i can't remember the model i had but it had a section between the blade and the roller that pieces of wood would get trapped in, it then would not let anything past!! you would then try and push it through with another lump of timber and the small section would get lodged. drove me mental it was on a 406 unimog so had the power.

used one a sawmill that we use to feed slab wood into it with the crane it was ok but even with new blades the chips were very stringy, not a patch on the tp for chipping though imo.