[ Closed ] Filament Extruder - Convert pellets to filament (Page 52 of 58)

Look for a solid brass plug and a coupler that has a flat surface at McMaster if you are in the US. I haven't found either of those in a hardware store.  Also use a #52 bit to drill the hole which is about 1.6mm.  The plastic will swell as it exits so you want a smaller hole than the filament diameter.

Line laser:

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

@Ian - I have seen in the picture that you have on your extruder a different setup, as the nozzle hole is 90 degrees to the axis of the extruder. Also, I noticed a screw in the brass cap. What is the role of this screw, and could you, please, explain your setup. I would really appreciate a draft drawing - hand drawing of your brass cap if possible.

Thank you.

Hi Ian,

I'm thinking of attempting a similar set up,

How are you controlling the light gates and motor?

I was thinking of just using a light gate and a relay, but clearly as you have two gates and a motor delay you must have a slightly more complex set up!

Any pointers appreciated!

Cheers,

Rob

Ah I thought you might be,

If you're happy to post the details that'd be grand!

Thanks,

Rob

50ft/min...so I'm gonna need a a lot of filastruders if I want to go into mass production...

Right you are. Carl seems to have around 750lbs left. I will probably end up buying him out.

Those prices direct from Sabic include delivery, so they aren't as outrageous as I thought.

I can, though shipping might be pricey. It is hard for us from the US to help you find local suppliers, though.

Make that 750-15-15.  Got my order in yesterday.

Trying to come up with a set up that would only have one drive motor on the take up reel and no capstan to get costs down.  Thinking something similar to the dc gearbox motor I used on the capstan with PWM, but much lower RPM to drive the reel.  There would have to be a friction brake on the filament to keep tension on the reel.  Maybe sandwich the filament between some small blocks of PTFE?  Not sure a fancy encoder on the caliper idler would be necessary, it would be a good idea to know if filament is moving and to get a rough count of length, so maybe a one pulse per rev optical would work.  I am also thinking of a tosduino for $11.50 as the controller interfaced into the digital calipers as a safety check/log.  And of course use something similar to Ian's laser optical droop sensor. 

Started playing with the HF digital caliper serial interface last night and put together a level shifter with junk box parts.  The Chinese calipers use a binary format.  Lots of info on the web.  http://www.shumatech.com/support/chinese_scales.htm  Problem is the metal body is connected to the + side of the 1.5V battery, so if you ground the "-" side of the battery to your Arduino, the metal body is now at 1.5V and is "hot".  I chose to ground the body and to capacitively couple the clock and data outputs to the level shifter.  At some point in the future, I'll add a charge pump to replace the negative battery supply.  If running the metal body hot doesn't bother you, there are some minimalist solutions on the web that power the calipers from a +1.8V ground referneced supply and drive a 3.3V supply Arduino directly (might be  a little squeaky on noise margin).  Rise and fall times out of the level shifters were good, but haven't connected it to the cap load of the Arduino yet.  If you pull the Data output line up to GND, the calipers cycle thru different min/max secret modes.  Once it is in the special mode, you can use the zero button to toggle the data rate from 300msec to 22msec.  Hitting the On/Off button just turns on/off the display and has no effect on the serial port output.

I'm hoping he comes up with some code that I can figure out how to copy and paste into the arduino.

Using an encoder to count the length of filament spooled is a bit complicated.  It occurred to me that it would be simpler to just leave the winder on a postal scale with an AC adapter and watch the weight increase..  You can get one of those from Amazon for about $25.

I can try out using only the spool motor with a brake by taking the motor off the puller.  The tension on the idler bearing is adjustable, so I can see what effect that has.  Maybe the caliper roller can double as the brake.  I have a couple of cheap plastic calipers, and noticed that the movement is much smoother than the metal Harbor Freight caliper.   You don't have the advantage of a serial output but it's fine for seeing if you have the diameter you want.  It would be cool to log the diameter and get a graph after the spool is done to see if there were any problems.

So on the colorant front. I have gotten quotes for ABS Blue, Red, Yellow, and Glow in the dark. I know the primary colors will be easy to get but the glow in the dark may take longer than the rest. I also got a quote for PLA colorant, Red, Blue, Yellow and Black. My goal is to have a much better selection once the KS ends. Thank you guys for being patient!

Ian

Why not put a small stallable motor on the reel?? The ones I have played with start turning at about 1.5 volts and are good to 14 volts. The torque is adjusted with voltage.  I think the real problem with one, would be the torque would change as the spool got larger.

Rodney