Hi, Kindwriter. The sentence sounds strange. If you check out "utterly struggle" on Google, you'll find only 117 entries for the expression, which is not a vast corpus to rely on. Still, it has been used some times and, by the looks of it, in blogs of native speakers. Problem is: saying you "struggle to build a machine" sounds as if you have some trouble every time you build a new machine. If I understood what you meant, I would go with "I've been struggling to build a/this machine". I hope this helps. :) Regards.

Utterly, means carried out to the highest degree Struggle, means to proceed with difficulty or with great effort The phrase sounds unconventional. << I to the highest degree proceed with great difficulty to build a machine. >> Why not just say "I struggle to build a machine" or "I tried really hard to build a machine, but it didn't work"?

Hi Kindwriter, It is unconventional. I cannot think of situation where this sentence would be used. Even if I imagine it with a sentence before and after, it is difficult to understand what machine you are talking about or why you are telling me. Depending on this situation, these are more natural: "I'm really struggling to build this / that machine." (Current activity) "I would struggle to build a machine." (Future activity) "I really struggled building this / that machine." (Past activity) Struggle already implies extra effort or challenge. "Really" is simple enough to emphasise just how much you struggled.