Mandocello build thread

[Timbofood]

I'm with you Tree, I don't build but, the thought process of all these minute steps which render the amazing end product is fascinating!!

[Verne Andru]

It's like sculpting with wood - love it and thanks for sharing!

[Pete Jenner]

Dude!

[sunburst]

A little work on the peghead overlay.
After the spindle sander...

...and after some hand work in the areas inaccessible to the spindle sander. (Once again, work and time not required for an A, at least my A peghead shape.)

[Duct Tape]

John, thank you for the updates. I am really enjoying these build threads.

Me too. Thanks!

[sunburst]

Working on the fingerboard.
To determine the width and taper, I used the planned string spacing at the nut and bridge (taken from Mike Marshall's 'cello) and drew the outer string paths full size. I'm planning a 3/32" space from the first string to the edge of the 'board and the nut and a 1/8" space at the 8th string. I want those spaces to get a little wider toward the bridge, and with that info, determining the width and taper of the 'board is as simple as drawing and measuring.

[sunburst]

This is where things got a little strange.
I usually make my own fingerboards, but since this was a scale length I have not used before I ordered a slotted and radiused fingerboard from a supplier. I noticed that one edge was cut straight and the other side was just a rough cut from a bandsaw. In order to find center, I needed two straight, parallel cuts, so I simply ripped of the rough edge with the table saw. After doing that, I noticed that the side I had just ripped was not the same thickness as the other side, and that meant that the arch was not centered on the 'board!


That was a little disappointing, but It only meant that I needed to rip a little off of the thin side to center the arch. Fortunately, I could do that and still have just enough width for the fingerboard! If it had not been wide enough with the arch centered that would have been really disappointing, but it will work fine, so I guess I dodged a bullet, as they say.

[sunburst]

The off-center arch got me curious, so I checked to be sure that the fret slots were square to the edges and I was relieved to find that they were.

I made a test cut to be sure that my table saw miter gauge was square, found that it was, and cut off the excess wood from the end of the 'board.

In the pictures you can see my scribe lines indicating the eventual shape of the 'board.

[sunburst]

By measurement, I found that the total taper of the fingerboard is 5/8". I have only these two taper jigs, one for a 9/16'" taper and one for 7/16".

I needed one for a 5/8" taper, so I ripped a 5/8" strip from the edge of a piece of plywood...

...cut three sections from it and then ripped one to 5/16".

Those parts were then glued together into another taper jig that yields a 5/8" taper.

[sunburst]

I don't know if any of y'all use these taper jigs, but if you are not familiar with them, don't think I invented them. I got the idea from Sylvan Wells, and in fact, the first one I got is one he gave me.

[sunburst]

Since the radius has already been cut (and now centered!) in the 'board, I had to keep the flat side down on the table saw, so I had to use the jig first one way then the other.
Here's the set up for the first cut...

...and the 'board after the first cut.

Here's the set up for the second cut and the 'board after both taper cuts.

[sunburst]

I'm using my usual S-curve at the end of the fingerboard. I normally eye-ball that curve anyway, so I didn't have to spend much time on it. It looks good to me held against my full scale drawing, so that will do.

A little touch up of the curve on the spindle sander and the 'board is fully cut.

[Timbofood]

I'm going to need a second head to store all this information! Even though I have my doubts about EVER needing it for an instrument build. The information is simply fascinating!

[sunburst]

I re-checked and adjusted my center line (we can't expect jigs, even accurate jigs) to give us perfect results every time) and marked my inlay positions after double checking to be sure they are at the correct frets. Marking the wrong fret is an easy error to make, and one I've seen made many times. Hopefully I got these right.

For mandolins I normally use 4mm pearl dots for fingerboard inlays because my sense of proportion tells me that looks best. Since this instrument is significantly bigger than a mandolin I decided to see what different size MOP dots looked like in place. I keep an assortment of MOP dot sizes for various uses so I did a little experimenting.

I tried 4mm dots...

...and 5mm dots...

...and concluded that 5mm dots satisfy my sense of proportion for this fingerboard, so I went with those.
(FWIW, the huge 1/4" dots in an F5 fingerboard have always looked cartoonishly large to my eye. Apparently they just used what they had rather than choosing something appropriately sized.)
I center-punched the inlay positions to prepare for drilling the holes.

[sunburst]

I don't have a set of metric drill bits, but luckily I measured and found a brad point bit that is almost exactly the same size as a 5mm pearl dot, so I used it to drill the holes. I drilled using the drill press with the depth stop set so that the pearl dots lie in the holes just slightly proud of the fingerboard surface.
How am I able to have both hands on the fingerboard while drilling, you might ask? This drill press has a foot pedal, one of the main reasons I bought it!

[sunburst]

Here are the dots fitting very nicely in their holes...

...and all I needed to do was flood them with superglue (and be sure they stay fully down in the holes).

[sunburst]

After letting the CA cure, I moved on to binding.
I grabbed a scrap board and made this thing. It is about .120" wider and .060" longer than the fingerboard. (Perhaps you can guess how I cut the taper. Hint: I just made a brand new 5/8" taper jig for the table saw.)
Some blue painter's tape on the edges will keep me from securely gluing the fingerboard to the jig.

I clamped the fingerboard in position on the jig, with the jig extending .060" all the way around and started the binding process by bending the piece for the end of the 'board.

I used my usual Duco/acetone mixture and Stewmac binding tape.

[sunburst]

After letting the cement cure, I cut the corners for miters. If you look closely you can see the reflection of the binding in the back of the chisel. That is a way to tell when the angle is correct for the cut for the miter.

After making that cut the piece for the side of the fingerboard can be easily fit to the curved piece of binding.
As you can see, I was off just a little on the angle, but it will not matter. The corner will look fine when it's done (unless I mess it up some other way...).

[sunburst]

Miter both side pieces and glue them in place, set the 'board aside for the cement to cure, and that's it for the fingerboard for a while.

[sunburst]

Interesting color scheme; orange and blue. (I don't get to decide what color they make the tape.)

[tree]

Interesting scrap, too - beech? Bench top also?

[sunburst]

Yep, beech. It is left over from when I remodeled the work bench, so once again you're right, it is wood from the bench. It takes a real wood nerd to notice that!

[amowry]

Great, thread, John! It's always interesting seeing the different approaches builders have to all these things.

By the way (going back a few pages) I like how you capped the X brace and tapered the brace ends to nothing. I think those are two structural considerations that get left out a lot.

[Mandoborg]

This has been great to follow ! I always learn something with your posts John. I feel somewhat inadequate however in that I scribe my fingerboard taper lines on the blank, cut close on the bandsaw, then make two passes on the jointer to clean it up. I'm not so good with figuring angles and math !! :O)

[sunburst]

...I scribe my fingerboard taper lines on the blank, cut close on the bandsaw, then make two passes on the jointer to clean it up. I'm not so good with figuring angles and math !! :O)

I've done it that way for years; scribe, bandsaw, jointer, hand plane, but the fact is, I sold my jointer when I moved from Va. to Ky., bought another jointer here and haven't set it up yet, so I don't have a jointer to use in the shop. I did do a tiny bit of clean-up with a plane after the table saw cuts. I'm not good with math either. I have to double check, triple check, and continuously review math and measurements to try to minimize errors. I compared the actual 'board to my full scale drawing, and only then did I trust the math.