Building an archtop of some sorts

[bender]

Ahhh... macropcapa. Yeah, probably not the best choice. Knotty as fuck and easy to tear.

Top angle- So you've elected to keep the pickup area flat, and just angle the neck-join area. I would have thought that part of the advantage of angling from the bridge pickup to the end of the body is that the pickup heights don't have to be quite as greatly staggered. How high is your bridge going to be?

[Jay]

Ahhh... macropcapa. Yeah, probably not the best choice. Knotty as fuck and easy to tear.

Top angle- So you've elected to keep the pickup area flat, and just angle the neck-join area. I would have thought that part of the advantage of angling from the bridge pickup to the end of the body is that the pickup heights don't have to be quite as greatly staggered. How high is your bridge going to be?

Choice was on purpose as I did not want to use expensive timber on my first arched top in case things went wrong. But your assessment is totaly correct.

On the 6120 there is quite a difference already between the two pickup heights, despite the slope between them. Currently I am aiming for the strings to be between 20-25 mm above the top of the board when going over the bridge.

I was going to put a dummy neck on and take some more accurate measurements... I may yet have to do more planing/carving.

[Jay]

Has been a while, progress is very slow...

Made a simple 'pointy' tool so that the bulk of the inside can be removed by drill bit. Problem is I need a deeper throat...

[Bg]

apart from linda, yeah a deep throat is always needed. But do yourself a favour and get at least a 25mm forstner bit to get the bulk of that out? I use mine before routing anything big too.

[Jay]

apart from linda, yeah a deep throat is always needed. But do yourself a favour and get at least a 25mm forstner bit to get the bulk of that out? I use mine before routing anything big too.

Yes, a forstner bit is on my list for flat surfaces. Not suitable for this work as I am trying to achieve a uniform thickness of the arch.

[Bg]

yeah I get your point but can't you bulk it out a little first? Even freehand with a router and step it?

[Jay]

apart from linda, yeah a deep throat is always needed. .

Found Linda!

A router copyer would be sooo handy to have...



Lots more sanding to do. Dirty and tedious work

[Jay]

Anyone considering building an archtop? I thoroughly recommend the experience

My respect for reputable archtop builders is increasing quite a bit. Mind you, they have better tools than I have...

These F holes were a real F'in pain to make...

[bigporridgeday]

Looks great though.

[AiRdAd]

that's really starting to take shape! well done!

[bobiron]

What top thickness are you shooting for?

[sizzlingbadger]

Aren't they normally made from thin ply so they resonate ?

[Jay]

What top thickness are you shooting for?

Around 6mm after I have sanded the top back in preps for finishing. It is not a consistent thickness as I have reduced the thickness around the F holes to around 4mm (visually more appealing) and also reduced it around where the pots and switches will go (easier to mount). I am not going to use any bracing as you'll find in convential hollow bodies, as the top at 6mm is string enough to take the 'load'.

Post by sizzlingbadger » Thu Jan 26, 2017 3:42 pm
Aren't they normally made from thin ply so they resonate ?

Resonate or vibrate? I understand mass produced archtops use 3 way ply pressed into shape. That includes Gibson's 335. Some models will have an option for a 'hand' carved spruce top or something instead of the ply. Both will vibrate/resonate to produce sound. I think for an acoustic guitar I would prefer a solid spruce top over a ply one. But then again some very good ply top acoustics are around.

For the one I am making: look at it as a cross between a convential arch top and a solid body with an arched top Mine will be light but still very strong and hopefully acoustically a little louder. Although the latter doesn't matter as it will have two "badboys" in it.

[calling card]

I've used my compressed air die grinder fitted with a chunky router bur for hogging out spaces in wood. Got to hold on tight though @ 10,000 rpm free handing it

[Jay]

Hmmm, I used the grinder with flapblade on BG's recommendation. Works a treat but gives me the shits anyway. I find 100rpm already a lot!