Pencil Case with Piston Fit Tray:
Hone your marking and measuring skills with Ian Parker’s box project.
Hone your marking and measuring skills with Ian Parker’s box project
There can be no better test of a maker’s skill than the construction of one component to perfectly contain another. The highly desirable piston fit drawer is quite rightly revered among makers and an unmistakable sign of quality to the uninitiated or potential customer. Illusive they may be but unattainable they most certainly are not as Ian Parker demonstrates in one of his set piece projects to construct a box to house
a perfectly fitting drawer.
From the outside this small box appears to be a relatively straightforward exercise in very simple jointing. On the inside, however, there is a container that is made to tolerances designed to highlight any issues a student may be having with stock preparation. The box can be made over three days and is a great project for beginners looking to establish a level of accuracy in their marking out and measuring technique and set them on the right path to dimensioning with hand tools. This is the first project I teach my students as the ability to make components repeatedly square and to set dimensions is a pre-requisite to producing crisp work. This exercise highlights any errors or techniques that need improving.
Set the plane
STEP 1. This project begins by making the case. All the stock material is planed and sanded on the face sides to the required thicknesses: 8mm for the case and 4mm for the case ends, tray sides and base. Aim to get as near to a finished surface as you can as any further work after this will change the dimensions of the components
STEP 2. Plane a reference face on one side of each of the case sides and the top and bottom. Do this using a shooting board and ensure the plane is set to take an even cut across its width. A cambered blade, such as that used on a smoothing plane will require grinding to a straight edge
STEP 3. This is easy to check by holding the plane body upright and carefully pulling a thin piece of test wood over the blade and looking for a uniform shaving across the width of the blade. Some lateral adjusters can be less than precise so use a small plane adjusting hammer to tap the blade and align it correctly
STEP 4. Accuracy is checked at every step throughout the project as errors have a nasty habit of coming back to bite you at the end. To check that these four reference edges are actually flat and not curved, place two edges against each other and press them together at one end. A gap should not open up, if it does then check the whole batch to find the culprit and adjust accordingly. Remember it only takes one component to throw things out so adopt a methodical approach to quality testing
If you are new to furniture making or would like to test your hand planing skill, then use some scrap pieces about 400mm long, 60mm wide and 10mm thick. Plane an edge flat on one side of each and check your accuracy as described in ‘No bananas’. Keep practising this until you are confident that you can consistently plane edges flat.
STEP 5. Set a cutting gauge to the required dimension and mark one face on one top and one side only. Plane each of these to final dimension; you can set the plane to initially take a heavy cut and gradually reduce the cut until a final wafer thin shaving is coming from the whole pass. All the time check that you are planing parallel to your marked line. The other corresponding pieces are then planed to match. Place the reference piece up against this and use your fingers to check for evenness. When you are able to turn the piece around and upside down without detecting any differences in heights, then they must be a matched and square pair
Routing a groove
STEP 6. The pencil case is effectively a tube made with a simple tongue-and-groove joint. The joint is cut on the router table with a 4mm slotting cutter. The cutter is set to cut a depth of 4mm and set to 8mm high. Both parts of the joint are cut using this one setting. The groove is cut on the wide top and bottom sections with the tongue cut on the narrower sides
STEP 7. A block plane is used on an end grain shooting board to dimension all pieces to the same length. When complete, a slot is cut on the inside face of the tube at either end to house the end stops. The slotting cutter depth is reduced on the router table to cut a depth of just 3mm. This groove will need to be finished with a chisel on the top and bottom faces. The 4mm-thick end pieces are made to fit with a 1mm gap all around
Check if all four sides are the same length by using two pieces of scrap wood to try and pick up all four pieces at once.
STEP 8. Use a small paintbrush to apply a thin film of glue to the grooves and tongues, take care to avoid any glue squeeze out on the inside of the case as this will prevent the tray from sliding and is difficult to remove. The two end stops are not glued in. Assuming the case is square and true then only light cramping pressure is needed.
Splitting the case
STEP 9. A piece of scrap wood is cut and planed to 45° and a magnet inserted. This is then cramped to the case to help guide a fine toothed saw
STEP 10. If you are using a backed tenon saw it is unlikely you will clear the guide and so the final part of the cut will be freehand. The freshly sawn faces are cleaned by pulling each part against abrasive paper held on a flat surface
STEP 11. Now you have the case finished, the internal dimension can be taken using callipers and transferred to the tray side stock. The tray sides are planed to fit with just the smallest of gaps
STEP 12. The bandsaw is used to cut a single dovetail on each end. This is achieved with a simple 1-in-8 jig. The dovetails can of course be cut by hand but this is a beginner project and the emphasis is placed on using a jack plane and a block plane effectively, we will conquer dovetails another day. I have a special chisel vice that students use to cut the pins on. If used correctly these ensure clean level sockets every time
STEP 13. Finally a 2mm groove is cut in each end piece to provide a support to the tray base. I used a 2mm router bit in the router table, but a scratch stock would work just as well. The tray base is made to fit snugly and the tray glued up
STEP 14. Here are all the tray components ready for the trial fit
STEP 15. Despite all the accuracy employed throughout the making, the trays never go all the way down first time. Light sanding is all that should be needed to make the tray fit. Basically you are just flattening off any slight discrepancies on the sides and sanding off any glue squeeze out. Take your time with this stage as removing just the slightest amount will affect how slowly or quickly the tray descends. The tray should glide down on a cushion of escaping air regardless of which way around, or which end is inserted first