When your machine’s precision motion drive exceeds what can certainly and economically be performed via ball screws, rack and pinion is the logical choice. Best of all, our gear rack comes with indexing holes and mounting holes pre-bored. Simply bolt it to your body.
If your travel length is more than can be obtained from a single amount of rack, no problem. Precision machined ends enable you to butt additional pieces and keep on going.
One’s teeth of a helical gear are set at an angle (relative to axis of the apparatus) and take the form of a helix. This enables one’s teeth to mesh gradually, starting as point get in touch with and developing into line contact as engagement progresses. Probably 
the most noticeable benefits of helical gears over spur gears is definitely much less noise, especially at medium- to high-speeds. Also, with helical gears, multiple the teeth are always in mesh, this means much less load on each individual tooth. This results in a smoother changeover of forces from one tooth to the next, so that vibrations, shock loads, and wear are reduced.
However the inclined angle of the teeth also causes sliding contact between the teeth, which generates axial forces and heat, decreasing efficiency. These axial forces play a significant part in bearing selection for helical gears. Because the bearings have to withstand both radial and axial forces, helical gears require thrust or roller bearings, which are usually larger (and more costly) compared to the simple bearings used with spur gears. The axial forces vary compared to the magnitude of the tangent of the helix angle. Although bigger helix angles offer higher speed and smoother motion, the helix angle is typically limited by 45 degrees because of the production of axial forces.
The axial loads produced by helical gears can be countered by using dual helical or herringbone gears. These arrangements have the appearance of two helical gears with opposing hands mounted back-to-back, although in reality they are machined from the same equipment. (The difference between the two styles is that dual helical gears possess a groove in the centre, between the tooth, whereas herringbone gears do not.) This arrangement cancels out the axial forces on each set of teeth, so larger helix angles can be used. It also eliminates the necessity for thrust bearings.
Besides smoother movement, higher speed capacity, and less sound, another advantage that helical gears provide over spur gears is the ability to be utilized with either parallel or nonparallel (crossed) shafts. Helical gears with parallel shafts need the same helix position, but reverse hands (i.electronic. right-handed teeth versus. Helical Gear Rack left-handed teeth).
When crossed helical gears are used, they can be of either the same or opposing hands. If the gears possess the same hands, the sum of the helix angles should equal the angle between your shafts. The most common example of this are crossed helical gears with perpendicular (i.e. 90 level) shafts. Both gears have the same hands, and the sum of their helix angles equals 90 degrees. For configurations with reverse hands, the difference between helix angles should the same the angle between your shafts. Crossed helical gears provide flexibility in design, however the contact between tooth is nearer to point get in touch with than line contact, so they have lower power capabilities than parallel shaft designs.