New to CNC

[JAZZCNC]

You mention using the correct tool - is there a good reference source I should go to for which cutters to use ?

Not really other than making sure you use a tool suitable for that material and any good tool provider will have info on which tool suits what material best.
After that, it's more personal choice through experience and every machine cuts slightly different depending on stiffness and several other variables. So speed n feed settings can vary widely between users.
Not many will be cutting pewter so won't get too many suggesting what they use but I'd guess any tool suitable for aluminum would work. For aluminum you want uncoated tooling, carbide works best and lasts longest, but it's expensive and with your machine you probably won't be able to cut at the correct feeds to suit carbide. In which case you'll be better with High speed steel(HSS)

Why don't you go straight on to Fusion360, it is free and much more 'organic' than SketchUp. In fact I need to learn Fusion360, I am tiring of Sketchup.

I'm not sure it's still free.? Sure I heard that they had started charging a subscription for it, but I might be wrong so don't quote me on it.!

[Doddy]

I'm not sure it's still free.? Sure I heard that they had started charging a subscription for it, but I might be wrong so don't quote me on it.!

Damn, just quoted you on it. The licensing for F360 has certainly changed but there is an licensing option that remains free for hobbyists, although limited in terms of the extra tools/capabilities that it offered(collaboration, data translators, and more). This is a true personal-use rather than the earlier start-up license, and you are limited as a hobbyist to <$1000 revenue from your activities with F360.

That will suit many, but not all of us hobbyists.

I honestly don't know what licensing I get - I subscribe to another Autodesk product (Eagle) and that's resulted in me getting some form of subscription license for free, which I think includes collaboration, but not full-fat F-360.

To the OP, Fusion 360 is a good 3D CAD modelling tool, which, as discussed, can be got for free. Don't underestimate the learning curve associated with it, however, although it's time well invested if you do a lot of modelling. I've tried Sketchup in the past and, to be honest, wouldn't piss on it if it was on fire.

Understand also that you have more tools in the toolchain than just the CAD/drawing package. I'd start looking at the machine controller (e..g MACH3) and the CAM software (e.g. CAMBAM) and understand their place in the overall toolchain.

[Britannicus1]

To the OP, Fusion 360 is a good 3D CAD modelling tool, which, as discussed, can be got for free. Don't underestimate the learning curve associated with it, however, although it's time well invested if you do a lot of modelling. I've tried Sketchup in the past and, to be honest, wouldn't piss on it if it was on fire.
.

Thanks for the pointer, I'm interested in fusion 360, but the only free download is only for 12 months. Having talked to a few folks it's definitely the better product, but reluctant to spend a lot of time learning something if i only get to use it for 12 months .

I find Sketchup frustrating in that the menus seem to be endlessly re-written so good advice is difficult to get, but at least I have a licence to work with .