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Quality Parts

Posted by Mr Kroll 
Quality Parts
June 05, 2022 06:39PM
Hello, how is everybody?

I have an Anet A8, and have been having trouble finding consistent quality components.

I really don't want this post to become a venue to "bash component suppliers or components" If you don't have something positive to contribute, Please don't post.

I recently replaced the linear bearings with Ingus polymer bushings. I absolutely loved them. They were quiet and ultra smooth. They were supposed to be self lubricating. I found that they tended to run less and less smoothly with time/use. Silicon spray would lube them for a print or two, and then they would be dried out again.(running rougher/ noisier) I then tried a product called Super Lube (absolutely awesome stuff) Super lube would keep the printer running smoothly for a week at a time, with heavy use. It just seems to me that the polymer bushings get very loose fairly quickly, causing print artifacts. Link to Super Lube - [www.amazon.com]

I have now replaced the bushings with standard Chinese 8 x 15 x 25 mm linear bearings. Out of the box when I slide them onto the shafts, they seem to grind. I very carefully worked super lube into the new bearings, and installed them. They are quite noisy, and loose. They slide in a very inconsistent manner. Has any one found a quality supplier for bearings/bushings? If so, what brand and size? where were they purchased? What did you notice about the operating characteristics/performance?

Does any one have any results for other components that they would like to share?
Re: Quality Parts
June 06, 2022 01:52AM
For the most part, consistent quality means expensive. Therefore, I prefer to find ways to work around inconsistent quality smiling smiley

For linear motion, I think SBR rails are the safest bet. The set screws in the slider blocks allow you to adjust the tightness on the rails so you can get them just right without the need for high manufacturing precision.

Chinese MGN rails are a crap shoot, but if you buy enough you can mix and match slider blocks to whichever rails they fit best and then they're as good as anything. I have gotten a couple of curved rails too, which was fine for my project (mini-mill with a sturdy frame), but wouldn't have worked for a 3D printer with free-floating rail or only a piece of 2020 extrusion to screw to (probably would pull that into a curve too).

If building a one-off machine, you can look for high quality used rails on ebay and design around whatever you get a good deal on.

But all of those are noisy at the high speeds of 3D printing. Better for milling machines. For printers, plain old V slot wheels are a surprisingly brilliant design. Quiet, and even with poor manufacturing precision the wheels simply wear themselves to fit the groove, and the eccentric bearing allows adjusting the preload both when new and as they wear over time.
Re: Quality Parts
June 09, 2022 07:21AM
Another popular thing to do with inexpensive chinesium rails is to buy quality ball bearings and re-ball the carriages. Many people have found great success through doing that, although I haven't personally tried. If you're trying to stay in a low budget, aliexpress is a good source, provided you are willing to accept longer shipping/delivery times. Mellow and Trianglelabs are two vendors that are generally regarded as having reasonably good quality control. Whenever I decide to cheap out on components, I opt for one of those two vendors. Robotdigg is another reasonable vendor for better quality cheap parts, but also has slow shipping and sometimes their shipping costs can be a little high depending on what you're ordering.

I too am a fan of v-slot for 3d printers, and openbuilds.com is proof-positive that they can be used effectively in reasonably precise hobby applications for CNC Mills, 3D printers, lasers.... plenty of proven designs posted there.

Regarding your specific question about linear bearings, I have purchased excellent bearings from the Mellow store on aliexpress which have been in used for my print bed for over 2 years without issue.
Re: Quality Parts
June 09, 2022 03:13PM
If you're working off someone's BOM instead of designing your own machine, you're sort of stuck using whatever they chose to use, often because it was the cheapest available part. But if you have access to tools and a working brain, it usually isn't too difficult to substitute good parts for crappy ones. I prefer to buy quality used linear guides via ebay instead of poorly made, no-name HiWin knockoffs. You can screw around trying to get bad linear guides to work or you can screw around modifying the design to accommodate good linear guides that might be a different size. If I have to screw around, the latter effort seems more worthwhile to me because it will yield a better result.

When you look at ebay listings for the quality brands you'll find hundreds of crazy high priced parts. Keep digging. There are always some good deals buried among the overpriced stuff. Good brands to look for include THK, Bosch, IKO, Thomson, and a couple others I am forgetting. HiWin makes good stuff, but there are so many knockoffs around, I wouldn't buy them unless they are coming from a HiWin distributor. HiWin and knockoffs have the same MGN/MGH part numbers. When I search, I lsearch either a specific brand or use a search like this: "linear guide -mgn -mgh -hiwin -sbr -hgr -hgh -rod" which filters out a lot of the trash I'm not interested in. I buy linear guides that come with the number of bearing blocks I need and rails that are at least as long as I need. They can easily be cut shorter with a cut off wheel on a grinder.

Trying to mate separately purchased guide rails and bearing blocks is usually a bad idea. It's usually very expensive and you may end up with poor performance due to poor fit, especially if you're buying no-name parts.

Here are a few examples of a pretty good deals for name-brand industrial parts:
[mMAAOSwAoRXF00N" target="_blank" rel="nofollow">www.ebay.com]

Edited 1 time(s). Last edit at 06/09/2022 03:13PM by the_digital_dentist.

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]
Re: Quality Parts
June 10, 2022 11:10PM
Thank you very much for the information, I found the information about the SBR, and the MGN rails quite helpful. It is nice to know about the set screws and hopefully being able to set the pretension of the bearings as a possible solution to the system being loose.

Obelisk 79, thanks for the recommendation's of Mellow, Trianglelabs, and Robotdigg. - Robotdigg's web site sure looks like they may have a higher quality control than others. They may be a source for tolerable bearings.

the_digital_dentist - Great insight, into setting up rails, I appreciate you sharing what was probably quite a bit of trial and error learned the hard way.

To some up So Far;

1) SuperLube - Great stuff
2) SBR & MGN Rails - Allow for pretension to be set.
3) Mellow, Trianglelabs, and Robotdigg, - Look like they might have a least some quality control.

Does anyone care to share any further findings about components?
Re: Quality Parts
November 24, 2022 09:47AM
Hello Again, I ordered H5 tolerance shafts (Ground to between 7.994MM & 8.0MM) from Misumi USA. All 6 shafts measured exactly 7.994MM when they arrived. (Well worth the $20.30 EA) I ordered LMU8 bearings from them as well. (at $8.39 ea. for the bearings) It is absolutely amazing how quiet and smooth the printer runs now. Huge increase in first layer and wall quality. I have nothing but good things to say about the Misumi Corporation. www.misumiusa.com
Re: Quality Parts
November 24, 2022 09:48AM
Does anyone Know of A good quality GT2 belt?
Re: Quality Parts
April 08, 2023 11:44AM
I found Gates belts model number LLGT2. I have been running them for 3 months now, with absolutely no sign of wear. (or even stretching)
Re: Quality Parts
April 09, 2023 02:16PM
I've had Gates LL2MR09 belts in my printer for at least 4 years without and problems.

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]
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