How often are you tensioning your belts?
Hi,
I'm noticing that the belt tension in my Core One seems to need re-tensioning (using the mobile app to check frequencies) about once a week, with me doing an hour or two of printing per day. Since this is my first CoreXY printer and my Mk3 never seemed to need the belts tweaking, I was wondering if this seems normal for a Core One? How often do you need to re-tension your belts?
RE: How often are you tensioning your belts?
I check about a once a week. I've had the tension dialed in exactly 98/92hz then a week later it was in the 80's. Not a show stopper but annoying since the belt tuning app (both web and dedicated) are wonky at the best of times.
RE: How often are you tensioning your belts?
My assembled unit came with the belts set roughly at 90-92hz and I haven't had to touch them in the some 500 hours of printing I've put on the unit. I print high temp filaments often so I expose the belts to higher temps as well. I wonder why some units are requiring frequent belt tensioning? I check my belts maybe once a week and so far they haven't changed yet.
RE: How often are you tensioning your belts?
I retensioned today after 474h ~ but i did it because I saw the new belt tensioning process. My first time tensioning was not satisfactory, though it did give me good results. The new tensioning process is much clearer to me, so I'm looking forward to better prints.
RE: How often are you tensioning your belts?
I’ve had to do it about three times now I don’t know how many hours are on The printer.
RE: How often are you tensioning your belts?
Retensioned Aust yesterday, because I wanted to,try the new procedere.
Just tensioning did not work so I loosened the belt completely and sated from scratch.
what I noticed though: the gantry and head moved so much easier with loosened belts.??? Up to now, I thought the motors would induce the resistance
do you notice the same ???
RE: How often are you tensioning your belts?
Ps. the loose belts are still turning the motors and do not slip. 😊
RE: How often are you tensioning your belts?
that is the reason why you are supposed to disable the motors (or turn the printer off) before doing the belt tuning... 😀
RE: How often are you tensioning your belts?
Didn't I read somewhere that the Prusa app on some phones misreads the frequency ? Says its 92 when its actually 46Hz? Harmonics in the phone voice filters plus the their in-app filtering algorithm. If it happens with lower harmonics, I can see it happening with higher harmonics: reads 92 but is really 138 or 184. A belt that is overstretched this way may require a lot of attention.
We need a tuning fork reference to use to make sure our calibration tools are fit for the task. That or an AWG with the correct belt response... lol.
RE:
What is interesting is if I play a pure sine wave at (for example 92hz) the belt tuner app doesn't even register it. However, other apps like Gates Belt Drive give me a reading of 92hz. Wondering if the Prusa app is doing a Fourier transform to find the fundamental frequency and that if it's too close to a pure sign wave (i.e. no harmonics) it won't pick it up?
I'm using this online tone generator: https://www.szynalski.com/tone-generator/
RE: How often are you tensioning your belts?
Meant to say above I was testing on an iPhone
RE: How often are you tensioning your belts?
That's a nice tone generator, @hyiger. I think the Prusa app is looking for the 'twang' to trigger a new reading, and it responds 'hit detected'. You can trigger a new reading by doing a mute/un-mute to the mic. Using that trick, I find the belt tuning function to work fine.
RE: How often are you tensioning your belts?
On a properly designed core XY printer, build with quality components, it's recommended to retighten the belts one or two months after the machine has been running, because the belts stretch a bit in the beginning. After that, usually there's no need to change the belt tension anymore, unless you make hardware changes affecting the belt routing (changing a stepper, etc..). Provided that both belts have exactly the same length, and the tension is roughly the same .the exact value shouldn't matter much, No need to use tuner apps, for that, with a bit of experience you can feel by hand if it's too low or too high.
Of course, that's for a properly designed core XY build with good quality components, Judge by yourselves if the Core One could be qualified as such. 🙄
RE: How often are you tensioning your belts?
That's a nice tone generator, @hyiger. I think the Prusa app is looking for the 'twang' to trigger a new reading, and it responds 'hit detected'. You can trigger a new reading by doing a mute/un-mute to the mic. Using that trick, I find the belt tuning function to work fine.
Ah OK. I tried doing something similar by rapidly turning the generator on and off but that didn't seem to work. It's good to know if the app is really registering the correct frequency or not.
RE: How often are you tensioning your belts?
I tested a strobe light app today. That works amazingly good. The belt vibrates a lot longer than expected.
i used this one. Strobe light tachometer
https://apps.apple.com/de/app/strobe-light-tachometer/id978182913
so when the build in led lights do the flashing tuning gets very easy