Hydra x Tetras - Enhanced Bambu Lab AMS

Update September 2, 2026

I'm currently working on an upgrade kit for later versions of Hydra (1.10-1.13) to Hydra x Tetras as a few have requested it. 

It will not be quite as sealed as the “real” Hydra x Tetras as seen on this page though but it should work quite well. 

Please follow my profile for updates.

About

Notice: This is compatible with the original AMS only! A similar version is coming for the AMS 2 Pro shortly.

Hydra x Tetras is a special edition of the Hydra that is perfectly integrated with the Eibos Tetras (and Dyas) dryer system. It has extended spool dividers that seal against the Tetras lid and together with the Hydra x Tetras front divider set and cover set (both included), each section is effectively sealed off so one spool compartment can be heated to for example 65 C while the spool next to it can be PLA and not be directly affected by the heat.

Caution! For longer drying sessions you should use same type of spools in all slots as heat will spread over time. Also, ensure you have used the covers correctly everywhere and that you monitor the temps on the Tetras displays before an extended drying session.

Hydra x Tetras is fully 3D printed, no dividers or baffles from the Eibos kit are used inside the AMS box, apart from the dryers and electronics of course. The Eibos mounting brackets for the heater panels are still used.

The main changes / improvements over the standard AMS are:

• Perfectly integrated with the Eibos Tetras / Dyas

• Increased spool widths, up to 77 mm, meaning most 1 Kg spools will fit.

• Increased spool diameters, up to 202.5 mm diameter spools fit.

• Adjustable spool rollers in 10 positions for 120 mm to 205 mm diameter spools.

• PTFE tubes replaceable from top.

• Removable and reversible front and rear spool guides.

• AMS feeder / motor mechanism angled backwards to allow printing of full spools, use a PTFE load button to reduce angle and drag of low filled spools.

Discord Support

 If you need any help with the build or want to leave feedback you can join us on Discord:

• Discord - Hydra / Python / Kraken Mod Support

Our server is named “(Unofficial) QIDI Tech 3D Printers” so don't get confused when you join as it was initially setup for that brand of printers but we've expanded it to other brands and 3D printing in general as well as channels for some of my mods, it's where I generally hang out.

BOM - Bill of materials

Silica gel beads.

• 500 g Silica Gel Beads

Support Boxes

Although the support boxes may seem wasteful, they are highly recommended as they prevent warping of the tall thin parts, especially the sidewalls of Hydra x Tetras. There are also two support box containers included in this print.

They're set to just 1 wall and 5% infill in the Print Profiles and do not waste too much filament but of course add to the print time. And once you've completed the full Hydra x Tetras print you don't have to throw them away, they're usable, stackable boxes you can store things in.

Warranty

Hydra x Tetras does not void your warranty but be careful, especially with the AMS main board, use an antistatic wrist band. Although the mod is completely reversible and you can't tell the parts have been installed in Hydra, I take no responsibility and you're on your own. Be careful and take it slow, read this page twice before you start. 

Print Settings

Most parts print without supports and I recommend using 4 walls and 30% infill for the main parts and 3 walls and an infill of around 15% for the rest of the parts.

The support boxes should be printed with 1 wall only and 5% infill. All this is prepared in the Print Profiles, including supports so you I recommend using these. PLA and PETG builds can most likely be printed completely without the support boxes so there's a version of these available as well, or in case you want to create your own custom supports.

Assembly Instructions

The assembly is identical to the normal Hydra so please view the guide here or download the assembly guide in PDF from the files section.

Installing The Cover Set

Once you have installed Hydra x Tetras in the AMS box according to the assembly instructions above, continue with installing the four PTFE covers and the two motor covers, they're all press fit, marked in Dark Grey and Red here. Make sure you have installed the PTFE tubes first of course as well as the rest from the main assembly.

The Hydra x Tetras tray has little guide dots for the PTFE covers, while the motor covers (left and right) snap in place.

Next, installed the feeder covers, begin by resting the bottom of it at the curved area just in front of the lower part of the feeder:

Then just fold it back so it snap in place under the clear cover of the feeder.

Do the same for all four feeders.

Installing The Front Dividers and Silica Gel Boxes

As Hydra x Tetras has four individual high capacity heaters / dryers means you practically never have to remove the front silica gel boxes and dividers with integrated silica containers as these will dry the silica gel stored in the AMS, as long as you use the drying function every now and then. So it's sort of a set and forget setup, quite nice!

But if you wish to, it's a two minute job (at most) to remove them if you wish to replenish the silica gel externally.

Begin by filling the containers with silica gel and slide over the snap-in-place cover, no screws are used.

I'm using some silica gel I found on Aliexpress myself:

• 500 g Silica Gel Beads

A complete setup of front silica boxes and dividers holds a massive 240 g of silica gel, you can see my 500 g container I bought is less than half full after filling!

There are three main rectangular silica gel boxes that room most of the beads while the three dividers in front of them room around 20 g each as well. These dividers provide as seal against the lid as well as a curved surface for optimized airflow from the heaters.

The outer dividers are just curved in the same fashion as the dividers for airflow reasons, they do not hold any silica.

Begin with the filled main silica gel boxes (Dark Grey), tilt them a little and slide them in between each feeder.

Then push them against the front plastic of the AMS box:

Next, slide down the three dividers in front of the main silica gel boxes. There's a little tab that aligns it with the main Hydra x Tetras tray, circled in red.

At the same time, also slide down the left and right dividers:

Next, to have everything sealed against the top lid, install the four divider bars, they are press fit.

Finally, before installing the rear cover, ensure the PTFE tube in the back of the AMS is connected.

Then as the final step, just slide down the rear cover, there are tabs on it as well to align and lock against the Hydra x Tetras main tray.

All done! Install the rear rollers and the optional spool guides.

Pictures

Your build is now complete and should look like this:

The front dividers were printed in black to showcase the different sections.

The front dividers are curved for optimized airflow and the covers seal off the electronics and prevent heat from spreading to the different spool sections.

When you close the Tetras lid, the dividers will slide into the Hydra x Tetras main tray and seal off the different sections:

Rear Roller Positions

 Hydra x Tetras has a number of rear roller positions so it's suitable for almost all spools.

• The default rear roller position, suitable for almost all 1 Kg spools is marked in blue below, it's where the rear roller is placed at the moment.

• If you have slightly larger spools, just above 200 mm in diameter, try the position marked in red.

• If you have slightly smaller spools, between 195-200 mm spools, try the position in marked green.

• The rest of the spool positions are for even smaller spools.

Click the image for a larger view