This tutorial/project will focus on process rather than the specific design in hope of sparking your own creativity and innovation.
For most projects, it is ideal to begin with brainstorming and sketches. Sometimes it’s not necessary, but usually helpful to think about and list what functions your product will serve. Many times, this can unveil some interesting new ideas and characteristics for your design.
This project, however, was pretty straightforward as far as function, so I jumped straight to sketching. It’s an underused tool and is a great way to get ideas out rapidly without wasting time in software. Shown is how I generally approach sketching which is generally crude, messy, and nothing fancy. I was never a great sketcher and use them as notes to myself. Point is, don’t fret over not making amazing sketches if it’s not your forte. It’s a tool in the design process and should be used to your advantage.
After deciding on a concept, it is brought into a design program of choice. In my case, Rhino. With the ability to 3d model the project to get a full idea of how the product will look, Rhino has been an excellent asset in my own workflow. Other programs that can give a similar workflow that are free are Blender and Fusion360. However, to create this product and anything like it, it is not necessary to have 3d capabilities. It is just a huge help. A 2d package such as Illustrator, Inkscape, or anything else that allows you to work with curves can work. It will just require a great imagination to mentally visualize what you are creating.
It is important to keep your material thickness in mind when designing your parts. I used ¾” plywood I had laying around for the structure and ¾ mdf for the tops. It is critical that you measure the thickness of your material because it will usually not be the claimed thickness. When designing the joints, I usually offset the sockets by .01-.05 depending on how loose I want it to be. Another consideration to keep in mind is the diameter of the tool being used. The tool may claim to be .25” but in my case, it was .247”. Small difference, but it adds up on each side of the part and will turn a snug fit joint into a no-fit or loose-fit joint.
Keep in mind that these two versions are merely examples and need to be modified depending upon the thickness of your material. Notice the red curves in the image. These are the new adjusted curves for the smaller thickness. However, for this design, the stool steps slots do not cut through. the depth of cut remains the same regardless of material thickness. The DOC for the stool steps slots is 0.355.
When designing the joints, it is important to understand that you can’t cut a square. Hence the use of dog bones. I generally like to make my dog bones slightly larger than the diameter of the tool to ensure it will be cut correctly and I feel it is easier on the machine since it won’t be doing as much of a jarring motion which would give more opportunity for skipped steps.
When laying out, or “nesting” your parts, pay attention to the negative space that will end up being “drop”. For this design, there are almost 2 4×3 inch (-1/2“ due to the cutter) and 2 3×5” spaces which could be used for some other small parts. If you keep this in mind, you will be able to maximize your material usage. If you are selling products you are creating, this just means extra money in a sense. If not, it’s simply saving you money and some time since you aren’t setting up the machine for that other unrelated part.
To many veteran carvers, this will seem like common sense, but may be eye opening to some who are new and may save from some mistakes I have seen while in design school.
First, I have internal cuts made. Internal meaning anything inside of a part that will be cut from the stock material. This is important because if you cut the part from the stock before doing internal cuts, the part can fly off the table resulting in at best, a ruined part. At worst, a ruined you or spectator. Second, tape your stock down with double sided tape. The parts highlighted in green should be cut first.
I am still experimenting with feeds/speeds on my machine, however, here is what I have used with success so far.
tool: 1/4" downcut 2 flute
MDF = 75-85ipm setting 1-2 on dewalt
Plywood = 65ipm 1-3 on dewalt
After cutting, it is time to do some finishing. First, I like to break the edges with sandpaper to get any trash left over from the cut.
Next for this project, I wanted to round the edges. The quickest option is to throw it on a routing table with a roundover bit. If you don’t have that, you could always drill a hole with the radius you want in a scrap piece of wood and cut it in quarters. Put some sand paper in the curve and sand away. Takes a lot more time, but it will get the job done with great results.
Once everything is smooth, it’s time for one of two things. Depending on the material and finish you are going for, you can assemble then paint/stain or, paint/stain then assemble.
In my case, I will be assembling my MDF stool then painting. For my other stool with mixed material (MDF/Ply), I assembled the frame and will be staining the wood and painting the mdf followed by assembling the steps.
To assemble, insert the bridges in one side of the frame followed by the other after applying glue to the parts making contact. Be sure to clean off any glue that squeezes out or tape it off to protect it. This will save you from having to clean it up with sandpaper before applying paint/stain.
For my design, I purposefully added a slight amount of length to the bridges that would need to be flushed with the outside of the stool. It adds a little more work, but In case of any error during cutting, I can be sure It will be enough to flush out. To flush it, I used a pull saw and some sand paper.
next, the bottom step will need to be inserted at an angle under the top “foot”. Line up the slots and rotate it down. If you want the steps on permanent, apply some glue.
Finally, set the top step on and allow the glue time to dry.
Once dry, apply your finish and enjoy reaching new heights!
Enjoy! If you have questions, feel free to ask and I will try my best to answer and adjust the tutorial based on feedback.