torque of motor requirement???
torque of motor requirement???
(OP)
sorry to ask such a dumb question. but i am a newb.... anyway here goes,
i have a block of plastic which i need to move in a linear direction 10mm and back to start position. i am going to use a rack and pinion with a servo attached (the rack attached to the plastic). can anyone please give me some advice/formula's to work from, especially on which motor to use. (torque rating i.e. in-oz, kg-mm ).
thanks in advance.
i have a block of plastic which i need to move in a linear direction 10mm and back to start position. i am going to use a rack and pinion with a servo attached (the rack attached to the plastic). can anyone please give me some advice/formula's to work from, especially on which motor to use. (torque rating i.e. in-oz, kg-mm ).
thanks in advance.





RE: torque of motor requirement???
Force = Coefficient of Friction * Weight of Plastic
Force is also equal to mass times acceleration, so if you have a particular acceleration that you require, you will need to consider it in the equation.
Use the torque to calculate horsepower for the motor.
RE: torque of motor requirement???
Measure or calculate how much force it will take to move the assembly then multiply it by the pitch radius of the pinion gear.
For example: If it takes 5 newtons of force to move the rack and the pitch diameter of the pinion gear is 50 mm.
5 N * 25 mm = 125 N-mm or .125 N-m.
You then calculate at what the rpm needs to be.
Barry1961
RE: torque of motor requirement???
any thoughts would be much appreciated.
RE: torque of motor requirement???
If this is a reciprocating motion you may be better off with an adjustable crank on a regular gear motor.
Barry1961
RE: torque of motor requirement???
if it is not feasable to use rack and pinion i could use an adjustable crank as you mentioned. i am also keen to hear of any other alternative ways to do this preferably using a small hobby servo.
again thanks for the replies on this guys.
RE: torque of motor requirement???
RE: torque of motor requirement???
If you try this you will need a very efficient mechanical design and will still need to manually measure the force to scale your command to…..
Barry1961
RE: torque of motor requirement???
The responses above are correct, but they all left out gearing efficiency. You'll have to upsize your torque requirements to account for efficiency.
Your loads are light. Your repeatability & accuracy seem to be fat. There are a variety of methods to do this. You may consider timing belts, also. Do you really need a motor? Ever thought of using pneumatic cyclinders with the appropriate valving to lock the stroke in place where you need it? Stepper motors would do this task as well as servos.
TygerDawg
RE: torque of motor requirement???
RE: torque of motor requirement???
1.8/360*PI*2= .034".
Don't use a silder crank for this!
As a footnote, be careful about using the load cell for very small forces, since accelerating forces on the switch mass may be of the same order as the switching force you are trying to measure.
RE: torque of motor requirement???
http://ww
RE: torque of motor requirement???
also thanks again tygerdawg, found that paper very useful.