I joined the Spruce plate without a single bit of trouble shortly after writing the last blog post. Next came re-flattening the back side of the plates.

The set up:

I sanded out the plane marks with a random orbit sander, 60, 120 and 220 grit to finish. giving me this:

Smooth! Same thing on the maple. Some people get all excited about sanding instruments, they say things like “you’ll clog the pores with dust!” and “that’ll dampen the sound, it will never sound good!” Well I won’t say that they’re wrong but… On this particular surface all that will remain after shaping is a flat roughly 4mm wide around the periphery which will be glued to the ribs making a node, therefore not participating in the sound production of the instrument, unless it becomes partly unglued in which case it will add a nasty buzzing sound.

Next, flatten the other side!

Before:

The goal is to have a flat surface that makes the plates the thickness of the rough arch height. Normally I would shoot for 32mm on the spruce and 30 on the maple, but the cheapskates who cut the lumber restricted me to 30mm on the spruce and 28 on the maple. That won’t really change much, but it is annoying.

After:

After this, I center the rib assembly on each plate and trace around it.

Centering with the joints:

After tracing at the ribs, I re-trace 3.5-4mm out from the ribs, giving me a rough edge margin. I use a piece of plastic pipe as a guide which I turned to the right dimension.

Look how close the spruce came to not fitting! (I think it cost $600, but it might have been $300).

Even if it hadn’t fit it would not have been a big issue as I could glue wings on, and it would be nearly unnoticeable when finished.

Draw the corners at the same angle as the rib corners:

And complete the curves to make it 11mm long.

Next add the button, frankly I was about ready to head to the bandsaw and realized I forgot to mark it. There are ways to graft on a new button, but it is long tedious work, one is much better off if they don’t accidentally cut it off (or forget about it entirely). A little tip to prevent cutting it off; erase the outside line within its limits, and cut both sides of the button before cutting anything else.

The button, 40mm x 40mm, line erased:

It is starting to look as if everything is there!

Rough arching. This is the workout. You take a big gouge, and go at it… but first, mark the edge thickness plus a little extra around the plates. Finished is 5.5mm spruce, 5mm maple:

Ready to work hard!

Soon it will look like this all the way around:

Really, the spruce is easy, the whole thing took an hour and I was just marginally sore the next day. Maple on the other hand, ouch… I should get an apprentice before I do this again. It’s not even finished yet, I worked 2 hours to about 50% completion. I have a huge blister on my palm despite wearing gloves, and I’m quite sore in the shoulders, triceps and fingers, and I’m pretty sure I left a pool of sweat on the floor!

Maple 50%:

Oh yeah, I cut the button with a saw, like this:

After rough arching (wait what?!! I have to come back and do this again!!!) the edge thickness is finalized. The old way of doing this evolves hours of hunched over work with a small gouge that you push with your shoulder, almost always giving you a bruise and deep muscle pain. Luckily man invented the Delta DP-220 and a 3/4” router bit. The set up looks like this:

This particular drill press is good for this because it has a spindle quill lock. So you set the height and lock the quill. If anything goes wrong it is more likely to pull up away from your work than to pull down into it.

After the go around:

I left the corners rough because often they are thicker than the rest of the edges, though I have not yet decided if I will make them thicker, I figure it’s better to keep the possibility.

That’s it for today, back at it after the weekend, maybe I can get a massage or something… Thanks for watching!

(Disclaimer: Usually I re-read my blog entries to fix slight errors of auto-correct and or editing and comprehension, but today I did not.)

Thank you for all the kind words, I am very glad that this series is being well enjoyed!

Okay, so first up I cut some corners! Not to save time, but to make them even (ish). So they’re cut to length with a really big chisel.

The angle of the flat surface (if you lay a ruler flat) crosses the centerline of the instrument at the inside of the furthest away non-corner block. I should have a picture for this to make perfect sense, but I don’t, sorry.

More cutting

And the face of the corner should be square to the back surface plane. Next the corners are shaped to the proper thickness, being about 2-2.5mm depending on one’s personal preference. I used a dowel with sandpaper stuck to it, as seen here in this hard to comprehend photo:

So all that is left to do on the ribs is sand them smooth to say 400 grit, wetting in between each, and I usually do the rougher grits twice, seems to get a better surface. Also to shape the linings.

On to exciting stuff!!

Remember that back joint I made with my block plane? Well I didn’t like it, so I stuck a knife in it and it popped apart with zero tear out. That means it was a bad joint.

Magnified shot of why I didn’t like it:

It’s not that visible in the picture, but there’s a thick glue line in the joint.

The knife:

Parted joint:

I recently purchased a jointer, the electric kind. I did a practice joint using it on a piece of maple violin sized. Frankly it was the fasted joint I’ve ever made. I face jointed, edge jointed, cleaned up the joint with a block plane and glued a joint in about 20minutes. I was hoping the cello joint would go so smooth, but alas it did not. While the violin plates had no twist after running over the jointer the cello one’s did. I guess the tables are not flat! And they’re not, I checked with a straight edge, I guess that’s what you get if you’re not willing to spend more than $700 taxes in. So the jointer cleaned up my edge a bit, and the rest went by block plane.

Jointing edge:

Very slow work. After an 8 hour day I glued the joint:

Then took it apart again…:

Joints can be very discouraging, especially when you’ve taken them apart twice! I worked on it for another day, got really close, then screwed that up. Another day, closer… went on the LeeValley website and ordered a Veritas® #5-1/4W Bench Plane and a parallel jaw clamp…

This plane is the bee’s knees, check this out!

Though I have some reservations on their definition of sharp, because they say it come with the blade ready to use and frankly it had a burr on the back side the size of ceder hedge!

Anyway… 20 minutes and a perfect joint, yay! The parallel clamp made a huge difference too. Unfortunately (or not) I forgot to take pictures of the glued up plates and the clamp.

Next while that dried and I didn’t want to make a lot of noise I worked on my scroll design. The scroll template I have is about 1 cm too long to be convenient when fitting a cello in a case. Since this cello body is also shorter than the one the scroll was meant for, it would make sense for them to match a little. So I traced the template, and removed a central piece.

The new design:

The new, superimposed on the old, so you can see the difference:

That’s it for now, I’m going to work on the top joint next.

Exhibit A:

To fix this I soaked some paper towel in water and laid it on the offensive joint in order to soften the glue. After a long while soaking I squeezed it a few time with my fingers to get it moving, then clamped it up again; the result being something much more acceptable.

Once dry the flattening begins. First with a block plane to bring the linings flush to the ribs.

In reality this is the way one would normally flatten the whole assemble, but since I’m trying to save time (because time is money… or I’m lazy…) I used sand paper!

80 grit self sticking paper on an ostensibly flat surface:

I colored the whole thing with pencil to see if I got everything, and started sliding the the thing over the sandpaper. Back side of course, since I’ve not lined the top side yet.

Corner detail after some sanding:

About 20-30 minutes later maybe not even, no more black, the whole thing is flat!

By plane this would be at least a 2 hour job, and require sharpening once, maybe twice due to the glue and end grain.

Now for the excitement I promised last time! Before putting in the linings on the top side I have to trim the excess rib and block height. So I set the assembly on my flat table and lined things up… turned on the laser, a little burning and the thing is trimmed!

Okay, okay, the laser was to help me draw the tapered line between the top and the bottom block (as you may recall they are different heights), but frankly it was impossible to line up correctly as any minuscule movement at the laser was huge at the rib assembly. So that plan was scrapped to be replaced by…

Two adjustable feet attached to the mold!

So I leveled the assembly so the top block was the same height as the bottom, then drilled a tapered hole in a block of wood to hold my pencil.

Checking the pencil height:

Then I drew a straight line around the whole thing.

Detail:

After this I break out the oscillating saw, and zip around to cut off the excess.

Blurry action shot:

All done:

I mostly used the round blade, because it has nice little teeth with very little kerf, but switched to the plunge blade to get through the top block.

And now the assembly is ready for linings on this side, I’ve made the mortises, just have to bend and fit the linings, then another sand paper session, and oh so much more!

Dimensions of the linings are 22mm high, 2.2mm thick. After thicknessing I planed one edge smooth with this great set up:

Action shot:

Then trimmed them to 22mm on the bandsaw, leaving me with a bunch of little spruce sticks to use for toothpicks or model airplanes maybe…

After that I started on the mortises for the ends of the linings where they meet the blocks. In the Cs I set them in about 10mm, and a depth of 20mm (my notes say 18mm, but I didn’t look at them till afterwards, haha, it doesn’t matter). The mortise follows roughly the tangent of the ribs, not too tight or it’ll be impossible to bend the linings to fit.

Next I start the mortise by chisel on the lines (may not be necessary):

Then down with the home made mortising chisel:

Because my mortising chisel is not quite 2.2mm wide I need to clean up the mortise a bit, a finger plane blade works alright for this, but someday I’ll either make a new mortising chisel, or a nice thin straight chisel.

The wall of the mortise where the lining will butt is angled away from the open end of the mortise, the lining will be cut to match and that assures a tight fit as you push in the lining.

Next the mortise inspector, inspects: “You call that a mortise?!”

I did some little tiny (2mm long) mortises at all the other blocks. The reason they are longer in the Cs is because the tension of the linings unbending pulls them away from the ribs, whereas the others unbend into the ribs, making the risk that they pull off much less likely.

Now I figured a great trick to bend and fit linings. No need to use any muscles, just get your wife to do it!

Bending

Fitting

There’s not really a trick to bending linings, spruce is hard to bend, it tends to want to crack or compress, a little compression isn’t too bad, but cracking is not good. We only broke 2 out of 6 linings, one could be salvaged as a C, and the other was long enough to still use. That’s a bonus of not cutting them to length until they’ve been bent I guess. I mark the length of the linings and cut them with a chisel, with the ends beveled so it fits tight once dropped in the mortises. There’s a bit of finicking to get it right, they shouldn’t be too tight or too loose because then they’ll distort the ribs.

Fit and ready for glue:

The straps of poplar are to protect the ribs from the clamps, and are basically made the same way as the linings, and then covered with clear packing tape so they don’t get glued to the instrument. They are also reusable so find a storage place that you won’t forget about! Those really flexible clear plastic rulers from you school days also work great for this.

For clamps I have some 1” clamps with the T-bars cut off, and a bunch of reinforced clothes pins. Unfortunately I don’t have enough of either to glue the whole way around which I believe would be about 200 clamps on a cello. So I can do the two Cs at once, and then just one bout at a time, giving between one and two hours of drying time, it becomes a whole day affair. I’m trying to find a source for small clamps, hopefully under $1 each, but the ones that look good more than double in price when the shipping is tabulated. I saw some bent steel wire clamps once that are applied with a special pair of pliers, I’ll have to look into that some time.

Clamped up Cs:

Clamped up lower:

Oh and to check the fit on the bottom side of the lining I polished a piece of aluminum to use as a mirror. I have some real mirrors somewhere but couldn’t find them.

And there you have it, several pages of literature on a pretty simple subject, that won’t even be very visible when the whole thing is done.

Next time I’ll flatten this side of the assembly and trim the other side, before putting linings on there! The trimming should be pretty fancy if my idea works out.

Bending the tight bend in the corners

The long bend

Checking the fit

Adjusting

All bent up

Preparing the joint

Ready for glue

Joint glued

Corners

Viola!... I mean cello!

So I didn’t take a picture of an amazing butt joint because frankly I didn’t make one! ha! We can discuss ways of hiding a less than perfect joint when it come time to prepare for varnishing.

Now just as you figured I was ignoring the fact that you all waited three months for an update I will tell you that all this rib assembly work was done two months ago! What? Why so cruel?! Making people wait… horrendous. I don’t really have an excuse; but the poor cello sat untouched for so long. It’s a lonely life when you’re trying to become something great.

So after all that time I finally started making some linings. For those who don’t know, linings are a doubling of the ribs where the back and top of the instrument are glued. Generally they are about 25mm tall and 2.2mm thick. Once glued they are profiled or tapered to remove some weight. Their main purpose is to provide support where the plates are their weakest, at the purfling. Their thickness, plus that of the ribs, provides support either side of the purfling channel, they also provide a larger glue surface, but the utility of that is debatable.

Speaking of debates, I lost at least of week of work because I couldn’t decide on the material to use for the linings. Normally, what I was taught, was that the linings are the same material as the blocks. Unfortunately I haven’t any willow long enough to make linings from, and it would be pretty bad practice to make a joint in the middle of a length of lining. So I thought maybe poplar is similar, or Japanese lilac which I have some branches of, but requires I make a sled to mill properly (and by the way smells kind of citrusy when cut). So finally I asked a fellow maker about it and he just always uses spruce since that’s what he’s got a lot of. So there you go, I’m using spruce, because that’s what I have and it’s easy to resaw.

Stacks of lining wood and a billet

After each strip was cut off on the bandsaw, I planed the billet so I would have a good side on each piece. It’s easier to do with a thicker piece.

Then planing area

And the mess on the floor, because I know lots of you get a kick out of this sort of thing

My next plan is to bring the linings to final thickness with my mini thickness sander, but since it was made with oilite bushings, it got extremely hot the last time I used it.

Evidence

So I took it apart to hopefully swap the bushings for ball races, but of course I need to enlarge the mounting hole to 1 1/8” from 3/4” which means I must go out and buy a drill bit and figure a good way to counter bore.

One more photo of the sanding apparatus

That’s it for now I hope not to take such a long break again.

First up, in keeping with my light industry time is of the essence (wait? Didn’t I just slack for 42 days doing no work at all…) approach towards this instrument I didn’t want to thickness the rib stock the old fashioned way; being a block plane with a toothing blade and a cabinet scraper. I didn’t think the thickness planner would be a great way to do it because of the issue of tear out, and who knows what those blades might do to a piece of wood only 1.5mm thick. So I built a thickness sander. Normally a person would build a 24” or more thickness sander, but I’m not making acoustic guitars so about 6” would suffice. Here it is:

It’s a rather cute little gizmo I must say, with that manual feed crank on the side it almost looks like a jack-in-the-box or an organ missing it’s monkey. What you don’t see in this picture as it’s a set-up shot long after the work was done is that it’s driven by a hand drill. The sanding drum’s shaft sticks out the other side and I just chuck up the drill, set the right direction and I’m thicknessing wood! It has a few flaws, like friction of the oilite bushings and the high speed makes it get really hot, I nearly burned myself; but all in all it’s a nice tool, and I’m glad I have it.

Okay, now for the ribs. First things first you have to prepare the ‘C’ block, which means putting in the locating pins:

Then placing the template:

And tracing the template. I used a pointy screw and then ran over it with a pointy pencil. I also extrapolate the line out to the edge of the piece of wood.

Then another time saving device, I hot glued a scrap of 1/4” ply to the bottom of the ‘C’ blocks:

How does this save time? Well it’s simple, instead of cutting the blocks with my big incanel gouge that I forgot at work I’m going to cut them on the bandsaw! Which means I need a steady flat surface between all those blocks.

The results:

You’ll notice that on the left it looks unusable and on the right there’s still about a millimeter to go, that’s okay because I mounted the sleeve on my oscillating spindle sander up higher than the rubber and finished off with that:

Laying out the ‘C’ ribs for flame direction. I like when the ‘C’s point towards the top front which will be opposite to the upper and lower ribs:

Turns out I forgot to take any pictures of the bending process. It’s hard work with a hot tool, so I hope you’ll excuse me for now. Maybe I’ll remember to take a fake picture at a later time and add it in, but I’ll need to set up a tripod and it’s not feeling very appealing to me at 11pm tonight, so don’t hold your breaths please, we want no fainting.

So that concludes this entry… hey wait I said I glued one didn’t I? Hmmm so I did… One of the most prolific problems in woodworking seems to be not having enough clamps, or else, not having the right sized clamps, and then there’s the fact that cauls never work the way they’re supposed to! Well all of this is true in my workshop but I make do, so here you go jerry-rigged to perfection:

The big clamp is too big, the caul kept pulling the ribs away from the blocks when it’s supposed to do the opposite, so I added clamps to counter those forces and get everything all fit and fitting, there’s even a couple of wedges and what not.

So one rib is glued, the other has to wait because I’ve only got one big clamp, but even if I had two, my workbench isn’t deep enough to be able to turn the whole thing around to do the other side.

Keep your fingers crossed, but I think I’ll be working more now, I’m aiming for once a week, but there’s lots of wind.

Yesterday I set up to do the back joint. This joint is roughly a meter long, by 32mm wide, and is vital because in the end, after all the carving, it’ll lose about 98% percent of it’s glued area while still required to hold two boards each about 23 cm wide, together ad that under about 200lbs (oops where’d the metrics go!?) of string tension exerted mostly at a spot 1cm sq. Okay, maybe it sounds worse than it is, after all a lot of these joints last hundreds of years.

So first things’ first the set-up!:

What I have here one very long straight edge, an engineer’s square, a block plane, a workbench with an end vise, and a twobyfour with a wedge cut out of one end and a wingnut/carriage bolt for tightening. The latter can of course be made more fancy (and probably should be), and frankly in this case the wingnut isn’t strong enough to pull the thing closed, so I had to use a wedge to tighten the board to the support. As you can see, the board is clamped to the bench and supported on the other end, allowing me to work the joint with my block plane. You may say, “but isn’t a block plane a little small for making a joint of that size?” Well I don’t know any different, this is how I was taught to do it, and so this is how I do it! It’s like I heard a story once of a Christmas ham, this woman always cut 2 inches off the ham because that’s what her mother showed her, later in life she got curious and asked why here mom always did that, and her mom said “because our stove in those days wasn’t big enough to fit the whole ham.” So it may just be that it’s the only plane someone had, and that got passed on through the ages…

The Process:

I lay the straight edge on the joint to see if I have any high spots or whatnot. Also (not pictured) I check the squareness of the joint against the flat I made with the planner. While fixing the squareness I bring the joint to be flat and true, it can not have any twist to it or the joint will fail.

After this is accomplished it’s time to put a slight hollow in the joint length wise. I check the gap with the straight edge for now, it should be quite small, as it will double in size when the joint is made.

Here it is too big, so I had to re-flatten a little.

Once I feel that one board is nicely prepared I put it aside and start on the other in the same manner as the first. When that’s done I put the halves together to check the joint. I’m looking to see several things:

1- that there is no wobble, the top board should sit flat, if you touch it it should stay immobile.
2- that the gap is not too large or too small and that it is gradual, starting smoothly coming to a high point in the center and reducing smoothly.
3- and when test clamping that the gap closes evenly, that the ends don’t open up, and that both sides of the joint close.

I forgot to show the scraps glued on where the clamp will go, they are glued to the edge of the wedge and then made square to the back. This gives more surface to put the clamp on, and evens out the load so that one side of the joint doesn’t receive more clamping pressure than the other.

Congratulations! The joint is ready to glue!

Gluing the joint is rather interesting too, I should have filmed it I guess, but there’s not really enough room in my shop for that, nor am I well organized enough to accomplish such a feat. So the tools I use to glue are a P&G Hot Pot, a bristle brush, hot hide glue that is at least 6 hrs old, a big clamp (a parallel jaw clamp would be ideal, but I haven’t got one yet) and a hair dryer (again, a heat gun would probably work much better, but you’d have to watch out not to scorch the wood). With the one board still in position from jointing, I mount/hold the other one as close to the same position as possible. Using the hair dryer, I warm the joint surfaces, then slather on a ton of glue to both surfaces. Curly maple ‘drinks’ a lot of glue, European less than American for some reason but still significant. Then I slam the joint together because it’s fun, and rub the board with the other for a bit, though not until it grabs since I’m using a clamp. Get the alignment nice so I don’t have a lot of planing to do afterwards, and put the clamp on exactly the same way as when I did the test clamping. Now I run a strip of hot water either side of the joint, and some fresh glue on the joint (both sides of the board) and heat the area with the hair dryer. After all that excitement I get this:

A messy workshop with glue all over and a glued up joint drying nicely. The clamp will stay on for about 24hrs, and I won’t stress the joint for a while, though I’d say 48hrs minimum before working with a glued up plate.

That’s it’s for now, thanks for reading.

The back I’m using is some European (what ever that means) maple from Bois de Lutherie Aigrisse, it is far too expensive if you ask me, but lutherie wood always is, I guess I’m not a Luthier because I want to be filthy rich. At least it’s not more expensive than gold.

Okay enough ranting!

Thursday I finished my Big Shooting Board which you can see in the projects section. I then used that shooting board to shoot a square edge on the joint side, and the opposite side of the first maple plate. The reason I did both sides is that I’m not going to flatten the plates in the traditional manner, with a hand plane, but in a more production oriented manner, with a thickness planner. So after squaring up the two sides to the flat side of the plate I lay the flat side on the bench top and shimmed it to make the flat as level as possible. Then I glued on two sacrificial pieces of poplar, and it looked like so (actually this is an after flattening picture because I forgot to take a before):

These are needed to run the piece through the planner as the piece is wedge shaped. I glued them on in a temporary manner, a bunch of dots of hot hide glue along the length and let dry over night. I left the ends sticking out so they suffer the effects of planner “snipe” instead of my thousand dollar piece of wood. Action shot:

So after about 50 passes to make it flat I had a nice smooth board and surprisingly little effort exerted. On the next one I may try taking more wood at a time in the beginning, but this curly maple tears out something awful when you take too much wood… perhaps someday a helical cutter head will be a good investment. After the plate was flat I flipped it over an flattened the other side to a thickness of 32mm which gives me about 2mm extra.

Next I took my handy old butter knife and split off the sacrificial wood.

Once started you just pull and it comes right off.

And presto-chango! A nice flat piece of maple ready for the jointer, though it’ll need a sister first.

If at all along the way you have any specific questions, or things you’d like me to cover in more detail let me know, and I’ll do my best to comply.

That’s it for now, see you next week.

So today I spent 5/8ths of my work day making a huge shooting board (2’x4’) which is still missing some pieces, I’ll show it when I use it in a later installment, or maybe post it as a project.

The other 3/8ths was spent working on the cello. I split a large piece off a willow log and turned it into block wood. The log is from a tree that was cut down many years ago and has been slowly aging in my basement. The grain is wild and full of figure, which makes it hard to work with, but we don’t make cellos because of the ease of it! So after two days the cello is ready for the blocks to be shaped, though I should prepare some rib stock first.

That’s it for now, I’ll be back at it next Thursday.

I’m starting a cello from scratch so I thought I’d share the process. For the time being I’m only working on this two days a week, if it takes a few months or half a year, so be it. So first things’ first. You have to pick a design, or a model. In my case is it 100+ year old instrument that my colleague and I recently restored. For a few months it was attributed to my colleagues great uncle Charles Quenoil, but that was proved wrong because certain aspects of the construction were wrong. So it remains anonymous, but I now refer to it as the “Faux Quenoil.”

While the back was off the instrument I traced the outline. Then I picked a side, and used that as my half template. I’m not particularly interested in doing exact copies, so making a full body template is avoid at all cost (it it is much more expensive). In fact I’ve decided to go a whole other route with the template and only have it cover the corners and the C bout. This saves much money and effort, and is precise only where it really needs to be. The rest of the form is copied from my tracing of the instrument and cut out on the band saw.

The form is of a collapsible design, using my newly developed ultralight laminated material. It’s a piece of 2” Blue foam insulation laminated between two sheets of 1/4” birch plywood. It is stiff, flat, and weighs about 10 times less than my previous cello form. The only problem is you can’t clamp directly to the foam, so strategic clamping plates have to be used, but those are just left over pieces of 1/4” ply.

So here is the result of a short days work:

There’s more to come (and I’ll get better with photos I promise), thanks for reading.