if your in cork then i may be able to help u! i am based in youghal! (glide surfboards) if you know a electrician you can get a look at my despeeder if you want. i get my angle grinders from mcquillans in cork city €39 the vaviable speed u need to be working between is 1000-3000 max if you are using that grinder on 3000 all the time it will burn out very quickly! paul