I recently purchased a Hammond power transformer that met my needs electronically, and dimensionally, as it had to fit an existing chassis. I went from the Hammond PDF file with its dimensions for the mounting bolt holes. However, when it arrived, and I checked, there was no possible way it would fit my chassis as the mounting bolt dimensions were dramatically larger. (Seriously, there's not a snowball's chance in hell this thing will fit!)
Moral of the story, if you're trying to fit a Hammond transformer to an existing chassis, don't trust their measurements.
Moral of the story, if you're trying to fit a Hammond transformer to an existing chassis, don't trust their measurements.
+2 on this. While I waited to drill holes until the transformer arrived, the feet were definitely not square and even relative to the laminations.
Edcor's drawings have a .1" tolerance. When I asked their sales engineer about it, I was told it has to do with the tolerances on the bobbin which caused them to stack fewer or more laminations which moves the end bells in or out which moves the mounting holes in or out. I doubt Hammond is making their own bobbins. I wonder what the tolerances are on their drawings?
Also, I wonder if your power transformer will develop a buzz. I have one that has a buzzing end cap and it's annoying as hell.
Also, I wonder if your power transformer will develop a buzz. I have one that has a buzzing end cap and it's annoying as hell.
Hammond claims on the PDF that their tolerance is +/- .063". If mine was out within those dimensions I could make it fit .... it's not even close.
The issue with mine was very clearly a problem during the firming and bending of the covers. The feet were clearly bent off axis and either to close or far away from the intended bend line. Also the shield terminal on one of the lower bolts sandwiched between the lams and cover threw off the location even more. Definitely required careful hand layout and match drilling to get the transformer square and centered. Mines been fine without buzz.
This sounds more then strange to me, as more or less laminations means more or less core square area which in turn means more or less power capability and more or less voltage per turns.
Best regards!
I didn't doubt on your statements, mind you 😉?
Perhaps other manufacturers might emphasize closer tolerances to achieve higher quality products?
I know of a German bobbins manufacturer that keeps their products within very close tolerances.
Best regards!
Perhaps other manufacturers might emphasize closer tolerances to achieve higher quality products?
I know of a German bobbins manufacturer that keeps their products within very close tolerances.
Best regards!
Praireboy:
I suggest you contact Hammond directly and see if they can sort this out for you. It is worth a try anyway.
I suggest you contact Hammond directly and see if they can sort this out for you. It is worth a try anyway.
Hammond admits to having made an error in the description, which has been corrected. They're making arrangements for the reseller, A1parts.com, to refund me and will work out to whom I return the unit.
I am very pleased with Hammond's quick and pleasant response. I'm disappointed the unit I thought would fit, didn't, but they've been great.
I am very pleased with Hammond's quick and pleasant response. I'm disappointed the unit I thought would fit, didn't, but they've been great.