Screws vs. Magnets For Sail Attachment

[Das Boot]

Have seen both on the Skipjack builds. Opinions?

[wlambing]

Screws are definitely the stronger attachment for that big sail, with 2, 6-32 thumbscrews forward, and a small magnet at the aft end of the diesel exhaust fairing. The 2 screws will take the stresses of speed and impacts (hopefully minor!!) and will help to protect both the sail planes linkage from floppiness and the snorkel head valve. I use brass screws and brass nuts, available from just about any store featuring hardware. I think the screws in mine are 6-32X 3/4" . You could use magnets, but you will want to have something at least shirt-button size for good magnetic grip. Awhile back, I was in search of ~ 7/16" magnets and found that the gaming community uses many different shapes and sizes, I guess for certain board games. I found those at my local hobby store. I had already ordered some from Amazon. Another source for a 3/16", or so, is Staples magnetic "push pins", for use on white boards or other metal surfaces. To get them out of the plastic pin case just squeeze the pin in a vice, and it will pop out bit to a point where you can grab it with needle-nose pliers.

At present. the only sub I have with full magnetic sail attachment is my 1/72 Gato class, but those are beefy magnets in the hull, and the 1/8" units from Klikon type pushrod connectors glued into the sail, good attraction with less top weight.

Hope this was sorta helpful!

Bill

[trout]

It is up to you which way you want to go. Both have benefits. Most, no, all of mine the sail has at least one screw in it. Magnets are great, but the strongest pull is straight apart, the weakest is sideways. So, is it possible for the sail to come off with magnets? Yes, so you better have a tether to the main hull or run only in areas you can retrieve it. Since I do not have any that are magnet only, I cannot say if it would happen. Removing a screw or two does not take that much time, but magnets are certainly quicker. I can see both sides to the style of assembly. I just like the security I perceive with screws (I use SS screws and nuts).

[MFR1964]

I did build a type XXIII with magnets to keep even the hull parts together, it never let me down, that said the tower is screwed down with two tiny brass screws, the Ko Hyoteki has it's tower fastened with magnets, i did place the magnets inside a tube which receives the other tube connected to the tower.
As Tom stated, straight pull, no problem, shearing is, so i came up with the tube in tube design, this way i limited the shearing.

Manfred.

[He Who Shall Not Be Named]

It is up to you which way you want to go. Both have benefits. Most, no, all of mine the sail has at least one screw in it. Magnets are great, but the strongest pull is straight apart, the weakest is sideways. So, is it possible for the sail to come off with magnets? Yes, so you better have a tether to the main hull or run only in areas you can retrieve it. Since I do not have any that are magnet only, I cannot say if it would happen. Removing a screw or two does not take that much time, but magnets are certainly quicker. I can see both sides to the style of assembly. I just like the security I perceive with screws (I use SS screws and nuts).

Tall sails subject the fastener to greater shear forces than short sails. Tall sail -- secure it with mechanical fasteners (screws). Short sail -- secure it with magnets.

Like so:























David

[Das Boot]

Thanks, guys.