01. Tools

Do not use power tools for the whole assembly or you might damage hardware. Always use hand tools.

Tightening torque values recommended:

Max 4.5Nm for M5 screws on metal to metal assemblies (e.g. joining plate on an extrusion).

Max 1.5-2Nm for M5 screws on printed part to metal (e.g. y_rod_holder.stl on extrusion).

This step and the next one list the mandatory tools you need to build the Bear frame.

Small pliers with cutting capabilities

Hex key 1.5mm for MK2(S) and MK2.5(S) only, not useful for MK3(S).

Hex key 2mm.

Hex key 2.5mm. Ball end would be very useful.

Hex key 3mm.

Spanner 5.5mm

Slotted screwdriver #1

This step and the previous one list the mandatory tools you need to build the Bear frame.

Having a quality square will help you to build the Bear precisely. We recommend a 200mm long machinist precision square, ideally with standard DIN 875 / BS 939 (any grade).

If you don't have such a square or want to use a lower quality one, check these videos on how to test and fix your square:

How to Square a Square by Wesley Treat: https://youtu.be/FNpAQHrNpNU

How to Square a Square and Make it True by Wood By Wright: https://youtu.be/enEYzTXg2Jg

Caliper, 150mm long minimum. If you don't have a caliper you can use a steel ruler. (A vernier caliper is generally more accurate than a digital caliper, at the same price point.)

This step and the next one list the optional tools that can be helpful during assembly. You can build the Bear frame perfectly without them.

Sorry for this extra list, we love tools...

A long caliper of 200mm or more helps to align the Y axis smooth rods spacing on any "Prusa type" printer.

A general purpose clamp will facilitate the squaring of the frame when using a machinist square.

Tweezers are always useful :)

You can add a dab of blue Loctite #243 to the screws during assembly to prevent them from unscrewing.

An 8mm drill bit or 8mm reamer can be useful in case the smooth rods holes on Z axis are a bit too tight.

This step and the previous one list the optional tools that can be helpful during assembly. You can build the Bear frame perfectly without them.

Files and deburring tool can be helpful to clean the printed parts.

It is good practice to re-grease the bearings during the assembly.

We recommend the use off a lithium based lubricant that has a viscosity between 50 and 100mm2/s at 40 °C, NLGI class 2 and a thermal resistance of 100°C or more.

A torque tool can be useful to ensure you apply max torque without damaging hardware.

We recommend max 4.5Nm for the metal to metal assemblies (e.g. joining plate on an extrusion) and max 1.5-2Nm for printed parts (e.g. y_rod_holder.stl on extrusion).