I use two machetes, and old Collins SA (Guatemala) that has been cut to 14" with a tanto nose, and a 14" Tramontina Bolo... both edges were re contoured to be used a soft wood trimmers... the edges are increased in width from an initial width around 1/4" to better than 3/8" or so... I use a large grinding wheel but a belt grinder would be better, and work the blade from hilt to tip in a continuous motion to not over heat the blade... when you get a continuous feathering of sparks back over the blade, you have a constant angle... I finish and touch up with a good file...

if you have never used a machete, I would recommend a bolo that adds mass to the blade but keeps the blade short