I am making up a circuit to control 2 and 5 servo motors the servo motors are going to be 6 VDC don't know amps, they will have there own power supply. would it be a good idea to have capacitors on there power supply as I wont the servos to run very smoothly.
Yes, capacitors on motor loaded power supplies is always a good idea.
I used them on the pots controlling my servos and it worked great!
thanks for the reply I Just need to work out size a type to use now
would it be a good idea to have capacitors on there power supply as I wont the servos to run very smoothly.
I wouldn't start adding things until you actually determine that you have some type of issue.
I worked that out I might do it anyway so I know there wont be any problems
daniellyall:
I worked that out I might do it anyway so I know there wont be any problems
Based on that reasoning, add a couple four leaf clovers and a rabbit's foot to make sure ever thing is covered. 
for what these motors are going to be used for the servo will need to run perfect all the time so I need to ensure that they will.
this project is so I don't have to spend $20,000 on something I need what will only cost under $500 to make my self. it is something I am going to be using every day, so it being reliable is very important.
daniellyall:
would it be a good idea to have capacitors on there power supply as I wont the servos to run very smoothly.
I don't see where you have acquired the information that makes it logical to go from the above question to the following assertion
I worked that out I might do it anyway so I know there wont be any problems
Most people fly expensive model aircraft controlled by servos without worrying whether the servos will operate properly.
Have you any evidence of a problem with a servo and was that problem solved by adding a capacitor?
I suspect the key requirement for reliable operation is a generous power supply.
...R
when all parts arrive I will test it all out with and with out a capacitor, yes it will be the correct power supply to run it properly that's the easy part to work out. I work on CNC Routers and rebuild them so I know how to work out power supply needs.
Adding a few extra capacitors to a circuit, is like having breakfast. How do you calculate for sure if you need it? but most suspect that it will be more benefit with than without !
Any time you are running DC motors, you should have extra caps (at least that is my thoughs). Anyone suggest that you should run DC motors without any caps. ?
If the supply is decent and not far away it will be fine - reliability for a servo is
a question of choosing a well made (probably metal gear) model with a specification for how
long it will last.
If the supply is metres away at the end of a long wire then adding decoupling at the servo
is wise, it'll make up somewhat for the voltage droop in the cabling and will reduce EMI
from the cable. Several 1000uF minimum to make any real impact with a motor, note.
If you want ultra reliability you'll be starting with a brushless servo unit with ball-bearings
throughout, opto-coupled control input and a proper datasheet. But that's overkill for
occasional use 