How to determine the belts are tense?

How to determine the belts are tense?

I use a pitch test, place the print head dead center and pluck the belt on the short side of the belt (the long side tension doesn't matter, doesn't carry the load).  You can compare with the other belts of same length, tension all to the same highest pitch (and then remember for later), it is probably a good guess.

Listen to attached file, this is how my xy belts were set from factory.

The short stepper belts are a lot tighter, the belts feels almost stiff.

Listen to attached file, this is how my xy belts were set from factory.

When is your album coming out?  

I use a pitch test, place the print head dead center and pluck the belt on the short side of the belt (the long side tension doesn't matter, doesn't carry the load).  You can compare with the other belts of same length, tension all to the same highest pitch (and then remember for later), it is probably a good guess.

Listen to attached file, this is how my xy belts were set from factory.

The short stepper belts are a lot tighter, the belts feels almost stiff.

Even if the two different leghts belt have the same tension (pulling force in the cord), they would Sound different.

The Sound is determinded on their self frequency. frequency = tension x free leght.

​The necessary tension you calculate by “torque” x “safetyfactor” x “manufacturer info” for a standard belt drive.

But what we Need is stiffness. I'm not sure if it's raising linear with the tension.

best Regards

Michael

Hi Michael.

For the long belts, the reason I mentioned to move the print head dead center was to ensure the belt lengths are all the same.

Belt resonate frequency is an industry standard way of determining belt tension. However, the relation will not be linear between tension and pitch and there should be other terms (mass, width, and possibly damping). A formula/lookup table can be found from datasheets.

The motor belts (short) will be much higher pitch. I can record as well, but basically they are very tight, where the belt is almost solid feeling. I will record pitch if it helps.

Spring rate as a function of belt tension is harder to find. You can get a general idea from the stiffness parameter of the belt, but the actual function is highly dependent on construction so it's usually chart form. Higher spring rate does not necessarily mean better performance (assuming belt is preloaded sufficiently to prevent going slack) for a number of reasons (a common one is moving the motion stage into a resonance band). Basically want the belt tight enough to prevent slack during dynamic movements, but not so tight things break/wear; the optimal point between those is often found experimentally for the system, rather than trying to model.

When is your album coming out?  

'Tension' does sound like an album or song title lol

I use the Continental App Tension2Go to check the “plucking”-frequency (print head center position, long belt side)

Works not bad.

 

IMHO for a perfect belt tension one of the 2 pulley per belt should be loosened for getting an uniform tension on the whole belt. 

 

Unfortunately the pulleys for the long belts are glued on the rod (at least on my M200 V4). So for achieving an equal tension on left+right / front+rear belt pairs it depends on how precisely the pulleys being adjusted on the rods by factory (the teeth should be exactly in-a-line on the rod).