Chassis bolts problems

[jlatrace]

I just finished my RF 102, tweaked the voltages and put the chassis into the head cabinet and as I tightened it the screws locked up and I had to use my sawsall and cut the screws to get the chassis out.

Now my problem is how do I secure my chassis? I thought about drilling holes in the bottom and using longer screws (4 1/2 inches) and k-nuts (ala Fender). But I'm concerned that there is not enough room at the input jack and I will need to relocate parts of the relay power supply.

Does anybody have any alternative suggestions?

The head was made by Taylor Cox and the chassis (black) was obtained from Mark Roberts.

Thanks,
Les

PS - The amp sounds awesome and I want to thank the members of this site. Your posts and resources were invaluable.

[trane34]

Could you drill the screws out and use larger bolts for the now larger holes?

[67plexi]

Nut plate Two-Lug Floating 10-32

[boldaslove6789]

You can also use Rack Mounting clips to mount the chassis. All you'll have to do is drill out the existing nuts on the chassis.

[CHIP]

I did that once with one screw. I built my own cab for a d'Lite. I've learned that if one or more of the clearence holes in the cabinet are a bit off, they can bind up. I was able to get the cut screw out and re-tapped the hole. I think it was a 10-24 tap. Since it was just 1 I was able to save it. I also opened up the cabinet holes another 32nd or so.
Did you bind all 4 screws?

[ToneMerc]

tweaked the voltages and put the chassis into the head cabinet and as I tightened it the screws locked up and I had to use my sawsall and cut the screws to get the chassis out.

I've spoken about this issue several times as I had a issue with the first chassis I used. Here's the root cause, the chassis captive nuts and chassis mounting bolts are both stainless steel. You never dry fit stainless to stainless fine threads because the threads will surely gall and seize, titanium has the same issue with galling. A better combination would the carbon steel captive nut and then of course the stainless bolt for asthetics.

I highly recommended that you lightly lube the first 4-5 threads of the s/s bolt. I use a synthetic lube, but Never Seez works well too.

TM

[jlatrace]

Thanks to all, very helpful suggestions. I'll update you on the direction I take.

[jlatrace]

You can also use Rack Mounting clips to mount the chassis. All you'll have to do is drill out the existing nuts on the chassis.

Thanks Greg. I'll give this a try.

[jlatrace]

Nut plate Two-Lug Floating 10-32

Interesting. I found 10 on Ebay and will try this work around in addition to the rack monting clips suggestion.

Thanks.

[Structo]

I had that happen on a CE chassis.
My mistake was when I started the screws by hand one of them turned a little hard and I should have realized it was cross threaded.

When I went to zip them up with my screw gun, the one that was cross threaded broke off.
I was surprised but what TM says makes sense.

Unfortunately where the screw broke off was above the chassis so I couldn't pull it out of the head.
So I managed to saw it off.

Then I drilled out the stuck screw.

Now I am very careful when starting those screws and I put some Vaseline on the first five or so threads.

[vibratoking]

I broke the screw off on my Bludo chassis. Stainless screw and weld base nut. It was not cross-threaded, just locked up f^%$#&* tight and it happened instantaneously.

Here is the important part. When a screw is cross-threaded you can normally feel it as you turn the screw, but this was completely different. It was turning freely and then locked up instantly without any indication it was going to happen. This is called cold welding and is described in the link. I temporarily 'fixed' it using a rack mount clip, which is not a great solution, but is better than nothing, until I can get a replacement from Brandon.

If you want to read more:

http://www.estainlesssteel.com/gallingofstainless.html

[passfan]

tweaked the voltages and put the chassis into the head cabinet and as I tightened it the screws locked up and I had to use my sawsall and cut the screws to get the chassis out.

I've spoken about this issue several times as I had a issue with the first chassis I used. Here's the root cause, the chassis captive nuts and chassis mounting bolts are both stainless steel. You never dry fit stainless to stainless fine threads because the threads will surely gall and seize, titanium has the same issue with galling. A better combination would the carbon steel captive nut and then of course the stainless bolt for asthetics.

I highly recommended that you lightly lube the first 4-5 threads of the s/s bolt. I use a synthetic lube, but Never Seez works well too.

TM

I used wheel bearing grease.
It was the closest to my bench.

[ToneMerc]

I used wheel bearing grease.
It was the closest to my bench.

Lube it if you got it

TM

[brentm]

So best practices might be to use a little lube but no power toys. Sorry. Couldn't resist the innuendo. Seriously. I assume this happens quickly with cordless screwdrivers???? How many times when tightening by hand???