Gear Coasters

About: I have a compulsion to make stuff, all kinds of stuff. I'm glad to be here...

My friend Rick is a talented craftsman and tinkerer. Among other things, he’s made a career out of making artificial rocks. I know! Who woulda’ thunk you could have a career making fake rocks! If you’ve been to the New Orleans Zoo you’ve seen his work. A few months ago we started an inventors club. Really it’s just some time set aside each week for experimenting and tinkering. Lately I’ve been working on Rick to get him excited about CNC routers. A CNC router is a router that is controlled by a computer. You can use it to very accurately cut out 2D and 3D shapes that are drawn on a computer. Think of it as a wood cutting robot.

I built my own homemade CNC router a few years ago and I’ve just barely scratched the surface of its capabilities. I knew Rick would have some interesting ideas of things to make with it. He was a little skeptical at first but once he got on board the ideas just started flowing. One of the first things he wanted to make was a homemade spirograph. Spirograph? OK, why not? Whatever gets him hooked. He bought a computer program that generates drawings of gears of any size. We figured we could use it make a set of interlocking gears to make the spirograph.

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Step 1: Designing

First we drew a test gear to see if we could get from the drawing to a cut out gear. First we drew a test gear to see if we could get from the drawing to a cut out gear.  I exported the gear drawing into Rhino 3D and set up the instructions to tell the CNC machine how to cut it out. We cut a sample first in cardboard. After a few false starts we had the program worked out.

I've included the g-code if you want to cut your own gears out.  It's formatted for Mach 3.

Step 2: Cutting

Feeling confident, we tried a version in plywood. It looked just like a wooden gear.
You can see that I fiddled with the design a little to make it look like a bicycle sprocket.

Step 3: A Purpose

I brought it into the house and had it sitting on my desk to look at and think about what to do next.

stuck it under a glass.

Ah-ha! Gear coasters!

Step 4: The End

I liked them so much that I made a bunch. The spirograph is still in the works but the project had it’s intended result.

HEE! HEE! HEE!… Rick is completely hooked on CNC routers. Now we are in the process of designing and building him a CNC router of his own.

More on Rick’s router as it progresses…

If you like projects, and I know you do, check out our site- Mike and Molly’s House where we chronicle our Mighty Project on our Mini-Farm (AKA our backyard)


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    5 Discussions


    7 years ago on Introduction

    These look great, I like them a lot and now covet a CNC router myself! The holes look a little asymmetric - was this part of the design or is there a little bit of wobble in the system? If so, what do you think the tolerances are?

    2 replies

    Reply 7 years ago on Introduction

    You're right, you need a cnc router.  
    The CNC guides here are a great starting point.  Also, go visit CNC Zone.
    Let me know if you have any questions.  More CNC users = more interesting stuff being made.
    The holes in the coasters are a little wobbly.  I noticed that after I had cut this batch out.  The cross bar on my gantry has loosened up over time.  I just need to tighten it back up(and probably re-enforce it too).  The tolerances on a CNC router can be as fine as your budget allows.  I'd say mine is accurate at least in the hundredths of an inch which is fine for my needs.


    Reply 7 years ago on Introduction

    I can save them a trip to CNCZone and sum it up in 3 words, Mach3, Gecko and ballscrews. Now they have time to check out LinuxCNC and maybe my motor drivers too.

    I like to think design is a factor with machine tolerances. I'm sure one can spend a fair amount and still build a poor performer if they really set their mind to it.