Ridges in print.

[grasshorse]

Hi Folks,

While I'm pretty happy with how this print turned out. There was issues with it sticking to the bed. It peeled up around the neck. Do you think that is what caused the poor registration? That was my thought. The head may have been hitting the print knocking it back and forth creating these exaggerated ridges. If you look at the tip of the nose it has excellent registration and there is no course ridges there.

Does someone out there think that it might have been caused by some other problem? I'd love to hear your thoughts.

Edit: It truly says something when you can FAIL a post in the FAIL section! I have uploaded an image for your review!

[lordbinky]

Below the post section under submit there's a upload attachment tab. I know it would be helpful to me if you use that for uploading pics, my work's filter blocks imgur (but not i.imgur ). What my imagination comes up with in place of the picture will be of no help to anyone that isn't trying to lock me away.

[grasshorse]

Nothing like an accidental April Fools joke on myself! Sorry for the inconvenience folks. Looking forward to hearing you insight.

[lordbinky]

It seems that your carriage is being shifted out of position for a couple layers until it comes back in to where it should be. There's a few ways can happen. It could be anything from slop, nozzel catching a tiny bit, or just skipped steps, to a few more problem areas.
I would suggest:

Check your set screws on you're pullies.

Check the belt tensions on each tower, you want them equal.

Check the arms and carriage for any of the delta arm blues related issues.

If all those appear to be fine, there are two likely scenarios at play. First, you may require a small fan or heatsinks on the stepper motor drivers on the RAMBO board. They can trigger their thermal protection and skip steps that would otherwise be sent to the motors. (there's also thermal protections on the motors themselves, but those are less likely to be the issue) You can also turn up your stepper current limits in your firmware and re-upload it. Going over 190 in settings is very likely to require cooling on the board to ensure the thermal protections aren't triggred. Turning up the currents IS a cover up solution, there are units with the motor current settings down to 130 running well.

Turning down your jerk setting in the EEPROM may alleviate the issue as well (for testing set it to something like 4). If it clears up with that we'll be happy to go through finding the source of the issue so you can have it at a better value as well. Lowering your speed and acceleration are other values to change to see if it clears up, but again we'll do our best to help you have those at practical levels.

[grasshorse]

Excellent. I'll give those ideas a shot once I get more glue sticks!

Thanks!
Steve

[grasshorse]

Hello,

So I have been working on trying to get the ridges out of my print with little success. I have found some issues that needed to e fixed along the way, but nothing that gets rid of the error. The first problem I found was that the bed was super loose. Two of the blind nuts had stripped and weren't working. So I replaced those thinking that had to have been the problem. Nope. I also then checked the belt tension. Sure enough they were not all equal. At first I over tightened them, and was having prints that would crash Repetier. I loosened up the belts and that went away. I checked the set screws for the timing pulleys and they were fine. I added a fan to blow air on the RAMBO during prints, changed the current settings for the motors in firmware and lowered the jerk settings to 4. I'm pretty positive I don't have any of the Delta Arm Blues. I purchased a depth gauge when I upgraded to the Trick Laser Carbon Fiber Arms a couple of months ago. I have the Delta Radius dialed in pretty good. I'm looking for any other ideas to try. I'm going to try and post a photo of some test prints that I have made in a little bit here. Any ideas are greatly appreciated.

All the best,

Steve

[grasshorse]

Here is a photo of the aforementioned test prints.

Thanks!

Steve

[Eaglezsoar]

eyeballs.jpg

Here is a photo of the aforementioned test prints.

Thanks!

Steve

Have you made certain that the cheapskates are not too tight?

[grasshorse]

OK, I gave that a shot. In twisting each of the cheapskates I could feel that one of them could torque a little. So I turned the casters to add a little tension and remove a little slop in it. I then loosened up all of the cheapskates (the screws between the belt clamps) so they could move a little easier. Alas, the newest test print still has the same problem.

What I don't understand is how this just "shows up". Have others had this problem as well? Do I need to do a rebuild of the machine. It seems like I did that not so long ago as I mentioned before.

Is there something in the firmware that may be causing this? Could it be the slicer? It makes no difference if I use support or not.

Most of the speeds are around 27mm/sec with the exception of travel. If it will help I can do a screenshot of the speed settings.

[McSlappy]

A few have already suggesting checking the cheapskates and arms. I normally wouldn't suggest it again, but I've had this same issue just the past few days.

I pulled the arms off the little metal swivels (technical term) on the cheapskate ends and checked each one by hand. I found that 1 of them was extremely difficult to move so I pulled the axle off, took the swivels off, cleaned the axle (with VERY FINE grit) wet and dry and washed the axles, and swivels in alcohol (Jameson single malt ).
I put it all back together and it seemed to be good, but it showed up again the next day. I pulled the arms off again and found another swivel was a little stiff, not as bad as the other, but not smooth. I repeated the same; removal, cleaning etc. This time I put them back on and used some Selleys Ezy Glide (dry non oily lubricant designed for zippers) on each of the swivels. I'm not sure if this stuff is kosher, but it seems to be working beautifully and the ridges and wavy walls are gone.

Like you, I had this issue just randomly show up in some prints and not others, or halfway through a print, then it would disappear.

It doesn't seem too likely on the models you've shown, but I've also had it shift like this when the nozzle was repeatedly catching on the edge because the filament was curling on an overhang... By just choosing a higher Z-lift value it got rid of it (5mm just to be safe).

[grasshorse]

Thanks for your ideas! I'll give them a shot. I tried a much simpler print of a cube and it printed much better. There was one big ridge, and then some noise on two of the four vertical sides. I have the trick laser arms, so I wouldn't expect them to be much fiction there, but I will take them off and have a look. Anyone think putting graphite on them would help? I think the z-lift is a great idea. I'll up that and see if it helps.

I thought that maybe the part was not slicing well. I did use a bunch of booleans in modeling which is kind of a no-no, so I tried Cura to see if it was an issue there. I didn't get Cura totally dialed in, but it was clear that the problem was there as well.

I'll keep trying to crack this nut.

Steve

[grasshorse]

Hello,

So I have had a little success, kinda. I changed the part I was trying to print to a different one. The first print of it I did, had a lot more ridges in it because of some poorly designed overhangs. I fixed those, and I also adjusted the cheapskates and lubricated the arms. I first used "Elmer's Slide All" and that didn't seem to do anything. Then I tried 3 in 1 oils on the Traxxas ball joints from the Tricklaser Carbon Fiber arms. That didn't seem to do anything either. I then checked the cheapskates. I immediately noticed that one arm had so little friction, and moved so easily that it could barely stay in position under its own weight with the power off. The other two had more friction. I loosened things up loose as they can get and still have more friction that the first trolley. I basically adjusted the pinch rollers so they just touch the extruded aluminum legs. Trying to find a way to reduce friction some more any ideas? Should I be trying something else as lubricant? I see that people have recommended "Super Lube". I may order some of that stuff. Any ideas or insight is greatly appreciated of course.

All the best,
Steve

[grasshorse]

Ok, I think that I might have figured it out. I was thinking that it might be the ball joints were not lubed that was causing the problem, but I lubed those and it didn't make a difference. So then I started wondering about the kit bearings used in the cheapskates. I started replacing those and the first arm started to move a little more smoothly. I then moved on to the second arm that was stiff and l noticed what felt like flat spots (approx 4) in the travel of the cheapskate trolley. I pulled out the stepper motor and checked it over. Then I looked at the timing pulley and belt. They all seemed fine. Then with the stepper motor off I discovered the flat spots where still there. I then swapped out all of the bearing (with the exception of the one by the stepper motor) and the flat spots went away. I lubed up all the bearings on the machine. I swapped all the bearings out on it with the exception of the VERY easily moving cheapskate trolley. I'm doing a test print now, and everything is looking good so far. I haven't seen anyone else have problems with bearings, but I highly recommend changing them from the kit bearings. I upgraded to ABEC 7 bearings which are still fairly economical. I would love to see what something like Bones Ceramic Swiss bearings would do. Has anyone else swapped bearings? Any other recommended brands?

All the best,

Steve

[Eaglezsoar]

I am interested in what caused the kit bearings to have flat spots in them? You are the first that I have seen on the forum who has had a problem with
the bearings supplied with the kit. Do you have any idea what caused the bearings to have the flat spots?

[grasshorse]

The flat spots that I felt was in the travel of the cheapskate trolley on the leg entirely assembled, with the stepper motor uninstalled. So the source had to be in the cheapskate trolley. I inspected every bearing after taking them off them none of them were rough running as if they themselves had flat spots or were rusty. When I changed them the effect went away though. My machine has about 33 days of printing on it. I don't know if that is "a lot", but I wouldn't consider it so.

I did wonder if it was flat spots on the plastic clip on covers for the bearings. I did inspect each one, and it didn't appear so. Also I used the same covers on the new bearings I installed.

When the effect appeared it was on a very long print. Something like 48 hours.

I hope that helps.

Steve

[Eaglezsoar]

Steve, it really doesn't help me to understand but I'm just glad that you have reached the point where you are happy with the quality of your prints.
Good job in diagnosing and fixing the problem.

[grasshorse]

Just to give an update, the bearings weren't the problem. They certainly do help. I imagine reducing any friction in the system helps, but it looks like the flat spots were more do to the snap on "tires" for the bearings. I had some of them torqued down too tight and made flat spots. I also worked with the idea that there was too much friction to pull the filament off the spool and added a snap in bearing to reduce friction there as well. I think it has helped as well. Still trying to get all of the ridges out.

Steve

[grasshorse]

Ok, I really, really, really, really figured it out!
I had upgraded to the e3d v5 hot end. When I was assembling it, I just barely tightened the heater block. Over time this loosened up a lot and was spinning loose. Once I tightened the heater block back up all of the major ridges came out of the print. Yahoo! I had one big hiccup that was a result of not using support when I needed to, but other than that things are looking fantastic! Thanks for your help everyone. I greatly appreciate it.

Steve