Originally Posted by allanconway2 This makes it a better choice for many applications that typically use traditional rack and pinion, ball screws, and linear motors. See attachment for details. |
The attachment says it "eliminates the cumulative error problems experienced with ball screw systems". Could you please explain this further? It seems to me the cumulative error will consist of the accuracy with which the screw or rack is ground plus the thermal expansion.
In a ground and preloaded ballscrew with preloaded angular bearing block the precision is pretty much built into the unit at delivery. It seems that with your system some of the accuracy must be provided by the machine builder in that any guide system error perpendicular to the rack will affect the positioning error in the direction controlled by the rack/pinion. The effect of such errors are not described in the data sheet?
What is "Backlash Compliance". Ground and preloaded ballscrews have no backlash, but does have some compliance, usually expressed as a distance/force figure. What are the 3.2um? Are they backlash? Or are they compliance, if so at what force?
What about protection from the environment in which it is working. We're mostly concerned with processes generating swarf, dust, etc. here. What are your methods of keeping this debris from affecting the drive? When using ball screws there are usually 2 levels: An outer shield, often provided by the machine construction itself and the placement of the screw, a coiled spring or other shields. Then a secondary in the ends of the nut where many systems are used, some very effective, others not so.