Test Pulley & Control Box Mounting
It was a long work day today, so just a brief update on the Timelapse Engine.
This evening I was able to drill the control box and do a test fit of that mounted to the chassis. Everything seems like a good, sturdy fit at this point.
Today I also received a test print of one of the four idler pulleys for the drive track (shown here with a test fit of the 3/8″ idler drive shaft).
Timelapse Engine Update
It’s a good day today. Not only was it a beautiful day out, but I also made a ton of progress on the Timelapse Engine. Last week, thanks to some help from my dad, we were able to get most of the core chassis structure prepped. Today was a day of drilling the main chassis panels, and tapping lots of holes. After spending 6 hours out in the garage, I emerged with the first test fit of the chassis components. Obviously this lacks the outboard chassis panels and drive mechanism, but things are starting to take shape!
Custom Pulley
I’m thrilled to say that the first of the six custom pulleys for the Timelapse Engine are here. This drive pulley is the first of the two drive pulleys and four idler pulleys required by the design, which are generated using a 3D printer.
Additionally, during my dad’s visit over the Easter break we were able to make a lot of progress on the core components for the chassis. All of the chassis supports are cut, and most have been drilled. All that remains is to complete the M3 and M5 screw tapping, and several remaining through holes. Once those are completed, I’ll move on to the inboard and outboard chassis components.
SharePoint Branding Best Bets (SPSRIC2013)
Diving into the world of SharePoint branding can be a real headache. What is the best practice for deploying my branding? How do I select a design firm? What is the impact of mobile devices and how do I ensure cross-browser compatibility? What are the new branding tools available in SharePoint 2013? These are all common questions that must be answered during the course of branding efforts. In this session we’ll look at the various aspects of SharePoint branding, and common pitfalls to look out for during your next branding project.
Drive Belts Are Here
My 60 tooth, 2″ H rated timing belts arrived today, which will become the drive belts for the timelapse engine robot. I’ve also got the first of the six custom 3D printed timing belt pulleys on the way; we’re making one first to confirm the tooth profile is accurate before manufacturing all six. Progress!
Custom PCB Arrived
In a follow-up to yesterday’s post, the custom PCB has arrived, and should be ready to go after a few spots of solder and some components. With my current workload and the upcoming Easter holiday, it may be a couple weeks before I get around to wiring it up and testing it, but it’s great to see these finished components of the project starting to arrive!
Mechanical Orders Placed
The Timelapse Engine project is progressing nicely (despite my spending a lot of time on the road for work lately). At this point, all of the small parts have been received (almost all of them ordered from McMaster-Carr. I’ve also placed the orders for the drive belts (300DH200 timing belts). In addition, I’ve also now ordered all of the components that require custom manufacturing. I’ve managed to arrange for the custom 2″ thick pulleys to be manufactured on a 3D printer, which worked out to be substantially cheaper than custom machining the tooth profile out of 2″ thick solid aluminum bar. All of the square stock components (chassis spacers and the forward/aft supports) were ordered and cut to length through OnlineMetals.com. Lastly, all of the flat stock components (inboard/outboard chassis and the camera support) will be waterjet cut by BigBlueSaw.
I also elected to modify the designs before sending them off to be machined, as recommended by the kind folks over at BigBlueSaw. Due to the irregularities of the waterjet nozzle on small details and the precision alignment required on the stepper motor mounting holes, all of the holes will be cut to 0.1″ (~2.5mm) by the waterjet. I’ll then manually drill them up to the applicable M3 and M5 sizes once I receive the parts. This also gave me a convenient excuse to buy a drill press 
On a slightly unrelated note, the custom PCB fabrication was completed last week, so that should be making the trek over the Atlantic and be here any day now. I’m still having some issues with the stepper motor controller for the drive electronics, more to come on that.
Assembly Diagrams
Now that the design is finalized, I’ve started making progress on the final bill of materials (BOM) and assembly drawings. Be sure to follow the complete project for more information. This mechanical BOM covers all chassis and drivetrain components, as well as the control box sub assembly (which I’ll cover separately with the electronics BOM).
The chassis assembly itself is pretty straight forward. The left and right inboard chassis components are connected to the forward and aft rails, along with the internal chassis spacers. Not depicted here is the overall build process. During an actual production assembly, the drivetrain would be assembled before the outboard chassis components are installed (sandwiching the drivetrain). All of the core chassis components are connected with M5 socket head cap screws, while all flush mounted components are connected with M3 flat head machine screws.
The drivetrain is (second to the software) the most complicated component of the entire project. The drive pulleys themselves have been extremely difficult to source, but I hope to be able to share good news there next week. I also discovered that it was far more cost effective to simply buy stock for the driveshafts and cut it down myself, so we’ll be going that route vs. prefab components. The motor itself is bolted to the inboard chassis components with the same M3 flat head machine screws used on the chassis camera support. From there, the camera receives two 5mm shaft collars to step up to the 14 tooth 1/4″ pitch sprocket.
The drive pulley is keyed with a standard ANSI keyway (again, I just bought a foot of keystock and will cut down to the applicable lengths). The inboard side of the drive pulley receives two washers for spacing, and a 28 tooth 1/4″ pitch sprocket (also keyed to the driveshaft). Standard #25 ANSI roller chain will be used to connect the two sprockets. This facilitates a better motor position, as well as a 2/3 reduction on the stepper motor. The stepper motors used have a 0.9° resolution, which when coupled with the 2/3 reduction should give the ability for a very high resolution of motion. The outboard side of the drive pulley, as well as the inboard and outboard sides of the two idler pulleys are capped with set screw mounted shaft collars (5/8″ and 3/8″ respectively).
