Sunday, 11 August 2013
Ikebana base / top drawer base construction
Before cutting the miter joints for the edgings for the ikebana base and top drawer base I did the cuts on test pieces first to make sure that I obtained the right angles.
The saw I'm using is quite old and most of the angles that I did I had to roughly set it up to where the angle would be when angeling the cross cutting fence than make modifications whether to make the cross cutting fence more obtuse or acute.
The first set of angles I had to set the cross cutting fence to 65 deg to the saw blade. When these two edges came together they made up an angle of 130 deg. This is the front section point of the panel.
When doing the test pieces and also seeing whether the angles were cut right I drew down the angles on a piece of scrap timber using a protractor and a bevel square.
Now these angle point was the side corner points of the base. The whole angle measured to 72 deg which meant that each edging piece had to be cut at 36 deg.
The sliding bench on the saw has a cut off limit. When the cross cutting fence is set at a very acute angle I had to use a scrap piece of timber to pack out the edging so it could be cut. The fence gets locked down with a clamp and so does the scrap piece of timber to prevent it from slipping when making the cut on the edging. This means I only need to hold the edging and not the packer as well. You need to be very careful when doing this since your hands are coming quite close to the saw.
Angles finished on the wenge edgings for the side points now to do the back angle which is 86 deg which means that each edging piece needs to be cut at 43 deg.
Drew out the angle on a scrap piece of timber using a bevel square to get the 43 deg line. I lined up the ruler with the blade on the cut line. This was just a rough set up than tweaking was done afterwards to obtain the correct angle.
Test edgings add up to 86 deg.
Cutting the last of the edgings to meet up for the last angle. When cutting miters always measure the internal miter length. When making each cut I placed some painters tape over the joint to prevent blow out.
Did a dry run to make sure that everything was going to go together properly.
To avoid confusion marked all the edges with what deg it was and what panel edge it belonged to.
Placed painters tape on the top and bottom sections near the edges to prevent glue going onto the veneer. This makes clean up a lot easier.
Since I could not clamp this up with 'F' clamps or sach clamps unless I had a jig I used the painters tape as a clamp.
There needs to be minimal gaping on the top face and bottom face. The top face is the main important one since the bottom face wont get seen as much compared to the top face. Used plenty of glue to obtain a very strong glue. I decided on using tight bond 3.
I will take off the tape after two hours just enough time for the glue to cure. I don't want to leave the painters tape on the panels for too long since the adhesive is really annoying to clean off the panels.
Began cleaning down the edges of the wenge edging so it would become flush with the maple base faces. I removed most of the waste with a spoke shave and the last amount which was about .2-.3mm I removed with a card scraper.
I clamped to the bench to limit movement and placed down a drop shit to protect the faces.
I needed to make the joints for the bases. These joints would secure the panels to the sides. I wanted to use spline joints since this was going to make things really easy in construction.
The spline housing needed to end 25mm from each end to the edge of the edging. I used a two part open blade cutter. In basic terms its a blade in which can be adjusted to make a thicker or thiner groove. Although these types of cutters have limitations. The groove I wanted to make was 4mm which is roughly about the same thickness as a wood biscuit.
I marked on each side of the spindle moulder fence just where the blade starts to protrude and where it stops. I needed to see where these sections were so I could line up the 25mm marking that I had on the panel to it than set in a stop block on each end of the in feed and out feed table and clamp down.
You don't really want to do this by eye, setting up stop blocks will make things run more smoother and will make sure I don't blow through the edging.
When machining this theres a specific way of doing it correctly. First place the back of the panel to the end of the stop block than slowly feed the other side in ( pivoting the panel towards the blade.) Once the panel is set flush to the fence and the blade has hit is maximum set depth begin to feed it through until the panel hits the other stop block. Once you hit the other stop block pivot the panel away from the blade.
I used a pressure skid to place extra pressure onto the panel since the panels were slightly bowed a bit. I still needed to place hand pressure onto the boards when feeding them through.
I did a test run cut on a scrap piece of timber that I had machined to the right thickness of the panel which was 15.7mm. Now its very hard to get the groove exactly in the middle. I managed to get it about .5mm off centered from the middle. This does not matter just make sure that you machine the edges with the same face facing up so that the off center will be in the same places.
The depth of the spline grooves was 14mm. The width of the wooden biscuits are 24mm. Its always best to leave a little extra depth the play with since not every biscuit is the same.
Back edge section of the panel.
This is what I meant by 25mm from the edge. This is the front edge section of the panel.
Marking out the inlay strips for the bottom face section for the Ikebana base. The bottom section of the top drawer base does not get done since where the inlay strips would be there are drawer runners. These inlay strips will sit on either side of the drawer divisions.
Cutting the stop cuts in the panel with the circular saw. The depth of the cuts which will be the depth of the inlay rebates is 2.5mm deep.
Stop cuts made. I used a bit of painters tape at the ends of the edging to prevent blow out.
Cleaning out the waste sections with the hand router.
Now this is annoying when you have a router that does not have a dust port. This bump out was caused from some of the waste getting in the way of the fence and the side of the router plate while machining. Luckily this does not get seen this the drawer division will be covering it.
Inlay rebates cleaned out. I just need to clean away the .5mm bit of waste left near the edges with the chisel and mallet.
Cutting up the inlay strips for the panels.
Sanding the inlay strips with the drum sander. I placed the pieces between some mdf scrap to increase surface area which would prevent the pieces from tipping over.
Did dry run after cleaning out the small waste sections.
Masked off inlay rebate sections to prevent excess glue going onto the panel face.
Clamped up the inlay strips to the panel using some of the convex clamp beams that I had left over from previous jobs. I used these to give better central pressure to the glued down inlay strips.