New LM Bearings


The FLUX+ campaign mentions that it uses more accurate linear bearings, but it doesn’t seem that these are included in the upgrade kit. Does anyone know what the new bearings are and where to order them?

On that note, what other things were updated that aren’t in the kit? Is the control board or RPi new? I’d like to upgrade as many things as I can to keep the machine on par with the + version.



The Bearings are standard LM8LUU Linearbearings. I ordered some in a local store and its much better with the play of the carriages


I guess my question was more related to who makes the upgraded pieces. Are they an IGUS part number or are higher quality ones available through McMaster? I don’t want to order the eBay specials and end up with the same parts, or ones of even lower quality.


I’m also interesting on this, I tough the upgrade kit will include these things too but now I realize that it doesn’t


Jumping in here to follow along, although my options on some parts are a bit more limited.

No McMaster or Grainger here… But can buy electronics by the ton

Something wrong with first layer!

Maybe you can order them in a store where they have screws and other standard-parts.


The bearings used in the FLUX are kind of a oddball. They can be sourced, but not easily. The are the long version of the LM8UU. Jim found them before I think. Locally, stuff like that is hard for me mostly because of language difficulties, if I can get the right translation I might find it, but sometimes if I say it wrong, it could be months before anyone will tell me… Most hardware bits it is easier to order.


I guess if you order the official type (LM8LUU), they can find it for you?


Yes, that is the last resort plan, like everything else. I would rather get parts from FLUX but if we must get them from somewhere else, well, I gotta keep my machine running smooth.

Today I actually discovered what I would consider a serious engineering flaw on the Delta, and really the first thing I honestly think I am going to hack to make it right.

If you look at the underside of the top deck, where the PTC/PTFE fitting connects, about 4cm in front of that there is a small detent in the plate. That detent is a stamped punch and is exactly mirrored on the other side of the top plate. That tiny .5mm nub is what is supposed to hold the extruder follower pressure spring in position. It took me a good 30-45 minutes trying to figure out why everything checked out okay, but I was getting feed issues. My spring had slipped off that nub, so the extruder was slipping intermittently. I finally found it when I took off the top cover to clean the hobbed gear and follower pulley and just check for blockages. Everything was pretty clean, so after I just stared at it in frustration for a while, I noticed the spring looked a bit crooked. Sure enough, slipped off that nub and just sideways enough. It still had lots of pressure when I pressed it to load, but just out of place enough to let filament slip sometimes. I think the solution is going to be drill, tap, and grub screw so it cannot slide again.


Ouch! Hopefully the replacement extruder kit will help with that… with it apparently being all metal it should twist sideways as much as the current one does…

btw, I just realised when looking at the upgrade kit picture again, that strange clamp we saw on the video the other day holding the USB cable and filament guide is in the upgrade kit… I suspect it’s their way to trying to straighten up the filament tube as it enters the print head…I much prefer the design I saw someone else do which also serves as a finger wrench for the quick-release fitting.


There are two versions of that in the files on the FB page. Tube Spanner, and Tube Spanner with Wings I have been using the one without wings for a very long time, and yes, it is extremely handy. I wish there was a way to make one for the little bugger on top of tube.

That detent actually surprised me how poor that design really is. I have a theory I may go back and test. I think FS 0.7.5 is doing something different at the start of prints that no other version was doing, as I hear it. At the very beginning, the very instant a print starts it does a super fast retract of about 10mm. It is a noticeable buck if you pay close attention. It is hard and fast and after a few repetitive prints I think that may have been what caused the spring to slide off it’s little nub. The only reason I happen to suspect that is that I’ve got a large order so I’ve been sitting next to the printer a lot, and that double clutching bug keeps me close, so I’m listening for it to start and you can actually see the filament kind of whip a little. I do not recall any prior version doing that. I will try to reload earlier FS and test theory when I finish this order…

Oh, and I have a question for you about when you removed the heat break ‘threaded metal thingy’. From which end did you take that out, and how did you take it out? I’ve put together a series of photos to go with text on nozzle cleaning, but I’ve never removed that part, so I want to ask how you did it.


Yes, the one with wings is the one I am thinking of. I also did the one without them, and funnily enough haven’t had to use it since installing it… but I did have to tighten it a few times before that ;). Might get some use shortly as I’m thinking of running the laser up.

Well, I can suggest that it is new, as I’m still running 0.7.4… I was about to upgrade as things had been quite without any comments about it being problematic… then the complaints started rolling in… and I don’t remember that retraction behaviour.

Ah yes… the “threaded metal thingy” :stuck_out_tongue: I basically just unscrewed the heatsink from the heat block, and then used pliers on the heat-break thread (bad pfeerick! :blush:) to unscrew the sucker till I realised what was going on. Since it had stayed nice and tight on the heat block, I screwed the ‘good’ end back into the heat block, and then screwed the heatsink back on the ‘bad’ end… hence why it won’t be coming apart voluntarily again… scuffed up steel thread biting into aluminium… as good as superglue! Problem fixed! :stuck_out_tongue:

If I were to do it again knowing the construction of the assembly, I would try to hold the sucker with some long nose pliers right where it enters, as IIRC there is no thread just there… but the question is getting enough grip on it to keep it still or turn it as needed.


So you disassembled from top down then? Unplugged fans, thermistor, heater core, took board out, then screws and dropped the whole hotend assembly out of the toolhead? Hmm. Even I have not had to go that far.

Or am I missing something? Is there any other way to get to the heatsink without going in from the top?


Ah… yes. I had the bottom plate off already as I’d had to clean the nozzle again. I then took the top off, fan and heater connections, unbolted the PCB and removed it. Then unscrewed the heatsink. I think it was at that point that the heat-block could come come out… not before, as it is inserted into a slot in the case.

If you find an easier way, that would be great, but I don’t think there is one. Hence why it was annoying to have to do it twice to stop the damn thing leaking PLA!!! :wink:


No, I don’t believe there is any other way. I was just curious if you had gone through all of that. I am about to have to do that with ‘Old Leaky’ unless FLUX can process my RMA really super fast.

I’ve got a couple E3D V6 hot ends sitting here on my desk for another printer, if I do have to disassemble this damn thing again at least I will be able to take some measurements.


If you take it apart, please take pictures to document your steps, it would help me and probably others eventually. Good luck


Definitely will.

I have a nozzle unclogging write-up started and photos of the bottom end and nozzle cleaning process already.

If my replacement toolhead doesn’t get back soon, ‘Old Leaky’ may have to undergo the full procedure.


I bought the LM and try to upgrade those on my printer over weekend.
The reason of replacing LM because there were many shifting between layers on a printing.

New LM is tighter than old one after a year of none stop printing. Now I’m printing few new test printing. I believe the new LM does help. The Z-resonance test has with really nice result, smooth wall and straight line.

Five point positive features. It is almost perfect print. I’ve not seen the result like that for months of testing.

XY Resonance 1mm wall test.

Tool head gets lot of melting filament accumulating inside about 8 months since a last cleaning-up. I think it is from all filament stringing/oozing from printing OR leaking over time. Hopefully a new Flux tool head has a fix.

Filament feeder is still in a good shape.

Lastly, there are slightly wear and tear on balls and magnetic rings. Thanks for WD-40 Specialist Gel Lubricant.
Continuing on the update of test results on the new LM.


I’m convinced. There isn’t much that holds the bearings in place. I’ve thought about replacing rods too. I see one rod always has a lot of lubricant that turns black, and now another is starting to do the same.

What was your process to replace them? One at a time so it was easier to keep machine together and aligned?

You’ve definitely made a difference. I’m seeing a slight layer shift but it is still sporadic, nothing consistent yet, but I definitely can observe carriage twist/wobble and that should not be happening either.

Really bummed FLUX isn’t getting these parts available, but maybe aftermarket will be better anyway.


I have a lot more printing models that have the shifting layers. Therefore I decide to try it if it help.
It took me one hour for the first time. There some few places that you will need to pay attention.

  1. There are 3 screws to keep a back cover. One screw is covered by a rectangle tape in between 2 magnetic rings.

    It’s the old LM.
  2. There are 3 cables that run to a top control boards parallel with the rods. Release all belt spring tension and belts from a top bearing before lifting a top metal holder plate. Lifting top metal plate evenly is to release all 6 rods and slightly twist it, so a top rod is free, then you can remove and replace a new LM.
  3. Important step before put a metal top is that a metal conduit must be insert all the way until its stop on a base along with its cable.
  4. Put a belt back in place together with snapping the LMs onto a plate holder. After put a tension back in and make sure the LM plate holder move freely up and down with no belt misalignment.
    However, I haven’t got any print of five positive features as close as stl model until now.