Description Details GEARBOX is delivered with:Gearbox with big pulley and helical pinion (HTD pulley 90 teeth )HTD 550-5M Timing BeltHTD 5M mini pulley for motor / mounting hole ø14mm (18 teeth) GEARBOX 1:5 (NEMA34 Mounting Example)Compact gear reducer designed for CNC router applications. It features a 1:5 reduction ratio and supports direct mounting of a NEMA34 stepper motor.The unit provides stable torque transmission and improved motion control, making it suitable for hobby-grade and professional CNC systems. Racks GearsThe rack gears are available in two versions: a light-gray steel variant and a black oxide variant additionally protected against corrosion. Both variants are made from quenched and tempered steel (hardened).The light-gray (plain steel) version is the most popular because it fits aesthetically into most machine designs. Since rack gears are always lubricated, the likelihood of corrosion is very low.The racks cannot be cut, they are sold piece by piece. Each piece is 960mm long. The rack bars are finely milled and grind on the outside. Pressure angle 20° and tooth angle 19°31’42 Opposite Tooth GaugeOpposite Tooth Gauge short rack is used for assembly of Helical toothed racks. For the helical design, we offer companion racks, which are toothed in the opposite direction. In this case, you will always have stable and precise continuity at the joints of two racks and speed up the assembly time. Helical vs Spur GearsDue to its progressive contact, process performance is smoother and produces less noise. Dynamical loads are also reduced.This type of gears can work at higher speeds than spur gears.The contact ratio is also higher.The transmitted load is spread along an angled line making bending loads smaller.Tooth wear is reduced and they can transmit more power than spur gears with teeth of the same size.SPUR GEARHELICAL GEARIn case of spur gear, teeth are parallel to the axis of the gear.In case of helical gear, teeth are inclined with the gear axis in the form of a helix. This angle of inclination is known as helix angle (15° – 25°).In spur gear drive, contact between teeth of two meshing gears occurs suddenly.In helical gear drive, contact between teeth of meshing gears occurs gradually.Here the contact between two meshing teeth is always a line of same length.Here contact starts with a point, gradually becomes a line and leaves as a point.Sudden engagement of teeth results in impact loading. So teeth are subjected to impact loading.Due to gradual teeth engagement, load on the tooth builds up gradually. So teeth are subjected to gradual loading.Impact loading caused by sudden engagement of teeth results vibration and noise.Gradual loading provides a smooth and quite operation.Load carrying capacity of spur gear is comparatively low.For same size and same number of teeth, load carrying capacity of helical gear is comparatively high as larger number of teeth remains in contact at any instance.Life of the spur gears is usually shorter.Helical gears have longer life.Two mating spur gears must have same module only.Two mating helical gears must have same module, and same but opposite hand helix angle.Spur gears are suitable for low to moderate speed applications.Helical gears can be utilized at high speed also.Spur gear drive produces only radial force. As the teeth are parallel to axis, the thrust force is zero.Due to presence of helix angle, helical gear drive produces radial as well as thrust force. So the bearing must be capable of sustaining such thrust force.It is suitable for the velocity ratio of 1:1 to 1:3It is suitable for the velocity ratio of 1:1 to 1:5 DimensionsHTD 5M big pulley (90 teeth)HTD 5M small pulley for stepper motor / mounting hole ø14mm (18 teeth) DOWNLOAD 3D MODEL 3D Model / IGES / Rhino 3D / STEP / Parasolid Helical Tooth Rack and GearModulePressure AngleTooth AngleHelical Gear number of teethRight/Left hand AnglePitch per tooth*LA0BI D D1L1AC1C2EA1SKU1.520°19°31’42”23Right (Gear must be Left)5.015mm9602020120603090086.8118.818.41145002Pictures, dimensions , table data and technical drawings of this product are made with reasonable care and liability is excluded for the accuracy and correctness of this data.*The pitch of the rack according to the standard for the 1.5m module is 5.015mm, if you want to calculate the distance for a 360 rotation of the gear, then multiply the step by the number of teeth. For example, an 23-tooth gear: 23*5.015=115.345mm, the distance for one rotation of an 23-tooth gear is 115.345mm (please check it finally with the accurate gauge)An example of how to calculate the ratio of steps of a stepper motor to mm, that is, how many steps you need for one millimeter of movement along the axis: The reduction ratio of the reducer is 5:1 (HTD 5M big pulley 90 teeth , HTD 5M small pulley 18 teeth – 90/18=5 )We take the above calculation for the helical 23 teeth gear for a full rotation distance of 360 degrees = 115.345mmCALCULATION is simple:( Stepper motor steps * reduction ratio ) / Helical gear 360 degree distance = Steps per mm(200 * 5) / 115.345 = 8.669 – example for 200 steps (full step)(400 * 5) / 115.345 = 17.339 – example for 400 steps (half steps)(800 * 5) / 115.345 = 34.678 – example for 800 steps (microstepping) Stepper Motor division stepsMicrosteppingSteps per mm240017.33928649480034.678572985100043.348216228160069.3571459510200086.69643244163200138.7142919204000173.3928649255000216.7410811326400277.4285838408000346.78572985010000433.48216226412800554.857167610020000866.9643244128256001109.714335200400001733.928649256512002219.428671Here is an table with calculated “steps per mm” for standard stepper motor divisions. Example in Mach3 to set steps per (17.339) for 400 stepper motor division Pinion Gearbox
