msurunner

There should be a subtle release of tension as the cam in the lever engages itself, but it doesn't "click" or "latch" into place, if that makes sense at all. If it's tight all the way through and there's no release at the end you are probably too tight and the lever isn't getting to the break point in the cam, which holds it in place and maintains pressure. Are you seeing the track marks on your filament that has been through the feeder? If not, you are simply not getting enough pressure on the filament. If you are, you are likely having a slicing issue where you don't have the variables in the slice correctly aligned with the extruder/filament. Another test would be is the filament held in place when the cam latch is engaged (to the point you would have to muscle up to pull it out)? If not, you don't have enough pressure on the filament.

The scar is called more specifically the z-scar. It's the little bit of material that gets pushed out at the machine alters it's z-height. There are several ways to try to combat this, namely utilizing the "Joris the outer edge" (where it creates an ever changing height for the outer edge), but in my opinion, it's more of just a hazard of the print. Rotating the model to where it's going to be in a location you are okay with is the easiest solution.

They utilize Handmadecircuits.com for a US distributor. He does do a bulk buy discount I believe if you buy 10+ rolls. Just an fyi...

The new spring design will have some pressure on the filament which will likely require you to either disable the steppers and rotate the gear wheel or lift the lever up to relieve enough pressure to simply push it through by hand.

Heat it up again and pull it off with tweezers or simply take a cloth or paper towel and gently wipe it off. Sounds to me like your feeder mechanism is too loose. You should see a track mark of the teeth on the filament. Give that bad boy a couple extra turns if you don't see those. That will tighten up your black latch lever.

Hey Bill! Glad you got things up and running properly. I was going to suggest checking the pulley on the stepper. Those always seem to be the ones that bother me. You might put a marker dot on the pulley and stepper shaft to note slippage for future reference. Also, don't get too carried away with the belt tension. It CAN cause issues if not tight enough, but IMHO overtightening it can lead to just as many or more issues (particularly the shaft to pulley slippage on the steppers). Plus, once you stretch those belts out, there's no going back, so you have to keep stretching and stretching or order new belts. Also, I would suggest raising your print temps. I usually have to print at slightly higher temperatures than what everyone else seems to be able to. I don't know if it's altitude or humidity (both MT and NV are over a 1000 ft higher than the Netherlands) but I do know that PLA can be a bit finicky about that. My solution has been to increase the temp and increase the speed. Depending on your print settings, you may or may not be able to do that, but it's worth a shot. Finally, if it's printing well now, I wouldn't make this adjustment, BUT, if you do take things apart again, I would recommend sliding a bit more bowden tube through the bottom and NOT bringing the aluminum plate quite so close. It definitely does not need to be touching the bottom of the wooden box. I have about a mm or so of gap on the corners of mine. With that in mind, be careful about the amount of force used to tighten that aluminum block on there as well. If you are overtightening it, the bowden will compress, thus decreasing the inner diameter and you end up with plugging (especially if the filament gets compressed into an oval shape by the extruder or is over-dimensioned). Again, don't play with it if it's working, but if you do take it apart again, something to consider. Looking at your prints, you are good on alignment and tension now. Tweak your settings and monitor for pulley slippage! Congrats on getting through the headache! Hopefully your time now is spent on items of fun not necessity!

Just played with the plug-in a bit (especially nice for allowing you to create new support that are easier to remove than printed material...) and I'm liking it a lot. Any incorporation into the UltiController firmware? It would be cool to utilize this code as a pause print function!

Nice Daid! How's priming the printhead working on that? Also, how close of attention do you have to pay to it? If you leave it sitting for ten minutes before you realize it has paused are you going to be dealing with issues?

It's symmetrical, right? Flip it over and bend away?

I know that Daid's spoken of placing "marker dots" on the pulleys and shafts in the machines AT Ultimaker to determine if slippage has occurred over time. That means that the grub screw cannot indefinitely provide enough friction to prevent slippage. All I'm wondering is if there's one spot that could definitely use a flat, I would see it as on the axis steppers. I understand why you wouldn't want it on the axis itself, but I'm just thinking there ought to be some sort of mechanical solution available. Some companies utilize a second grub on their pulleys. Perhaps something to consider if the round shaft is superior to one with a flat.

If you increase the tension on the belts, the torque necessary to spin those is bound to increase as well. This is the simple way of limiting backlash. The by product of this, however, is the torque threshold of the frictional force from the grub screw to the stepper shaft is closer to the torque necessary to spin the assembly. A flat spot would require the grub screw to raise in the assembly to slip, not simply having a torque greater than the friction of the grub. Maybe I'm asking too much of the machine to run at high speed on some prints, I was just thinking that a flat spot would allow us to increase that point. As far as the tension goes, I can not count how many times I've been told/seen others told they have a tension issue for infill not matching walls or wall placement being off. Either quite a few people have gotten lazy with assuming it's a tension issue or there's something else at work. Now, I'm inclined to believe it's a combination of things, including, but certainly not limited to, belt tension. Regardless, I've been steadily trying to monitor tension, and have upped it a couple of the small belt tensioners http://www.thingiverse.com/thing:34785 to try to keep a constant tension. Problem is, there's not really a sound way of determining "correct" tension aside from everyone's twang method (talk about unreliability in reproduction...). I have got to assume that it couldn't be that difficult to get a screw on the flat spot, but if it is, that's fine. I'm also fine with an answer of that's the mechanical limitation of the machine. But, if everyone wants to keep saying tension tension tension, I'm not too happy if the by product is producing a failure elsewhere. IMHO... the max jerk values in the firmware are too high. I've been trying to take a more scientific approach to problem solving this by following a "solution" to fruition and as such have been with belt tension right now. BUT, I think the increases in our speeds over other RepRap type machines introduces a problem with high speed prints. When we are doing the vase type of prints, it's not nearly as apparent. But if you start doing pieces with sharp corners, that's when I've noticed the problems. I know I'm not alone as several others have noticed this too. Now, I haven't tested that, so I have no idea, but I would be interested in seeing if someone has lowered their max jerk and if it's helped. I don't think it would slow the prints down incredibly, but I could also be wrong their too.

I would generally beg to differ as the short belt tension seems to have to be high enough that the one grub screw on a smooth round surface causes slippage. I can see that it may cause more issues with some users not being able to correctly align the flat. I guess I'm just noting that if the wall placement and infill touching errors are related to tension, as you increase that tension you do increase the strain on a small grub screw. Factor in a lot of small movements for infills and what not, and it can easily work itself out. I was just wondering aloud if a flat spot would help prevent that.

Is there a reason why the axis steppers don't have a flat spot on the output shaft to help prevent pulley slippage? I understand it's easier to access that grub screw than the top ones if the belt tension needs adjusted but it seems to me that the grub "fails" like once every other week causing the infamous sideways print.

What types of objects are you planning on printing and what kind of strength are you looking for?

Try carefully tightening the printhead while it is warm. The brass and aluminum expand at different rates through the heating process so you should check to ensure both the male brass parts (nozzle and barrel) are making proper contact in the aluminum. Looks like you are running a Bertho upgrade, yes?

Not to hijack the post, but what is the small circuit board you have hanging off the left side, Robert?

There is a certain satisfaction from seeing your creation at work, too. Interested to see where this goes. I'd be curious what your cost would be after everything's done (both with and without labor estimates) so we could get a comparison on what the cost to build and buy a comparable setup should look like.

I think that we solved one of the problems with the horseshoe clip preventing the bowden from sliding up and creating a gap in the PFTE, but I think your extrusion settings are off slightly. If I'm correct, your extruder is gradually building pressure now until it creates too much pressure for the extruder teeth to handle and it begins a grind. Try lowering your steps per e about 10 or increasing your filament diameter .1 mm. We might get a sparse part but it would show if the extrusion settings are correct.

You might try swapping your Pololu drivers to troubleshoot and see if that's the issue... Make sure you have completely disconnected the power before swapping them!

Your feed rate should be a byproduct of the speed you are printing. The E value should be the determinant on the amount of material fed. If you have already done the Cura first step wizard to get an approximate value of steps/e then you probably need to adjust filament size. You could get that feed rate back to 600, though, by matching your print speed with your first layer speed.

Looks like a V2, Sander, seeing the PFTE "cold zone" part

This is a Daid post of earlier issues but it reflects my next course of action for you... It looks like you might have yours flip flopped from the photo shown. 220* can produce backflow but certainly not after only a couple mm of extrusion like that unless somethings blocking the output.

I would say it's easier to swap nozzles... Not quite "easy" yet, especially if their has been filament ran through it.

...Perhaps just a touch.... What did you purchase that for???

Try heating the unit up to 250 for five minutes with NO filament in it, then try to feed the filament in manually. This should allow the heat to liquefy any PLA/ABS in the hotend and "ooze" towards the nozzle. You would not want to do this with the filament still in the hot end as the heat soak will start to warm the PLA near the PFTE part which can create the dreaded plug. If you can't feed the filament through, with relative ease, after this then I would say it's semi-safe to say you have some sort of obstruction in the nozzle and to disassemble and clean it.