Filament
July 24, 2008 06:13AM
Hi smiling smiley where i can buy a abs filament? As i am protuguese, how i do it in the best way? thank you
Ru
Re: Filament
July 24, 2008 07:35AM
I believe a couple of european reprappers purchased ABS filament from the rrrf, though of course you'll pay a bit extra for shipping from the US. There is a UK supplier, but they aren't very cheap and you'll probably have to pay quite a bit for postage from there, too.

As for local suppliers, you'll have to search for those yourself, I suspect winking smiley The product is called 'plastic welding rod'. You'll have to translate that one yourself too.

Best of luck!
VDX
Re: Filament
July 24, 2008 08:25AM
Hi Bruno,

... maybe you can find something here: [www.orbi-tech.de]

The norm-diameters is 4mm, but they can extrude any size ...

Viktor
Re: Filament
July 24, 2008 09:02AM
I got a quote from New Image Plastics in the US as recommened by Forrest. It is $7.95 per pound and an estimated cost to send 10 pounds to the UK is $50.00 via USPS.

That makes it cheaper than buying it locally even for 2Kg. They also offer any colour.


[www.hydraraptor.blogspot.com]
Re: Filament
July 24, 2008 09:04AM
Keep in mind that New Image likes to sell in minimum rolls weighing 5 lbs. That's a touch over 2 kg.

Edited 1 time(s). Last edit at 07/24/2008 09:06AM by Forrest Higgs.
Re: Filament
July 24, 2008 09:47AM
Yes I will buy 10 pounds in two colours for $129.50 ~


[www.hydraraptor.blogspot.com]
Re: Filament
July 24, 2008 09:53AM
Sounds like it is a break even thing for UK.
Re: Filament
July 24, 2008 12:17PM
It is also known as plastic welding CORD. I dont know how that translates into Portugese though.
I assume rod is usually associated with thicker, rigid fixed lenghts of stuff.
Re: Filament
July 24, 2008 07:15PM
A supply of filament is the one thing that has been holding my repstrap progress back. I've given up making rod from CAPA granules, as it is never a consistent thickness and therefore causes the extrusion rate to randomly fluctuate.

I've noticed Ian is now stocking the following at bitsfrombytes:
HDPE
LDPE
UPVC
PP
(all
Re: Filament
July 24, 2008 07:20PM
HDPE is the only one of those that I have a lot of experience with. It has a lot of warping problems, too. You really need ABS.
Re: Filament
July 24, 2008 08:20PM
greenarrow,

No I haven't used anything but PCL, PLA, HDPE and ABS. I imagine LDPE will not make very rigid objects.

The melting point is the point where it just starts to flow but is very viscous. As the temperature increases above that, the viscosity decreases. HDPE is still viscous at 240C but when you burn it it drips like candle wax so it does get a lot less viscous when you get hot enough.

PLA rapidly gets less viscous and you can get it running out of the nozzle under gravity like syrup. I.e. you can get it too hot to extrude as a filament.

If you can only get 140C I think PCL is your only option.


[www.hydraraptor.blogspot.com]
Re: Filament
August 06, 2008 01:31PM
I got 2kg of 3mm ABS from Tempatron but it is very oval, up to 3.5mm in places so I don't think it will work in my existing extruder.


[www.hydraraptor.blogspot.com]
Re: Filament
September 17, 2008 10:14AM
I ordered 10 lbs of ABS from New Image Plastics @7.95 / lb. I actually got about 4.9Kg.

Shipping was $58.50 and took 11 days to the UK.

I didn't have to pay VAT or import duty, seems completely random whether you do or not (the value was correctly declared on the customs form). Total price charged was $138 which came out at


[www.hydraraptor.blogspot.com]
Re: Filament
September 17, 2008 11:00AM
I've found New Image a pleasure to work with if you're not in a big hurry.
Re: Filament
September 25, 2008 11:29AM
I'm looking for a German supplier for ABS filament. I've found various places able to sell me filament, but they mostly seem to have 4mm thickness. Am I right in thinking that I'd be better off with 3mm?

Many places seem to have 220mm lengths rather than spools - I'm guessing this is going to be too short to be of practical use?

Assuming I definitely want 3mm on a spool, I'll start e-mailing people for quotes and report back.
Re: Filament
September 25, 2008 11:32AM
Jon Bright Wrote:
-------------------------------------------------------
> I'm looking for a German supplier for ABS
> filament. I've found various places able to sell
> me filament, but they mostly seem to have 4mm
> thickness. Am I right in thinking that I'd be
> better off with 3mm?
>
Yes, unless you want to design your own extruder for 4 mm. It could be done, mind.
>
> Many places seem to have 220mm lengths rather than
> spools - I'm guessing this is going to be too
> short to be of practical use?
>
In my opinion, definitely.
>
sid
Re: Filament
September 25, 2008 12:17PM
check here:
[forums.reprap.org]

hdpe filament is available in 3mm spools

still searching for abs though

'sid
Re: Filament
September 26, 2008 07:03AM
Sid, yeah, I saw that thread. I definitely wanted to go with ABS, though - its properties seem to be better all round. If I end up getting nowhere finding ABS, I'll fall back on HDPE. At the moment, I'm still in the process of building my McWire and I only ordered my extruder yesterday from bitsfrombytes, so I've got some time to do some searching before I need to have plastic.
Re: Filament
October 06, 2008 04:32PM
I've now investigated various possibilities and have decided for now to order from New Image Plastics. I've had a quote from someone in England who would be prepared to produce 3mm ABS, but only with a minimum order of 5km, which is apparently about 37kg (81.5lbs). Rough cost: 600GBP.

New Image: $7.95/lb = $17.53/kg = 10.04GBP/kg
English quote: $12.83/lb = $28.30/kg = 16.21GBP/kg

For the New Image stuff, I'll potentially have to pay 19% German VAT, making the comparison

New Image: $9.46/lb = $20.86/kg = 11.95GBP/kg

There's then delivery, of course. Overall, the English stuff probably works out about the same price as ordering from New Image (I can get it from England myself) - but New Image wins through on minimum order volume and being a known quantity, quality-wise. If nobody else has by the time I'm through this plastic, I'll seek quotes from German producers and see if I can't get some reasonable price for reselling to at least German and English reprappers.

On that subject, it would be interesting to know how long the 15lbs I plan to order is going to last me. I'm currently building my repstrap, so my first task is going to be configuration and then printing my reprap. I'm guessing 15lbs is enough to do this a couple of times over?
Re: Filament
October 06, 2008 04:39PM
You're going to spend more than a few pounds of plastic just calibrating your system and getting it working acceptably.

I hope you factored in shipping into those costs you were quoting.
Re: Filament
October 06, 2008 06:28PM
Hi Forrest,

I only mentioned shipping in the abstract ("There's then delivery, of course") because it'll vary non-linearly with size of shipment and destination. If I factor in delivery on a 15lb order to Germany, I get to

New Image: $12.42/lb = $27.38/kg = 15.69GBP/kg

Or, with German VAT:

New Image: $14.78/lb = $32.58/kg = 18.67GBP/kg

Although the price with VAT is more than the English price, I'm happy enough to accept that for my first purchase in exchange for getting a known quality and a smaller minimum order.

When you say more than a few pounds, how much are we talking about? I'd like to have enough for calibration and printing parts for a Darwin (with the attendant losses and being prepared to do quite some amount of manual cleanup), so if 15lbs isn't going to be enough to do that, I'd prefer to do a larger order now...

The actual amount needed will obviously be a matter of how accurate my Repstrap turns out being, how much calibration it needs and my personal competence, but a ballpark figure would be handy. Having no previous printing experience, it's difficult to say whether 15lbs is a large amount or not...
Re: Filament
October 06, 2008 06:41PM
15lb is a lot. I used 5lb to do all my calibration and experiments and make a set of Darwin parts. I do make most of my objects with only 25% fill though so YMMV.

I would recommend getting plain to start with. Coloured ABS from NIP seems to be more difficult to work with.

I am also finding the diameter varies between about 2.7mm to 3mm, which is a pain. The most consistent ABS I have had so far was from Zach at the RRRF. It was consistently 2.75mm.

If anybody has an idea how to measure the cross sectional area on the fly as it enters the extruder I am all ears.


[www.hydraraptor.blogspot.com]
sid
Re: Filament
October 06, 2008 07:36PM
Rollerways: two ball bearings, one fixed one "clamping" the clamping mounted an an arm that is connected to a poti.

pro: easy to do
cons: measures only one point and looses any ovalness (is that the right word?)
accuracy depends on the poti maybe smaller changes are not even measurable (oh dear, is that right?... I'm sorry, close to braindead)

Optics:
It is possible with one or two webcams and proper software, please don't ask me how;
it's done in commercial sorting machines, Never saw software like that somewhere for free (or available at the net)

pro: no moving nor touching parts
very fast very accurate
cons: very hard to find software
even harder to program yourself I'd guess sad smiley

'sid
VDX
Re: Filament
October 07, 2008 03:19AM
Hi sid,

some years ago i did some tests with a low-cost (DIAS, 650
VDX
Re: Filament
October 07, 2008 04:08AM
... i've found the sources (and some aditional too):
- ICE - free C-library and tools for IR: [www.inf-cv.uni-jena.de]
- DIAS - maybe now for free too?: [www.inf-cv.uni-jena.de]
- VIGRA: - IR-package from University of Hamburg: [kogs-www.informatik.uni-hamburg.de]
- and the CImg-library: [cimg.sourceforge.net]

Viktor
Re: Filament
October 07, 2008 04:11AM
Sid,
It's easy to measure the diameter in one direction, but filament is quite often oval so we would have to measure at least the minumum and maximum diameter and assume an ellipse to calculate the area.

Edited 1 time(s). Last edit at 10/07/2008 04:59AM by nophead.


[www.hydraraptor.blogspot.com]
VDX
Re: Filament
October 07, 2008 05:07AM
... it's no problem to measure both diameters with one web-cam, when you arrange two mirrors behind the filament - so you have two perpendcular sides of the filament in one image and have only to measure the distances of the border-lines ...

here a sketch of the setup:


Viktor

Edited 1 time(s). Last edit at 10/07/2008 05:09AM by Viktor.
Re: Filament
October 07, 2008 06:05AM
As the filament isn't aligned with the axis we might need more mirrors I think.

Or we could slowly rotate the camera, as the filament moves very slowly and it's dimensions change even slower.

The camera could be a one dimensional ccd array out of a scanner, I am sure I have some of those, no idea how easy they are to use.

For a low tech Repable solution we could have ball bearings pressing against the filament, mounted on something that slowly rotates in a semi circle. One ball could be on an arm that amplifies the movement up to a scale that we could measure with a linear encoder.

Perhaps we could just pass the filament through an aperture with a light source behind and then diffuse the resulting shadow with the light that gets round the edge so that the average intensity is a measure of how much smaller the filament is than the aperture.


[www.hydraraptor.blogspot.com]
VDX
Re: Filament
October 07, 2008 06:41AM
Hi Chris,

... AFAIK the web-cam/ICE-solution actually should be the simplest and cheapest solution, as you can use any web-cam/video-grabber you have at hand. My cheapest web-cam was 20 Euros and an USB-videograbber around 40 Euros - some PC's have built-in grabbers.

With a line-cam (e.g. salvaged from a scanner) you need the right software or videograbber to work with ...

With rough feeding the filament beside the mirrors (e.g. two wire-loops) there's no need for aditional mirrors or ball-bearings - the IR-software is capable of 'ignoring' the displacement of the filament, as it's only measuring the relative distances of the contour-lines.

Viktor
Re: Filament
October 07, 2008 06:49AM
Possibly a crazy idea but; as we are interested in measuring volume could we measure displacement?



I'm not sure what liquid would be good to use, several of the plastics need to maintain a low moisture content so water isn't an option. I'm also thinking that creating a good seal would be quite hard, hence the 'bath' idea.
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