Hi to all

I can offer how I sharpen my Mafell mortiser chain. Makita chain will take a different but similar jig. On a flat board that the chain loop will fit around freely, I have screwed two pieces of thin bar that create a snug way the chain can nestle into, then I wedge between the chain and board on the underside to prevent rolling at the links. I cut a slot in a block at the hook angle and insert a raker file into slot at a level height. I file square across the chain in a two handed manner, hands on block and handle, with the block resting on the jigged board. I feel that I have good control on height, angle, metal loss and heat. Mini expense and quick.