Comments on RepRap: Blog: Foundations

I made one and got about 1mm curl so possibly I ca...

2008-08-01T19:34:36.821+01:00

I made one and got about 1mm curl so possibly I can improve on that by reducing the speed.

If you stress relieve in an oven, you will releave...

2008-07-29T15:02:34.740+01:00

If you stress relieve in an oven, you will releave stresses. In releaving the stress, the thing will probably warp in even more ways.
I assume the warping results from laying a hot layer on top of a cold one that has already shrunk - as the new hot one cools it contracts and so the combined beam is warped up at the ends.

The solution is to keep all the layers hot and contract the completed part as a whole = even contraction = hopefully no warping.

"Thanks Forrest. Now. Enough with the Bible quotes...

2008-07-29T01:53:21.980+01:00

"Thanks Forrest. Now. Enough with the Bible quotes, already."

ROTFLMAO! :-D

I've been meaning to try putting it in an oven jus...

2008-07-28T21:57:53.522+01:00

I've been meaning to try putting it in an oven just below the melting point to relax it before removing it from the raft. The problem is that my base materials melt at the same temperature so would probably warp themselves. Now you have got it to stick to balsa that should be possible.

PS. The file is http://reprap.svn.sourceforge.net...

2008-07-28T21:23:49.598+01:00

PS. The file is

http://reprap.svn.sourceforge.net/viewvc/reprap/trunk/reprap/mechanics/polymer-extruder/AoIs/motor-holder.aoi

There are two objects in there; you want the flat one called

motor-coupling-direct-drive

"Every valley shall be exalted, and every mountain...

2008-07-28T21:19:27.517+01:00

"Every valley shall be exalted, and every mountain and hill shall be made low: and the crooked shall be made straight, and the rough places plain."

Thanks Forrest. Now. Enough with the Bible quotes, already.

The black ABS came from:

http://www.plasticweldingequipment.co.uk/

It was £18 a kilo, so not the cheapest.

Like Henry F. they said I could have any colour I wanted as long as it was black...

I've just measured my pancake. It does have a slight curl: 0.6mm in a length of 50mm. And Nophead is right: it developed that quite a while after I separated it off. It was flat when I first made it to within 0.2mm.

Conditions: my thermistor reckons that the barrel temp is 200 C, and I'm laying down the material with an XY head speed of 420 mm/min (thanks to Zach's stirling efforts at making all the code work in real units internally on his way to the G-code stuff). I'm using the geared extruder with the PWM mark set to 215/255; I don't know what that is in ml/min; as soon as I get some more pins on a bigger Arduino I'll implement Nop's extruder feed control - the hardware (slotted disc + optoswitch) is all in place.

Yeah, nophead like myself is dying to print those ...

2008-07-28T20:04:06.114+01:00

Yeah, nophead like myself is dying to print those black chess pieces :P

LOL! I'd have thought that Isaiah 40:4 would have ...

2008-07-28T19:31:47.252+01:00

LOL! I'd have thought that Isaiah 40:4 would have been more appropriate! I guess that's just me and HDPE, though. :-p

If the separation isn't destructive, perhaps a who...

2008-07-28T18:01:21.222+01:00

If the separation isn't destructive, perhaps a whole-range, re-usable foundation would use less material in the long run?

Along those lines: understanding separation would also make the platform replicable, naturally.

BTW, where did you get the black ABS from?

2008-07-28T17:20:13.129+01:00

BTW, where did you get the black ABS from?

Is it still flat after a day off the raft?I wouldn...

2008-07-28T13:16:47.148+01:00

Is it still flat after a day off the raft?

I wouldn't describe anything I make more than 20mm across as "flat as a pancake". There is always some visble warping.

I also find Balsa is not strong enough for ABS but here you show that it is and BruceW is using anti-stat foam successfully I think.

It leads me to believe that I get more warping than the standard RepRap setup for some reason.

Please can you point me to the file and describe the build parameters so I can try a comparative test.

Yup - that was printed on balsa. I set the initia...

2008-07-28T12:29:32.809+01:00

Yup - that was printed on balsa. I set the initial layer so the head was only 0.1mm above the balsa. That forced material into the grain, giving a good bond.

One more thing Adrian, are you using balsa wood fo...

2008-07-28T12:09:38.095+01:00

One more thing Adrian, are you using balsa wood for ABS as well? I knew it worked for some plastics (either PCL or PLA if I recall correctly)...

If so, I think I'll order some.

That's great. skeinforge is still a bit exotic to ...

2008-07-28T12:03:44.193+01:00

That's great. skeinforge is still a bit exotic to me, even though I usually prefer modular CLI tools over GUI.

I'll try it as soon as my extruder works again. Don't know when that will be though...

Nice to see a different color for a change (neither black nor white can officially be called colors...).