SoliForum - 3D Printing Community — Polycarbonate

Re: Polycarbonate

2014-06-09T23:35:17Z

Unfortunately, there was no additional documentation on the type of PC, other than the Jupilon label. If you know of another source of PC, please let me know!

Also, I haven't been able to get it to print without warping. I managed to get it to stick to the bed using superglue on blue tape, but it just ended up pulling up the tape. I tried superglue on glass, and it didn't stick at all. I tried higher strength adhesive green tape, and it still pulled up the tape. I'm going to give garolite one last try, but I'm about to give up on this particular batch of PC...

Re: Polycarbonate

2014-06-09T16:04:39Z

Did you figure out which grade of PC you were using?
I am looking at buying some PC and was wondering if you would recommend that grade or another?
Thx

Re: Polycarbonate

2014-05-31T22:37:11Z

https://imgur.com/a/Pgpjn Here's some pictures of my print as well as the setup I found that works.

Re: Polycarbonate

2014-05-30T22:07:01Z

Nice! Looking forward to pictures.

Re: Polycarbonate

2014-05-30T18:06:23Z

Well, I'm happy to report that printing this extruded PC looks great! It comes out very clear (far more clear than the transparent PLA i've printed with), and it's SUPER strong. I needed pliers to break a piece that was less than 1mm thick.

I initially had problems getting it to stick. I tried it on PET tape, blue tape, with and without raft, and they all lifted up after just a few layers. However, on suggestion here: http://reprap.org/wiki/Polycarbonate, i put down some superglue over the blue tape, and it's looking pretty good. I'm printing at 270 C, 120 C bed right now. I will take pictures once this print is finished!

Re: Polycarbonate

2014-05-30T17:04:26Z

Pulling out an auger jammed in a bent barrel with hardened plastic is almost worth $12 by itself, without getting a new barrel in the bargain.

Re: Polycarbonate

2014-05-30T16:50:41Z

$12 got my twisted barrel removed and new barrel made!

Re: Polycarbonate

2014-05-30T15:54:22Z

If there's some space in the thrust bearing stack, what you described would happen. Also, the nylon bushing "beds in" to the flange, and will allow a few mm of axial translation. This is why it is recommended in the instructions to leave a few mm gap in the hex socket.

Also, I am jealous that $12 gets you a single new barrel, machined and all.

Re: Polycarbonate

2014-05-30T15:41:48Z

What happened to me was that as the pressure in the barrel grew, the auger slide back toward the motor and the plywood uprights bent out into a 'V' shape. It is completely possible that I had some or many misconfigurations, but the design is pretty straight forward. I have v1.5 and thinking about it now, there must have been some space between the nylon bushing and the rear flange in order to have pushed out without moving the shaft collar.

The recycled ABS/PC pellets are irregularly shaped and a good portion of them are ~10mm on one side, which also added to the increased pressure. So it is no mystery to me that I tore it apart. When the barrel twisted, i took it down the block to a machine shop. They cut it apart, checked the auger (not bent!), and made me a new barrel with a slightly smaller opening for the hopper to give it a little more strength. So two hours and $12USD later I was up and running again.

Re: Polycarbonate

2014-05-30T05:03:50Z

IanJohnson wrote:

If the shaft collar isn't up against the beginning of the auger flutes, it relies on the set screw to hold it in place. If that is the case, the auger can get pushed hard enough to slide through the shaft collar and either try to push the motor out the back or push the barrel out the front. I struggled with the Randolph case trying to destroy itself in that manner until I got everything positioned just right.

v1.4/1.5 uses full clamping shaft collars, no more set screws. Actually the shaft collar is undersized slightly so it grips even harder. If one of those is sliding then it either wasn't tightened or I'd guess thrust loads are exceeding 300lbs.

Re: Polycarbonate

2014-05-30T04:55:13Z

If the shaft collar isn't up against the beginning of the auger flutes, it relies on the set screw to hold it in place. If that is the case, the auger can get pushed hard enough to slide through the shaft collar and either try to push the motor out the back or push the barrel out the front. I struggled with the Randolph case trying to destroy itself in that manner until I got everything positioned just right.

Re: Polycarbonate

2014-05-30T01:40:04Z

Glad it worked out for you after its trip south of the border, back, and down again!

What you mean mean "pushed the auger out through the back"? That's a 1/4" steel flange...

Re: Polycarbonate

2014-05-30T01:36:58Z

I ran a batch recycled ABS/PC mixed at 80/20 after my initial purge. It came out fast at 220C, prone to kinks, was was very stiff and almost burnt looking once cooled. It came slow at 180C (3 in/min), but the pressure was too much. First it pushed the auger out thru the back. So I refortified it, and it twisted the barrel like taffy at 190C. So then I mixed a new batch of virgin/recyced at 50/50 by volume and it comes out very well (7 in/min) at 195C..

Re: Polycarbonate

2014-05-29T23:38:04Z

I think I just had a minor breakthrough. With the extruder propped up about 30 degrees, I let it extruder about 1 coil's worth of filament down onto the ground. Then I took the coil and fed it through the winder, which doesn't cause any kinks. I let the winder do its thing until it catches up. This seems to successfully allow both extruding and coiling!

Downside is, since I have to let extrude off a table, the filament is very thin, 1.35mm or so. However, it remains very glassy. I will print with it very soon and see how it goes! Also, the filament is very very stiff, to the point that my winder is having trouble winding it. It makes a rather odd crackling noise as it winds. I might have to jack up the voltage on the winder a bit...

Tim, I don't actually have a real filastruder -- I built mine back when the filastruder still had a 6 week lead time and I was impatient. It's very close to your design, except I used a pair of leftover cartridge heaters held against the coupling with a metal zip tie. This design is much less elegant, but it does have plenty of power. It doesn't need any additional insulation or voltage to hit 260 C. I might try cooling the barrel with a fan though.

Re: Polycarbonate

2014-05-29T22:30:50Z

You could cool the barrel with a fan. Are you still powering the heater with 12v? Have you added barrel insulation?

Running horizontal, did you try moving the filament guide closer to the nozzle, and possibly cutting off an inch or so of the base? That should make ramen less likely.