Sourcing Parts

Hi,
I've finally decided to build a robotics project that's been tempting me for years, but I haven't got a clue where I can source parts from.
Essentially, I need a simple gripper on a lead-screw, with fairly accurate positioning. Can anyone recommend a good source of lead screws in the UK, preferably with appropriate parts to attach a robotic arm relatively easily?
I don't have access to much machining equipment at the moment, so am willing to pay a slight premium for pre-fabricated parts.
Also, can anyone provide a good source of information on building grippers and where I might find parts?
Many thanks in advance,
Tim
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RS will sell you linear steppers at a price. However, for many purposes a simple piece of threaded rod driven by a stepper, and a nut will suffice - at a cost of around one fifth to one tenth of the 'real' thing !
You may find such linear actuators rather slow, so consider also using things like bell cranks and push rods, as well as toothed belts.
Gripper design depends very much on what you want to grip and how much force and accuracy is required. People make very satisfactory grippers for light loads from LEGO.
dave

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