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View Full Version : Should the back on a tenor uke be arched?



Leftypeter
02-08-2016, 11:25 AM
Just got plans from LMI on a tenor uke that I am going to build. I have built guitars in the past but this is first uke. The plans don't indicate a radius arch for the back but my intuition says this is a good idea. If so, what is a good radius to follow? Also, wonder about tapered sides but I see there is another post on this topic today. Thanks

Michael Smith
02-08-2016, 11:35 AM
15' radius

BlackBearUkes
02-08-2016, 02:58 PM
Yes, by all means taper the sides and radius the back.


Just got plans from LMI on a tenor uke that I am going to build. I have built guitars in the past but this is first uke. The plans don't indicate a radius arch for the back but my intuition says this is a good idea. If so, what is a good radius to follow? Also, wonder about tapered sides but I see there is another post on this topic today. Thanks

Beau Hannam Ukuleles
02-09-2016, 08:29 AM
There are few "HAVE TO" with anything, but a arched back is alot better then flat, but it isn't a MUST for a first time build!!!!!!!-

Michael N.
02-09-2016, 08:44 AM
Here's a guitar with a flat back. Don't sound too nasty to my ears.

https://www.youtube.com/watch?v=yGKan6eX5ug

Allen
02-09-2016, 09:37 AM
I'm with Beau. While most of us do build with an arched back, and quite a few of us with a arched soundboard, you certainly don't have to. Nor do you need to taper the sides from butt to neck block.

Leftypeter
02-09-2016, 01:58 PM
Just got plans from LMI on a tenor uke that I am going to build. I have built guitars in the past but this is first uke. The plans don't indicate a radius arch for the back but my intuition says this is a good idea. If so, what is a good radius to follow? Also, wonder about tapered sides but I see there is another post on this topic today. Thanks

thanks to all for a timely response!

ksquine
02-10-2016, 07:05 AM
I use a 16' radius on the back braces. Why?...because I have a 16' dish for guitar building.
Its barely noticeable on a uke size back, but it helps the back keep its shape better.

Beau Hannam Ukuleles
02-10-2016, 08:52 AM
I use 15' on the back but i want to try 10' for no other reason as i like the look of a curve (which you get on a guitar with a 15' back, but not wiht a uke wiht a 15' back)

Diogenes Blue
02-10-2016, 09:04 AM
I use 22' on the front, 12' on the back.

ChuckBarnett
04-12-2017, 09:45 AM
Okay, newbie here. So you use a circular "dish" with a set radius and, what, put the vertical and horizontal midpoint of the back in the center of that dish? When glueing the reinforcement strip on should I do that in that dish as well?
BTW, I am working off that same LMI plan. Anything I should know?

Allen
04-12-2017, 09:54 AM
I glue all braces in the dish. Helps keep things in the intended shape.

I aim for the mid point of the waist to be in the centre of the dish. There's a fair bit of latitude here though, so don't get too obsessive. Just try and get the shape to be even from side to side. Easy to got heavy handed and not paying attention, ending up with one side getting more material removed than the other.

ChuckBarnett
04-12-2017, 10:26 AM
Thanks, Allen! :-)

jcalkin
04-12-2017, 11:25 AM
I glue all braces in the dish. Helps keep things in the intended shape.

I aim for the mid point of the waist to be in the centre of the dish. There's a fair bit of latitude here though, so don't get too obsessive. Just try and get the shape to be even from side to side. Easy to got heavy handed and not paying attention, ending up with one side getting more material removed than the other.

In the words of the immortal Peewee Herman, "I meant to do that!"

jcalkin
04-12-2017, 11:33 AM
I glue all braces in the dish. Helps keep things in the intended shape.

I aim for the mid point of the waist to be in the centre of the dish. There's a fair bit of latitude here though, so don't get too obsessive. Just try and get the shape to be even from side to side. Easy to got heavy handed and not paying attention, ending up with one side getting more material removed than the other.

A radiused dish is the same everywhere. Put the waist anywhere on it you like. I usually make my tail block and ribs the same depth. The neck block is shorter than the ribs, and I grind down to the neck block while try to take almost nothing off the tail block. After doing it once you can make a template of the rib shape and saw to shape before bending. Saves a lot of time.

jcalkin
04-12-2017, 11:43 AM
I use 15' on the back but i want to try 10' for no other reason as i like the look of a curve (which you get on a guitar with a 15' back, but not wiht a uke wiht a 15' back)

I made a 9' radius dish for "flat top" mandolins, and you can definitely see the arch. I've used it on the back of ukes and it looks great.

Then I made a cylindrical "dish" with a 3' arch and used it on the top and the back of a mandolin. The sides looked weird but it sounded great. Ukes don't need that kind of support, though.

ChuckBarnett
04-12-2017, 05:19 PM
I made a 9' radius dish for "flat top" mandolins, and you can definitely see the arch. I've used it on the back of ukes and it looks great.

Then I made a cylindrical "dish" with a 3' arch and used it on the top and the back of a mandolin. The sides looked weird but it sounded great. Ukes don't need that kind of support, though.

So making a radius dish... or spend $100 plus tax and shipping. Can I make a radius dish? How would I go about doing that? I guess 15 foot is what I would need.

Sven
04-12-2017, 06:26 PM
Hi Chuck. Have a look at this thread here:
https://forum.ukuleleunderground.com/showthread.php?30203-How-to-make-a-Radius-Dish&highlight=Radius+dish
I have made some nice drawings with measurements but I'll have to be on my computer to find them.

Edit: found it!
http://forum.ukuleleunderground.com/attachment.php?attachmentid=48252&d=1359550555

sequoia
04-12-2017, 07:20 PM
I do not use a radius dish to make my radiused braces nor use them to glue the braces in. I just sand in the radius I want to the back braces using a spindle sander and guide by copying a known radius and then glue the radiused braces to the back using a lot of clamps so everything conforms. Works for me fine. Although a radiused dish and a go-bar deck is ideal, it is not necessarily needed. I also use a much more radical radius then people have posted here. I use a 24 inch radius (2'!!!) on my backs because.... I don't know! Just because. My theory is that this is twice the length of a 12" bodied tenor. Also there is 3/16 straight taper on the body.

Timbuck
04-12-2017, 08:51 PM
Brad Donaldson ,who used to post on this forum a few years ago , he designed and built a concave back ukulele for ladies with large boosom's :o here is video of it being played. https://www.youtube.com/watch?v=Vmi4pr2BM-k

orangeena
04-13-2017, 02:25 AM
Here (https://www.youtube.com/watch?v=V1q5NUK6y1o&t=0s) is a link to Sue Gardener's amazing technique for making a 15ft radius dish. Can't wait for part 2 when she spins up the router.
Max

Diogenes Blue
04-13-2017, 03:56 AM
For my radius templates I bolted various lengths of scrap angle steel and aluminum together and attached a cheap Harbor Freight trim router at the required distances. I used the middle hinge pin on my shop door as the pivot point. Was pretty easy. For the dishes, I used the typical radius dish router jig / sled you can find with a google search. Does a very accurate job...