cutting perfect circles in plywood

[caramba22242]

Any advice on how to cut perfect circles in plywood or who would have the tools to do it for me. I myself don't have any specialist tools. I marked the centre of where i want the hole to be and the diametre I want it but my local DIY stores only do straight cuts

thank you

[Oneeyedtic]

Of what diameter?

[caramba22242]

12 inches maximum diameter.8 inches minimum

[Tweed]

A jig saw or a band saw. You could cut a pretty good circle with this, and it shouldn't be too difficult to smooth it out, especially if it's the circle, rather than the hole you want. If it's the circle, a lathe would smooth it out perfectly.

[Blues Dad]

See if you have any Timber Merchants in your area, quite often they will also offer joinery services and will do this sort of thing for you.

[Oneeyedtic]

If you have to do it yourself, you will require an electric drill with a 1/4 inch bit and a variable speed jigsaw with a small blade for cutting circles (just look at the jigsaw blade chart, you will easily see it). Drill a hole inside your circle, insert the jigsaw blade, have the jigsaw on a fairly low speed and then cut out towards your line and then slowly and carefully along it. Keep the sawdust clear so that you can see your line, and you can cut cheese shapes out by going backwards and forwards towards the hole if you find this easier. Sandpaper afterwards. 

[Clanad]

Another good investment for all kinds of cutting is a "rotary power tool".  This device is not expensive and the kit comes with a circle cutting guide.  They're marketed here in the U.S. under the brand name Dremel, as well as others and are available at all DIY stores for about $70 U.S.  I have one and it is one of the most useful devices I have...