
> The advantages of 1.75 (or lets say thinner)
> filament is definitely that it can be extruded at
> higher speeds as the surface to volume (or better
> perimeter to x-section) ratio is much better.
> When Increasing filament diameter from 1.75 to
> 2.8mm the x-section increases 2.5 times as opposed
> to the perimeter that only increases 1.6 times.
> So the transfer of heat is definitely less
> effective.
>
> On the other hand I also believe (correct me if I
> am wrong) that a thinner extrusion (up to a
> certain dimension of course) is easier to control
> than a thicker one.. (easier to get homogenous
> temperature because of above said...)
>
> And last but not least the increased definition
> for extrusion with thinner filament. When
> extruding very thin lines this (often neglected)
> parameter becomes vital. Assume you are
> extrudimng the perimeter of a hole (d= 5mm, 0.2mm
> layers, 0.3mm extrusion width, split up into 18
> segments) the extrusion distance between vertices
> would be 0.87mm and the corresponding extruded
> filament would roughly need a volume of about
> 0.042mm3. That would correlate to about 0.0022mm
> of raw filament with 1.75mm and 0.000869mm with
> 2.8mm. !!!!!
> So even if your extruder has an E steps value of
> 1000 you still dont hit 1 step. (Lower gearing
> would result in even lower retraction speeds..)
>
> And a bit off topic but strongly related : You are
> lucky if you are extruder is working with absolute
> distances as even if the distance is less than one
> step, it will be covered for in the next step that
> reaches that threshold.
> If you are running relative distances with your
> extruder...... Well the information is lost
> then...


www.Fablicator.com
Re: Polycarbonate printing
October 14, 2011 12:57AM
Hi Andrew,

> I have extensively run both methods at this point,
> and have noticed absolutely no difference of
> quality either way.
In regular extrusion as long as your E values are within the "chew-size" of the FW thats true. I fully agree.
>
> I'm not convinced the firmware doesn't deal with
> them properly already, though. If I send 1000
> 1/1000th of a step extrude commands, does the
> firmware round each one down to zero, or does it
> internally sum them up and send a pulse when
> appropriate?
Well I tried it out thats why I am concerned. (Take the Hellokitty face file here: http://dl.dropbox.com/u/38819298/HK_20mm.stl and skein it at 0.2*0.2 mm
then look at the last layers perimeter.,
With absolute E values and Extra decimals set to 2
******
( outer )
G1 X104.6291 Y99.5811 Z6.2 F900.0 E0.0002
G1 X104.661 Y99.5897 Z6.2 F900.0 E0.0003
G1 X104.6931 Y99.7183 Z6.2 F900.0 E0.0003
G1 X104.6865 Y100.1821 Z6.2 F900.0 E0.0003
G1 X104.6576 Y100.2293 Z6.2 F900.0 E0.0003
G1 X104.5446 Y100.2123 Z6.2 F900.0 E0.0003
G1 X104.5033 Y100.1354 Z6.2 F900.0 E0.0003
G1 X104.4691 Y99.9138 Z6.2 F900.0 E0.0003
G1 X104.473 Y99.7529 Z6.2 F900.0 E0.0004
G1 X104.5045 Y99.6398 Z6.2 F900.0 E0.0004
******
And all same settings just extrusion changed to Relative distances.
( outer )
G1 X104.6291 Y99.5811 Z6.2 F900.0 E0.0
G1 X104.661 Y99.5897 Z6.2 F900.0 E0.0
G1 X104.6931 Y99.7183 Z6.2 F900.0 E0.0
G1 X104.6865 Y100.1821 Z6.2 F900.0 E0.0
G1 X104.6576 Y100.2293 Z6.2 F900.0 E0.0
G1 X104.5446 Y100.2123 Z6.2 F900.0 E0.0
G1 X104.5033 Y100.1354 Z6.2 F900.0 E0.0
G1 X104.4691 Y99.9138 Z6.2 F900.0 E0.0
G1 X104.473 Y99.7529 Z6.2 F900.0 E0.0
G1 X104.5045 Y99.6398 Z6.2 F900.0 E0.0

And Extra Decimals set to 4:
absolute:
( outer )
G1 X104.629137 Y99.581152 Z6.2 F900.0 E0.000249
G1 X104.661083 Y99.589734 Z6.2 F900.0 E0.000251
G1 X104.693155 Y99.718223 Z6.2 F900.0 E0.000262
G1 X104.686558 Y100.182052 Z6.2 F900.0 E0.0003
G1 X104.657666 Y100.229229 Z6.2 F900.0 E0.000304
G1 X104.544659 Y100.21229 Z6.2 F900.0 E0.000314
G1 X104.503349 Y100.135409 Z6.2 F900.0 E0.000321
G1 X104.469215 Y99.913782 Z6.2 F900.0 E0.000339
G1 X104.473112 Y99.752913 Z6.2 F900.0 E0.000352
G1 X104.504506 Y99.639768 Z6.2 F900.0 E0.000362
relative:
G1 X104.629137 Y99.581152 Z6.2 F900.0 E2.3e-05
G1 X104.661083 Y99.589734 Z6.2 F900.0 E3e-06
G1 X104.693155 Y99.718223 Z6.2 F900.0 E1.1e-05
G1 X104.686558 Y100.182052 Z6.2 F900.0 E3.8e-05
G1 X104.657666 Y100.229229 Z6.2 F900.0 E4e-06
G1 X104.544659 Y100.21229 Z6.2 F900.0 E9e-06
G1 X104.503349 Y100.135409 Z6.2 F900.0 E7e-06
G1 X104.469215 Y99.913782 Z6.2 F900.0 E1.8e-05
G1 X104.473112 Y99.752913 Z6.2 F900.0 E1.3e-05
G1 X104.504506 Y99.639768 Z6.2 F900.0 E1e-05

The FW handles the Exp expression but all of these values remain below the threshold of a stepper move.
As the FW does not add up the previous values in any way they are just lost.
In Absolute extrusion assuming your Stepper steps at 1/1000 mm you would at least get "some" movement in every 4th command..


www.reprapfordummies.net
IRC: #reprap on freenode.net (Action68)
[github.com]
Re: Polycarbonate printing
October 26, 2011 03:41PM
I think the polycarbonate prints would have more warp than abs, am i right about this? I didnt had a chance to test PC, but that would be my impression.

I also noticed a mix of ABS+PC - how about that? Maybe it would increase the abs strength without warping too much in exchange.

Anybody tried that?
Re: Polycarbonate printing
October 26, 2011 11:41PM
Polycarbonate has the same shrink factor as ABS at 0.007inch per inch (or mm per mm), so I don't see why it would warp any more. In comparison, HDPE and PP can shrink up to 2% - very huge! To run PC you would need to modify (or severely alter) most of the extruder / hot ends available in order to boost the heat high enought run it. PC/ABS on the other hand could be run at about 25-35 degrees C hotter than ABS, so it possibly could be run with most extruder designs currently used (without melting the cold end).

PC/ABS is a great material, it's impact resistance is why cell phones, dash boards, and laptops are made out of it.

I saw that Nophead has tried acrylic, but haven't seen if anyone else has tried it. I would be curious to know the brands and grades of Acrylic that have been tried. I have some Atofina Plexiglass V052 (their injection molding grade Acylic). If Acrylic can be used, this is the grade. The other acrylic filament rods that is available is an extrusion grade, very slow moving stuff.

I'm also curious if anyone has tried either High Impact Polystyrene, or regular Crystaline Polystyrene? Their shrink factor is the same as ABS, and PS adheres very well to itself. Straight PS is clear, and could be used for light refractions in things like Christmas Ornaments, etc... PS is also Non-Hydroscopic, it requires no drying for processing into filament and wouldn't absorb moisture over time to degrade it's performance.

In the next couple of weeks, I will be extruding some PC, PC/ABS, Acrylic, HIPS, and ABS resins into 1.75mm filament for testing. I have selected grades that I believe have the most favorable specs for being able to extrude them for 3D prints. Anyway, if anyone is interested in testing any of these, let me know.

Oh, my disclaimer: "I break things in order to make better things."
Re: Polycarbonate printing
December 01, 2011 03:37PM
This is really awesome. Any idea where I can get some of this filament?
Re: Polycarbonate printing
December 22, 2011 02:55AM
Hey guys,
We'll have an official post up going over our experience with PC soon but we did add Polycarbonate to our product lineup. The current listing is a pre-order and will ship January 30, 2012. Shipping within the US is included in the price with world wide shipping available for an extra $9.00. The filament is extruded to standard 3mm and 1.75mm so no more trouble dealing with 1/8" or 1/16" (that was the 1.6mm people were using).
Find it here:

1.75mm PC

3mm PC

Happy Printing

Luke
luke(at)protoparadigm(dot)com

Edited 1 time(s). Last edit at 01/02/2012 02:45AM by ProtoParadigm.
Re: Polycarbonate printing
December 28, 2011 10:32AM
What resin are you using for the PC filament? (Thank you for posting the resin info for your ABS and PLA!)


[haveblue.org]
Re: Polycarbonate printing
January 01, 2012 09:02PM
The sample we worked with was Lexan 143R, when we saw the mold release we had our supplier source what should be the same resin minus said mold release agent with the hopes of improving stick to print bed and interlayer adhesion.
Re: Polycarbonate printing
January 02, 2012 02:44AM
Hi again,

Here is a link to our post about printing with polycarbonate.


We've been really impressed with its properties.

Good luck!

Alex
Re: Polycarbonate printing
January 03, 2012 02:45PM
Looks promising - just ordered a coil to test out on the Stratasys.


[haveblue.org]
Re: Polycarbonate printing
June 25, 2012 09:00PM
Got some of the ProtoParadigm PC today and did up a few prints. Pretty significant warping and very poor layer adhesion on all counts. Printed it at a variety of temps (90C-120C bed temps and 260C-330C Extruder temps.) I also tried different bed materials combinations (glass, abs solution, Kapton)

It extrudes wonderfully, but I just can't get it to behave at all so far.

Any thoughts or similar experiences?


www.Fablicator.com
Re: Polycarbonate printing
June 25, 2012 10:23PM
Question time! :-)

What layer heights/widths

Feed-Rate?

Printer?

Hotend?

It seems the thicker, wider layers definitely help with adhesion. Doing so increases the flowrate which can increase the required temperature. One trick is to go slow and print as cool as possible, this is especially true if you aren't using a heated chamber. It seems the sharp temperature differential makes the PC want to contract, heat up the air or lowering the extrusion temp seems to help. Seemingly contradictory, so can a fan. A fan blowing warm air can get some of that contraction all done and out of the way so it doesn't happen after you've got a nice long printed trace trying to buckle your print.

As for the heated bed, hotter is better but not required. I'm able to get decent sized prints done on the Ultimaker using an ABS/acetone slurry painted before hand. Though you said you've already tried that; does the PC detach from the Kapton with the ABS Slurry, or does it pull the Kapton tape off the bed?
Re: Polycarbonate printing
June 26, 2012 04:10PM
Answers!

Feed-Rate 25mm/s perimeter, 50mm/s fill, 200mm/s travel.

Printer: Fablicator

Hotend: Custom, .35mm orifice, direct drive, 1.75mm filament. No problem maintaining 330C.

I've been doing everything pretty much exactly the same as ABS (no fan, 120C bed, .4mm width, .25mm thick layers)

How big is "Decent Size?" I pull the Kapton right off the bed on all but the smallest prints.

Have you tried doing thin walled parts like the stratasys twisted bottle?

Thanks,

Andrew


www.Fablicator.com
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