Linear Bearing Lubrication Frequency
Patricia
- Checked all screws 2x
- Lubricated the Linear Rails after contacting the support (2 years warranty?)
- Removed the Metal Covers to reduce Noise
- Checked and had to slightly adjust belt tension
Tried to record the sound, guess the IPhone Speaker can not catch or handle the high frequency so good.
Yet you can hear, that the from time to time when he moves 2 axes at the same time, the sound increases.
The Printer is placed on an massive Wooden Table which is 80mm thick, in the basement.
However, I can not run the printer during the night anymore, the sound level is so high, that its easy to hear during 2 floors and 2 closed doors.
Has someone a good explanation for this?
I've tested quite a bit and the source seems to come from the 2 Motors next to my 5 Toolheads and in the Nextruder itself you feel heavy vibrations.
Tested with this procedure ->
Before the latest Firmware it seemed to be better, maybe this is something I have to check too
Would greatly take any advice, which is not cosmetic like foams to absorv the noise.
But to kill the source also for the sake of the lifetime of the Printer. (4K $ with Tax btw...)
Mine does since since the beginning (5.1.2 firmware). Depending of the speed, the X/Y motion system generates strong vibrations that let different parts of the machine to resonate. The extruder cover and LED strips are the most noticable, followed by all metal sheets.
I talked with the support, but they weren't that helpful except directing me to youtube where another user described his efforts to dampen those vibrations. For a machine of this price I had hoped that the support would be acknoledging the issue, and promising to get rid of the vibrations.
Now after the first grease session with the new "optimized" one.
The Average DB came down to 59 was 73 before
Peak is now 70-73 and frequency is not shooting up so high anymore, still able to hear it but runs now on lower frequency. (Less painful)
You don't have to switch back to the non-input shaper profiles, because then you also do without Pressure Advance. It is sufficient to change the speeds and acceleration values to those of the non-IS profiles.
Unfortunately, Prusa probably has a general problem with greasing moving parts such as bearings or rails. Even their linear bearings on the Mk4 are sometimes not greased. Even the support team once told me that the bearings on the Mk4 don't need to be greased, which is total nonsense.
Influence factors
The relubrication intervals are affected by several factors. Load and contamination usually have the strongest effect. Accurate relubrication intervals for a specific system can only be determined after the actual operating conditions have been assessed for a sufficiently long period.
Lubrication interval for conventional linear guides and grease lubrication
The default value for relubrication with grease for conventional guide systems (LGBX series) under normal operating conditions is every six months or after 100 km travel distance. This value can be adjusted upwards or downwards under special environmental conditions. The lubrication interval should not be longer than two years or 500 km travel distance, even under optimal environmental conditions, without contamination and low load. The amounts specified in Table 4.8 of the Linear Guide Catalog should be used for relubrication.
Lubrication interval for linear guides with ball chain and grease lubrication
These values significantly improve for the same conditions when guiding systems with integrated ball chain (LGBG, LGMC series) are used. The default value for NTN linear guides with ball chains under normal operating conditions is lubrication once per year or after 500 km of travel distance. This value may have to be adjusted upwards or downwards under special environmental conditions. A travel performance of several thousand kilometers between maintenance steps is possible when the environmental conditions are good and the load is low. The maximum usable life of the lubricant must be considered when the lubrication cycles are very long. Our NTN Automation application engineers will gladly help you to determine the maintenance intervals.
Lubrication is a very application specific topic and Thomson linear bearings are compatible with a wide variety of lubricants on the market. Lubrication specialists can give recommendations for demanding applications but in general Thomson can advise:
Careful monitoring of the application is required to develop a good preventative maintenance schedule. The shafts should be kept with a slight film of grease/oil at all times. It should feel slick to the touch, but not dripping.
Linear slide tables should be lubricated per the manual, using a different grease that what was supplied at the factory can cause the grease to degrade. Thomson offers LinearLube grease which is suitable for most industrial applications. DO NOT use any type of dry lubricant (PTFE powder, graphite powder, etc.) with any recirculating ball or roller type of bearing. While these lubricants are good for sliding motion, they do very little to aid rolling friction.
I do not have an HDZ but do have a Shark. I use Super Lube Dri-Film Lubricant. The lubricant is dry and does not attract dust and dirt. It is slightly moist when sprayed but evaporates the carrier and becomes dry with a white teflon mist left behind. I have never had any trouble with the linear rails being dirty. Occasionally I clean the faces of the bearings because they tend to collect dust over time.
The dry lube does not attract dust like petroleum based lubes. The rails are a sliding friction but I agree that the acme screws/balls may not benefit from the dry lube but I dont think it hurts them. So one train of thought is to just wipe them down and let them wear and replace them periodically. Another thought train is to lube the rails and acme screws/balls with a lube. Since any type of wet lube will attract dust and make it cling to it the best may be some type of dry lube. In the end you just try some things based on experience and your best knowledge and change as things do not seem to work. I do not think that the dry PTFE lube is a long term detriment to my equipment and better than leaving it dry. Remember the rails are steel and I have a very humid environment in East Texas so a protective coat is better than no coating.
HIWIN ballscrews require appropriate lubrication either by greasing or oiling. Antifriction bearing oil is
recommended for ballscrew oil lubrication. Lithium soap based grease is recommended for ballscrew greasing.
Although the frequency of lubricating your linear guides may vary depending on the type of cutting you do and the frequency of use, we would recommend doing this procedure every 20-30 hours. However, if you experience any grinding noises or roughness in your gantry, we recommend doing this procedure more often.
To replicate the issue I first cleaned all of the grease and debris from a spare ZX gantry using brake cleaner. This provided a situation where the linear guides would have no lubrication. Then the guides were coated in MDF dust and were moved back and forth.
Although I was not able to create a complete failure of the bearings, were was a noticeable increase in friction, and over a longer period, I suspect that the bearings would be able to be coaxed into seizing.
After this testing, I applied machine oil to the guides as discussed in the section above and the linear guide returned to its original smooth movement. I believe that cleaning and relubricating the linear guides can return seized linear guides back to life, and maintaining them should ensure smooth operation for the years to come.
Use this handy calculator as a general guideline for establishing grease frequency and volume in bearings. If you need help creating precision calculations for your equipment, consider contacting a Noria lubication expert to help you get started.
This formula can be used with metric measurements as well; just use 0.005 instead of 0.114. The result will be grease quantity in grams. This formula works for all bearings and is widely accepted as the best way to calculate grease quantity.
Temperature is known to affect both grease and oil, so naturally one of the first correcting factors that must be collected is operating temperature. The hotter the environment, the more frequently the grease must be replenished. The ambient contamination (how dusty the environment is) and moisture (how humid the environment is) work in a similar manner. The dirtier and wetter the environment, the more often the bearing must be regreased.
The final correcting factor is that of the bearing element shape. This is important because each different element stresses the grease differently. For instance, a ball rolling across the race churns the grease differently than a spherical element, which churns the grease much more heavily.
Below is a chart of these correcting factors and how they operate together. Once they have been calculated properly, the final pieces of the puzzle are the bearing ID and speed of rotation. Through some simple math, you are left with a run-time (in hours) frequency for regreasing.
Rtec SRV test system measures friction and wear of lubricant, oil, grease, and additives in linear oscillatory motion. Generate data compliant with several ASTM, DIN, and ISO standards. Test collected samples from the field or for research purposes.
The SRV tester comes fully automated and computer controlled. The setup is easy to calibrate and comes with standard oil and samples. Additionally, it runs several standard test methods and allows for new custom methods. This insures for future petroleum product standards.
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