I have Janome machines and have never heard of the hump jumper. But, MeadowMist, I hear you! I've broken needles sewing over ultra bulky seams trying to make fabric books for my grandkids. I go stitch-by-stitch slow and use a pusher stick and/or pull from the back to keep the fabric moving under the needle. My Janome is supposed to sew heavy duty items and it does, but needs help sometimes. Reading the suggestions, I realize I could do some fine-tuning as well.