What is the heated bed Neodymium Magnet power ?
Hello,
I am looking at the heated bed magnets of the i3MK3S, specifically to the ones sized 20x6x2.
Since this info does not seem indicated in any manual, and I think is very important (as example a too strong magnet may interfere with PINDA while a too weak magnet may not keep the bed plate fixed) I am asking to Prusa Research:
- what is the magnetic force of those magnets ?
- are they N35 or N52 ?
Regards
Roberto
Re: What is the heated bed Neodymium Magnet power ?
It's probably not a concern. Magnetic force falls off with the *square* of the distance, so very rapidly. The 3.7 firmware has magnet correction in the bed levelling, which means it ignores the measurement points affected by magnets anyway; since the next point is a few cm (about 3.5 cm) over, the field will be ~1/13th what itis directly touching the magnet. Of course, the real answer depends on how that factor relates to some absolute field measurement the PINDA can tolerate.
HOWEVER... I don't think they are standard N-grade Neodymium Fe B magnets. According to this chart:
https://www.amazingmagnets.com/t-magnetic-grade-chart.aspx
N-grade magnets have max temperature ratings that are 80C or below. Which means they won't be magnets anymore if you heat your bed anywhere near that temperature.
So you will want to look elsewhere at a different product if you are asking this in order to source some replacements for your bed.
Re: What is the heated bed Neodymium Magnet power ?
if you have lost some, ask on prusa chat...
regards joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: What is the heated bed Neodymium Magnet power ?
Another thread mentioned a 150c variety were used on the Prusa, if I recall the temp correctly.
RE: What is the heated bed Neodymium Magnet power ?
@vintagepc
You provided the absolute best answer I've seen anywhere on the web. Thank you very much for your help.
Faith is not believing. It's believing when all odds are against you and failure is inevitable. Believe in yourself, that's the key.
RE: What is the heated bed Neodymium Magnet power ?
I think Prusa are using H or SH grade (120°C and 150°C respecively) as for field strength (the number), I have no idea; however as vintagepc points out, they don't need high field strength.