Thursday, March 31, 2016

A Ming-Inspired Cabinet (49)

Today I started out with some fitting work on the strips which serve as backing for the rear demountable panels.

Small stopped rebates were taken from the rails to accommodate the ends of the strips:


The ends of the strips are rebated in two directions:


The rebating means that when the interior arris of the strips are chamfered, there will be no gap at the joint.

First the strip for the top of the carcase, which is mitered on both ends, was fitted, and then the runs on the carcase sides could be slotted in:


At the base of the rail:


The ink denotes the arris to be chamfered. The strips are housed in 1/8" (3.17mm) and are proud of the surface by 1/4" (6.35mm). I will glue them in later on.

At the lower end of the strip, you can see how the rail connects to the carcase and strip end:


After the strip was down, the lower rail with stopped rebate was slid into place:


Almost there:


Down:


Tried as I might I was not able to get a clear picture of the junction, despite three attempts. Oh well.

The task was completed similarly on both sides, and then on the other cabinet parts as well. That took care of half the day.

Then it was on to fitting the lower carcase board to the stand. Here, I've carefully positioned the carcase board and clamped it in place atop the cornice of the stand:


I used a digital caliper to set the spacing very precisely and was please to find that after the front edge was at the correct offset, the rear edge offset was only about 0.003" from target dimension. After so many layers of interconnected parts were stacked, it was nice to be on track still.

The entire assembly was flipped over and then some drilling was undertaken:


Flipped back over again, the results of the drilling are clear to see:


Then I used a bottom bearing spiral carbide to clean out the rest of the mortises to the same dimensions as the mortises in the frame members below:


Here's a view from a bit further back after all four were cleaned out:


 Then onto a little layout. The front mortises are to be the same length as the mortises in the frame below:


The rear mortises, however, will be elongated relative to the mortises below, to allow the carcase to move:


Working next on cutting a housing at half depth:


This is a completed front housed mortise:


Hammer-headed drawbars will be fitted later on. I save the work to make most of the pins and keys for the end.

A while later, all four are done:


Another view:


I will work on the other cabinet's lower carcase board in the same manner tomorrow, and then on to the shelf panels. Getting close now to completing the cut out on the carcase.

That's it for this round - thanks for your visit to the Carpentry Way. Comments most welcome. Next up is post 50

Wednesday, March 30, 2016

A Ming-Inspired Cabinet (48)

Things started out kinda groovy today - namely putting dadoes down the back of the carcase sides and top board:


A reader asked in a previous post why I didn't process grooves in the boards using an adjustable-width grooving head in my Martin shaper. Besides the fact that I don't happen to own such a cutter,  and it wouldn't make sense to buy one for just a few grooves (though I do want to get several such cutters eventually), several of the grooves on this cabinet do not run through the board length but are stopped on one or both ends. Thus, other strategies are called for - namely my smaller Festool router in this case with an edge guide.

Since the groove on the back of the panel was the same distance inboard as the front groove for the sliding doors on the front of the board, I simply changed to a longer cutter, kept the edge guide at the same setting, and continued to use the router to clean up those dadoes as well:


The grooves for the sliding doors had been roughed out earlier using a table saw, leaving the router with trimming work, which is the ideal way to use a router.

Still, two of the four trim cuts involved in processing these sliding door grooves to final dimension were cuts where the material is sandwiched between the cutter and the router guide fence, which is a risky cut to take as any errors in handling the router can quickly lead to a spoiled surface. It's  preferably avoided, but sometimes it is the most straightforward approach. So, I was vigilant and took great care with guiding the router.

The results were checked with a gage block, (9/16" equalling 14.3mm):


The arrises were sharp afterwards and could not be readily worked with a chamfer plane, so I used a hardwood block with some #320 paper glued on to ease those arrises:


I was relieved to get through all the dado work without mishap. One less thing to get stressed about.

Then it was back to fitting the second set of drawer vertical dividers to the second cabinet carcase base piece. Fitting the first one went smoothly:


With one side fitted, it was on to the last one, which also went in nicely and tightly:


A look along the lower interface:


Another view, this time from on high:


Too bad that stripey figure will not be in view when the cabinet is complete.

At the end of the day, I prepared some stock for fitting in the dadoes cut earlier. These sticks were surfaced to 0.003" oversize in thickness, which makes them a slight interference fit in their 0.5" grooves:


The purpose of these small sticks is to provide a backstop for the demountable panels which will be fitted to the back of the cabinet later on. I don't want to look into the back of the cabinet and see light gaps at the rear panel frame edges. An alternative might be to rebate the back of the carcase, however then you are digging into the roots of the dovetails and that is best avoided. I chose to rebate the rear rails, and fit strips in to other areas.

One other piece of news is that there has been a slight redesign of the cabinet's 'bonnet'. I had long felt slightly dissatisfied with the design and mulled over how I might improve it. As the cabinet carcase construction draws near the end my attention is now of course turning to the bonnet. I had an inspiration one day a couple of weeks back and drew a new version.

Here's what I came up with, the old version on the left and the new on the right:



Another view:


I believe the new frame and panel top is more harmonious with the overall lines of the cabinet, which is quite rectilinear, and provides more of a 'bookend', so to speak, with the framing in the support stand below. The waist in the middle section of the bonnet, to be made of shedua, echoes the support stand frame's upper beam, also waisted, and hints at the fact that more interplay of bubinga and shedua will be found within the cabinet. The client has approved the change, and agreed with my reasoning for making the changes at such a late juncture. I would have been fine with building at least one of the cabinets with the older version of top, however I was glad he liked the new version as it allows for a continuation of the slight economies of a fabrication that come with making two identical cabinets. Onward and upward.

All for this time. Thanks for your visit. Post 49 is next.

Tuesday, March 29, 2016

A Ming-Inspired Cabinet (47)

Fitting rails to carcase boards continued this morning. In the following picture, I'm showing that the joint is sufficiently tight in fit that the rail holds a horizontal position from the connection without any opening occurring:


Looking closer, it was another miter which had come together satisfactorily:


And then, strangely, I found myself without rails to fit, as they had all been fitted. I was adrift, bereft of purpose....

Not so much.

Onto the fitting of the drawer dividers to the floor of the carcase:


I was very careful in laying out the parts so that the divider assembly is centered over the floor.

At this point, the dadoes are cut and I'm marking out tenon locations on the dado floor:


Locations marked, I drilled out most of the waste, using a clamp-on depth stop on the brad point drill to ensure no mishaps:


I then routed the bottoms of the mortises flat and about 1/32" deeper than the tenons which will be fitted to them.

Some chisel work ensued on those mortises to square them up, and then it was time to do a trial fit:


It was tight, but after a little tuning, I got the divider to squeeze most of the way down:


At that point, the outer pairs of tenons, which are done blind, were trimmed back, so as to leave the middle pair of tenons long, as these will be through tenons. I marked out the reverse face of the board and proceeded to cut the mortise openings for those through tenons:


Afterward, a check with the board on the wrong side, just to confirm the middle tenon pair is a decent fit in the mortises just cut:


With the board then placed back on the correct side, and tapped down with a rubber mallet, the tenons emerge:


The pencil lines indicate the amount of flaring these mortises will receive later on. This connection would only be visible if you laid on the ground by the cabinet stand and looked up at the base of the carcase. Still, I try to obtain a decent fit at every connection, exposed or otherwise. That said, I am 10x fussier with connections which are exposed, particlarly those at normal viewing position.

Here's a look at the fitted divider:


As the drawers occupy this area of the cabinet, none of the joinery just completed will be seen. Only the front edge of the divider will be exposed to view. It does save on the amount of finish that needs to be applied, looking on the bright side :^)

A while later the opposite divider was also fitted:


As I tend to want to err on the side of a tighter joint than a looser one, sometimes in test fitting the withdrawal of one piece can cause an injury to the other:


It's annoying, but it does happen sometimes, especially with the curly bubinga.

When this occurs, so as not to risk the uplifted piece detaching and being lost, I get on with the repair work immediately - for this, I use cyanoacrylate glue and accelerator:


See? I use glue sometimes! It's good for some things.

After clean up:


The completed dadoes with multiple mortises on the floor board of the carcase:


A meeting with my tax preparer ate up some of my morning, so completing the above joints was the total accomplishment for today. Before leaving, I fitted the floor board back to one of the sides:


Sometimes it feels like things are progressing slowly with this project, but I am working somewhat cautiously as I have no extra material whatsoever, and extra material of this sort is rather hard to come by anyway. There is no room for error, and, as more and more joinery is cut, I become increasingly nervous about any mishap occurring. Joinery work requires an ability to visualize spatial relationships, and it is easy, especially when fatigued, to get one part backward, things like that. If I'm not totally clear about how something goes together, I don't layout or do cut out on that part. 'Winging it' does not tend to lead to satisfactory outcomes in most cases I have found. So, whenever I feel annoyed about any sense of slow progress, I remind myself that it is better to be moving forward without mishap than be stressing out over some mistake that occurred as a result of rushing.

All for today - thanks for your visit to the Carpentry Way. On to post 48.

Monday, March 28, 2016

A Ming-Inspired Cabinet (46)

Post 46 in a continuing series.

The past few days have seen a spate of fitting rails to carcase. Fitting rails to carcase...fitting rails.... It's not that many parts, just 8 sticks and 16 mitered joint abutments, but given that these are through-tenons, extra care is well worth taking because mistakes will tend to show.

Fitting the first of the upper rails to one board:



The piece is down as far as it will go without having done anything yet with the housings on the edge of the carcase board:


A little trimming ensues to ease the fit at the housing opening:


Another try, after the housing on the front edge has been cut out:


Down but not quite all the way seated:


A little cleaning out of the housing floor came next:


That's a special type of kote nomi used for trimming the tsutsumi ledge Japanese plane mouths. It happened to be handy at the time - other tools would have worked equally well I'm sure.

Afterwards, the fit was fine:


The next rail end also fitted:


I put a black line on the carcase board arris which will be chamfered afterwards. By the way, in case it wasn't clear, the reason for doing the mitered return is so that chamfers can proceed cleanly around the intersections .

A check is also made on the inside face to make sure that the shelf panel dados align with one another:


Another one done:


And another:


Could it be...? Yep, another one:


Another one completed, with a different camera angle to show how much protrusion I have with the through tenons:


The tenons will be wedged on both ends and trimmed flush afterwards. I have yet to flare the mortises to accommodate that arrangement. I'm planning to use bubinga wedges so the joints should be relatively unobtrusive.

Any slight discrepancies at the meeting of the parts, edge to edge, could be readily attended to with a plane:


How about another look at another junction?:


I also rough cut the dadoes in the top carcase boards which form the sliding door upper tracks:


That was a nerve-wracking task. I sawed close to the lines with the tablesaw, but kept a distance off those lines. The final trimming will be done with a router bit in my shaper.

The spacing of the dadoes - indeed, the design of the sliding doors themselves - was carefully worked out so that the dadoes did not cut into any of the dovetails at all:


It's an easy, and, I dare say common mistake to make with dovetailed boxes: not planning the joinery around where dadoes might be located. Having made that sort of error in the past, I take care to consider this detail in, well, detail. The above dadoes have yet to be taken to full depth and width yet, as you can see by the saw blade marks on the floor of the dado. In working out a solution for the sliding door upper tracks I have come up with an unorthodox arrangement for the tongues on the top and bottom edges of those sliding doors. More on that when we get to it.

Back to fitting, now onto the last carcase board:


I should have those buttoned up sometime tomorrow, and the next step after that will be to cut the housed joints on the bottom of the carcase, which have multiple mortises. Should be fun! After those joints are done, the carcase joinery will be nearly complete, with just the shelf panels remaining. At least, that's what I'm telling myself....

Thanks for coming by the Carpentry Way. Next up is post 47.