What a difference a quarter turn makes!

[Landon Johnson]

Just received a Mullen PRP (1989) last week and noticed that the sustain up on the neck wasn't what I was expecting. Kinda thunka-thunka. I'd read somewhere on here about tightening cabinet screws, and sure enough, my little Mullen had some play around the corners.

I tightened up the four screws on the back chrome apron (one almost a half turn), and wow what a difference that made! Noticeable increase in sustain above 12. Also reduced cabinet drop (what little there was is now almost nil)

So check those screws etc. every so often. They do work loose. Now it's like driving a classic car with a new suspension.

[J D Sauser]

Wood changes in size quite noticeably during seasons.
It settles too. Aluminum reacts to temperature changes as well.
If it's all loose, you should take the oportunity to "knock the guitar together" while you tighten it. You need to be 2 or 3 people to do it.
Carter Steel Guitars would do that on EVERY guitar sent out after they developed that practice which consist of placing a "2-by-4" against the changer end and on the other end on the key head and knock the two ends towards each other with heavy rubber melets, while tightening the crews (typically from the under belly) so that the parts have their bolts snug against the perforation walls facing each other end. It makes an audible difference and help in having a guitar with a more stable tuning.

... J-D.

[Ross Shafer]

wood screws for body/endplate assembly...JUST SAY NO!

[J D Sauser]

wood screws for body/endplate assembly...JUST SAY NO!

Agreed. Contrary to all mechanical rules.

... J-D.

[Donny Hinson]

Carpenters and cabinet makers will solidly argue the idea that you should always use wood screws for wood. Well then, I guess I'm a pinhead, but I'm a smart enough pinhead to recognize that wood screws are tapered throughout their length, and that means that if they back out (even a little), the entire screw body tends to get looser in the hole. For that reason, I use sheet metal screws (always) because they're tapered only at the point, and if the screw gets loosened somehow or backs out a thread or two, the remainder of the screw body is still holding with full contact and friction, retaining almost all its holding power.

[J D Sauser]

Carpenters and cabinet makers will solidly argue the idea that you should always use wood screws for wood. Well then, I guess I'm a pinhead, but I'm a smart enough pinhead to recognize that wood screws are tapered throughout their length, and that means that if they back out (even a little), the entire screw body tends to get looser in the hole. For that reason, I use sheet metal screws (always) because they're tapered only at the point, and if the screw gets loosened somehow or backs out a thread or two, the remainder of the screw body is still holding with full contact and friction, retaining almost all its holding power.

I agree too, in CARPENTRY, when you connect wood to wood, Donny.
Actually, dowels are the art's preferred way, nails are frown upon and screws made their way into the industry.

I think that what Ross alluded to is, when you attach a wooden cabinet to a metal frame or metal parts to a wooden cabinet, the preferable way would seem to be mechanical screws "sandwiching" the wood.

One thing I have often criticized, is the tendency by some SG builders to treat passage holes and mechanical bolts not exclusively as tightening devices but also as positioning devices. Yet, we know that for bolts passage holes are typically bored wider then the bolt's diameter to allow for easy passage and even positioning adjustments. One part being bolted with many bolts may require a laxer tolerance so ALL bolts will pass thru without locking up or excessive "rub" as their centers may not be all properly aligned with each others.
Dowels or in the mechanical world, PINS are the device used to POSITION parts among each others where precision is needed.

This is why Carter SG developed it's rather crude but quite effective protocol of "knocking guitars together" (a term they also created along with the practice). My answer was, you should use pins to lock keyheads and changer plates in a definitive place. But then again, we have a wooden cabinet that "moves" due to seasonal changes in temperature and humidity.
Franklin PSG's have an interesting hidden detail underneath the changer plate... a steel cross bar inlayed in the cabinet against which the changer shaft "ears"/"posts" is bumped against while tightened onto the cabinet with mechanical bolts. I haven't inspected the keyhead end, thus I can only suspect the thinking may have been mirrored over there to make the opposing key parts snug in the direction of the string's tension. They are not known to be inconsistent sounding guitars and this would seem a likely factor why.

... J-D.