Building an arch top ukulele

Morning, all! Brad was nice enough to send me his set of plans last week. I'm waiting for some wood to come in. In the meantime, I've drawn up a top plan using Brad's as inspiration (and for technical details). It's a 5 string, concert-sized. I intend to tune it in fifths like a 5 string mandola (C-G-D-A-E). I love the design of those Rex Parker archtops, so this is an homage to that. Of course, he has all kinds of skill and, well, I intend to try hard.

Here we go:

uke-mandola-complete.jpg
 
Thanks Mr. Juju!

Should I start a new thread for this? I don't know this board's protocols.

Well, I live in the land of Engelmann spruce and found some from a local guy on Ebay. He sent it out yesterday and it arrived today (but it only had to go from Denver to Boulder). This is a piece large enough to serve as a one-piece top for an F5 mandolin. You can see on the photo that the uke design is quite a bit smaller.

That's a question for you all: Are you all satisfied with the sound from this design? From what I gleened from the drawings, we're looking at sides of about 1.5" and a small body. Mandolins are about 2" deep (total, with the top and bottom thickness, plus the arch) and a bigger overall body. Just wondering. I'll follow the design for this one, as I don't know well enough to start messing around too much.

top.JPG
 
Nice top. I am going to start with some inexpensive wood for my first build (perhaps first few). Following the advice from a luthier from a local group (see www.lint.org) I obtained some western red cedar fence pickets from the local HD and L home improvement stores. I was able to find a few pieces that were cut right through the center of the trees with the center grain to the far edge. A couple boards have grain close enough to almost be book matched. All of these boards are currently drying out in an interior closet at the house. I just hope they are thick enough. Though they are sold as 5/8" they measure a little less in some places.

From what I have read most who have followed Brad's design seem quite pleased with the results. I plan deviate a bit from Brad's plans. I'm going to scale down the Benedetto design to tenor size similar to the one built by Garry Petrisic. I just need to work out the size reductions of the Benedetto plans. If I calculate the percentage of body length reduction from 20.75
" (Benedetto) to 9" (tenor ukulele) I'll use that as a reference to calculate the rest of the dimensions and draw up my final plans.

I was wondering about starting a new thread, myself. But then if we continue here at least the posts are in one place. I suppose if you are going to post extensive build documentation it might be better to have a separate thread and maybe just updates here.

Perhaps Brad can decide if he would like to continue this thread or not. I'm fine keeping it all under one roof.
 
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The rib depth on a F style mandolin is 1 3/8", the top and back arch should be 5/8", for a total body depth of 2 5/8". With my 1 1/2" sides the body depth should be 2 3/4". Keep in mind that the distance between the top and back is critical on arch top instruments. If you are going to document your builds on UU, it would probably be better to start your own thread, this one may be a bit cumbersome now.

Brad
 
Thank you both! I did some reading between then and now and heard some people saying that it's not so much about air volume inside as it is about the ratio of air volume to sound hole size. Totally cool stuff, honestly. I'm looking forward to getting moving. Work's been crazy and we had a big snowstorm to deal with, so I'm still waiting to start. Maybe tonight.
 
I just found this forum and this thread and I'm hoping it is possible to get in on the materials that have been shared with the build group. I notice that Brad (the OP) hasn't been active on the UU forum since 12-30-2014.
Regards,
Dan Rowka
Jacksonville, FL
 
I emailed Brad the other day asking about some dimensions. He is still on Kauai and it seems that his shop, materials, and ukuleles are still in Cannon Beach, OR. Matt's link above provides all the plans that Brad drew up and shared. Brad does strongly recommend Bob Benedetto's book, Making an Archtop Guitar, as well as Roger Siminoff’s books on building mandolins. Brad also has a YouTube channel. Bradford Donaldson As you can imagine, the most recent video is from five years ago but there are some good build videos.

If you haven't already, search this forum for archtop ukuleles. There are a few. Also, if you use Google (I searched "archtop ukulele" "build") you will find a few blogs, articles, videos, etc.

I hope some of this helps and good luck with your build. Definitely post pics of your progress. :)
 
Get in with a group build from 2009? How slow do you think these guys build?

Welcome to the forum.
 
Ha, yeah, late to the party and all...

I did recently get the Benedetto book with the intention of adjusting to a uke, and got the files from Matt's link. We'll see where I end up.
 
Aloha everyone, this is Bradford and I am surprised that this thread is still alive! I have not been on the forum for so long , I forgot my original sign in info, so I set up a new account. I am on Kauai now, but we split our time between here and Cannon Beach. I have duplicated my shop here and am starting to up my production again. I had some health problems, as well as some other issues a few years ago and had to abandon my wait list. Anyway I am glad to be building again and happy that there is still interest in arch tops. Will be happy to help any way that I can.
 
Thanks much, it is nice to be back

Yes, Bradford, it is indeed wonderful to have you back! I'm glad that your health has improved!

I'm still playing my Custom Concert that you made for me - it is my most favorite of all of my instruments, and my primary gigging ukulele.

Thank you, thank you, and thank you again!

Let me know when you are again up to speed -in the event you buid a soprano on spec, I would be very interested (particularly if it has peghed or gotoh UPY tuners...)


-Kurt​
 
Hey Kurt, thanks much for the welcome, and it is wonderful to hear from you. At the moment I am building whatever strikes my fancy. Just finished a concert with some Maccaferri/Selmer concepts; bent top, tailpiece etc., fits right in with my arch top work.
Bradford
 
Nominally my plans call for 5/8” thick, but you could probably make do with as little as 3/8”, especially if you are talking about a flat board. Bookmatched wedges need to be a bit thicker as you will knock off some of the thickness shaping things.

Brad
 
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