Show HN: Compass CNC – Open-source handheld CNC router
compassrouter.comHey HN,
I am Cam, and for the past two years I have been working on Compass, an open-source handheld CNC router that brings computer precision to woodworking while keeping the user directly involved in the process.
The idea started as my senior design project at UC Berkeley, with the goal of making a more approachable CNC machine—standard CNC machines are expensive, bulky, and remove you from the tactile “maker” experience. Compass solves that by combining a handheld router with real-time robotic assistance. You move the router roughly along a design path, and Compass uses four optical flow sensors (like in computer mice) and a 3-axis motion system to auto-correct for precision cuts.
What is different about Compass: - Open source: All plans, firmware, and CAD files are available on GitHub. - Affordable: The DIY build costs ~$600 in parts, and I am selling kits for <$800. - No external markers: The sensing technology allows for positioning without external markers, so no setup or consumables required. - Portable: Fits in a backpack and is not limited by a fixed work envelope.
We recently completed our first beta program and have just launched V1 kits for pre-order. You can find more info and the launch video at the listed URL.
Beautiful. I made few CNC's in my previous life, started a CNC company and bankrupted. Bankrupt because I tried to make everything myself, including electronic circuits. Your work looks great, congrats.
I suggest you keep a small video on the homepage(maybe youtube video). Also your site took a little time to load because of huge images (especially github image is 11mb).
Looks like a very interesting project.
A little feedback: I found a video of this in action in the forum link, but it should be on the landing page. Also, photo examples of larger completed projects to judge accuracy are necessary. If none of your kits include the 3d parts (not the best choice IMHO), you should at least have a link to uploaded 3d files on a site where they can be ordered.
It's probably worth noting that a commercial version of this exists (Shaper Origin). It's a bit pricey but is remarkably nice for a variety of tasks that can't be handled by a stationary mill. And because it's hands-on, it's also easier to catch mistakes as you go.
On the flip side, it's just much, much slower than a stationary setup. You can't really push it quickly while retaining enough control to stay in the narrow range it can compensate for. Further, because it's less rigid, high feed rates produce nasty finish.
A big difference between this and that is that this appears to determine relative positioning through multiple mouse-style optical sensors, rather than visually checking relative to patterned tape.
How does it solve linearity and repeatability problems of mouse sensors? Or is it just not mouse like but not in literal sense?
Yeah IMO the Compass appears to be a more convenient design
The reason Origin uses tape is to maintain precise, absolute registration over large distances - so that you can for example machine a pattern the size of a kitchen table.
I am very skeptical you can have that level of registration with mouse-style sensors that can only measure relative motion. I might be wrong, but it seems unlikely.
Yeah mouse sensors actively throttle update frequency at slow speed to mitigate drift, as they appear to suffer pretty much random walk steps of sort each time they generate an update. Exceptions are probably limited to zero-motion deltas.
The shaper is super cool, but a little pricey understates it.
You can get a very nice router for $300-ish; the Shaper Origin is 3k.
A CNC router with a work area suitable for typical woodworking projects is definitely not $300 - you're probably thinking about 3018 kits, but with 18 cm of travel, that's really not enough for the usual scale of woodworking projects. Not even enough for a typical cutting board.
A ready-made unit in "woodworking" size will likely set you back $2-$4k.
Handheld router != CNC. A fixed-base 2.25hp DeWalt handheld router runs about $370. The 1.25hp Makita 700 in the Compass' glamour shots and assembly instructions runs about $130. Most fall in that range.
The tape is also like $20 a roll, I realize this pales in comparison to even medium tier wood, but was sorta immediately off putting for me since it reminded me of all the stuff with inkjet printers.
I wonder why not use those simple laser rangefinder things and instruct the user to put CD-tracking like servo steering suitable retroreflectors at fixed-relative-to-workpiece locations. 2 should suffice for planar work.
Probably "tape money" reasons for that engineering trade-off...
It was a pleasure trying your demo at Open Sauce 2025!
I've always wanted a Shaper Origin, but the cost and subscription fee required for accessing some features always turned me off. I don't need it for anything other than fun hobby projects and couldn't justify it. Now I get double the fun: building a tool, and getting to use it! Nice work.
Could be interesting, but I didn't see any /PICTURES OR VIDEOS/ of what I could create with this product.
It looks like you're selling your own control board PCB design as part of the kit. I'm guessing that it doesn't have Wifi by itself, so that would make it an unintentional radiator under FCC rules. How did you deal with EMI testing and certification? Can you recommend any services or labs? Would you be willing to share how much it cost? I'm asking because I am considering publicly selling prototypes of my 3D sound hardware, but the regulatory stuff has so far prevented me from doing it.
Have you seen the opulo yt video on this?
Not yet, thanks for the pointer.
There are loopholes for kits if it acts like a subassembly: https://emcfastpass.com/fcc-rules-kits-subassemblies/
Yes, but my understanding would be that this kit is not a subassembly, because the user is expecting to end up with a full product after assembly.
> You can find more info and the launch video at the listed URL.
Maybe I'm a complete dumbass but I could not find a video at any of the URLs on this post using Chrome under Sonoma.
https://youtu.be/t5xDmslfzvs
It’s on the compass home page. Admittedly the Play button does blend into the background image of the router a bit.
Had a lot of fun building one of the demo units. Straightforward build and incredibly rewarding to build your own machine.
CAD, meet Cam ;)
I’m curious why Jupiter Notebook is involved.
?!?
I'm not seeing that --- sounds interesting! Link?
Yoooooo. I am very seriously considering buying that kit. Do you intend to provide an upgrade path between revisions?
Is this anything like the Maslow?
Maslow is self-propelled using cables. It's the same goal - expand the work area by getting rid of a rigid frame of the mill - but a fundamentally different way of getting there. Here, you're the one moving the mill to follow your desired pattern, and the device simply corrects for your errors to stay on target.
Interesting project. I am sure it was a lot of work (and fun as well).
I was introduced to the general concept when the Shaper Origin came out a while back. Here's my problem with the idea:
What's the use case?
Any xyz gantry router will run circles around this approach, by far. They will be much faster, more accurate and, more importantly, hands off. There's a lot to say for clamping the material and mashing the "go" button. The pattern shown in the video on the YT channel literally takes three seconds to cut on a gantry router. And you can swap material and push go again, very quickly (or cut as many as possible out of one piece of material.
For around $1K you can have a much more capable machine. Unless the use case is cutting/engraving on items that cannot be cut on a traditional router, I am not sure what these would be used for. Then the question becomes: How many of those projects do DIY hobbyists have?
The other question is one of accuracy and repeatability. Having done loads of CNC metal machining, CNC and manual wood routing, I can tell you that nothing beats a rigid xyz machine.
So, if someone has just one or a few odd parts that cannot be cut on an xyz router, well, maybe that's a use case. Other than that, why would anyone guild one of these rather than a gantry?
Size I assume - this should be able to handle massive projects at the same price, while a gantry router would be much more expensive. Or so I would assume, I didn't dig into this to see how large it can go.
The workflow on the shaper origin is extremely nice, --- apply tape, swing it around to capture the environment, load svg and position. If you need a regular spacing grid, you just press a few buttons and ram the tool into three non-colinear points on the edge of your object.
You can cut objects in place, including irregularly shaped stuff you'd need to disassemble to put on your gantry. That comes up frequently for engraving but it's not exclusive to it.
The whole device is basically the size of a sewing machine. Yet it can cut parts that won't fit on an gantry you're able to fit in your garage.
It's quite tedious for repeated work. So I think it's really more in the class of manual power tools than in the same class as a CNC setup.
As far as accuracy goes, the tracking tape eliminates some source of errors. Say your clamping is not 100% and the part shifts slightly while being worked-- tape the part moves with it and all is still happy. Of course, it introduces some of its own problems too.
So in summary:
1. Very small device, yet can work with arbitrarily large pieces. 2. Good workflow means very fast setup suitable for one offs. 3. Works in situ, especially useful for engraving things in place.
I imagine that if it weren't a bit pricey that many people who do CNC woodworking would also have a shaper origin like device-- much like you probably have a skillsaw in spite of owning a CNC router.
Plus the simplicity of setup and the size makes it attractive to anyone who only wants a tiny amount of CNC for precision engraving, hole positioning, or cutting an inset for a hinge... and would never own a CNC gantry.