Core ONE 3DO Nozzle Camera Mount - 25cm FPC with LEDs

This is an evolution of my Simple 3DO Nozzle Cam Mount which moves the PCB into a small enclosure on the back of the extruder, between the extruder and print fan, allowing it to be more protected and route the USB cable behind the extruder instead of in front of the heatbreak fan. It also supports a small heatsink for the main PCB chip. While this mount is much more complicated than the simple one (it has 5 separate printed parts and requires the 25cm FPC ribbon cable instead of the 5cm one) it protects the PCB much more and is far less prone to random issues while still staying within the tight clearances of the Core One's enclosure.

Required Hardware

You'll need these to put this together:

• 3DO Nozzle Camera (Fixed Focus, 3.45cm)
• 3DO DSP PCB
• 3DO 25cm FPC Ribbon Cable with LEDs
• 3DO USB Camera Cable (I suggest at least 2.5m long, I used a 3.5m cable from KB3D)
• 1x M2-14 bolt OR 1x M2-16mm bolt + 2x M2 hex nuts (in addition to the 3 below)
• 2x M2-8mm bolt
• 3x M2 hex nuts
• 1x M3-30mm bolt (if you have one with a half-height head use that but it's not required)
• 2x M3-20mm bolts
• 1x M3-10mm bolt
• 1x M3 hex nut
• (Optional) A 9mm x 9mm or smaller heatsink (I used one meant for a Raspberry Pi)

The 4 M3 bolts will be replacing 4 shorter bolts on the extruder. Clearance is tight so be very careful with lengths and making sure everything is tightened and positioned properly or you may run into issues with auto-homing or movements at the front or right sides of the print area.

The M2 bolts will be to secure the PCB. If you have an M2-14 bolt that should work for closing the PCB holder. If you don't have one, an M2-16 and two M2 hex nuts should work just as well (this is what is in the pictures as it's what I had at the time).

See the 3DO GitHub page for links to places to buy the 3DO hardware or how to build or source them yourself.

Printing

The mount in the pictures was printed with Prusa Shimmering Violet PETG. I would recommend printing in either PETG or PC/PCCF. PETG should work fine for most applications, you should only need PC or PCCF if you're printing heavily with higher temperature filaments, and even then PETG should generally be fine as the camera mount shouldn't be getting nearly hot enough to deform. Then again, Prusa prints their Core One extruder parts in PCCF for both heat resistance and long term resilience, so if you want to ensure that everything is as strong as the rest of the extruder you may want to go with PC or PCCF. That being said, I printed and used mounts in both PLA and PETG and they worked fine for both PLA and PETG prints, at least in the short term.

For print settings, either use the provided 3mf or import the step file and then make sure to place the shared bottom face on the print bed and block supports from the M2 nut holes on the bottom of the PCB holder second from the left. Turn on automatic support generation, I recommend organic supports. Enable brim as well as several parts have a very limited footprint. I would also recommend a 0.2mm layer height with a 0.4mm nozzle, this doesn't need a higher precision.

Depending on the material you're printing with and your print settings the fit of the camera end of the FPC with the LEDs in the camera holder may be either too tight or too loose. I found that with PLA the fit tended to be more loose but with PETG the fit was a lot tighter. You may want to try printing just the bottom of the camera mount (the middle of the 5 pieces, use the slicer's Cut tool to snip off everything else) and test the fit of the LED strip in the mount first. If it's too loose, open the FreeCAD file (the one with the fcstd extension) and then open the Spreadsheet near the bottom of the Model tree on the left and change the led_strip_hugger_fraction value to a higher fraction, such as 0.5 or 0.65. If the fit is too tight, try a lower number, like 0.4 or 0.25.

Also note that all 5 pieces of the mount are included in a single model file, connected by tiny little lines. There's probably a better way but this was my first real use of FreeCAD and this is how I got things to work for me.

Assembly

Remove the supports and brim. Pay extra attention to the brim on the bottom of the camera mount and on the end of the side channel where it will insert into the camera mount as extra brim sticking out will make it much harder to fit in and the camera mount will be close to the print bed and could catch on your prints. If you're using an M2-16mm bolt instead of an M2-14mm one, take two extra M2 hex nuts and screw them up to the head of the M2-16mm bolt so that about 14mm is left. If you are opting to put a heatsink on the PCB I would recommend not putting that on until you put the PCB in the holder at least once to make sure it won't interfere with the hole. It needs to be a 9mm x 9mm heatsink or smaller. Here's what you should have:

Start by connecting the fan mount and the side ribbon channel together. These are the two printed parts in the picture above. The little squarish part on the top of the support of the right channel goes into the indentation on the right side of the fan mount, with the holes lining up. An M3 hex nut goes in the hole in the back and the M3-30mm bolt goes through both and into the nut. Depending on how the prints fix you may not be able to get the nut in on its own and may want to use the bolt to pull it in, screwing it in slowly until the nut takes its place. When it's all together it should look like this:

Next slide the LED end of the FPC ribbon through the big hole in the fan mount and into the camera holder. There are small hooks at the sides of the holder that you're trying to put the edges behind. The fit can be tight but work slowly at it until you have both edges behind the hooks and can work the strip slowly down. Here's a closeup picture of the model so you can see what I mean about the hooks:

Here's what it looks like once it's in:

Turn the fan mount back around and fold the ribbon cable gently to the right and thread it through the hooks on the right side of the mount. Once this is done, loop the ribbon cable over one time again, loosely, and thread it carefully through the side channel. While sliding it through the connector at the end should be facing up, out of the channel. Be careful of the fold between the two pieces, it needs to be guided carefully while pulling the ribbon cable through so that the end of the fold between the pieces ends up behind the fan mount. Essentially you want to make is so that the cable isn't poking outward when you're done so it doesn't get caught up while auto-homing. Hopefully a couple of pictures should help:

If you find a better way to do this let me know! Originally the side channel didn't go diagonally at this end so it had more space for this fold, but that ended up interfering with the tight clearances so I opted for this instead.

Make a 90-degree turn in the ribbon cable at the end, with a loose 45-degree fold, and thread the end through the read channel, this time with the PCB connector facing away from the channel opening. Pull it out of the channel behind the X-shaped supports then attach it to the PCB, ensuring that the white dot on the PCB matches up with the white dot on the connector.

Take the PCB holder with the 4 screw holes and turn it over to the back, where the hex nut holes are. Put M2 hex nuts into the right two holes and top left hole. I didn't use the bottom-left hole as it interfered with the heatsink I used. If you're not using a heatsink or find it doesn't interfere with yours feel free to put a nut in there too. The holes are likely to be tight, I recommend screwing the a nut onto the end of a long M2 bolt and pushing it into the nut hole until it's in there a good way, then straighten it out and unscrew the bolt. If you're still having trouble you can try screwing the long bolt in from the other side and pulling the nut in, or tightening the bolt from the other side to pull it in. Be careful, though, as you could deform the standoffs by screwing in too tight.

Turn the holder back over and place the PCB inside, lining up the screw holes at the 4 corners with the standoffs. Make sure the ribbon cable stays attached and goes through the hole at the bottom of the holder. Use two M2-6mm bolts to secure the top-right and bottom-left corners. Make sure they have bitten into the nuts and are holding securely, but don't tighten too much or you risk deforming the standoffs or breaking a component on the PCB. You also don't want the bolts sticking out of the back of the holder at all or they may make scratch the back of the extruder or make it impossible to connect the mount.

Connect the camera to the LED end of the FPC Ribbon cable, ensuring that the white dot on the camera and the white dot on the connector line up.

Connect the USB cable to the PCB and pull enough of the cables inside so that the thicker outer shielding it in the half cylinder at the top of the PCB holder.

Carefully put the PCB cover over the PCB, lining up the slits in the bottom of the cover with the side walls of the holder, ensuring that the cables aren't pinched, and that the cable strain relief holds the thicker part of the cable (which will protect the connector and unsheathed cabled from being strained during printing). While holding the cover securely, put the long m2 bolt through the hole int he cover, through the PCB and standoff, and screw it into the nut on the back of the holder. You may have to squeeze slightly to make it reach. Make sure this bolt is biting into the nut and holding the cover on as you don't want the cover falling off while you're printing. Make sure the bolt doesn't poke out of the back of the PCB holder. At this point if you have a heatsink apply it through the hole and onto the chip.

Now you're ready to start mounting everything on your extruder. Start by taking the top cover off of your Core One for easier access. Remove the top bolt on the “Print-head-cover-right” on the right side of the extruder. See this Core One assembly page for which part I'm talking about. Put the original bolt aside and prepare the M3-10mm bolt. Take the PCB holder and rear cable channel and line up their mount m3 bolt holes in preparation for mounting. Make sure the ribbon cable between them isn't twisted too much while you're holding the two pieces together and that there's enough slack that the cable's connection to the PCB isn't being strained and potentially pulled off.

While holding the parts together, place the PCB holder behind the extruder and line up the bolt hole on the mounts with the newly emptied bolt hole on the right side of the extruder. Insert the M3-10mm bolt and tighten securely.

Move to the front of the extruder and remove the two bolts on the left front of the fan, releasing the fan. Carefully remove the fan then remove the bolt that was behind the bottom right corner of the fan. Set all 3 of these bolts aside, we will be replacing them. Pick up the nozzle camera fan mount and carefully unscrew the long bolt holding the front and side pieces together about half way, leaving the nut in the back piece and the two pieces connected together. Line up the fan back where it goes on the extruder, then line up the camera mount so that the bolt goes through the bottom-right hole of the fan and into the hole in the extruder behind the fan. Carefully tighten the bolt most of the way, ensuring that the fan is oriented correctly and that the bolt is connecting into the heatsink behind the fan. When you let go the fan and mount should stay where they are, with just a little wiggle.

Insert the M3-20mm bolts one by one into the left two holes and tighten them fully, top left first, then bottom left, then fully tighten the bottom right bolt, ensuring that the mount is fully against the fan and the bolt head is fully against the mount. These need to be as close together as possible so as to not bump into the front gantry of the CoreXY.

Now you'll need to route the USB cable out of the printer. Leave a little slack and bring it up along with the PTFE tube and the cable bundle, tying it up with the existing velcro ties along the bundle, then along the cable gantry arm. Just like the other cables, thread it behind the corner of the CoreXY and down into the bottom of the printer, then through one of the holes into the outside of the printer in the back.

That's it!

Using the camera

There are lots of other resources out there about this but what I've done is to use a Raspberry Pi with the stock OS, then install v4l2rtspserver and use that to run an RTSP stream of the camera that I can tap into from another computer with mpv or VLC. You can even connect it up to a Synology NAS with Surveillance Station to centraliz your cameras. That's what I do with this camera, the two Buddy3D cameras I have installed, and several external cameras so I can stream it on Twitch, mostly for my own monitoring.

Thanks!

Thanks so much for checking out my camera mount! It was a challenge to get something like this to fit within the very limited space in the Core One and I had a lot of fun learning FreeCAD to get this all made. If you have any suggestions for improvements I'd be happy to hear them! ^_^

Update 2025-11-06: Updated to move the camera holder a bit higher to not interfere with the various nozzle wipers and to have a slightly better connection between the camera holder and the mount.