12" I3V Build

[printbus]

Congrats on the first prints and a fairly painless startup.

On the clicking, one suggestion is to use a short length of garden hose or similar tubing as a listening aid to help locate the source. I know I had a very annoying click that seemed to be coming from the area of the guidler bearing and hobbed bolt area. I was never really able to pinpoint it, but eventual replacement of every component involved seemed to solve it. A couple of others have reported a similar clicking from that area. I've even wondered if it was simply the sound of the hobbed bolt cutting or creasing into the filament.

Another possibility is the extruder motor is skipping when attempting to do retractions. Assuming your gcode includes retractions, they're not happening based on the rotation of the large gear in your video. Looking through the gcode file in a viewer like gcode.ws will help you understand what the printer is being told to do, including whether or not retractions should be occurring when the nozzle makes a non-printing move from one location to another, as it likely would on infill. Colin's firmware baseline used to set the extruder maximum feedrate (the fourth term in configuration.h DEFAULT_MAX_FEEDRATE) to 22mm/sec. At least two of us determined the extruder motor can't be driven that fast, and that something in the range of 10mm/sec to 15mm/sec is more appropriate. If the extruder motor is driven too fast on a retraction, it'll just twitch a bit without movement each time a retraction is attempted.

The steps per unit for X, Y and Z are fixed by the hardware design and the microstepping selections for the stepper motor driver boards. You can work through an understanding of how the settings are determined through something like Prusa's on-line calculators. Changing the settings based on a fixed size test print will likely create a printer that can only print that dimension correctly, with all other dimensions off by some scaled error. What was the LCD displaying as a print height on the last layer? What does a viewer like gcode.ws show as the height of the last layer?

Jumping into early prints with 100% infill is gutsy. If the extruder steps per mm aren't right, 100% infill won't turn out very well. For example, if there's a bit of over-extrusion, the excess filament has no-where to go and you'll be left with ratty walls and a bad top of the print. The sticky on calibration might be a place to start. Simply listed as another source, Triffid Hunter has a calibration guide that touches on extruder calibration and the countless other things involved in bringing up a printer from scratch.

[Dustin B]

The clicking sounds like it's coming from below the print bed. I think it's something to do with the Y axis. Only makes it during the rapid direction changes of infill. My first 100mm extrusion test was 2mm short of 100mm so I adjusted the steps before printing the bars accordingly. The perimeter walls look perfect including the top of them. The infill however sticks up above the perimeter walls. That would indicate over extrusion? The code definitely had retractions in it as I saw them happen during some portions of the print. It was making some pretty rapic retraction movements. 1/8 or so of a turn of the spur.

https://goo.gl/photos/SCAJ5Jfd5NFsUBd9A

Reading your calibration link. I'll have to try the stepped cube and see if adjusting the multiplier makes the top layer not stick up. Also measured my filament and it's 1.85mm and I had 1.75mm entered.

[Dustin B]

First PETG print. Think I might need to slow things down a bit for a part this small Got a lot of stringing and at the beginning the nozzle was dragging through the bottom layers a bit so I reduced the extrusion multiplier to 0.99 which seems to stop it. Overall I think not bad for my 4th print ever.

https://goo.gl/photos/Scm7zzHA5s4H5DmK8
https://goo.gl/photos/2usDzJjBDDJFfTo76

[Dustin B]

Slowing things down and leveling the bed again (feeler gauge sure beats paper) resulted in a really nice 3rd attempt on the idler pulley. Now have them installed on the x and y axis. Printed a Benchy after that. Thought it was over extruding and reduced the multiplier, then decided it wasn't and increased it back to what it was. Should have never touched it as you can really tell when I put it back (this pick doesn't really show it as you can see it in the outside consistency, it's pitted on the lower portion and smooths right out on the upper).

IMG_20160229_142353410.jpg

The bed leveling manually with a feeler gauge would be trivial if I could one hand adjust the screws with just a wrench or a thumb wheel. Thoughts on modifying the heater board to accept an m3 carriage bolt?

[beerdart]

Looking good.

[printbus]

...The bed leveling manually with a feeler gauge would be trivial if I could one hand adjust the screws with just a wrench or a thumb wheel. Thoughts on modifying the heater board to accept an m3 carriage bolt?

The thumbwheel approach is great. Rather than hassle with carriage bolts, I just used locknuts to attach M3 screws to the heater. Note that when another user replicated the thumbwheel approach from my 8-inch i3v onto his larger printer, he found it was necessary to notch the rear brace across the back of the printer for the thumbwheels at the rear of the heat bed to clear it.

[Dustin B]

I knew I'd seen someone do a thumb screw that only took one hand. I was looking and looking again trying to find it. It was your thread I'd found a long time ago and forgotten about. Yes the second lock nut is a much better solution. I'll be printing some thumb screws and an LCD knob next and getting them installed. Then a print cooling fan shroud. Then I'll decide what I want to do with the x and y belt attachments. Definitely going to use your X-Axis one but I'm thinking about trying my hand at designing my own Y solution. Having used some 12mm counter sunk screws to mount the end stops I'm not really worried about printing new ones of those. Although the new end stops he supplies are thicker, 12 mm won't let you get a nut on the other side, but 2.5mm threads on enough that I think I'm ok. But since they do still twist when you tighten them down I might still end up printing some new ones. At that point I think I'll have enough done that I'll be pretty happy with how it's working. Oh but I will have to make some sort of improvement to the spool holder.

[BLKKROW]

The next time I have my printer disassembled I will be taking M3 PEM Nuts and pressing them into the aluminimum bed. This will make it possible for me to adjust the heat best with a hex key from above.

[Dustin B]

I thought about printing something to lock the bottom nut. I like the thumb wheel on the bottom better though as then the hotend and stuff around it will never be in the way trying to fiddle a hex key into the head of the screw and I don't need any tools, besides a piece of paper or my feeler gauge. Place the hotend over the part to be leveled, one hand on the feeler, other on the thumb wheel tweak till it just slides under. Got one that printed ok last night and got it installed. Works really well.

Wanting some feedback on what I should be changing to get my PETG prints better. Thought I was doing better than I apparently am when printing the idler pulleys. Am I under extruding, hotend temp too low or have I maybe leveled my bed with too much space to the nozzle?

https://goo.gl/photos/tBLiXoRCtCeVfUFN7
https://goo.gl/photos/6VU628gR7xVeJW4V7

[beerdart]

I run PETG @ 260 and 60 bed.