Making Your Own Chain Sprockets, The Tidy Way

Chain sprockets are a key drivetrain component in a lot of builds. Unfortunately they can be difficult to source, particularly for those outside the reach of retailers like McMaster-Carr. In such situations, you might consider making your own.

The toothed profile on a chain sprocket can be produced in a simple manner by drawing a base circle, along with a series of circles spaced appropriately for the chain in question. This involves measuring the pitch and roller diameter of the chain. With these measurements in hand, a template can be created to produce the sprocket.

From there a series of holes are drilled to rough out the basic shape of the teeth, before the sprocket is then cut down to its appropriate outer diameter. The finishing work consists of chamfering the sprocket’s thickness, as well as the filing the sharp edges of the teeth for smooth engagement.

It’s a quick and easy method for producing sprockets with well-defined, accurate profiles. We’ve featured other rough and ready methods before, too. Video after the break.

from Hackaday https://ift.tt/35F6IBQ

Comments

How To Play Doom – And More – On An NES

Doom was a breakthrough game for its time, and became so popular that now it’s essentially the “Banana For Scale” of hardware hacking. Doom has been ported to countless devices, most of which have enough processing ability to run the game natively. Recently, this lineup of Doom-compatible devices expanded to include the NES even though the system definitely doesn’t have enough capability to run it without special help. And if you want your own Doom NES cartridge, this video will show you how to build it . We featured the original build from [TheRasteri] a while back which goes into details about how it’s possible to run such a resource-intensive game on a comparatively weak system. You just have to enter the cheat code “RASPI”. After all the heavy lifting is done, it’s time to put it into a realistic-looking cartridge. To get everything to fit in the donor cartridge, first the ICs in the cartridge were removed (except the lockout IC) and replaced with custom ROM chips. Some modifica...

Try NopSCADlib for your Next OpenSCAD Project

Most readers of this site are familiar by now with the OpenSCAD 3D modeling software, where you can write code to create 3D models. You may have even used OpenSCAD to output some STL files for your 3D printer. But for years now, [nophead] has been pushing OpenSCAD further than most, creating some complex utility and parts libraries to help with modeling, and a suite of Python scripts that generate printable STLs, laser-ready DXFs, bills of material, and human-readable assembly instructions complete with PNG imagery of exploded-view sub-assemblies. Recently [nophead] tidied all of this OpenSCAD infrastructure up and released it on GitHub as NopSCADlib . You can find out more by browsing through the example projects and README file in the repository, and by reading the announcement blog post on the HydraRaptor blog . Some functionality highlights include: a large parts library full of motors, buttons, smooth rod, et cetera many utility functions to help with chamfers, fillets, precis...

The Newbie’s Guide To JTAG

Do you even snarf? If not, it might be because you haven’t mastered the basics of JTAG and learned how to dump, or snarf, the firmware of an embedded device. This JTAG primer will get you up to snuff on snarfing, and help you build your reverse engineering skills. Whatever your motivation for diving into reverse engineering devices with microcontrollers, JTAG skills are a must, and [Sergio Prado]’s guide will get you going. He starts with a description and brief history of the Joint Test Action Group interface, from its humble beginnings as a PCB testing standard to the de facto standard for testing, debugging, and flashing firmware onto devices. He covers how to locate the JTAG pads – even when they’ve been purposely obfuscated – including the use of brute-force tools like the JTAGulator . Once you’ve got a connection, his tutorial helps you find the firmware in flash memory and snarf it up to a file for inspection, modification, or whatever else you have planned. We always apprec...

All Things Tech

Search This Blog