Strange STUTTERING on complex parts

[mrbi11]

Has anyone solved the studdering issue yet when using the new ezstruder? has anyone found a suitable geared extruder replacement?

For anyone printing from a pc or mac, try the sd card. If the problem goes away, use the SD.
IMHO, pc's do too much on their own, like rebooting for updates, to ever trust them to
do a print longer than a few minutes. ( which is all of my prints)

For my complex parts i get strings and blobs everywhere. Tried to "fix" it by increasing retraction speed and distance, which helped.
But, made ABS dust pile up in the Ezstruder. Eventually i got different problems with intermittent ABS stalling in the struder.
I could watch the gear turn smoothly, while abs started and stopped. I disassembled the extruder to clean out dust, and it worked again,
and I backed out the retract changes so am back to "normal" abs dust. (and blobs and strings).
I also modded the Ez struder to give dust a way to escape.

I think the Ezstruder design traps dust at the aluminum piece the bowden screw in to.
I made some small front openings to let the dust escape if it gets really packed in.
I also blow it out with compressed air every time i check a print in progress.

All apparent problems become more obvious when your print has multiple vertical sections.
I have no idea how to get a clean print of that. I always get strings.
I don't think complex prints cause the printer to make blobs,
I think simple prints avoid jumping place to place, and so avoid blobs.

[geneb]

If your machine automatically reboots on updates, that's because you've got the Windows Update service set to do that.

You're constantly getting "ABS dust" because the hot end pressure is so high it's stripping the filament. You've been told this REPEATEDLY. It doesn't have a thing to do with the EZStruder design. NOTHING.

g.

[mrbi11]

I would appreciate not being treated as a dummy.
When I told everyone about a repetier bug you said I was clueless, right up until i sent you the software bug fix.

I did EVERYTHING you suggested to address the issue. I checked temperature, CHANGED OUT TIPS.
The Eztruder makes tiny cuts in the side of the filament, even with no tip at all. Just feeding through into air.
You can feel the cuts easily with your hand. Smooth going in, cut up coming out.
You can't make tiny cuts without generating tiny dust.

So, if I get dust feeding into air, is it still my tip pressure?

Your instructions did reduce the amount of dust, but not to zero. Close inspection of the drive wheel shows
the drive wheel grooves accumulate material, which eventually build up enough to slip.
Takes a magnifier to see it.

I listen to everything you and anyone else responding to my posts tells me, but sometimes i get different results than you predict.

[geneb]

I would appreciate not being treated as a dummy.
When I told everyone about a repetier bug you said I was clueless, right up until i sent you the software bug fix.

Link? I don't recall this at all. (that's not surprising however. I have a mind like a steel sieve.)

I did EVERYTHING you suggested to address the issue. I checked temperature, CHANGED OUT TIPS.
The Eztruder makes tiny cuts in the side of the filament, even with no tip at all. Just feeding through into air.
You can feel the cuts easily with your hand. Smooth going in, cut up coming out.
You can't make tiny cuts without generating tiny dust.

The hobbed gear presses a tiny notch into the filament. The only time it would create "dust" is if it's scraping the filament, which it can't do until it's got some back-pressure.

So, if I get dust feeding into air, is it still my tip pressure?

No, but it might be your filament.

Your instructions did reduce the amount of dust, but not to zero. Close inspection of the drive wheel shows
the drive wheel grooves accumulate material, which eventually build up enough to slip.
Takes a magnifier to see it.

I've got five different machines that I've run tens of kilometers of filament through and the only time I've EVER seen the kinds of issues you describe is due to high hot-end pressures. (Even in my LulzBot TAZ, which is direct-drive.) Try some filament from Ultimachine or SeeMeCNC and see what results you get.

I listen to everything you and anyone else responding to my posts tells me, but sometimes i get different results than you predict.

Then you have the unenviable position of living in Cornercaselandia.

g.

[cope413]

Don't take it personally Mrbi, Gene sometimes comes across like Clint Eastwood in Gran Torino, but with very few exceptions, he just wants to help people get their machines dialed in.

It is very frustrating, though, when good information is given and then ignored, or seemingly ignored.

I can guarantee with absolute certainty that there is no design flaw with the EZstruder that would cause your issues. There certainly could be a mechanical/manufacturing defect, but it's unlikely.

If you unhook your bowden tube and just extrude filament through the EZstruder, the hobbed bolt will leave it's imprint on all filament. It's supposed to. Ideally, it leaves only the minimum amount required to push the filament through so as not to affect the diameter of the filament, but a lot of that depends on your filament quality, type, and beginning diameter.

Just in the past week I have printed just over 2kg of ABS, and I have absolutely no need to clean out my EZstruder.

So, let's assume 2 things to start...

First, the EZstruder, as long as it isn't damaged or defective, is not the culprit.

Second, we're here to help you, not to hurt your feelings or insult your intelligence (including Gene), so if it comes across that way, take a breath, crack a cold beer, and let malted barley and hops wash away any hard feelings. Sculpin IPA and Stone Enjoy By IPA are really fantastic choices this holiday season.


Now, let's forget about everything you've done so far to try to fix the problem and start fresh.


First thing to do...

Completely clean your hobbed bolt of all dust, remove the PTC connector and bowden tube, and feed 100cm of filament through the EZstruder. Is there dust afterwards (and there should be virtually none)? If so, what is the measured diameter of your filament? What brand is it?

If there's no dust, then we know that your EZstruder is function properly when run cold...

After that, reconnect the bowden tube, remove your hotend nozzle, and bring your hotend up to 240C.

Extrude 100mm of filament at 50mm/s in rephost. Any dust? Skipping or stuttering? There shouldn't be any. If there is, you either aren't at 240C (bad thermistor seating or you need to retune PID), your filament is bad quality and needs to be printed at higher temps than ABS needs to be printed at(which means it's unusable with the stock end).

If it extrudes easily with no dust. Put the nozzle back on (don't burn yourself), and try the same thing with the nozzle on - 100mm at 50mm/s. If you extrude successfully without a nozzle, but then have dust/stuttering/skipping with the nozzle on, then you likely have a clog in the nozzle, you don't have the nozzle firmly screwed on, or you're not at the right temp. There are some other possibilities, but let's start big to small and go from there...

[Nylocke]

I just have 2 words to add, plastic deformation. How hobbing works and what it relies on. The groves aren't cut necessarily, they are pressed into the filament to grip it, the only time it cuts is when there is a lot of back pressure from the hotend. No one, especially Gene, is calling you or purposefully treating you like a "dummy", we're trying to help you. I know how gene can come off as sometimes, there was a time that I got frustrated with him, I don't even remember why, some dumb reason, but we are just trying to help with what we know and have experienced.

[mrbi11]

Thanks everyone.

First, I did not intend to imply the ezstruder is in any way flawed. By all accounts it is the best out there.
Having said that, out of the box filament would not feed through my ez struder AT ALL, although oddly it would feed thru each piece fine.
Eventually I found a misalignment problem, which I solved by drilling out the nylon a bit. So Myine may allow more wiggle than it should.
Then it still generated some filings, which I tracked to the edge of the aluminum bit. Even though the edge is beveled down, machining left a very sharp edge.
So a bit more work to smooth the lip of the inlet to the aluminum part. No more shavings.
Then it still jammed, but only when mounted, which tracked down to the cut out on the
melamine spacers was not quite wide enough to miss the round aluminum part, and was pushing it out of alignment, again.
Exacto to the edge of melamine spacer, now it finally works.

The issue I am having is after running for a long time. Running 24 hours straight, I still see dust.
Cleaning it out and watching through a loop, I see very tiny bits come off in normal printing.
It takes quite a while for it to become visible.

Its entirely possible it is my ABS.
Other people may get similar ABS with similar issues.
Anyway, I have a "dust filter", very high tech of the kleenex and wire tie sort, so ABS goes in clean.
With no tip, ABS come out rough, and there are tiny ABS colored dust that come off on my hands.
Very small amount.

Its entirely possible my drive wheel has sharp bits on it, like my aluminum piece did.
There is a lot of variation in the individual parts.

However, It isn't just my issue. At least two of the "experienced" contributors told me what to look for, and it is there.
And anyone else encountering this needs a way to manage it. After all the tweaking, I check my print every few hours and blow it out.
Works, no more slipping. Not elegant.

The topic here wasn't what is wrong with EZstruders, but how to manage the stuttering problem. Its a real problem, I didn't post this thread.
I shared what I had to do, AFTER changing tips and checking temperature.

It isn't helping anyone telling them you don't have the same problem. I'm glad you don't.

[geneb]

Don't take it personally Mrbi, Gene sometimes comes across like Clint Eastwood in Gran Torino, but with very few exceptions, he just wants to help people get their machines dialed in.

Yeah, you just wait till I enter my Dirty Harry phase. Then you damn kids will _finally_ get off my lawn!



g.

[cope413]

Mrbi, you posted in the wrong thread then. This thread was not related to the EZstruder. No idea why Cambo posted that question on 11/30, but original issue was nothing close to related to what you're describing.

But because we're here to help...

Having said that, out of the box filament would not feed through my ez struder AT ALL, although oddly it would feed thru each piece fine.

What does that mean? I won't try to guess, but please clarify

With no tip, ABS come out rough, and there are tiny ABS colored dust that come off on my hands.

With no tip? Does that mean you're extruding through the hotend with no nozzle?

What about just extruding, as I just said to do, through JUST the EZStruder - not through the bowden or through the hotend - JUST the struder

And anyone else encountering this needs a way to manage it.

No, we need to figure out the problem and fix it. No one here is interested in band-aids.



As for what the problem is, I'm still unsure because you haven't been very clear. Are you saying your extruder starts to skip because you generate so much dust/shavings from your filament that the hobbed bolt isn't able to properly grip the filament and push it through the end?

If that's the case, then what filament are you using and what is the measured diameter?



Have you disassembled your hot end to ensure that there are no clogs or other issues that could lead to increased pressure?

[mrbi11]

Mrbi, you posted in the wrong thread then. This thread was not related to the EZstruder.

I had problems with complex parts printing irregularly, and it appears related to the ezstruder skipping. In my opinion there are two causes
to the issue described, one of which is extruder.

Having said that, out of the box filament would not feed .

What does that mean? I won't try to guess, but please clarify

I mean my brand new EzStruder you could NOT get anything through with a hammer. The NEW ezstruder was seriously
out of alignment. It has a nylon pieces and an aluminum piece with the correct sized holes, but they were about 30% off center.
The design looks fine, the quality control most definitely was not.
How hard is it to stick a filament in the bottom to see if it goes thru?

With no tip? Does that mean you're extruding through the hotend with no nozzle?

No, extruding filament out the bottom of a disconnected EZstruder.

What about just extruding, as I just said to do, through JUST the EZStruder - not through the bowden or through the hotend - JUST the struder

Yep.
However,...
I was tired of talking about this, but my Z axis motor chose now to give out (skip long boring story), so I thought I would double check.
Extrding out the bottom of the extruder DOES make the filament rough, but inder the loop they are well formed dimples with no flakes coming off.
I think I did this the first time with some dust still in the extruder. Dimples yes, flakes no.

I examine CLOSELY the filament after printing at a very slow pace, with a very small amount, 0.1mm thickness by 0.2mm wide.
This feels rough too, but under the loop it has serious divot shapes, with a sharp edge. There were many flakes, and several flattened spots.
It was natural abs so is very hard to see. So printing speed in slicer set to 20 (instead of the 30 recommended) tiny little dribble of ABS.
Should be much lower pressure than printing 30 and 0.2 by 0.5 trace.

By the way, the shot below with stuff stuck in the groove is AFTER having 120 psi air blown at it.
The bits that get stuck are really stuck. Even a wire brush has trouble getting it out.

(my preview is showing the same pic twice with the second at the bottom?)
This is hard to see, but the before picture has 3 grooves filled with natural ABS, but it is semi transparent, so i can barely see it.
The second pic is the same grooves after i cleaned them out with a sharp tool.

So, printing way too slow and too tiny for there to be any point, at 235C, new tip, I get flakes and they definitely come from the EZstruder.
Maybe its cheap ABS, maybe my filament drive gear has sharp edges, maybe both. Maybe bad karma I have earned

As for what the problem is, I'm still unsure because you haven't been very clear. Are you saying your extruder starts to skip because you generate so much dust/shavings from your filament that the hobbed bolt isn't able to properly grip the filament and push it through the end?

No I observe (under loop) the filament having flat spots. I cannot tell if it applied so much force it shaved it flat, or
if it coincided with a turn of the drive wheel when its grooves were clogged, although I think the latter.

If that's the case, then what filament are you using and what is the measured diameter?

spot check with caliper show as close to 1.75 as I can get repeatable measures with my caliper.
I have not noticed variations.

Have you disassembled your hot end to ensure that there are no clogs or other issues that could lead to increased pressure?

[/quote]

Yes, I spent a day or two tearing down the hot end, finding nothing, finally installing a new tip.
Hence my large frustration at being told I was not listening.

Honestly, I think I want to move to nylon.
I have ordered my e3d head.

Speaking of which, cambo3d was advertising aluminum J-head adapters for sale, but has not replied to my post.
Does anyone know him well enough to ping him that a sale is waiting?

[Eaglezsoar]

Speaking of which, cambo3d was advertising aluminum J-head adapters for sale, but has not replied to my post.
Does anyone know him well enough to ping him that a sale is waiting?

I sent him an email to his private email address. He has not been on the forum in a while. I gave him the link
where you requested to buy one. Hopefully he will contact you or if he sends me an email I will let you know what
he says.

[cambo3d]

well my stuttering didn't start till after i installed the ezstruder..(page 2 of this post).. so i'm still looking for a geared extruder replacement or another fix.

mrbi11, im not able to make the jhead adapters at the moment. I'm currently away from the machine.

[brand_in]

Ok guys helpe me out I am having the stuttering issue!!! it does it on complex parts with lots of little precies movements usually a model with splines and stuff.

anyway its becoming a major problem, ruining a lot of my prints because when it stutters it stops for a half second to long and melts a blob and totally ruins the parts finish because its usually doing this on the perimeter for some reason.

i dont want to use the sd card i just want it to work is there anything anyone has done to fix this issue besides us a sd card???

[Xenocrates]

There are a few potential things to reduce stuttering when streaming code from a computer. Increasing the priority of your host program (Mattercontrol, Rep host, Rep Server, ETC), reducing or eliminating other tasks being run. you could also improve your computer to attempt to reduce latency, as well as disconnecting any other USB devices on the same controller (Although I'm not certain that would do too much, and it would be difficult to tell which controller a given USB is on if you don't already know) I believe it has to do with latency being introduced either while running the slicing/host program, or at the USB, which causes the Rambo's USB to serial chips to hiccup as they lack data to send, causing the printer to not move. Could be entirely wrong, but that's the only theory that makes sense to me.

Why though, are you set against using the SD card? Is there a particular reason?

[Polygonhell]

You can trivially tell if it's a starvation issue, the number of buffered moves is displayed on the LCD, if it's consistently 5 or less it's probably the issue, if it's consistently >10 it isn't.