551

Re: Filament Extruder - Convert pellets to filament

DePartedPrinter wrote:

It's good that your getting no contaminates. I'm assuming the longer you have run your machine the less you will get.  How many hours are you at now?

On that auger/pipe combo, probably about 70 hours.

I made completely sure all of the lips of the nipple were gone. Going to run some more clear today as well.

552

Re: Filament Extruder - Convert pellets to filament

BTW I found a good tutorial on gears at Make - http://blog.makezine.com/2010/06/28/mak … own-gears/ 

Inkscape has a gear generator plugin.  You enter the # of teeth and the circular pitch, and it creates a gear which you can export as DXF.  Make has a table that shows how to calculate the various values so you can figure out what to enter for # of teeth and pitch to get the gear you want.

553

Re: Filament Extruder - Convert pellets to filament

Got my line laser in today, which I plan to make into an optical sensor for a winder this weekend.

554

Re: Filament Extruder - Convert pellets to filament

What will you use for the switch?  Does the laser plug into power?  I have a laser level, but I don't know how long the battery would last.

555 (edited by Jason 2013-01-25 20:12:26)

Re: Filament Extruder - Convert pellets to filament

I decided to take the entire extruder apart and inspect for wear, etc... All looked good but I did grind the nipple down some more just to be safe.

I am up and running again but can't seem to decrease the diameter size no matter where I position the fan and guide. Any tips? Possibly a temperature issue?


Jason

556

Re: Filament Extruder - Convert pellets to filament

Increasing temperature will reduce filament size. What sizes are you seeing?

557

Re: Filament Extruder - Convert pellets to filament

Ran 3 hours of clear today, inspected the whole thing. Probably 20 micro bubbles (like 300 microns or so in size, way less than a millimeter) and one contaminant speck. Hmmm...

558 (edited by elmoret 2013-01-25 20:31:16)

Re: Filament Extruder - Convert pellets to filament

IanJohnson wrote:

What will you use for the switch?  Does the laser plug into power?  I have a laser level, but I don't know how long the battery would last.

I plan on using photoresistors and a microcontroller.

https://www.adafruit.com/products/1057

559 (edited by Jason 2013-01-25 20:42:30)

Re: Filament Extruder - Convert pellets to filament

Well after increasing the temp and running about 10 feet I had between 1.22mm-3.5mm. It would start out thick and decrease in size as gravity pulled the filament to the ground. Once it hit the ground it would increase in size again. The picture below is of this run. This was without any fan.

I have a feeling my temp probe isn't firmly in place causing fluctuations in temperature which is probably contributing to the size changes.

http://db.tt/8k5HRzxf

560

Re: Filament Extruder - Convert pellets to filament

Wow! I've never seen 3.5mm filament come out of the Filastruder.

I know Ian gets +/- 0.03mm. Something's gotta be up with your unit. To you have a temperature probe of your own, by chance?

561

Re: Filament Extruder - Convert pellets to filament

Maybe without the fan the back pressure from the filament hitting the ground is able to deform the filament more than if it were being cooled immediately.  Also is the space under the table clear?  If it can reach the ground without any obstruction, the forces at the nozzle will be more consistent.

562

Re: Filament Extruder - Convert pellets to filament

Didn't catch the bit about no fan. You need that on.

563

Re: Filament Extruder - Convert pellets to filament

With the fan on it will stay consistently larger in diameter. Right now I'm waiting for the nozzle to cool down so I can attempt to more securely hold the probe in the nozzle. I'm out of kapton so I am going to try and use some safety wire.

564

Re: Filament Extruder - Convert pellets to filament

What size did you drill the smaller of the two holes?

565

Re: Filament Extruder - Convert pellets to filament

elmoret wrote:

What size did you drill the smaller of the two holes?

1/16"

566

Re: Filament Extruder - Convert pellets to filament

Work-in -progress, It has successfully made one wrap. The motor is a 528:1 rpm pittman gear-motor, the speed control is out of a cordless drill (7.2-12 vdc) with a drywall screw through the switch trigger for adjustment. The switch is variable and I believe it is PWM . I have the gear-motor down to .5 RPM and the PWM maintains torque. The microswitch opens the motor drive circuit when it senses enough tension on the take-up. The drive belt is elastic strung over metal screws through the side of the wheel and the pulley is the fishing line pulley on the kossel delta robot on thingiverse or github. Hoping to replace the mechanical switch with an optical and replace the gear motor with a stepper motor controlled with an Arduino.

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567

Re: Filament Extruder - Convert pellets to filament

Ian/Tim
Can you provide details on the voltage regulator and gear motors, I can not find the part numbers from Mr. Lymans list on ebay.
Thanks for all you do. I have been quite entertained learning new skills.

568

Re: Filament Extruder - Convert pellets to filament

elmoret wrote:

Ran 3 hours of clear today, inspected the whole thing. Probably 20 micro bubbles (like 300 microns or so in size, way less than a millimeter) and one contaminant speck. Hmmm...

I'm getting less contaminates now. I will spool some and compare to the first batch.

SD2 with E3D, SD Press, Form 1+
Filastruder
NYLON (taulman): http://www.soliforum.com/topic/466/nylon/

569

Re: Filament Extruder - Convert pellets to filament

This is the gear motor I bought - "12V DC 0.5A 120RPM High Torque Gear Box Electric Motor 37mm"   The specific listings seem to come and go, but the specs are in the ballpark.  Stick with 37mm to have it fit the mount.

This is the voltage regulator he used, still available - http://www.ebay.com/itm/180914591883?ss … 1439.l2649


Tim, did you buy more than one line laser?  I've been thinking about a way to track the filament size as it spools-

http://solidoodletips.files.wordpress.com/2013/01/photo-34.jpg 

If you get the filament right up on the laser, and get enough throw distance, you can get a pretty wide gap, and therefore bigger changes.   It would require a mount that will hold the filament in place against the laser as it feeds past, but that could be done pretty easily with spring loaded idler bearings.

I was wanting to avoid getting a microprocessor involved, but if the bigger gear ratio I'm trying later doesn't work out I think it might be better to drive the haul off roller with a stepper rather than a DC motor.

The haul off spooler could make a nice kit on its own as an accessory.  The Filastruder works on its own, and you can get good tolerances but it is fiddly and conditions have to be just right for the filament to pile up properly.  You have to just get out of its way, any effort to make it go where you want ultimately ends in disaster.  It might seem be cooperating with you for awhile, but then it will change direction, twist around and screw everything up.

The spooler, if the accuracy can get dialed in, would make it easy to directly control the dimensions, keep them consistent, and keep the filament off the floor.

570

Re: Filament Extruder - Convert pellets to filament

I only bought one of those lasers.

I think steppers are the way to go - you can control position accurately with them, and with a DC motor, you can't hold a speed without some sort of feedback. Steppers have the advantage of being able to be run in open loop.

Agreed about it being a good kit. Looking forward to playing with it this weekend!

571

Re: Filament Extruder - Convert pellets to filament

Just a heads up - heater connects to terminals 2 and 4, not 2 and 5 as incorrectly stated in the instructions (and incorrectly shown in the picture)

572

Re: Filament Extruder - Convert pellets to filament

So, a few notes on my experiences printing with filastruder filament:

You may need to adjust print settings/print speed. I'm not sure what the standard melt flow index is for ABS filament, but I can say that some of the pellets I've bought need to be run at a slower speed to extrude without the motor skipping steps. Increasing temperature within reason doesn't seem to help too much - you just have to slow down. For example, the white I use, I print at 45mm/s perimeters, 50mm/s infill. If I go much faster, I'll start missing steps on the extruder.

Anything over 1.85mm is asking for trouble - it might be fine, might not. Depends on how well your hot end is toleranced.

573

Re: Filament Extruder - Convert pellets to filament

Made a half pound of clear today. No contaminants, definitely bubbles. None big enough to show up on the surface of the filament, which is why I never saw them in natural. I'd say 1 spherical bubble, 300ish microns in size, every 15 feet or so.

574

Re: Filament Extruder - Convert pellets to filament

Tim, looking up your plastic, I ran across this link - http://haveblue.org/?p=596

The MG94 has a much higher melt index than the PA-757 from Village Plastics sold by Makergear and I assume other suppliers.  However it is apparently the plastic used in Stratasys machines, or something equivalent.  It extrudes at 275C which for the SD equates to 240 with the SD which is way too hot.  So at the very least boost it to 215 and see what happens.   It is supposed to be a superior plastic in regards to dimensional stability and warping, so hopefully it will work on the SD.

575

Re: Filament Extruder - Convert pellets to filament

Well, it's worth noting that I'm using the QU-BD hotend. I typically run at 220C. Perhaps the different style hot end plays a role too - the SD hotend may create a smaller or larger melt zone.

I need to produce some reliable prints, so I'll leave it as is for now, and experiment later in the week.