I needed a new project for the eternal lockdown, so after a chat with my musical chum and ideas man, I have started on a mandola.
The wood for this experiment/instrument comes from an elm tree which grew in the garden of my previous house but had to come down 10 years ago due to dutch elm disease. an unusual wood for instruments I am told, but it was either this or a coffee table.
Photos to follow soon.
🗝️ "Life's what you make it"🗝️
The log.
The design was based on lots of looking at you tubes and drawings and photos until I was confident (?) about scale lengths body sizes widths etc. having concluded that there is no standard size. I eventually decided on more of an octave mandolin style with archtop front and back.
So work commenced by slicing the log into one inch slabs to make the back and front plates. Not having a handy sawmill or a chainsaw, I looked for an old style rip saw. I couldn't find one so what you see is a blockwork saw. I re-profiled the teeth to get the rip saw cut and offsets. Success. It cuts really straight (if slowly) leaving minimum planing to get a good idea of what the plates will look like for bookmatching.
Top marks for doing it the hard way. I did that years ago with setting and sharpening a hand saw converting it to rip. I only did it once, never again.
Some people call me a tool, others are less complimentary. Tools being useful things.
Practice on scrap...
After a lot of cutting of more bits of the log to get the right grain direction, I cut 3 slices about 6mm thick x 70mm wide to be the sides. I then planed them down to about 3.5mm with my router in a jig ( no dancing) and then refined them with my hand plane to 2.5mm thick. Jings. That took a while and left me wondering how C F Martin etc. made instruments in the mid 1800s. Just hand tools for these boys.
The carbon truss rod is purely a stiffener 4mm wide x 7mm deep as I am unsure of the potential for elm to flex even in a short length. I am thinking about 22mm thickness at the nut as well . Too much thinking is bad for you!!
Today's offering is the front and back (planed to 17mm thick) with the perimeter reduced to 5mm using my router in a stand and carefully running the edge past the blade. it took a day to do at 1mm per pass and now I can start on the inside and outside profiling before final carving begins.
spent some time making the front and back profiles for key points (bridge, waist and longitudinal. Now for the fun bit. I'm carving the profiles into the wood using a "Kutzall" carbide spiked ball in my flexidrive from my drill. it's a dangerous bit of kit if you get it wrong but can be used with great finesse if allowing plenty of time.
Once the profiles are in, out will come the plane/s for further rough shaping. this should keep me busy for some time doing both sides of each plate.
That is the outsides of the plates rough planed to the profile lines. quite happy with the results but can't finish the neck area of the top plate until I get the mortice joint done and the neck rake set up.
Also hollowed out the insides using the "spikey ball" technique. it took about an hour each plate but is far quicker than the wee mini plane for this stage. that will be used for final thicknessing along with the calipers to measute the thicknesses accurately.
Remarkable progress considering what you started with. One quick method for hollowing is to drill holes inside with a depth stop on the drill, then rough out till the hole marks disappear. Big makers use CNC or copy routers to allow their time to be focussed on final thicknessing.
Some people call me a tool, others are less complimentary. Tools being useful things.
Hi Rocknroller. Without all the right modern piller drills and cnc stuff I had to think of another way to "carve" the plates. The spikey ball technique worked exceptionally well on the "Thistle 2 archtop" maple as opposed to sharpening the plane every 15 minutes, so I opted for it again. I like to think of myself as imaginatively delicate when required and with constant use of the calipers, it is working quite nicely.
Yours,
Spikeyballman
I would say it’s worked very well. I started like that with no fancy tools and violin callipers which are not long enough to reach the middle, so it was a guess on thickness.
Some people call me a tool, others are less complimentary. Tools being useful things.
