Oddly shaped holes?
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@bondus Yes, the Igus bearings are built to quite tight tolerances, and to not like any mounting error or rod misalignment. Industrial equipment, which is what they are designed for, usually is toleranced more closely than 3d printers. I designed a bearing mount: https://github.com/mendenm/hemera_mount_plate which has a self-aligning lower bearing block which avoids this problem.
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@zapta Yea I was looking at those but I wasn't going to pay 20-30 dollars a bushing when I need 8 of them. I'll just stick with the regular bearings. Are there any recommendations on good bearings? I have all chinesium ones right now, but if I find out that it does end up fixing my problem, I'll most likely upgrade to better bearings.
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I used to use Thomson Super8 bearings when I was still using 1/2" round guide rails. I was buying them new on ebay for $5-8 each. They allow adjustment of preload and the races can tilt a little to compensate for slightly inaccurate mounting.
Make sure your rails are hardened- ball bearings will cut grooves into unhardened rails.
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@mrehorstdmd @zapta @mendenmh @mwolter @arhi I just replaced the Igus bushings with the LM16UU I ordered. No more issues. Now I have no idea what to do with all these Igus bushings I have.
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I'm a little late to the party I know but I started down the carbon fiber/igus route back in 2017 and although it "worked" it was way too finicky. The plain igus bearings MUST be press fit into a very specific hole diameter to be usable with the specified diameter diameter rods. Most of the carbon fiber rods I bought needed tuning with 1000-1500-2000 grit sandpaper to get them to have constant and reasonable friction in the bearings. Some could never be tuned properly because they were too narrow to begin with. Also, while most of the roll-wrapped ones were spot on for straightness, some were not which made trying to get matched sets almost impossible. In the end, I gave up.
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@Surgikill said in Oddly shaped holes?:
Are there any recommendations on good bearings?
When I need good quality bearings and rods I get them from Misumi. They have a large selection and they sell them also in small quantities, including but to length rods.
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@gtj0 said in Oddly shaped holes?:
I'm a little late to the party I know but I started down the carbon fiber/igus route back in 2017
The lure of light weight moving mass.
I tried bowden, igus bushings and carbon and aluminum rods but after a lot of trial and error realized that a solid design with stainless steal rods, real ball bearings and a direct drive give me the best print quality.
Time to adopt this term from the bicycling world
https://www.urbandictionary.com/define.php?term=weight weenie
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@Surgikill said in Oddly shaped holes?:
Now I have no idea what to do with all these Igus bushings I have.
ebay?
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@zapta You're correct of course but you can always learn something new by trying something no matter how it turns out.
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@gtj0 But many others have tried before with the same results.
How many times does a known failure have to be duplicated? It's one thing if you think you understand why something failed and have some new twist to apply that you think is going to fix the problem, but something else entirely to simply copy other failures and expect that it will magically work this time.
Of course, you don't always know that something is a failure. A lot of people post their designs on the web, but not many of them post their failures. Sometimes you have to read between the lines to recognize a problem that the designer doesn't realize or won't admit exists. Also, the web never forgets. Maybe you post a bad design, then learn later that it's a problem, but that bad design is still out there. It can be a lot of trouble to try to update or expunge old posts, especially if there are a lot of them.
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@mrehorstdmd Yeah isn't the definition of insanity "doing the same thing over and over again and expecting a different result"?
Still, as I've said in other posts, I learned a great deal in that exercise and would not trade it for anything. Some day someone will do something that "has been done 1000 times before" and discover something new. -
@gtj0 If you can gain the knowledge by reading, watching a youtube video, or even just thinking a problem through, is it worthwhile to spend time and money testing the failure yourself? The whole point of people bothering to publish their results is to show others how something can be done or to show how something doesn't work so others don't have to duplicate the same errors/failure. That's the way progress is made. If everyone had to reinvent the wheel every time they needed a wheel, we'd still be living in caves.
"Some day someone will do something that "has been done 1000 times before" and discover something new."
No, they won't. Not if they do it the same way those 1000 other people did it. No one who knows what a hammer is has to hit their thumb with it to know it's going to hurt. You can try 1000...00 times and it's going to hurt every time. -
But many others have tried before with the same results.
hm, I have igus on my M150 and it works flawlesly. not only it is silent I got rid of all the ringing I had with linear bearings fore that .. I changed to igus 'cause I seen some superb results from other ppl so I would not agree that it's a given that igus will bring you problem
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@mrehorstdmd said in Oddly shaped holes?:
is it worthwhile to spend time and money testing the failure yourself?
Sometimes! I find the spark of creativity only comes when you're bashing your head against a problem with your own bare hands. Reading about it just doesn't generate the brain activity needed.
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@arhi I have no doubt that they can be made to work, especially if you follow the manufacturer's recommended methods of using them, which few people building 3D printers do.
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@mrehorstdmd The dozen or so patents I have are all for stuff others tried and found impossible to do.
@Phaedrux +1
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@gtj0 They don't hand out patents for doing the same thing everyone else has done.
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@mrehorstdmd said in Oddly shaped holes?:
@gtj0 They don't hand out patents for doing the same thing everyone else has done.
No but people who try and fail don't usually apply for a patent.
All I'm saying is that there can be value in trying something that others have failed at. Maybe it's just personal growth or maybe the 1001th person will be smarter than the previous 1000. Or maybe it's just wasted time and money. Who knows?Anyway I think we've probably derailed this thread enough. Sorry guys.
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@mrehorstdmd In my case, I watched a guy on youtube who had great success with the CF rods and IGUS bushings, so that's why I went with it. That was the only time I had seen it done.
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@Surgikill Well, that's the problem, isn't it? People post a snap-shot of their work at one point in time. Maybe after using it a while, they discover that it wears out quickly, or maybe they left out some details in what they did, so their result isn't reproducible. Details matter, but details are boring, so they are often left out. Getting something to work long enough to shoot a video and getting it to work for 5 years are two different problems. Few go back to show if something went wrong and what went wrong or why.
If you look at the printers people build from BOMs and plans posted around the web, you'll see a lot of variation in the final printer even though people built from the same plans/BOM. People make substitutions when they can't locate a specific part, or design changes when think they have a better way to do something, or their printed part quality doesn't match the original, or their assembly technique was different/sloppy, so everyone's Voron (just to choose a popular design) looks different from everyone elses, and some of them work and some don't. Details matter, especially in precision mechanisms like 3D printers.
CF rods and tubes aren't generally made for use as linear guides. The manufacturing techniques used to produce them don't generally result in precision surfaces or accurate shape or diameter.
What is the reason to substitute CF rods/tubes and plastic bushings for proper linear guides in a 3D printer?
What is the reason to substitute CF rod/tubes for the guide rails that the plastic bushings are specifically made to work with?
What are the chances that combining some random CF rod/tube, not made for precision linear guidance, with some random plastic bushing, will result in the precision linear motion needed in a 3D printer?
