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Dan Gleibitz
09-26-2016, 02:27 PM
Hello brains trust,

I figure these are probably aesthetic questions, but would like advice. I'm building from my own plan and trying to work out how to cut the sides to fit the back radius. The maths is easy, but where should the high point be? Somewhere around the one on the right feels right, but I don't know why.

http://i.imgur.com/GYUaPH5.jpg

The second question is does anybody incorporate a wedge shape as well as the radius, leaving the body thinner near the neck? One of my (bought) ukuleles is built like this and I think I like it but just wondered if it's a normal building thing or unusual.

Edit: Realised the second question is answered by the first. Different approaches, same outcome.

Alain Lambert
09-26-2016, 05:02 PM
If you use a radius dish, the high point (apex) will be at mid distance between the heel and tail ends.
For my tenors I use a slightly wedge shape the tail end being 73 mm and the neck end at 60 mm

Dan Gleibitz
09-26-2016, 05:28 PM
Thanks Alain.

That makes sense. If the neck and tail heights are the same, the high point will be centered; if you make the neck end lower, that will shift the high point down toward or into the lower bout, right?

In any case, I drew my plan in 3D and decided I like the look of the option on the left, which is the more wedged shape. I've ended up at 55mm at the neck end and 66mm at the tail (plus top and back).

http://i.imgur.com/vsgDyZn.png

Timbuck
09-26-2016, 10:25 PM
I put my first set of tenor sides together (with no taper) with end blocks in the mold,then with a small block plane i took it down to the approximate shape I wanted then sanded the workpiece down with the radius dish to the required finished shape and size that I was happy with ..then with some thin plastic/thin card I wrapped it round the profile and I made a template of the final shape.. I then transfered this shape to some 3mm polycarb .. Years later on I still use this same template to pre shape all my sides in the bandsaw leaving just a small amount to sand off on the radius dish..Saves a lot of work ;)

With soprano 's I just made a template the same way off a real Martin Uke :D

Michael N.
09-26-2016, 10:49 PM
If you use a radius dish, the high point (apex) will be at mid distance between the heel and tail ends.
For my tenors I use a slightly wedge shape the tail end being 73 mm and the neck end at 60 mm

That's sounds more like old style, when they didn't use radius dishes.

Dan Gleibitz
09-27-2016, 12:08 AM
That's a great idea Timbuck. I shaped my first (yep, very first) set of sides tonight, so I'll take a template off them and store it with the mold for future builds. That'll help with the bending too - my sides were supplied with very little to spare at the ends so last night when I bent the waist a few millimetres short I had to redo half a side. Could have been avoided if I'd made the card template first.

On a side note, I just want to genuinely thank you for this detailed build thread: I'm going to make some concert size Ukes (http://forum.ukuleleunderground.com/showthread.php?121329-I-m-going-to-make-some-concert-size-Ukes). It's been a huge inspiration, pretty much my bible the last couple of weeks, and copying your mold has made the job much easier than I could have hoped. So thanks!

Timbuck
09-27-2016, 06:49 AM
I try and leave about 30mm spare at each end of my sides it makes it easier to bend..In the rolling mills when a large thick section of steel plate is being formed into a cylinder the roller man pre-sets the ends of the plate to the radius first before the rolling commences to avoid a flat or peaked area when the seam is welded
http://i219.photobucket.com/albums/cc143/shiregreenbod/presets_zpsreapvbgx.png (http://s219.photobucket.com/user/shiregreenbod/media/presets_zpsreapvbgx.png.html)
it's difficult to do this with thin wood co's it can easily split at the ends if youre not careful...So i leave a bit on when bending and cut the flat bit off later. but thats my way;)...Oh yes! by the way if you have bent a side with the waist short..you can unbend it with heat and redo it in the right place..I have bent some sides the wrong hand :mad: and flattened them out again and re-bent them the correct way :)....I didn't believe it could be done at first but the old builders on this forum assured me it could be achieved.

Matt Clara
09-27-2016, 09:37 AM
...by the way if you have bent a side with the waist short..you can unbend it with heat and redo it in the right place..I have bent some sides the wrong hand :mad: and flattened them out again and re-bent them the correct way :)

Now I need to build a reverse Fox bender... I should apply for a copyright on the form for it now.
http://i.imgur.com/LH6Ldf6.png

gozierdt
09-30-2016, 07:45 PM
The caution I would make is to consider the body volume/soundhole size before thinning out the body too much. Granted my experience is mostly in guitars with much larger volumes. And certaintly Kala's Travel Ukes sound pretty good with very thin bodies, so perhaps this isn't as large a consideration with the smaller bodies (just as back/side wood choice doesn't seem to be as big an influence as in guitars), but then again, perhaps Kala compensates for lower body volume by adjusting soundhole size? Anyway, I wouldn't ignore it...

Dan Gleibitz
10-01-2016, 05:29 PM
Thanks gozierdt, I'll look into that in the future. I've just gone with about the deepest body I could fit in my case!

Pete Howlett
10-01-2016, 06:16 PM
There is a separate thread on body depth about a year back. I experimented with this and now no longer make the standard 3" depth - it's much more logical to have a shallower body on all fronts. I and my assistant have been unable to notice any loss in volume, tone or sustain.

ChuckBarnett
06-20-2017, 02:11 PM
This being my first build, I have no experience to draw from to answer my questions. This forum is a God-send! I have been trying to get my brain around this whole area of profiling sides and fitting the back to whatever that profile is. I see options like no taper, taper from butt to neck, taper beginning at the waist to neck, taper that is in an arc over the length of the back, and arc-shaped taper beginning at the waist toward the neck. I haven't seen anything addressing how the back can possibly match any side profile other than no taper or a straight-line taper. I think that I would like to build this tenor with either a rounded taper from waist to neck or a rounded taper the full length of the back. Is that possible? If so, how do you shape the back to the sides? Do you simply muscle the back to bend with the side profile you've created? If so, how does that mesh with using a radius dish to glue the back braces in place?

Thank you, again, for your patience. (And, BTW, I intend to be at the Guild of American Luthiers Convention in Tacoma in a month so, perhaps, my answer will be found there. But I'd like to bring what I've gotten done to have folks critique there if possible.)

sequoia
06-20-2017, 07:46 PM
Your are over thinking things. Simple. Make the Neck block lower than the tail block by about a quarter inch. Sand sides flat until the neck block and tail block are flat. There is your taper. There is no "muscling" of the back on. It conforms quite easily. Now radius of the back as well as taper is just as easy. Just radius the two back braces (24 inch or what ever), glue them on to the back (instant radius!) and glue the assembly onto the body. No dish needed. Viola! Tapered radiused back!