Filament routing pully specs

[Steven Yaeger]

Could someone post the specs for the filament routing pulley?  (I'm looking for the diameter of the center section of the pulley)

As you can tell from my pictures, My kit was missing the pulley, so I made an aluminum slug to use as a pulley. 

I'm having problems with the spooler motor not turning off as expected.

When it doesn't turn off, it pulls on the hot filament near the extruder, the filament stretches, and it gets too thin.  If I let it coil onto the floor it works great.

Since the optical sensors and emitters are working fine (finger tested).  I'm thinking the filament must not be staying in front of the sensor long enough.  So maybe my replacement pulley is the wrong diameter and the filament isn't remaining in front of the sensor long enough to trigger it.
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[Herb Winters]

Hi Steve,

The outside Dia. is about 1.1 inches I was able to find them at a local hardware store if you have a Ace or true value hardware they both had them they are in the area with all the slide out boxes of assorted bolts where you buy the bolts by putting them in a little bag and writing down the price. they have a box in they with this kind of assorted hardware I will get the name next time I go back and will post here that way it will be easier to find.

[Herb Winters]

also fogot to mention it is about 0.38 inches thick.

[Herb Winters]

Hi Steven I have my machine running now and I have only run it a little bit but will work with it more next week.
however I thought I would tell you I am having the opposite problem thing happens to mine I think it depends some on the spool you use.
I had a wide spool and when the filament rolled toward either sidewall of the reel the filament would come down on the top of the bottom sensor then the spool would not get started and the filament pile up all over the reel.
not sure this is the same problem as you are having but I thought I would run it by you.it almost seems like the distance needs to be wider between the left and right side of the sensor bracket.

[Steven Yaeger]

That does sound like exactly the opposite problem from what I'm having.  I narrowed my problem down to a bad PhotoTransistor.  The top Phototransistor wasn't switching the unit off.  The power feed to the Phototransistors was 5V.  So I ordered a lot of 20 - 3mm by 5mm, Phototransistors (with peak detection in the 940nm range) from a U.S. seller (and 50 - 5mm x 8mm, 940nm IR LEDs from a China seller) on EBay.  The Phototransistors should be here by Wed, Nov. 27th.  I will give the spooler another try when they arrive.

The 1 Volt that is being used to drive the IR LEDs is very low.  I couldn't find any available 1 Volt Forward Voltage 980nm IR LEDs.  I did find a part number for an unavailable 1.15 Volt forward voltage 980nm IR LED. So I ended up ordering 980nm IR LEDs with a 1.2 volt forward voltage...  I will probably have to drive them my self or if the board is using a simple resistor driving circuit (instead of PWM), I may have to replace the resistors on the board.

In the meantime, I generated a couple of hundred feet of filament, just letting it fall to the ground.  And I've finally been able to start using my 3d printer...  Turns out the SanguinololuSanguinololu n my 3d printer is having a problem keeping the HotHead resistor working. The mosfet, or the logic that controls the mosfet, that powers the hothead heating resistor fails after about 5 minutes into the prints.  At about 5 minutes into the print the hothead cools off and stops emitting plastic.  If I disconnect the resistor, monitor the temperature, and toggle the power to the hothead resistor on and off by manually (via a switch), it works fine. Isn't 3D printing fun...