Transformer / PS board bolt interference
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- Ron Worley
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Transformer / PS board bolt interference
I'm attempting to layout the holes in my Alllynmey chassis, and I think that I have an interference problem with the heads on two of the PS board standoff bolts (on the tranny side of the chassis).
The one under the PT might clear due to the cutout in the tranny base, but the bolt under the OT is right under the flat base of the tranny. See the attached Word document with the blot positions circled in red- it would be the opposite bolt on the other side of the circled standoff position.
Perhaps I am missing something very obvious here, can anyone help??
Thanks in advance,
Ron
The one under the PT might clear due to the cutout in the tranny base, but the bolt under the OT is right under the flat base of the tranny. See the attached Word document with the blot positions circled in red- it would be the opposite bolt on the other side of the circled standoff position.
Perhaps I am missing something very obvious here, can anyone help??
Thanks in advance,
Ron
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- Ron Worley
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Re: Transformer / PS board bolt interference
This is the initial drill pattern template for the Express Chassis I developed, which lead me to question the interference of the one or two PS board standoff bolt with the trannnies....
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- Ron Worley
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Re: Transformer / PS board bolt interference
BTW, any and all corrections on dimensions are appreciated... this was tough to do trying to scale things from the Francesca pics...
Ron
Ron
Re: Transformer / PS board bolt interference
You need to use a counter sunk head screw and carefully drill out the holes under the trannys to except the counter sunk screes so their heads end up flat with the top of the chassis
- Ron Worley
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Re: Transformer / PS board bolt interference
Thanks Dana... that makes a ton o f sense. Any comments on the dimensions for accuracy?
Ron
Ron
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Re: Transformer / PS board bolt interference
I've got a countersink bit and I didn't even think to use it when I built my express, I just threw some washers under the transformer. :oops:It worked fine, I've since used the countersink bit with great results. Just go slow and check the depth with the screw so you don't take out to much metal. Phil
- Ron Worley
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Re: Transformer / PS board bolt interference
It's funny... rather like an onion... as you peal back the layers you discover so many minor yet important details as to how Ken built these amps.. I guess that's part of the fascination I have with the Wreck...
Ron
Ron
- geetarpicker
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Re: Transformer / PS board bolt interference
In a real Express of few of the standoff screws aren't even really attached by a screw at all, at least in mine. The ones that go right under the transformer are simply sitting on stand offs that are screwed to the board, but actually just glued with a dab of silicone to the chassis. I did my two clones the same way. You simply attach all the standoffs to the board and put a little silicone on the ones that float as you mount the others with screws. I guess a counter sink is nicer, but in my original none of the siliconed standoffs have ever come loose. The 3 screws down the center go all the way though, the one near the ground tab at the back is screwed, and the other 3 are siliconed.
Needless detail I guess.
Needless detail I guess.
- Ron Worley
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Re: Transformer / PS board bolt interference
Glen-
I wouldn't say needless at all- it just depends on you level of detail (or anal behavior I suppose). It doesn't seem to have been addressed before, but I will search the board to make sure. Probably should have first.
It seems to me with the sensitivity of this amp, having only about half of the PS board securely mounted is not really such a good idea over the long run. But what do I know?
Thanks for the insights as always!
Ron
I wouldn't say needless at all- it just depends on you level of detail (or anal behavior I suppose). It doesn't seem to have been addressed before, but I will search the board to make sure. Probably should have first.
It seems to me with the sensitivity of this amp, having only about half of the PS board securely mounted is not really such a good idea over the long run. But what do I know?
Thanks for the insights as always!
Ron
- Noel Grassy
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Re: Transformer / PS board bolt interference
Ron, IMO that board mounted with just 2 standoffs diagonally opposed would seem quite stout since nothing changes the pressure applied on this surface. The silicone/"glue" dabs should be ideal as they could absorb some deflection should it arise. YMMV
All excellent things are as difficult as they are rare__B Spinoza
- Ron Worley
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Re: Transformer / PS board bolt interference
It did occur to me that the silicone might actually act as a "shock absorber" as you mention.....
I bought some flat head #6 stainless just in case I want to mechanically mount them all.
Ron
I bought some flat head #6 stainless just in case I want to mechanically mount them all.
Ron
Re: Transformer / PS board bolt interference
The aluminum on Allyn's chassis was thick, so I just threaded the hole to accept the mounting bolts. The length of the bolt was adjusted to keep it flush. I wouldn't want to do them ALL that way, but with all the other bolts and nuts in place, the PS board is plenty stable.Ron Worley wrote: ... an interference problem with the heads on two of the PS board standoff bolts...
Tim
In case the NSA is listening, KMA!
In case the NSA is listening, KMA!
Re: Transformer / PS board bolt interference
Two of the bolts holding in the power tranny that are nearest to the "Stack-o-caps" need to be reversed with their heads on the inside the chassis in order to have room for the caps between the boards.Ron Worley wrote:It's funny... rather like an onion... as you peal back the layers you discover so many minor yet important details as to how Ken built these amps.. I guess that's part of the fascination I have with the Wreck...
Ron
- Ron Worley
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Re: Transformer / PS board bolt interference
I did notice that on the Francesca pics (attached)!
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- Ron Worley
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- Joined: Mon Dec 24, 2007 8:21 pm
- Location: Keller, TX
Re: Transformer / PS board bolt interference
Here's the latest drill pattern with some more adjustments on dimensions (moved the Preamp board closer to the pots)
Ron
Ron
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