Some of the idler pulley bearings that came with the Robodigg metal corners are quite noisy after just 6 hours of use. I found some good Japanese bearings here ezo f623zz but you need to buy 20 or more for the price to go down to 2.33£ +vat. I only need 6 and I was thinking, if you live in UK and want some I could buy in bulk and then post them to you for the same price plus a 1st class stamp.by Ad-1 - Delta Machines