London Power ad

[-]
Search the Forum








(Advanced Search)

Hammond chassis mounting question
#2
Hi Guys

Cage nuts might be a little difficult for hobbyist to use since most such nuts (cage nuts not hobbyists) require a square hole.The return on the chassis may not be wide enough to provide much support the nut mount. Hammond's chassis in general can be a bit flexible when they are asked to support as much transformer weight as a medium-size tube amp is.

An alternative to the cage nut is the J-clip. In cross-section, a J-clip looks like a 'J' made out of a folded over strip of metal with a clear hole on one side and formed "half nut thread" on the other. Slip the J-nut over a round hole drilled in the chassis return. The J-clip spreads the load over a small amount of the return and again may not be the best means of securing a heavily loaded chassis.

With either the cage nut or J-clip, if one were to go beyond the traditional and intuitive four mounting points then either would be quite viable on stock Hammond chassis. Best to consult with the hardware catalogues to make sue the chassis return is deep enough to accommodate the prospective mount.

An alternative is to do what Traynor did with most of their tube amp chassis. They drilled pairs of holes lined up in the return and the top of the chassis, both near the fold for the side apron. A long bolt is passed through the amp sleeve and both of these holes, atop which a washer and nut can be tightened n. The washer should be larger than the nut so the compression forces will be spread out more. Traynor often used nuts with integral toothed washer to lock the nut in place, in addition to the flat washer suggested above.

Large diameter washers are often called "fender washers" - they won't clean your Fender amp or guitar, but are so named because of their use for automotive body repair and/or assembly. Some general hardware stores carry these as do specialty stores that carry extended varieties of mechanical hardware.

Have fun
Reply


Messages In This Thread
Hammond chassis mounting question - by FormyxAmps - 11-27-2019, 05:57 PM
RE: Hammond chassis mounting question - by K O'Connor - 11-27-2019, 10:29 PM

Forum Jump:

[-]
Come in where it's warm!
A warm welcome to tube amp modding fans and those interested in hi-fi audio! Readers of Kevin O'Connor's The Ultimate Tone (TUT) book series form a part of our population. Kevin O'Connor is the creator of the popular Power Scaling methodology for amplifiers.
Please remember these three principles: respect, sharing, community.
Not familiar with The Ultimate Tone book series? See discussion topics, or click here to visit London Power/Power Press Publishing.

[-]
Tube Amp Forum Hosted by London Power
London Power logo