How to lock chassis to wooden frame?

[ice9mike]

It happened. My top plate with tubes installed fell out of the frame while I was carrying it to my workbench. The 6080 tube was forced out of the socket and chipped the porcelain. The corner of the top plate bent and the 6080 is now unusable (unless you enjoy the sounds of an arching tube that is extremely microphonic).

I decided that a quick secure fastening system had to be developed. Being a mechanical engineer I have access to sample hardware from Southco. They make great fasteners including the quarter turn Dzus bolt. It comes in several styles and is often used on race car hoods and motorcycle fairings. I was able to install the hardware on the Crack frame and top plate.

Here is a picture of the finished product:

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fdl.dropbox.com%2Fu%2F12774652%2FImages%2FForum%2520Pictures%2FCrack%2520Amp%2520ice9mike.jpg&hash=648fa630b557cef0652d65a379aa2d596936ab88)

A closeup of the Dzus Fasteners with D-ring:

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fdl.dropbox.com%2Fu%2F12774652%2FImages%2FForum%2520Pictures%2FDzus%2520Fasteners%2520Closeup.jpg&hash=6e3a98e4ea863e86b9ab6f444bc1859e90c4257b)

A closeup of the unsecured Dzus Fasteners showing self ejecting springs and plastic washer:

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fdl.dropbox.com%2Fu%2F12774652%2FImages%2FForum%2520Pictures%2FDzus%2520Open%2520Closeup.jpg&hash=f199ff0cdca800e66aae87a4b992fd065b545603)

A closeup of the retaining washer under the top plate:

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fdl.dropbox.com%2Fu%2F12774652%2FImages%2FForum%2520Pictures%2FBottom%2520Plate%2520and%2520Dzus%2520Stud%2520Washer.jpg&hash=542330b4910e8d03616dac82250ec447d9ba478a)

A picture of the frame with Dzus retaining brackets:

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fdl.dropbox.com%2Fu%2F12774652%2FImages%2FForum%2520Pictures%2FFrame%2520Base%2520and%2520Dzus%2520Brackets.jpg&hash=77cc72f144856523dd419212e6e2f8fd85748d31)

A closeup of the Dzus retaining brackets:

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fdl.dropbox.com%2Fu%2F12774652%2FImages%2FForum%2520Pictures%2FFrame%2520Wall%2520and%2520Dzus%2520Bracket%2520Top.jpg&hash=35e44e379dfde038991658fb0dbfd954c8554970)

A closeup of how the Dzus retaining bracket is fastened to the frame:

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fdl.dropbox.com%2Fu%2F12774652%2FImages%2FForum%2520Pictures%2FFrame%2520Wall%2520and%2520Dzus%2520Bracket%2520Bottom.jpg&hash=7f3bf8e5b3bfddeaaee5e0994f165a539a2f9d31)

Here is a parts list for one connection. Multiply by number of fastening points:

Dzus Bolt - D8-316-413-190
Side Bracket - D8-336-310-121
Plastic Washer - D8-376-001-049
Metal Retaining Washer - D8-326-101-200
Ejection Spring - D4-EHF5-3-950QA
2 wooden screws of your choice

The solution works great and I think it looks appropriate aesthetically. I would caution those with big caps or other components. Make sure the side brackets clear your hardware.

The biggest problem with this solution is that these fasteners are not easy to find. They aren't sold at Ace or Home Depot, and they can't be purchased directly from Southco. They are sold through distributors and may have minimum order quantities. There are some speed shops and online stores that sell similar versions, but they might be different from the part numbers listed above.

This post is really to just put out another possibility for securing your investment in time, money, and dedication. If you love you amp as much as I do, you will understand why I spent more time on this than might seem necessary. Good luck, and I will do my best to answer any questions.

ice9mike

[Doc B.]

That is awesome. Takes me back to days I used to watch Trans Am racing and all the cars had Dzus buttons holding down the hood.

[Grainger49]

That is an excellent idea, and looks good too!

[Armaegis]

I decided that a quick secure fastening system had to be developed. Being a mechanical engineer I have access to sample hardware from Southco. They make great fasteners including the quarter turn Dzus bolt. It comes in several styles and is often used on race car hoods and motorcycle fairings. I was able to install the hardware on the Crack frame and top plate.

<snip>

This is slick enough that I would be totally willing to pay the extra few bones for it to be included in a stock kit.

[Grainger49]

Well, we are a DIY community.  Maybe someone can find a dealer who will sell pairs of them to the community?  Then on a future run Bottlehead might get the holes cut for those who want a secure top plate. 

[Jim R.]

Mike,

Way cool!  I have often wondered about those but had no idea what they were called or where to find them.

Think I'm going to start looking...

If anybody comes up with a source, let us know.

[bjorgens]

Pro bolt stocks all sorts
www.probolt-usa.com/

Bryan

[Jim R.]

Thanks, Brian.  Very helpful!

BTW, how do you like the Traveller with the 2M Bronze?

[ice9mike]

Thanks for all the kind words. I did a lot of looking for these fasteners online. There are similar solutions such as the pro-bolt quarter turn products, and McMaster Carr has some as well. The thing to remember is that setting the gap between the bolt and receptacle is critical to a good fit. The nice thing about the Southco website is that you can configure your product with their form based tool and it will let you know what hardware you need.

Here is the page to find out where local distributors are in your area. I doesn't hurt to call them and ask if they will sell directly to the public:

http://www.southco.com/contact/

ice9mike

[bjorgens]

Thanks, Brian.  Very helpful!

BTW, how do you like the Traveller with the 2M Bronze?

Hi Jim,
I've been very pleased with the traveller.  I'm a relative newb to vinyl, so am still learning my way around things, but it is (IMO) a remarkably good platform for the price.  Once I get my overall setup settled a bit (just received the paramount kits last week), I intend to try pairing it with a modestly priced MC cartridge like the Denon DL-103R so that I have some additional context for differences in sound presentation between cartridges.  That said, and thus far, the bronze MM cartridge has seemed really revealing to me.

bryan

[Jim R.]

Thanks, Bryan.  Don't know how much time you have on the Bronze, but most people say that the 2m series, especially the bronze and black take a good 80-100 hours of playtime to fully balance out.  I myself have the black mounted on a Clearaudio Concept, but it still has not been played.  As soon as my Mint protractor gets here I have a friend locally who is going to come over and help me get it setup, so it shouldn't be long now.

[Grainger49]

Groan!  Jim, I didn't know you hadn't gotten your vinyl rig up and running.  It would have driven me over the edge by now.

[Jim R.]

Grainger,

Well if I weren't mostly pre-occupied with recovering from pneumonia and recently, the killer flu, it would have driven me nuts too.  I also took some extra tie to ship the table to Pete Riggle for some tweaks and installation of his VTAF mechanism -- something that is likely to be very useful with a shibata stylus and varying record weights/thicknesses.  My Mint should be shipping this week.