Chassis Bottom Plate

[JammyDodger]

I just received the chassis plate from Allied

"Bottom plates can be bought from Allied Electronics:
http://www.alliedelec.com/Search/Search ... 806997617F"

With the way Nik's chassis is made I'm wondering if it wouldn't be better to secure the plate to the cabinet and have the chassis slide in over it. I'm concerned that becasue the chassis dosen't have support for it on the front and back that it could bend and touch some of the componants inside.

How important is the grounding of this plate? Any comments?

Cheers, Mike

[Rick]

I would think the plate should be ground connected to the chassis, but I question the necessity of the plate at all. I have never needed to use one and it seems that if you use good wire routing you won't need to use one either. Me thinks that sealing off the bottom of the chassis may cause interior temps to rise more than otherwise depending on how well it's actually closed up. Temp being a major factor of capacitor life calculations along with voltage ratings, it would seem a good idea to keep the innards cool as is reasonably possible. It may be a non issue, just my 2 cents...which is about all it's worth...

[UR12]

Fixing it to the inside bottom of the head cab should work fine as long as there is a connection between the chassis and bottom plate. I usually just drill 4 holes in the bottom plate and use the bolts that hold the chassis in the cab to also align the bottom plate and chassis. I agree with Rick that 99% of the time you can probably get away without using one, but I'm also sure there will come a day, if you are a giging musician, where your playing somewhere and you will wish you had installed a bottom plate. Breaker breaker one nine.......gotch yer ears on good buddy

[Allynmey]

Use 14 #6X3/8" screws to hold it to the chassis. Then use nutserts by drilling 3/8" holes in the center of the embossed feet. Use 1/4-20 screws to insert in the nutserts through the cabinet if you want it to be TW "Correct".

Allyn

[Rick]

Fixing it to the inside bottom of the head cab should work fine as long as there is a connection between the chassis and bottom plate. I usually just drill 4 holes in the bottom plate and use the bolts that hold the chassis in the cab to also align the bottom plate and chassis. I agree with Rick that 99% of the time you can probably get away without using one, but I'm also sure there will come a day, if you are a giging musician, where your playing somewhere and you will wish you had installed a bottom plate. Breaker breaker one nine.......gotch yer ears on good buddy

Good point, I keep forgetting, there are folks who go out and actually get paid to play!!

[drhulsey]

Use 1/4-20 screws to insert in the nutserts through the cabinet

Allyn, am I correct that you are using the 1/4 20's and nutserts to hold the chassis to the cab? Are you using aluminum or steel nutserts? You know, I thought I was somewhat tool-savvy, but I had never heard of nutserts. With >14,400 hits on google, I guess I wasn't as savvy as I thought

... I keep forgetting, there are folks who go out and actually get paid to play!!

Yes, but not enough to quit the day job I do have to gloat a bit and say that it's nice not to have to worry about how LOUD the Express is

[geetarpicker]

The professional "Nutserts" insertion tool can be a bit pricey. However you can get a cheap little "expendable" tool apparently good for about 100 uses. They work fine and are only about $6 for the tool. The trick is to practice on some scrap sheet metal, and start with a hole that barely fits the nutsert as in very tight already. Then the finished installed nutserts will be good and tight.

http://www.wicksaircraft.com/catalog/pr ... index.html

[drhulsey]

The professional "Nutserts" insertion tool can be a bit pricey.

Yes, I saw a some of those for a few grand I found this on ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... :IT&ih=009
We'll see how much muscle it will take to put one in I understand there can be issues with how stable some nutserts are. Since I'm not building aircraft, I can experiment a bit
An entirely new tool How cool is that
(I can't help it It's just my Y-chromosome expressing itself )

[Rick]

I use a tool identical to that one or another similar one on almost all my chassis. The rivets that came with it fell apart instantly. I got some good blind rivet nuts and shimmed it properly so it wouldn't overcompress the nuts, now it works great.

[skyboltone]

The professional "Nutserts" insertion tool can be a bit pricey. However you can get a cheap little "expendable" tool apparently good for about 100 uses. They work fine and are only about $6 for the tool. The trick is to practice on some scrap sheet metal, and start with a hole that barely fits the nutsert as in very tight already. Then the finished installed nutserts will be good and tight.

http://www.wicksaircraft.com/catalog/pr ... index.html

Those are rivnuts Glenn. Nutserts snap in after a little swearing.

For rivnuts I use an ordinary pop rivet tool with a conversion kit from (you guessed it) McMaster Carr.

[Phil_S]

The bottom plate is primarily as an RF shield. Since I don't play out, I just mount my heads on a pine board. Before doing that, I smear the board with a thin layer of glue and apply some heavy duty kitchen aluminum foil. It works great and it makes a difference. I was totally surprised at how it cured the symptoms of an amp I built. It made me a convert. If you have a head cabinet, the foil thing should be very easy to do and, IMO, it couldn't hurt.

I've heard people going to the expense of buying sheet metal, roof flashing, etc. None of that nasty stuff is necessary once you understand that all you need is RF shield.

[Brad737]

Does anyone have any recommendations on where to get a bottom plate for a Ceriatone chassis? I just ordered a Liverpull from Nik, but to my knowledge, the Ceriatones don't include that plate. (Or do they?)

Thanks,
Brad

[BBQLS1]

I make mine out of roofing flashing. Score, break, sand edges, drill holes in press with paddle bit, staple into headbox, done!

USE GLOVES! This stuff is SHARP!

[ericb]

The bottom plate is primarily as an RF shield. Since I don't play out, I just mount my heads on a pine board. Before doing that, I smear the board with a thin layer of glue and apply some heavy duty kitchen aluminum foil. It works great and it makes a difference. I was totally surprised at how it cured the symptoms of an amp I built. It made me a convert. If you have a head cabinet, the foil thing should be very easy to do and, IMO, it couldn't hurt.

I've heard people going to the expense of buying sheet metal, roof flashing, etc. None of that nasty stuff is necessary once you understand that all you need is RF shield.

I very much appreciate your info .. I have many amp heads and some have had bottom plates and some have foil or thin aluminum stapled or glued on the wood , instead of the plate mounted on the chassis.. Does anyone else have any experiences as to why they feel 1 method is better? IF not, I'll definitely go the foil route on a few heads I'm taking care of. . THANKS

ERIC

[Brad737]

I like the idea of putting foil inside the headbox, as long as it seals up well. There's this cool aluminum foil tape that's pretty thick that we use on the jets at work. I think this might work out nicely.

Thanks,
Brad