TAZ Very loose Solid rod bearings?

In other words… Do not use ball bearings on the stock rod! lol.

I personally use these rods: SFJ10-500 the have a HRC of 58 plenty hard enough for bearings.

Exactly. That’s why the plastic bearings work here. If I were to upgrade to steel bearings a rod upgrade would be an imperative.

Any update on the solid bushing and holders? To me, this looks promising to solve both the looseness issue and to quiet the movement.

I’ve just ordered harder 10mm rods from Misumi, PSFU10-500, as well as linear bearings, LMU10, and the solid bushings to try, SHBZ10-25.

BTW, Misumi has a promotion going on now for first time web credit card buyers…if you put in “First150–Reddit” in the promotion code area, they will take $150 off your order! There doesn’t seem to be any restrictions…i.e., you order $150 worth of stuff, you only pay shipping.

Ross

Hi Ross! looking to buy the same components myself and give it a makeover, mine is also loose and i can’t seem to print anything fast without noticeable resonance issues. I am stuck trying to find the different rod sizes needed, namely the lengths of the x and y rods. would you mind pointing me to this information? thank you so much!

This is what I ordered from Misumi:

PSFU10-500 52100 Chrome rods @ 58 HRc hardness --> http://us.misumi-ec.com/vona2/result/?Keyword=PSFU10-500

LMU10 Linear Bearings --> http://us.misumi-ec.com/vona2/result/?Keyword=LMU10

SHBZ10-25 Solid Bushings --> http://us.misumi-ec.com/vona2/result/?Keyword=SHBZ10-25

As an update, I printed off the solid bushing holders ( http://www.thingiverse.com/thing:263630 ), and the solid bushings fit well. However, I found that I wasn’t able to use them because I wasn’t able to get the alignment perfect. Using two solid bushings on the same rod requires perfect alignment, otherwise they bind up on the rod. I’m not sure if it would help to redesign the holders to have the slot in the round portion to allow the bushing to “float” just a little bit…just like the stock holders. At the moment, I’m going back to the noisier linear bearings :frowning:

Ross

An update: I replaced the soft stainless steel stock rods with the hard 52100 chrome rods, and upgraded the linear bearings with the Misumi ones. I was pleasantly surprised at how quiet this set-up is. No more squealing or resonance problems. I did see on the removed stock rods that there were many indents and score lines, due to the very hard ball bearings. I’m sure this is what was causing the very loud squealing.

Now the loudest part is the stepper motors, and I’m not sure what we can do about those :slight_smile:

So far I am happy with the lack of bearing/rod play and the low noise level!

Ross

Ross,
I have updated the Single Bearing holder with a split at the top. Please let me know if that works better. On my printer I just used a piece of metal as a guide for the bearings to align them. I do believe that the break in the top may solve the absolute precision of it and allow for easier installation. If the single bearing holder works well for you then I will make the double one as well. Please let me know.

EDIT: I just went ahead and made the Double Bearing holder with a split in the top. You can get both on the Thingiverse page: http://www.thingiverse.com/thing:263630

Thanks very much!

I will try them, but maybe not very soon. Before I saw this thread, I was using the stock stainless rods with cheap bearings, and they squealed quite a bit. I then started using the much harder 52100 chrome rods with better bearings from Misumi, and it is day and night. No more slop and play and the only noise is from the stepper motors. Hopefully it stays this way…if not, then I’m going to try the solid bearings with your updated holders with the split.

Are you not having any issues with binding?

thanks, Ross

Thanks for all the pointers chaps, I’m having the same problems. Lots of slop, everything goes out of alignment on every print, hard to line up the Z axis as it move about so much.

Also when my machine turned up the table and fixture fell apart as the brass set-screw holders that hold the rods in have been mounted in a way that makes the hole too big. I emailed lulzbot sales and was ignored.

Sigh will visit my local bearing firm on Sat morning to see what they have.

I’m sorry to hear that the brass heat-set inserts on the Y axis wasn’t secure. That’s doesn’t happen often. Is it currently secure? If not, contact our support team at support@lulzbot.com as it will come directly to us to minimize any potential delays. We work rather diligently on making sure that every contact is responded to within one business day, so we apologize if your message was missed. I’ve found the thread from earlier this month and will have more information for you shortly.

Before you replace anything, how well is the Y axis smooth rod secured in it’s housing?

I have also found a bit of play on my x axis solid rod bearings. I don’t know if or how it affects my prints yet but I am curious, for those who have tried. Have there been any significant improvements after changing to the Hardened Steel Rods / Bearings?

My experience was the hardened rods and metal bearings took out the wiggle but imparted a texture to my prints. I have moved on to piercet’s openbuilds mods on X and Y. HUGE improvement! I highly recommend openbuilds over hardened rods. The openbuilds mods also take out all of the rod flex on the x axis.

You may also try other bushes, I will change to RJUM-01-10, see also here. I will do a comparison when I have them.

I have read several comments about loose bearings and problem with extruder vibration. It seems to me that if the center of gravity of the entire print head assy could be determined in 3 dimensions, (requires removal), then a counterweight could be fabricated and mounted on the opposite (back) side of the rails. The counterweight does not have to be very heavy; if for example the moving extruder assy weighs 1 lb, and the center of gravity is 1.5 inches in front of the belt attachment point, then a 1/4 lb counterweight cantileverd 6 inches behind the moving extruder assy, opposite the center of gravity, then there would be no twisting moments created by acceleration in the X direction.

Is this feasible?
Pete

Try it and report here :wink:
But I think it may introduce new vibrations if you get no super-stiff connection…Like the rods itself acts as springs.