Acoustic side height calculation

Talk about musical instrument construction, setup and repair.

Moderators: kiwigeo, Jeremy D

Post Reply
mac007
Kauri
Posts: 31
Joined: Mon Jun 15, 2020 11:14 am

Acoustic side height calculation

Post by mac007 » Thu Mar 14, 2024 8:14 am

Hi,

Does anyone have a tip on calculating side height contour for various back radiuses?

I have seen a spreadsheet (Dooling guitars) which is pretty tedious.

Or is it common practice to approximate and then scribe the sides while the braced back is in the radius dish and fine tune with a block plane?

Suggestions appreciated

MK
Last edited by mac007 on Thu Mar 14, 2024 9:53 am, edited 1 time in total.

User avatar
kiwigeo
Admin
Posts: 10594
Joined: Sat Sep 29, 2007 5:57 pm
Location: Adelaide, Sth Australia

Re: Acoustic side height calculation

Post by kiwigeo » Thu Mar 14, 2024 8:23 am

mac007 wrote:
Thu Mar 14, 2024 8:14 am

Or is it common practice to approximate and then scribe the sides while the braced back is in the radius dish and fine tune with a block plane?
This is what I do.
Martin

User avatar
TallDad71
Blackwood
Posts: 193
Joined: Thu Jan 19, 2017 6:20 am
Contact:

Re: Acoustic side height calculation

Post by TallDad71 » Thu Mar 14, 2024 6:57 pm

Side heights are difficult to use as the top is also radiussed(!) hence there is no straight line to measure to.

I scribe, hand plane it rough. My dish has a 60cm diameter round piece of sandpaper in it, so I sand the kerfing and sides using that.

I also use the radius dish on top of the sides and back when gluing the back on. That way it applies even pressure all around the rim.

I also find if I sand the top edge of the sides with a different radius board first, I can sandwich the whole thing between two boards under the go bar press. The sides are still in the mould and I’m not gluing the top on at the same time.
Alan
Peregrine Guitars

Dave M
Blackwood
Posts: 597
Joined: Tue Jul 15, 2014 6:44 am
Location: Somerset UK

Re: Acoustic side height calculation

Post by Dave M » Thu Mar 14, 2024 10:03 pm

Yup, fine tuning with the sandpaper covered radius dish. Must admit I haven't worried too much about the exact depth of my guitars. They all come out a bit different. I may be wrong but I don't think it makes a lot of difference - within reason.
------------------
Dave

Post Reply

Who is online

Users browsing this forum: No registered users and 294 guests