Building a "credenza" unit for under a big screen TV
A special thanks to Forest Products Supply in Maplewood, MN who supplied the walnut for this project. ( https://forestproductssupply.com )
Step 1: The idea.
Theme: Doing something different.
The task at hand: replace the aging bookshelf/TV stand I created 16 years ago as we moved into our house. At the time, I had little time and needed to get something in place fairly quickly. I also had many remodeling tasks and a full time job. Needless to say, I, nor certain children in my family were impressed with my work.
The goal: to create an “up to date”, crisp look. Thus was born the idea represented in the picture below. In reality, this smaller than previous things I’ve created. However, it had those darn angles. I’ve never built a trapezoid shaped item before. Frankly, I had to dig back in my memory to remember what a trapezoid is. This is a record of what I did and how. I hope it may be interesting and helpful.
First off, I needed a picture. Now you’re probably wondering why I didn’t use a nice 3D modeling tool. The answer is… this is the beginning of my retirement and darn if I didn’t fall back to the trusty tool I used for many software models over the last 5 years. Maybe next time.
Editorial comment: In this you will notice I left out the creation of the curved legs that support this. Perhaps in a future post.
Before the story begins, I thought I’d give you a sneak peak of the finished product. The journey I took will be the subject of the following steps.
Step 2: Figure out all the crazy angles of a trapezoid
Theme: Creating a trapezoid requires really understanding the angles.
Like they say, measure twice, cut once. In this project I spent a majority of the time trying to do two things: 1) understanding the exact angles I needed to make this work, and 2) figuring out how I was going to do it.
My journey led me down a path of using Google AI to help me understand the angles of a trapezoid that I would need for such thing. To help work the precise angles, and support configuration of the saws, I purchased a digital angle finder. This proved very helpful because I found that the protractor my kids used in school just didn’t “cut the mustard” :).
In the end I finally was able to work through and record the angles on paper that I quickly posted in my shop, least I loose it.
Step 3: Prototype, Prototype, Prototype….
Theme: A picture is not enough. Let’s see what this looks like.
I think this is where my software background kicked in. The picture I created above was helpful, but I really needed to create a section of the final state to validate if the angles were correct. This also validate the saw cuts I would need and how to make the cuts.
Boy, did I screw up several times here. I’ll get more into the Jig Step below, but concept to reality is always a key test.
Now, a disclaimer. In addition to the prototype you see here, I did create a small “beta” version in the form of a shoe rack to try this out. But, as we say in the IT industry, scale matters.
It may not be surprising that the time spent on Step 2 and 3 were nearly equal to the rest of the project.
Step 4: The “stock” used to create this
Theme: I “cheated” and “outsourced” the glue up and prep of the walnut boards.
Realizing that I wanted to focus on the hard stuff, I did leverage my trusty wood provider, Forest Products Supply, to handle the hard part. This entire project consisted of 4 -10’ x 17” walnut boards. Truly, a key timesaver.
Step 5: Creating a jig to cut the angles
Theme: The angles require a special Jig. Spoiler alert… I had to create 2 versions of this.
To make this project a reality I primarily used my table saw. The challenge I encountered was that the angles identified per Step 2 required 2 table saw Jigs. I thought.. ok I have those. Well.. they were crap, and so now that I had time to do this right, more work was required.
First, the Jig I used to make a cut of a vertical board was just not big enough to hold a 7’ board, which is what I need. Therefore, I quickly created another. See the picture below. Note the key word is ‘quickly’. Screwed that up massively. So, I created a bigger, better, stronger jig. I don't have it shown here.. but trust me, taking time to do it right made the difference. You can see it in action in Step 7.
Second, I also needed a proper cross-cut jig for my table saw. Once again, I first fell into the trap of quick and dirty. Yup. Failure. SO .. I created a proper one with clamps and everything. This made all the difference.
Again.. I fell into the same trap I’ve seen in software development. “I don’t need a test harness or coding framework”. Yes you do.
Step 6: Cutting the pieces
Theme: “He used a circular saw!”…. yes… I’ll explain.
This is one step that actually went as planned right off the bat. That’s probably because I’ve had more experience at that. Since I had nice planed 17” wide walnut boards I brought out the combination of a movable fence, circular saw, and blue tape.
Here, like before the key was planning and measuring, many, many, many times to not screw up the cuts to maximize the use of walnut. Walnut is not cheap you know.
You will notice in the picture below I wrapped the cut line in blue tape many times. This helped to eliminate the nasty frayed cut edges that can occur when using a circular saw like this.
NOTE: one thing I noticed doing this. The boards, after glue up, they had an ever so slight curve to them, across the width. This would come back to bite me.
Step 7: Cutting the angles
Theme: This is where version 2 of the jig came into play.
On a project like this you often get into an “oh crap” situation. This one occurred to me in the middle of the night.
Given the angles, I needed to cut the top board vertically. It was 7’ long. That, plus the height of my table saw wouldn’t fit in my shop. Thus, using the vertical jig V2 I created in Step 5, I had the unique situation to wait for a day that was dry and had minimal wind outside. Fun Fun.
When that day finally came, and after all the prep, amazingly the cutting only took a few min. Done!
Or… so I thought.
Step 8: Dry Fit - Pass one
Theme: Close but not close enough
Darn. In my head I thought.. this will go away. It didn’t. I needed to make a minor adjustment of the jig and do it again.
It was especially apparent given the curve I talked about in Step 6. It’s always the little things.
Step 9: After adjustments…and more cutting…
Theme: I had to pull out the jig and “tweak” it.
Well.. it was fixable. That’s the key. I did have to pull out the jigs and carefully adjust the cuts, ever so slightly.
I then gerry-rigged up a table structure big enough to do another dry fit. “Yeah Blue painters tape!” All seemed ok. So I then took it apart again and made a ‘side-tour’ to prep and cut the internal partitions.
Step 10: Prep for the vertical partitions
Theme: Creating the cabinet in the middle
Ever had that middle of the night thought that woke you up? Well, for some reason I did here. I was all set to just create dado’s across the whole width of the board for the internal partitions. BUT…. I woke up realizing.. if I do that the doors in my design would not be inline with the rest of the unit.
This meant I needed to have a way to carefully create the dados so that I left 3/4” in the front for the location of the door. Note I was planning on using frameless hinges.
So, back to creating a Jig, and once again… the Homer Simpson “DOH!” … I looked on my wall and I have the perfect jig. I re-purposed my shelf hole drilling jig, with the help of a little stop block and LOT’s of measuring.
I had the dado I needed, but I still needed to enlist the wood chisels to get rid of the rounded corners. Ah the details.
Step 11: Actually assembly of the unit
Theme: Ok.. time to get serious.
I then pulled out the blue painters tape again to start to put this back together and really glue and screw the frame together. This is where that ever so slight curve I mentioned earlier impacted me.
To address this I took a two pronged approach. First, I used as many clamps as I could to get corners as close as possible when glued. Second, I employed 1 1/4” fine cabinet screws to pull the corners together as much as I could. Again.. a learning experience.
Another middle of the night idea… based on some Youtube videos I’ve seen, I realized I could create clamping blocks for the bottom corners. I could temporarily screw those in to the bottom to help snug the unit together. This did the trick on the bottom.
A quick “how’s it look” check….
Then I slide the partitions in from the back. You know what? They fit perfectly!
Step 12: Installing doors, shelves, and sanding applying oil finish
Theme: Wrapping up.
The final steps were fairly straightforward.
- The back: This is 1/4 Walnut veneer plywood that is inserted into a dado in the back and held in place with staples
- The Doors: Sourced from the same 3/4” thick walnut boards. I did add a small dada and inserted a maple strip to add color and break up the walnut.
- The side shelves: Again, the same 3/4” walnut. This did require me to take out the handy digital angle gauge, and table saw jig to carefully cut the angle and length. Once again: measure. measure. test.. measure.. cut.
Finishing: The step that really brings out the beauty of the wood. In this case I used Rubio Monocoat oil to give it a rich look.
More importantly, I also finished the legs, back, doors, shelves, and case separately. That really was crucial to getting the finish right.
When it was all dry I put all the pieces together.
