As I was having trouble with the existing bushings on the Flux 3d printer, I made these replacements with the Flux itself.
Problem is described more in depth by others here:
Getting them to work is a lot of trickery and might void warranty, so please use at your own risk and be prepared for trial and error, but I was tired of waiting for a solution and wanted the darn machine to work better. And now my printer is working a lot better.
Not as good as it can I think, but at least I can print again.
Make sure they are not too loose after printing (or you will the same issue as with the original ones), this also depends on print(er) quality.
If too loose, scale the file in X-Y by 99% or so, until you have one that fits tightly on 8mm rod.
I then slightly sanded the outside of the new bushings until they were nice and smooth and fit inside the existing housing.
For a tight yet smooth fit on the 8mm rod:
Take an old piece of 8mm steel rod, heat it with boiling water and slide the bushing on it. Let it cool or slide to cool part and it should be a nice fit.
On some this was not enough so I put some whitening toothpaste and water on the old rod.
(not the bleachy but the gritty kind, it polishes well)
Then either manually or with a cordless drill polish the inside of the bushing with the tooth-paste (thing layer) covered rod,until it runs smoothly.
You have to remove (part) of the top of the printer and the belts, to be able to remove the old bushing and place on the new.
But make sure they run smoothly individually before you re-assemble.
Also make sure they run smoothly in pair when built into the housing (no belt needed yet for this) before you re-assemble the rest. Sometime a slight twist on the rod for each bearing will make it nestle better.
If printed in PLA normally you do not really need any lubricant.
Stiction and friction is minimal enough and a lot of lubes dry out and increase friction or stiction in the long run.
Although I hear silicon lubes (bicycle spray did not work for me, dried up to gummy mess)
or lithium grease may help.