Hi there! I’ve had this printer about a year now. I used to use my buddies og Ender 3, and when the V2 was on sale I “upgraded” and got my own.
I realize now that for just a bit more money I could’ve had a much more performant machine, but, oh well. I’m gonna use this for a good long while. I only print as an occasional hobby, or to augment my other hobbies.
Anywho, it’s been on a shelf up and out of the way all winter, unused, in a climate controlled room.
I pulled it out the other day to do a few prints, it works great. Ran about 12 or 16 hours of prints through it. But today I noticed these cracks. This seems to be the belt tensioner for the bed? Did I have it too tight? Am I supposed to relax it while it’s being stored?
I can probably print a replacement. But I was just wondering what your thoughts were.
Thanks!
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I repair 3D printers for a living, this was dropped or slammed into something else. That connector on the v2 is NOT a flimsy plastic. But you’re right, you can just print another one. The belts don’t have to be so tight; at best “snug”.
Thanks!
I would say it was a combination of being too tight and the tensioner being made as cheap as possible. You don’t need the belts “rock solid” and I would check the bearings/bushings on the other end for damage too. Any kind of wobble is going to amplify enough to show on your prints, but if that matters is up to you.
Also yes. It’s more than possible to print a replacement and I would check if there are better designs on Printables. Ideally, you want a metal one unless you print one out of PC or another strong, high temperature plastic. Repetitive bending creates heat and heat will eventually deform PLA or PETG. You will get a lot of repetitive motion on a tensioner. However, nothing really needs to be perfect, just temper any longevity expectations based on what you are willing to invest in time and materials.
Thanks for the recommendations! PLA and PETG are all I’ve ever printed with.
Maybe I’ll look into buying a replacement one, I’d rather not worry about it 🤷♂️
PETG will almost certainly be fine. Just use lots of walls (6 walls, maybe 30% infill). PETG’s heat resistance is more than good enough for a non-enclosed printer. Prusa has used PETG for their printer parts for a very long time without issues.
Heat isn’t the issue to worry about IMO. The bigger issue is creep/cold flowing, which is permanent deformation that results even from relatively light, sustained loads. PLA has very poor creep resistance unless annealed, but PETG is a quite a bit better. ABS/ASA would be even better but they’re much more of a headache to print.
Infills over 10 to 15 percent get you very little increase in strength. It’s not until you get to the sweet spot of 80-85 percent infill rates do you get a real boost in strength. Then above about 85% the gains again taper off dramatically all the way to 100% infill. Otherwise you are merely wasting filament and money to just feel good. If you need more strength, add more perimeters and tops and bottoms.
I would use a .60mm nozzle, PETG or PLA will work just fine, 4 perimeters, and 4 top and bottom layers. And either 10% cubic or gyroid infill. That should create a part that will last for years.
Thanks!
In my experience doing a bit more than 10% can be helpful in the event of underextrusion, plus I’ve seen it add a bit more rigidity. But you’re right that there are diminishing returns till you start maxing out the infill.
4 perimeters at 0.6mm or 6 at 0.4 should be fine.
That’s good to know, maybe I’ll give it a go then 👌
Totally. There is heat from repeated deformation, but I didn’t explain how little heat it was, so I clarified in a later comment. All motion creates heat, etc, etc. (TBH, I shouldn’t have mentioned it. Oh well. I let that cat out of the bag, so it’s too late.)
But also yes, I have experienced PLA “cold flowing” on some parts as a well so I can confirm that for sure.
All good, it’s still something to keep in mind (especially if OP thinks about enclosing their printer in the future). Thanks for your comment!
Keep in mind that any heat created from stress on plastic will still be minimal and it will just take lots of time to create visible deformation. You can mitigate this mostly by printing critical parts at 100% infill.
I always over-engineer parts that are mechanical. That is just my preference. If you look at the original part, it is likely designed to be strong on only one axis. This saves money and time for bulk manufacturing. (Compensate home prints with better materials or bulkier printing is my own rule of thumb. Everything is a trade-off, is my point.)
Maybe I’ll take a crack at it then, thanks!
Please do! Success is awesome, but failure is important. Enders are pure hobby printers, after all. Half the fun is tearing them apart, rebuilding components and learning what works and what doesn’t for your own use cases.
IMO heat formed from stress will not be a big deal, especially considering that people frequently build machines out of PETG (Prusa’s i3 variants, custom CoreXYs like Vorons and E3NG). The bigger problem is creep, which suggests that you shouldn’t use PLA for this part.
Petg inside the enclosed though can definitely have a short service life, the original x axis idler on my mk3s gave up the ghost after a month or so of pretty consistent printing of abs in the summer, had expected it so i the first thing I did in abs was a set of prusa spares which lasted until I did a bear mod last year.
There’s obviously variation in filament though so YMMV, petg is still a solid material to use if you don’t have an enclosure (though I’m always recommending then if only for gasses and fine particles while printing)Yeah, I agree. In the photo I didn’t see an enclosure so I said PETG is fine for this application. With an enclosure you’d really want to use ABS/ASA, though PETG could work in a pinch.
I also agree that an enclosure (combined with a filter) is a good idea. I think people tend to undersell the potential dangers from 3D printing, especially for people with animals in the home.
What filter would you use? I’ve never played with abs because I didn’t want to have to vent an enclosure outside, especially in the winter. But if it could all stay inside that’d be great.
I have a cat. Cat tax:
Cute cat! Nevermore and Bentobox are two super popular ones.
Since you’re running an E3 V2, first make sure you’ve replaced the hotend with an all-metal design. The stock hotend has the PTFE tube routed all the way into the hotend, which is fine for low temp materials like PLA, but can result in off-gassing at higher temperatures such as those used by ASA and some variants of PETG. The PTFE particles are almost certainly not good to breathe in during the long term, and can even be deadly to certain animals such as birds at small quantities.
If there’s enough thread I’d probably stick a big washer under that to help prevent it getting any worse
Thanks for the suggestion
Yes you’re supposed to relax it while it’s being stored but this wouldn’t cause that.
This thing was dropped on its front.
Don’t know if you got it like this or if you got someone else in the house but that y axis tensioner sticks out pretty far in the front and it looks like it got knocked pretty good.
Hmmm, I don’t remember it being this way when I bought it. I suppose it’s possible someone dropped it, I’ve had people watch my house over vacation. But then again, I didn’t align anything or even level the bed before I used it after storing it, you’d think it’d be at least a little out of whack?
