calculate width of Teflon lead nut for silent actuator
calculate width of Teflon lead nut for silent actuator
(OP)
I've a short bar of teflon and made a 15mm wide lead nut for a M12 steel rod (standard thread) to build a silent linear actuator mechanism.
The nut raises a platform with a load of up to 250N.
Have limited material to experiment, so don't want to proceed entirely by trial and error.
Can anyone say whether that's an appropriate width of nut - whether it should be more or less? How to estimate?
Anecdotally, when the platform is fully loaded, the lead screw seems to become rather more difficult to turn than I would have hoped (having played with this calculator: http://www.daycounter.com/Calculators/Lead-Screw-F... ): which left me wondering if this was perhaps due to some kind of overload at the lead nut?
The nut raises a platform with a load of up to 250N.
Have limited material to experiment, so don't want to proceed entirely by trial and error.
Can anyone say whether that's an appropriate width of nut - whether it should be more or less? How to estimate?
Anecdotally, when the platform is fully loaded, the lead screw seems to become rather more difficult to turn than I would have hoped (having played with this calculator: http://www.daycounter.com/Calculators/Lead-Screw-F... ): which left me wondering if this was perhaps due to some kind of overload at the lead nut?





RE: calculate width of Teflon lead nut for silent actuator
The nut width has nothing to do with the friction it will only need to be able to carry the 250N load. I.e. the number of threads has to be strong enough to work with the 250N load as long as needed. I assume you used the 0.1 friction coefficient. But the real life will be at lease 0.2. The 0.1 is for light loads and high speed and usually received in lab tests and samples but, for working conditions in real life the reality is 0.2.
RE: calculate width of Teflon lead nut for silent actuator
However it did all work quite well at lower loads.
If, as you suggest, the observed coefficient of friction increases at higher loadings, that would perhaps explain it.
In which case, if I double the width of the lead nut will that not halve the loading per unit area of teflon and thence reduce the coefficient of friction at higher loads? Hopefully back from 0.2->0.1.
RE: calculate width of Teflon lead nut for silent actuator
RE: calculate width of Teflon lead nut for silent actuator
RE: calculate width of Teflon lead nut for silent actuator