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Electronics => Mechanical & Automation Engineering => Topic started by: coppercone2 on July 13, 2021, 04:42:56 am

Title: rubber durometer and type for transformer mount
Post by: coppercone2 on July 13, 2021, 04:42:56 am
so I have some nice transformers I want to mount and I remember when I got a big torroid it came with a rubber sheet but these little guys did not. I don't see a reason why not to get rubber sheet to put them on.

I thought to get 1/8 inch rubber, but there are different durometers available. I don't know whats good. Any suggestions?

Also, should I choose a particular type of rubber? I.e. fiberglass rubber, etc.
Title: Re: rubber durometer and type for transformer mount
Post by: floobydust on July 13, 2021, 05:26:43 am
A rubber sheet I don't think is useful because the vibration goes through the four mounting screws.
How many VA and lbs?
I've used the general purpose (https://www.mcmaster.com/rubber-mounts/general-purpose-vibration-damping-sandwich-mounts-with-studs-6/) neoprene mounts with 8/32 studs on 1,500VA, about 28lbs. These say Durometer 50A medium.  Small weight is around 7lbs each x4 for 28lb but I might have bought the 20lb each for 80lb capacity.
For some reason, the core vibrates quite a bit even at light load in a steel chassis, but it's totally quiet on these mounts.


Toriodal transformers have the rubber disc to prevent the windings from getting mashed by the mounting washer, and they have an insulator to prevent making a shorted turn with the mounting hardware.
Title: Re: rubber durometer and type for transformer mount
Post by: coppercone2 on July 13, 2021, 07:12:49 am
yeah its the rubber disk I mean, I know its not perfect but I think it does something

I thought I can put two disks when I do it myself

maybe I can consider the neoprene mount too but it seems better to bolt it to a plate then glue the plate down with rubber, I have done that in an experiment
Title: Re: rubber durometer and type for transformer mount
Post by: coppercone2 on July 15, 2021, 05:11:31 pm
I bought flurosilicone sheet to try out
Title: Re: rubber durometer and type for transformer mount
Post by: floobydust on July 15, 2021, 07:49:56 pm
I have an old sheet of 1/8" neoprene, used to cutout and make gaskets. That would work too.
For acoustic noise, it gets conducted through the mounting bolt(s) even though on a rubber cushion, so that can limit it. The transformer vibration can also be due to nearby steel grabbing some flux, so moving or rotating it can make it quieter too.