Benedetto Archtop Build

Post by **Barry Daniels** » Thu Apr 09, 2015 6:54 pm

Those variations in channel width will show up in the final product. Any chance for recutting the channels and evening it out?

Ron Sommers · Post by **Ron Sommers** » Fri Apr 10, 2015 12:02 am

I thought that might be the case. Thanks.

I can attempt to recut. I'll set that back up over the weekend.

Michael Lewis · Post by **Michael Lewis** » Sat Apr 11, 2015 1:35 am

One answer to irregular binding ledges is to re-cut them more evenly and fill the added depth with more binding/purfling. Barry is absolutely correct about the unevenness showing when you are done. So make your best effort to make the ledges as even as you possibly can. This often makes the difference between a good job and a junky one.

The unevenness mostly comes from allowing the axis of the router to wander in the process.

Ron Sommers · Post by **Ron Sommers** » Thu Apr 23, 2015 2:02 am

Not sure if I asked before, but does anyone suggest/recommend a carbon fiber insert in the neck above the heel for strength?

If so, how thick and long? I've seen videos where they put two parallel to the truss rod. Are they overkill, or worth the time and effort??

Sizes I found at Geminimusical.com
.125 x .325
.125 x .500
.200 x .250

Michael Lewis · Post by **Michael Lewis** » Thu Apr 23, 2015 2:16 am

So much depends on what the neck actually is. The material and the shape determine much. If the neck is thin it should benefit from reinforcement.

Size and placement of CF reinforcement is sort of an engineering job. Since CF is extremely strong in tension it makes sense to place it near the exterior of the neck surface. If you covered the neck with CF it would be very stiff but CF is not a very practical material to have on the surface. Draw a few views (top, side, cross section) of your neck and think about the stresses involved.

You get the most strength by using the CF is a tensile / compression load. Think I beam.

Ron Sommers · Post by **Ron Sommers** » Sun May 24, 2015 8:45 pm

Thanks for the input on CF.

I've been rather slow getting things done, but here is the body with the binding completed. Just sanded the edge round for comfort.

Same pattern as the 'f' holes: mahogany/maple/mahogany and it even looks 'even'!

Thickest on the outside edge.

Have to do a little scraping to clean up the top and back.

Now onto the neck!
I have to route the body and neck and channel for the truss rod.

I hope to have this guitar done and strung by July!

Greg McKnight · Post by **Greg McKnight** » Mon May 25, 2015 2:18 pm

That's looking great Ron.

Dan Smith · Post by **Dan Smith** » Mon May 25, 2015 3:27 pm

Nice work, Ron!
The binding looks great, and the F holes look awesome!
Dan

Patrick Hanna · Post by **Patrick Hanna** » Mon May 25, 2015 11:45 pm

Very nice work, Ron. I'm looking at all the details on your closed box...all the fussy stuff, like miters on your f-hole bindings, uniformly scraped recurves in the top and so on. You are doing very nice detail work, as far as I can see from way out here in central Missouri. I think you're building a real nice guitar there! Press on and keep the photos coming. You've got me excited! I like any nice guitar, but nothing does it for me like a nice arch top!

Patrick

Dan Smith · Post by **Dan Smith** » Wed May 27, 2015 10:12 pm

Patrick Hanna wrote:Very nice work, Ron. I'm looking at all the details on your closed box...all the fussy stuff, like miters on your f-hole bindings, uniformly scraped recurves in the top and so on. You are doing very nice detail work, as far as I can see from way out here in central Missouri. I think you're building a real nice guitar there! Press on and keep the photos coming. You've got me excited! I like any nice guitar, but nothing does it for me like a nice arch top!

Patrick

Hey Patrick,
Good to know you still frequent the forums!
Thanks for learning me the tricks of truoil.
Dan

Ron Sommers · Post by **Ron Sommers** » Thu May 28, 2015 12:23 pm

Thanks for the kind words guys!

I probably overdid the scraping early on.
I could have saved a bit of time by waiting to scrape the top and back till this point in the process.

Guitar building is way harder than violins! Sure, there's purfling, but that's a piece of cake compared to binding!

I can hardly wait to play it! It has a nice 'thump' to it when I tap the center.

Just need to get some spare time to work on the neck.
I've been mulling over whether I need to split the neck, or just go with one piece.
Probably will do the one piece as I don't trust my table saw to cut a square line.

Too bad the forum limits photo size. I'd love to post a detailed image.
I'd also like to see others work up close too!

Dan Smith · Post by **Dan Smith** » Wed Jun 03, 2015 7:00 pm

Ron,
Did you glue the lining and support strips with the sides clamped in the mold?
This is the instruction in the book, but I cannot figure out how to do it with spring clamps.
The photos show the lining installed outside of the mold.
I reckon I'd see the answer if I bought the video.
Thanks,
Dan

Ron Sommers · Post by **Ron Sommers** » Sun Jun 21, 2015 11:09 pm

Dan,

Sorry for the late reply. Been busy with other projects.

I did not, and yet I did. I started with it out of the mold, but then realized that the shape of the body would warp unless it was in the mold.

So, the 'fix' is to get two turnbuckles like this: http://www.homedepot.com/p/Lehigh-1-4-i ... /100207338

Then you can fashion two pieces of wood per each turnbuckle to fit between the sides. I put one at the 17" point and the other at the waist.
I put notches or slots in the ends of 2x4's to fit the eye bolt in. I went overboard and also recessed some bolts to hold it all together.
You then shape the business end to fit inside the body. These when tightened will push the sides into the mold.

For the end and neck blocks I just used two of those Erwin clamps to pull it snug.

One thing to watch for is when putting in the linings. I didn't measure exactly when putting the support strips in. I put them all in first.
If I was to do it again, I would measure the kerf wood (say 4"?) and then glue those in using spring clamps THEN put a support lining in and repeat.

What ended up happening with mine is I got a few 4 1/4" kerfs (halfway through one kerf block) several times and while it worked, it's a little sloppy.
Not that anyone would open it up to examine, I just like things neat!

Hope that helps??

Dan Smith · Post by **Dan Smith** » Tue Jun 23, 2015 12:57 pm

Thanks Ron!
Dan

Ron Sommers · Post by **Ron Sommers** » Wed Oct 28, 2015 10:59 pm

Well, it's coming down to the witching hour!
Not because it's Halloween... I'm almost finished building!

Some thoughts:

I decided to buy the mortise and tenon cutting jig by Robert O'Brien from LMII. I recommend watching the video therein many times.

The critical area is the angle board and attaching the top face and keeping things square. I screwed and glued most of it except for the top. It will need to be moved. At least mine did to effect minor adjustments. Use some good birch ply too.

The blueprints/plans are amusing. If you've ever read a plan before, unless it's several feet, callouts are typically 16", not 1' 4".
It's full of that type of nomenclature that has to be 'figured out' before using. It's easy to make a mistake. I rewrote them.

In addition, they could have really made the drawings cleaner by adding one more sheet of paper and rearranged the layout.
It's kluged together and stuff is difficult to decipher at first glance. The point of technical drawings is to convey information.
One shouldn't have to figure out what the draftsman intended to portray before understanding the information conveyed.

I hate to be so judgmental, but in my drafting class I would have received a 'D' for this work. When you're charging $$ you need to be spot on IMO.

For the money, other than the above, it's not such a bad deal because they bird-dogged all the parts for you and supplied the plans. You bring the wood.

They forgot to include two of the knobs (finally received them after a 2nd email) so I made my own. I actually like my own better than the plastic they sent!

It's a pretty slick setup. HOWEVER you really have to test a lot of pieces to get it correct. At least to do the dovetail mortise & tenon per Benedetto's plans. It does hold an archtop securely, however I had to modify it as it's really set up for flattops.

===

I also purchased a Dewalt plunge router ($200). It works well, HOWEVER make sure you are absolutely certain you crank on the plunge locking lever!

I thought I had and as I was cutting the actual body mortise it slowly released and rose up. I had to shim the body after that fiasco. Yes, there was screaming and crying and gnashing of teeth!!! ARRRRGH!

I think the better model is the Porter Cable for $100 more. My neighbor has it and it's really easy to lock it in place. The lever is large and is designed to easily function in a positive way.

If one was going to have 3 Dewalts permanently set up to do various jobs and never messed with they'd be fine.

Ron Sommers · Post by **Ron Sommers** » Wed Oct 28, 2015 11:04 pm

More jig pics

Ron Sommers · Post by **Ron Sommers** » Wed Oct 28, 2015 11:07 pm

Tailpiece jig and chiseling out grooves.

Jig also doubled as a tail adjuster hole jig.

Ron Sommers · Post by **Ron Sommers** » Wed Oct 28, 2015 11:11 pm

Some neck shots. 3 piece hard maple (hope it's not too heavy) made out of the same maple I made my bench out of. Also, black walnut.

Got the idea for the vice setup from Stewmac. Price for the vice was cheaper online and came in blue, not red.