Unfortunately, the idea of buying large potatoes to get long fries Fites is a mistake. For large potatoes no longer fit in the longitudinal direction into the opening. Best let fall into the hole along the potatoes, so as long as possible French fries from potato. The theoretical max. Length 6cm.In practice rather 5 - 5.5 cm.
And maybe you can make the disk not correct accusation. Possibly the machine is to blame. However, it looks at first glance, before purchase of the machine as if you can produce its own long fries.
Homemade fries taste much better. The thickness is greater than what we know from Burger fast-food restaurants.