Hi logbook,
You're a 'lucky genius'. The center of the shear line was designed to be on a 5 inch diameter circle ... which is what it is. The dimensions of the hub and ring (each) were backed off from that circle to create the gap and the recess locations based on the dimensions of the magnets...
OK ... I guess someone will need to show me how to attat more than one picture to my posts. so here's the 'gap' picture.
gmeasthttp://files.engineering.com/getfile.aspx?folder=61c10a16-2d49-4f73-bbcc-96d770943f8f&file=test_fixture-gap-s.jpg
Hi all,
Well I joined everything together and I was pleased with the test results. I uploaded two pictures of the test setup. One shows the entire test fixture and the other is a (blurry) close-up shot of the gap. The over-all shot shows the moment arm at 12" (1 foot) ... it's labeled on the...
Hi logbook,
You're right ... don't know what I was thinking. When I build it, I'll do exactly as you have pointed out ... a pair (or maybe 3) above with iron backing and a pair (or maybe 3) below with iron backing. I guess what I was actually trying to show was a practical method for...
Hi logbook and MagBen,
I'm going to construct a linear test fixture to accurately measure the shear force of two magnets. logbook, your setup has inspired me. MagBen, your analogy is also correct in how the measurement of a single pair of magnets put in shear can be projected onto my coupling...
Hi MagBen,
The material is hot rolled steel. Hot rolled steel is usually pretty stress relieved as is ... enough for these tests anyway. I'm in the U.S. I live in Wyoming and the parts were made several states away in Wisconsin. These parts were cut by waterjet using a .DXF file from my CAD. It...
Hi logbook,
I have not calculated the field strength. The magnets are grade40 so I will eventually need to make some determinations because I know that grade52 are reliably available. In the proposed application configuration the Hub and Ring are kept in radial register by those bronze shoes...
Well I received the magnets. Not wanting to permanently mount them quite yet, I'll just temporarily secure them with some Gorilla Tape(tm) somehow, but here's a photo of them stuck to their pockets...
Hi all,
I've received the Ring and Hub for my test fixture and have uploaded a picture of them. Get this: I uploaded the two files.DXF on Tuesday the 9th, they shipped on the 10th and I received them today, the 12th! I'm totally blown away. This kind of service deserves major KUDOS ... $147.00...
Hi MagBen,
I am searching for some published data about the various Stainless Steel Alloys with regards to my coupling project. I work occasionally for a restaurant and we recently upgraded the hood system and I noticed that some of the S.S. used for the hood components is magnetic, and some is...
Hi logbook,
Thanks for the pdf on the eddy current kitchen presentation. Isn't it amazing how easy it can seem to be to "bias" data. The political idiots in every government uses various techniques of 'data biasing' to further their respective agendas. It happens here in the U.S. all the time...
Hi logbook,
The sketch you're referring to is NOT of the test fixture. What you're looking at and commenting on is a near-final design. In production, both the wedges and the magnets are sintering candidates and the cost would be low. I come from the gas turbine R&D field and always look at...
this sketch should have come through first.http://files.engineering.com/getfile.aspx?folder=73de3e69-a6e7-4a29-8bd1-1c80795a418a&file=coupler_test_fixture.jpg
Well I took the advise of those who commented and made a design change to the test fixture which suggested an approach to a near-final design ... or at least 'a step closer'. So I've attached two sketches ... one is just a mod of my initial one and the second is a little more comprehensive...
Hi SparWeb,
As you can see, logbook already made me painfully aware that the magnets must NOT be embedded as deeply as I have shown in my sketch. As you have deduced, what I am exploring is a torsional coupling more than a brake. Also, yes ... I am also planning to take advantage of the...
Hi logbook,
Here's the link to the quick video showing the low loss Stainless Steel I'm using for the sleeve. It just shows the simplest of tests for Eddy Currents:
https://www.youtube.com/watch?v=_OY30sA6was
Thanks again for your input,
gmeast