Help with material purchasing. Should I base my dimensions on the material available?

[trialanderror]

I need to make a product that is 30cm x 15cm x 1cm of Aluminum. I was wondering if it is best to try to source blocks of aluminum that are these dimensions or to get something a bit bigger and dimension it myself with a milling machine. It seems to be extra work to machine the dimensions myself. Getting my CNC machine in a couple weeks.

- If I do use the ready dimensioned material, I am assuming that setting the zero access would have to be a lot more accurate than setting it when cutting out my own dimensions correct?

- Would the finish usually be the same?

Just wondering what most of you would do if you had this option.

[RICHARD ZASTROW]

Depends on the required workpiece dimensional tolerances and finish requirements as well as the supplied material dimensional and finish tolerances. Check with the material supplier if he can meet your requirements.

Dick Z

[trialanderror]

thanks, so if I use precut dimensions I assume that the home zero axis has to be completely accurate. I will try both methods.

[RICHARD ZASTROW]

Ex.; If your supplier can deliver 15CM wide X 1CM thick stock with the finish you require, all you would have to do is saw it into 30CM (plus a few MM for machining stock). Then locate the stock in a vise (as an example) and mill the ends to an accurate 30CM finished length.

If any more features are to be machined, they could possibly be machined in the same set-up.

Dick Z

[DareBee]

I typically find that 6061 aluminum barstock is up to .01" oversize in most cases.
Sheet stock is often different and I don't know what grade you are looking at.

Also - good luck finding metric stock in Canada (and if you do it will be way overpriced)