Horace Heffner wrote: > > On May 12, 2009, at 4:12 PM, Kyle Mcallister wrote: > >> >> >> --- Harry Veeder <hvee...@ncf.ca> wrote: >> >>> Kyle, >>> >>> I have a construction suggestion. If you haven't >>> already thought of >>> this, try using double sided tape to position the >>> rotor magnets instead >>> of glue. >> >> Have to remember that for future. On Saturday, I spent >> a while hot gluing them down to the aluminum disk. The >> hot glue didn't like to stick unless pressed JUST >> right and fast enough. The magnets didn't like >> standing in line, so to speak, either. 2-sided tape >> might have saved a few swear words. :) >> >> --Kyle > > > > It's also a worry that heating magnets can demagnetize them.
According to Wikipedia, high temp hot melt guns run around 195 C. Of course the object being glued won't typically get quite so hot as the heater in the gun itself, so we can probably take that as an upper bound on how hot the magnets would get. Also per Wikipedia, the Curie point for iron is 768 C. That's over 500 C margin between the hot melt temp and the Curie point, so one would guess that hot gluing the magnets is probably harmless. > > Best regards, > > Horace Heffner > http://www.mtaonline.net/~hheffner/ > > > >
