U shape magnets come with a keeper bar…. time to google… 🙂
Magnetic Circuit
A magnetic field holds its strength best when the entire magnetic loop, or circuit, passes through a ferromagnetic metal at all points. A horseshoe magnet has an air gap between its two poles; the keeper closes this gap. A bar magnet, left by itself, will lose its strength over several months. Though a bar magnet has no “keeper,” if you lay two bars side by side, with the north pole of one touching the south pole of the other, they form a magnetic loop in iron and preserve the strength of both magnets.
Well, as the old saying goes, “you learn something new every day”. Thanks for posting this crosbyman. After reading your post, I googled magnetic circuit and found everything I ever wanted to know about circuit models, magnetomagnetic force, magnetic flux, reluctance, and a number of other things I vaguely remember studying in science and physics classes a LONG time ago. Also found a “keeper” is also known as an “armature” which sure sounds familiar.
So if I just put a common steel hex bolt across my Champion flywheel magnets, I should be OK.
Bob
1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1957 Evinrude 3022
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20
1982 Evinrude 25hp
“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."
