4 Bar Linkage: Part 1
July 27th, 2020
Linkages are hard. I think they are powerful mechanisms, I just find them difficult to visualize and time consuming to iterate. I’ve been thinking about a device that could turn and push a small wooden block over and over again, and I fear a four bar linkage may be the answer.
I saw a great video from Disney Research on creating animated mechanical characters. Their software appears to be proprietary, but it was a great starting point. Then I found an incredibly useful 4 bar linkage simulator from Mechanical Expressions. Thanks to this simulator, I quickly dialed in the desired motion and got my linkage dimensions.
Drew up some designs.
And milled some parts.
The first prototype is a hand cranked 4 bar linkage built from aluminum and delrin parts. Linkages need to be built well in order to operate correctly. There can’t be too much slop in the mechanism and precision counts. Hopefully, the second prototype will actually move a block around.
Oak Lamps
June 5th, 2020
I turned a few lamps out of oak and got some finish on them. I experimented with stain (I rarely use stain, but when I do it is usually on oak) and tung oil on one and the other two got some Danish oil. I like how the Danish oil brought out the contrast between light sap wood and the darker inner oak.
Day Light Savings and Flexures
May 12th, 2020I’ve been working on a analog clock that can easily change the hour during daylight savings time. The clock face can rotate one hour ahead or one hour back. I’m using a flexure mechanism based on a design by AmyMakesStuff. The click is very satisfying.
Unfortunately, it falls back 55 minutes and springs forward 65 minutes. I guess this is why I haven’t seen this design before. I recently talked about the project (among other things) with Zach Dunham on the Bantam Tools Livestream.
Donut Controller
April 17th, 2020
Almost done. I’ve been working on a game controller for the 9 year old daughter of a friend of mine. She programmed a donut video game in Scratch. You press the “B” key and the background changes. The “D” the donut flavor changes. “S” for sprinkles. “F” for frosting.
The game is awesome and so is she. Hope she likes it.
Lake Lamp
April 17th, 2020
It’s been awhile since I’ve turned a lamp at the lake, feels good. This hunk of oak was rough turned about two years ago and left to dry. This week I put the final shape on it and now it’s time for the finish.
Motorized Mechanisms
February 15th, 2020
Laser cut acrylic parts assembled around a geared DC motor.
What Not To Do Clock
February 15th, 2020
Pulled together a quick clock project with Tom Igoe. Tom works on the insides, I work on the outsides. We made so many bad choices along the way, we decided to call it the “What Not To Do” Clock.
Can you turn a spoon on the lathe?
February 15th, 2020Milling Lenses
February 15th, 2020
I CNC’d some acrylic on the 4 axis into lens like shapes. After a polish on the buffing wheel, they actually worked.