Jonathan Mocan greenBull 4X CNC Router and His Beautiful Work

Here are some additional images of Jonathan's latest creations from his greenBull CNC router.

Jonathan Mocan purchased a greenBull 4'x8' CNC Router back in October 2016. Since then, he has produced some amazing things with the CNC router including framed carvings, an incredibly ornate table with some strikingly embellished drawers, and some signage/iconography.

Jonathan created a stable base and frame using standard 2"x4" studs. The base of the frame was set on casters for portability. Knee braces were used to maintain stability for the overall frame and the end of the machine overhangs, so the actual base on the casters has a smaller footprint. The base is where Jonathan chose to set most of the electronics. Since the VFD (Variable Frequency Drive) is an item that requires some control, he mounted that on one of the verticals of the frame. To stabilize the cable carrier and keep it from sagging, Jonathan created a ledge for the cable carrier to rest.

It appears, from the table that he designed and carved, that Jonathan has an affinity for the Warhammer 40,000 universe as the table that he designed and carved contains the symbology, graphics and titles of the Warhammer 40,000 novel. The graphics, depth of engraving and color give the table a very bold and intense feel, which must have been intended. The depth of the engraved graphics which appears to be around 1/4" gives the table a nice light and shadow appearance.

In this image, the table top is being cut and engraved.

Here is one of the frame sides that frame the main top of the table. The greenBull CNC engraved the letters quite well, especially at the inside corners. He must have used a small end mill to get the inside corners to have a very small radius. /p>

The table also contains drawers that were also embelished. Jonathan took a different approach here where the graphics is the protrudes rather than is carved away. He kept a small edge frame around the face of the drawer.

Here is the CNC router engraving the letters in the plywood and where it is clear that Jonathan is using a small end mill to get the small inside corner radius. If he was using a small end mill for the entire job, the engraving would take a great deal of time. One way that many would approach this type of job would be to start with a larger end mill to rough out most of the material and then change the end mill to a smaller radius end mill and only cut the inside profile of the letters and other graphics. However he did it, it looks great.

You can see in this image that carving depth deep enough to show a nice shadow effect.

Below are some more examples of Jonathan's work. You will notice the intricate detail that Jonathan put into the work. This also shows the capability of the greenBull CNC router.

Below is Jonathan's review of the greenBull CNC Router and his experience with the support he received from BuildYourCNC

The starting cost was nice, it was affordable for me and did not break the bank in terms of overall size versus cost. Saying that though it was still a bit pricy if you were just a hobbyist. The cost of over 5k after everything was said and done put it close to the price of the Chinese knockoffs. For 5k you can get a Chinese knockoff that’s fully assembled but there is no support and its never clear what sort of post processor they support.

Another note though was after I tacked on my cad cam software the total price went to about 7800USD when it was all said and done. Still within range of what I was after though.

Another reason I was ok with the price is that the whole machine is parted out. So if something breaks I can easily get something on line or at the local hardware store making it very easy to maintain the machine which was the main goal of what I was after.

Performance is still up in the air. As you can see from the pics I have some lining and chaff in my cutting and I have tried to calibrate it a few times. I’m sure it’s probably just my end on that part but I noticed that the machine bound up a lot more then what I saw in the vids. Such as the vid that did full cut depth on the MDF at 80IPM. It will hit and the stepping motors will start clicking away forcing me to recalibrate. Buildyourcnc's response: First to make sure you are using an end mill that will allow for fast feeds and speeds. We typically don't cut at full depth when cutting 3/4" plywood. For that thickness, we will do a roughing pass at 0.4 inches deep allowing for two passes at around 100 IPM, then we will follow up with a finishing pass that skims off a tiny amount of material along the cutting edge and this is done fast (around 120 IPM) and at full depth.

Another aspect was getting the spindle completely straight up and down. I had to shift and use some shims to get it closer to a full straight up and down 90 degree angle. Buildyourcnc's response: I would say that is a good method to ensure a perfectly vertical alignment of the z-axis.

As of right now though it seems that I am probably about .002 off on my X and .004 off on my Y which is good. I’m just nitpicking as it’s easy to sand the lining and clean the chaff. Buildyourcnc's response: The roughing and finishing process may improve this. When milling material, the end mill will have load against it, causing it to have a bit of displacement. This is true with all CNC routers and CNC machines. A good way to get better accuracy is to have a roughing pass then a finishing pass. The finishing pass has a very small load on the end mill and the material will be removed in the correct location, not where the displacement is located.

Stability of the machine is decent. The gantry has no issues and seams very sturdy. Some of my complaints on it is the chain system. It really should have a double nut system or lock tight, and then the pole for the x and y axis should have flat parts ground out of them so the hex screws have a better hold on the overall action of the bar. Those are my only real complaints about the design, shipping wise I was lacking washers and a bag of bolts that was supposed to come with it. You guys were kind enough to give me a discount off one of my orders to make up for it though which was fine.

Assembly wasn’t too bad. The biggest complaint is you have several lapses in your videos that made it hard at times to figure out what went where. Such as you did not have the z carriage electronics part done very well. There was an error which then you had to backtrack to fix and it did not show the placement of the part that goes between the stepping motor and the bar. Also I was given wrong set up details on mach3 which was fixed by a call from you guys that logged in and helped me out. Support was great something I really wanted.

Overall quality of parts sent is good. The 3phase has worked well, the spindle is great and the stepping motors seam to work well. The redfly box works good.

The only part I think might be so so is the water pump that was sent. It took a lot to get it primed and if it loses that prime it takes a bit to get it going again. So maybe a different water pump.

Pros:

Mid-range cost, support makes it worth the extra cost. Size for cost. Getting a machine to do a full 4 by 8 instead of getting a cnc that its table is 4 by 8.Easy to maintain and repair. Flexible, I was able to build mine on a table that can roll and add a drop off for oversized projects or upcoming 4th axis.Helpful staff.Fun learning.

Cons:

Somewhat confusing install instructions on the website at the time of assembly. Harder to calibrate. Lot more factors to take in to consideration. Setup instructions for Mach 3 were conflicting. Some shipping mess-ups (3 phase and nuts and bolts.) You have to have a good understanding of the machine and how it works so you get what you want. Not something that can be just bought and put together by any one. Knowledge of basic concepts, electrical and mechanical are needed.

Overall:

I am very pleased with the overall product and happy to step into the CnC group. I plan on expanding to a 4th axis the more proficient I become as well as laser. The only thing keeping me from buying your laser setup is the lack of auto controlling its strength. Options like that in glowforge make me want to spend the extra 2 or 3k to have auto discover and laser strength options available.