Posted by Michael Ignat on June 07, 2006 at 22:00:28:
In Reply to: Re: Three wires worm measurment posted by Marta on June 07, 2006 at 07:32:58:
For 3.340 mm wire diameter, a very accurate calculation gives 27.5049 over 3 wires. This is a theoretical value, without taking into consideration any tooth thinning for backlash.
The wires practically used are of different standard sizes and the closest one should be used. Obviously, M.O.W. will change.
In most cases, the dimension over wires should be larger than worm OD, otherwise it is difficult to measure. For that reason, at lower pressure angles (typically 14°30' normal PA), the practical wire diameter will be larger than the one that would contact the worm at the pitch diameter.