CNC Update Blog: The Parts & Costs
A number of people have responded positively to the project video I published last summer on converting my Grizzly G0704 milling machine to CNC, and one of the biggest questions has to do with parts sourcing and total costs, so I thought I would do a quick breakdown. Any links in this post are affiliate links so if you use them, I get a few pennies to keep breaking end mills with! I’ll share the major components I used, any parts that are specifically referenced ONLY WITHIN Hoss’s plans, I will let you buy his plans from him to discover them, but will share a basic cost breakdown.
Let’s start of course with the milling machine, the G0704 (https://ebay.to/2y7Ximm) I chose it because not only is it a great candidate for CNC, but it’s a decently capable machine for its size and price. It has a 1hp motor and runs off of single phase 110v, which is handy for wiring. The table size and motion are tremendous, and it even comes with a (usable but not amazing) stand. If you were to get this mill just for small home shop manual work, I think you could do an awful lot with it, although a DRO would help quite a bit. It’s cost is $1325.00 plus freight shipping.
Next we have the set of electronics that drive the CNC operation; the stepper motors, their controllers, power supplies, and a breakout board. I went with a kit from Long’s Motor on eBay that had 3 1600oz/in Nema34 motors, and all of the required components like the drivers, power supplies, and breakout board: https://ebay.to/2t9tkc6 It’s cost is $399.00 Shipped
What is not *necessarily* required, but is a very good idea for more accurate motion transference and minimal backlash, is a set of ball screws to replace the 3 axis acme lead screws. The ones recommended by most homebrew CNC builders come from this guy, who now has a package specific for the G0704 Hoss Conversion, and costs (and seems to be) the exact same as the ones I got from Automation Technologies, these: https://ebay.to/2LRzPHY Cost: $229.00 Shipped
This would be enough to get you going, provided you have a donor computer to serve as your controller. I won’t count this cost because it’s extremely variable– I had a couple of old PCs around the house to be used for this, and one could easily be found used for next to nothing, OR you could build a PC just for this purpose and spend whatever you like. So the computer cost is kind of a wild card, but you don’t need a very advanced setup to run Mach3.
One controller upgrade I did use though is the USB Smooth Stepper from Warp9. This adapts the parallel port from the breakout board that controls the CNC stepper motors, to a USB plug on your controller computer. The additional benefit of this is that it has its own processor and offloads a lot of pulse generation load from the controller computer. They make one that uses an ethernet port, too, and it’s supposedly superior, but this is the one I have: https://ebay.to/2JI804m Cost: $159.99 Shipped
In your controller PC, you’ll need the software to run the G code that drives the CNC machine. There are a few options for this but the two main choices are Mach3 and LinuxCNC. I do not know much about LinuxCNC other than you can do a lot of modification to it if you desire, and it is free. If you know a thing or two about setting up Linux systems, it’s definitely a good option (Tormach PathPilot is a modified build of LinuxCNC). Mach3 is the other option and just installs and runs like normal on a Windows PC. To be honest I’m still getting used to all of its ins and outs and how to use it most effectively. You can download a free trial of Mach3 that will load up to 500 lines of code (btw, that’s not much) to get you started and get you testing all of your connections and settings. Do NOT try to use a “borrowed” version of Mach3, it won’t work and will cause you problems. You can buy it directly from the publisher, or from here: https://amzn.to/2ybvkpP Cost: $159.99 + shipping
Lastly there are the plans, you can buy the Hoss DVD from g0704.com for $65 which is what I did, and then I later found there are a number of free and open source designs to choose from as well, there are two Youtube Contributors who have come up with plans for very similar machines for free, their names are dctteacher1 and franco cnc, so go check them out!! The hardware outlined in the Hoss kit ended up costing around $200. This includes 6 angular contact bearings (2 for each axis) plus a support bearing for the other end of the x-axis, the shaft connectors for the motors and ballscrews, and other random small shims to adjust the bearings with.
Lastly to make all the motor mounts I think I used about $40 in aluminum/steel materials, and maybe $15 in random screws and hardware, plus another $25 worth of random supplies (wire, plywood, switches) for the controller box to house all the electronics.
SO, to answer the questions:
$1325
$399
$229
$159.99
$159.99
$65
$200
$40
$15
$25
Total: $2618
[UPDATE: the price of the G0704 Milling Machine has varied since this post and definitely since the original project. As it has increased significantly due to what Grizzly attributes to tariffs, it’s seen a price as high as $1800+, while as of this update, has settled on $1495, bringing the quoted “total” to $2788]
Now as you see, you could shave a few dollars off if you want, and you could certainly spend a whole lot more, but I feel like my build represents the lower side of average as far as TOTAL cost for the CNC G0704 conversion. I will also add that I had the milling machine for nearly 2 years before starting the conversion and many of the supplies were gathered slowly and piecemeal, so it definitely didn’t feel like as big of a chunk of change as it ended up being.
In the next CNC blog I’d like to share some of the smaller projects I’ve done on the machine, some issues I’ve had, and some plans for the future with it.
