I'm looking to create a cheap direct drill to use to add legumes to existing grass swards and, possibly, for sowing multi species grass mixtures as well. I have acquired an old international 511 cultivator drill cheaply and I'm thinking of making up new coulter frames with Weaving double disc openers like in the photo below as they are available within my budget. Every disc direct drill I've looked at is way outside my budget and tines will make a right mess of the grass swards. Has anyone used them for legume seeds and down to perhaps 75mm sowing depth? Are they up to it or would I need heavier coulter assemblies? I'm happy to engineer additional pressure spring arrangements myself.