Digital Counter From Stuff You Have In Your Junk Drawer

In vehicle racing, a properly tuned suspension is essential for making good time around the track. Weekend Race Warrior [Julian], thought that his right rear suspension might be bottoming out when making hard left turns. After thinking about it for a while, he came up with a super simple way to measure how many times his suspension bottoms out during a lap: a digital counter made from a calculator.

There are two types of calculators out there, one is good for this project and the other won’t work. To figure out which one you have, type in 1+1=. All calculators should display 2. Then, press the = button again. Some calculators will continue to show 2, but some will change to 3, then 4 and so on as many times as the = button is pressed. This is the type of calculator this project requires.

[Julian] opened up his calculator and soldered a pair of wires across the = button terminals. After a hole was drilled in the case for the wires to exit, the calculator was put back together. To count how often his suspension bottomed out, a normally open limit switch was installed on the car at a point where it would be triggered when the suspension bottomed out. The 2 added wires coming out of the modified calculator connect to that switch. Switch presses now emulate a = button press. Before starting a lap, 1+1= is pressed to display 2. At the end of the lap, if the suspension bottomed out, the switch would be triggered and the displayed value would increase. Remember to subtract 2 from that value to get the total number of events that occurred.

A mechanical switch makes this a great application for counting when things move a certain way but there are some more options. Connecting the switch-side of a relay to the calculator allows [Julian] to count brake presses (via the break light signals) or count how often his boost pressure goes over a certain amount (using a pressure switch).

Shirt Printing With Freezer Paper

There’s a pretty good chance that you’ve wanted to add a graphic or design to a t-shirt some time in your life. There are certainly ways to do it but most of us don’t have silk screening equipment or a steady enough hand to have the end product look cool. Lucky for us, [UrbanThreads] has put together a stenciling tutorial for personalizing garments. The process is easy and inexpensive. The results are good, although it can be time-consuming if the pattern is intricate.

To get started, a black and white graphic is printed on a sheet of paper. The design is then taped to a sheet of the secret ingredient: freezer paper. The two sheets are then placed on a table with the freezer paper up. Since the freezer paper is semi transparent, the printed out design shows through. It’s now time to use an exacto knife and trace the design while cutting through the freezer paper. The two sheets are then removed from each other and the freezer paper is put wax-side-down on the garment and ironed into place. The wax melts and acts as a temporary adhesive to hold the stencil down. At this point, fabric paint can be sprayed or dabbed on with a brush (avoid brushing back and forth as it may lift the stencil). Once the paint is applied, the stencil is removed and the paint is allowed to dry. According to [UrbanThreads] the freezer paper doesn’t leave any wax or residue on the garment.

For more garment modding, check out t-shirt bleaching or get ambitious with this DIY screen printing setup.

Down-Draft Table Keeps The Shop Dust Free

Wood working is great but it can certainly get the shop dusty. [BigD] is a wood worker and needed a way to keep his shop from getting super dusty while sanding or routing. He ended up making a pretty slick dual-use downdraft table with a hidden filtration system.

The table’s frame is made from standard 2-by dimensional lumber you’d likely see most shop tables made from. It was built so that the top of the table would be flush with the table of the table saw. This allows the down-draft table to also act as an out feed support for the table saw, making it easier to cut longer pieces of wood.

To allow airflow to pull any generated dust down, a plethora of holes were drilled in the table top. Down below are a couple sealed chambers, one for the incoming dust and one for the air blower that creates the down-draft air flow. The two chambers are separated by a pair of filters which keep the dust from being blown back into the shop. A little door on the side of the table allows access to clean out the accumulated dust and debris. Now [BigD] can sand up a storm on his down-draft table without breathing in a sapling worth of dust.

DIY Rotary Tool

[Shashank] has a modest tool collection but is missing a rotary tool. He needed one for a project he was working on but didn’t think that it would get much use after the current project was completed. So instead of buying a rotary tool, he decided to make one to get the job done.

The project started out with a 40mm PVC pipe that would serve a the main body of the tool. Two MDF disks were cut to fit inside the pipe. One was used for mounting an RC vehicle brushless motor and the other was bored out to accept a pair of bearings. The bearings supported a modified pin vise that acts as the chuck for securing rotary tool bits. A 20-amp ESC and a servo tester control the motor’s speed and can get the motor up to 18,000 rpm.

Although this worked for a while, [Shashank] admits it did fall apart after about 20 hours of use. The MDF bearing mounts crumbled, thought to be a result of vibration due to mis-assignment between the motor and pin vise. He suggests using aluminum for the bearing mounts and a flexible coupling to connect the motor to the pin vise. If you’re interested in making your own rotary tool but don’t have any spare motors kicking around,  this 3D printed vacuum-powered rotary tool may be for you.

DIY Plywood Camera Dolly Looks Professional

While [Ted] was poking around the ‘net, he came across a neat little product called a camera dolly. These are used to add an artistic flair to filming. They are similar to a camera slider but can roll around on the floor or a table and do not need to follow a track. [Ted] wanted a camera dolly but the cost of a professional product seemed too expensive for what he’d actually be getting, so he set off to make his own.

[Ted] first designed the dolly in a CAD software and printed out templates for the parts. Those templates were then transferred to plywood and cut out with a jig saw. Three inline skate wheels support the frame and allow the unit to roll around. Mounted in the center of the frame is a pan and tilt camera mount.

The extraordinary part of the build is that the angle of each wheel can be adjusted independently.  This allows the dolly to do anything from rolling in a straight line to gradually traveling around a curve or even just spinning the camera in place. Each wheel mount has degree indications so that they can be adjusted very precisely as well as be returned to a previously recorded position.

Hand Drill To Band Saw Conversion

Need a band saw but only have a drill kicking around? That may not be a common problem but if you ever run into it, [Izzy] has got you covered. He’s on a mission to make a drill-powered workshop and in his YouTube video, he shows a small bench top band saw he made that is powered by a corded hand drill.

The main frame is made from doubled up 3/4″ plywood. The saw blade is strung between two wooden wheels. Those wheels have tape applied to their outer diameter to create a crowned roller. That crown keeps the saw blade tracking in the middle of the wheel. The bottom wheel is mounted to an axle that is supported by bearings in the main frame. That axle pokes out the back and is connected to the drill. The top wheel has integrated bearings and ride on a stud mounted to the frame. The blade seems to be pretty tight although there is no noticeable tensioning system.

The video shows that this DIY band saw can cut through 1.5 inch wood fairly easily. Even so, there are clearly some needed features, like guide bearings for the blade and an overall cover to prevent accidental lacerations. But we suppose, even professional saws can be dangerous if not treated with respect.

Making A Bobblehead Of You

Bobbleheads, you remember them, small figures with a spring-mounted comically large head. They brought joy to millions of car drivers every day as at least 97.5% of all registered cars in the 1960’s had bobbleheads mounted to the dash. Years later bobblehead popularity has waned but [Luis] is trying to bring them back, this time not as your iconic sports hero but as YOU!

[Luis] uses software called Skanect along with his Kinect to scan a persons geometry. There is a free version of Skanect but it is limited to exporting STL files no larger than 5,000 faces. That means that 3d printed bobbleheadscans of large objects (including people) come out looking noticeably faceted. [Luis] came up with a work-around that results in a much finer detailed scan. Instead of scanning an entire person with one scan, he would do 4 separate scans. Since each individual scan can support 5,000 faces, the resulting merged model can be up to 20,000 faces. Check out the comparison, the difference between the two scanning methods is quite noticeable. MeshMixer is the software used to merge the STL files of the 4 separate scans.

Once the full body is assembled in MeshMixer, it is time to separate the head from the body. A cylindrical hole is then made in the bottom of the head and the top of the body. This hole is just slightly larger than the spring used to support the head. The parts are then printed, painted and assembled. We have to say that the end result looks pretty darn good.