I know all about the advantages on reinforced tuttleboxes for foiling. Some work, some don't. Has anyone tried an Ultrasonic (pre foiling models) 147 with foiling? Any thoughts on using this with an older NP foil with a mast height of 80cm?
Hi, I've been using a 2012 UltraSonic 147 for foiling with both a NP Glide (small front and rear) and a Lokefoil LK1 with freeride wings. I found both work fine and I've had no issues after 18 months of use. One reason for going with Lokefoil though is the flange at the head of the mast to help prevent any rotation in the box. I think AFS also have a similar flange. I'm 68kg and generally sail with 6m sails or less. If you're heavier or are planning on using large (= heavy) rigs then loads on the tuttle box may be greater. I find the footstrap positions to be fine - I use the inboard positions. I tend to sail with the back foot out and only go into the rear strap to power up the foil in marginal conditions, or blasting up wind.
Unless you're planning on jumping or foiling in heavy conditions I'm not 100% convinced a foil box is necessary. I've only seen one person have a problem with a foil rotating in a non-foiling box. That was a Starboard GT foil in an old Starboard board but could have been due to sailing in high winds and some crashes.
Since you are talking about boards and foils with deep tuttle interfaces, the critical thing to remember is that you MUST make sure that both the front and back tapers are firmly seated. This is how the tuttle was designed. If a foil is rotating in the box, then it was not properly seated in the first place. You will ruin the box, ruin the foil fitting, probably ruin the deck of the board. and break a lot of screws.
Some boards have deep tuttle boxes that are not deep. If you try to mount a truly deep tuttle foil into one of those, it will bottom out in the roof of the box. This is disaster in the making. For example, you cannot fully seat a non-flanged AFS foil into a Fanatic or Slingshot box. I know this from personal experience.
Measure the taper lengths for both your box and foil to make sure it will go all the way in. If it does not, you can trim the top of the tuttle fitting on the foil, but make sure to maintain sufficient edge margin for the screw inserts. For my Fanatic/AFS combo I had to trim the top of the AFS foil by about 0.5 cm.
DO NOT ALLOW THE FOIL TO BOTTOM OUT INSIDE THE BOX. Sorry for the caps, but this is the engineering requirement of the tuttle design.
The best solution is to just get matched sets. Not only will they fit together properly, but they will also be pre-balanced. A good example is Slingshot foils and Slingshot boards.
