(A worried automaton, Ma helps out, Pleased Pappy, and The humans also leak)
The Spine knew somehow that he was failing at everything. Rabbit was already the strongest and the fastest at learning. Rabbit never worried about breaking things. In fact, his copper sibling had to be actively discouraged from breaking things.
Rabbit liked the interesting sounds, and thought they were funny.
So when Ma came to show The Spine something to help him, he naturally thought that it was because he had done something wrong.
"It's all right, dear," soothed Ma. She always used a singsong voice when she spoke to himself or Rabbit. Though she used more gentle tones and careful words with him. "This is a kind of practicing. I used to have naughty hands, when I was... younger. So I practiced every day until my hands got better."
The metal frame held sack cloth. The needle held yarn. Ma showed him what to do, then helped him with the movements. He got over being frightened of the small things in his big hands. Concentrated on the simple, repeating motions.
And, for the first time in his short existence, he forgot to be worried. He forgot to be scared. He didn't even feel his boiler cooling from its usual frenetic pace. He felt... relaxed. Yes. Entirely calm and at peace.
He graduated from rough potato sacking to flour sacking to scraps of cloth from Ma's sewing basket before Pappy found them together. Right when he was showing her how he could thread a needle all by himself without getting any oil on it.
"Has something happened to him?" asked Pappy. "There's a lot less steam..."
The Spine grabbed his old oil rag and held it where he leaked the most. "Self functioning, Pappy. Status green."
"I've shown him how to sew, Colonel. It's helped him calm down a treat," said Ma. She bobbed at Pappy.
Pappy strode in to feel for himself. "Amazing work, Miss Iris... And here was I trying to figure out how to fit more chimneys into the poor fellow's back." He admired The Spine's needlework with happy coos of, "Splendid, splendid," or, "Astonishing..." Pappy had a lot of smiles and laughter. "If this is what needlework can do, imagine the potential for crochet! Or knitting! Do you know how to tatt, Miss Iris?"
"Can't say I've ever had the time for lace tatting, s-- Colonel."
"What about weaving?"
"I have spent some time at looms..."
"Which explains your robust biceps," Pappy patted Ma on the arm and made her turn an interesting colour. "Brilliant! Teach him everything you know." Then he dashed away without another word.
Ma was still a new colour and drops of water leaked out of her eyes. "He didn't mean anything by it," she said. "He just gets excited about things."
The Spine offered her his rag. "Leaking?"
"I don't want to cry," she had a much neater rag for cleaning her face. Smaller and prettier than his. "I guess I can't help it."