> For the complete documentation index, see [llms.txt](https://hrftank.gitbook.io/hrftank/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hrftank.gitbook.io/hrftank/i-getting-started/things-youll-need-bom-and-tools.md).

# Things you'll need (BOM & Tools)

BOM for a drivable chassis. No fancy stuff included.

## Materials

* 10 kg of PETG filament
* [*300 g of TPU filament*](#user-content-fn-1)[^1]
* Threaded rods:
  * M6 x 238 mm (6 pcs)
  * M6 x 246 mm (2 pcs)
  * M3 x 238 mm (1 pcs)
  * M3 x 262 mm (1 pcs)
* Smooth rods:
  * 6mm x 66 mm (4 pcs)
  * 6mm x 36 mm (2 pcs)
  * 6mm x 110 mm (2 pcs)
  * 4mm x 100 mm (4 pcs)
* Bearings:[^2]
  * 696 bearings - 6 x 15 x 5 mm (52 pcs)
  * 626 bearings - 6 x 19 x 6 mm (4 pcs)
  * 623 bearings - 3 x 10 x 4 (12 pcs)
  * LM4UU linear bearings (8 pcs - use cheap ones, there's no need for much precision)
* RC suspension & springs:
  * 1/10 scale RC car shock absorbers - 15 mm outer diameter, 90/70 mm uncompressed/compressed lenght ([like those](https://www.aliexpress.com/item/1005003230553475.html))
  * steel compression springs ([example](https://www.aliexpress.com/item/4000635809257.html)):
    * 18mm x 35 mm spring, 1.8 mm wire (8 pcs)
    * 18mm x 35 mm spring, 1.4 mm wire (12 pcs)
    * 15 mm x 60 mm spring, 1.2 mm wire (*2 pcs - for track tensioner*)
* Tracks:
  * 2 x 70 mm steel rods (250 pcs - you can find them on Chinese marketplaces for around [$1.45 per 10 pcs](https://www.aliexpress.com/item/1005008218886259.html))
  * *M2x6 self tapping screw (500 pcs - rubber pads version only)*
* [3650-type motor mount ](https://www.aliexpress.com/item/1005001949762031.html)([like this](#user-content-fn-3)[^3])
* [Pololu 2674](https://www.pololu.com/product/2674) wheel adapter for 6mm shaft
* Gearbox:
  * 1M 15T gear, 6 mm bore (2 pcs)
  * 1M 18T gear, 6 mm bore (2 pcs)
  * 1M 30T gear, 6 mm bore (2 pcs)
  * 1M 35T gear, 6 mm bore (2 pcs)
  * 1M 40T gear, 6 mm bore (2 pcs)
  * 1M 60T gear, 6 mm bore (2 pcs)
  * 1M 20T gear, **5 mm bore** (2 pcs)

{% hint style="info" %}

* I suggest using [aluminum gears](https://www.aliexpress.com/item/1005005672306720.html) - they are twice lighter than steel ones (432 vs 1195 g)
* 20T gear's bore must fit motor shaft diameter
  {% endhint %}

{% hint style="warning" %}
All screws are socket head cap screws, unless otherwise stated.\
You can use different screws than those specified, as long as their heads aren’t significantly larger than the ones listed in the BOM.
{% endhint %}

* Screws:
  * M3x6 (46 pcs)
  * M3x8 (54 pcs)
  * M3x10 (14 pcs)
  * M3x12 (2 pcs)
  * M3x14 (12 pcs)
  * M3x18 (slot pan head screw - 10 pcs)
  * M3x35 (full thread, button head - 10 pcs)
  * M3x50 (full thread - 6 pcs)
  * M3x60 screw (full thread - 8 pcs)
  * 3x8 mm self-tapping screw (14 pcs)
* Nuts:
  * M3 self-locking nut (18 pcs)
  * M3 serrrated flange nut (4 pcs)
  * M3 wingnut (optional, 2 pcs)
  * M6 serrated flange nut (16 pcs)
  * M6 self-locking nut (14 pcs)
* Washers:
  * M6 washer (12 pcs)
* Heat-set inserts \[thread x length (outer diameter)]:
  * M3x4 (OD 5 mm, 76 pcs)
  * M3x5 (OD 5 mm, 80 pcs)
  * M6x8 (OD 9 mm, 22 pcs)
* Electronics (*basics*):
  * RC receiver and transmitter of your choice 
  * Not necessary but highly advised: Ardurover/INAV compatible RC Flight controller for fixed wing aircraft
  * Mini-size (22 mm wide) FPV camera 
  * FPV video transmitter *(my design fits 37x60 mm max VTx, with 20 or 30 mm mounting holes spacing)*
  * 2x RC motor and compatible ESC  (I suggest using brushless 3660 motors with 5mm shaft and reversible ESCs)
  * Gold bullet (a.k.a banana) 4.0 mm connectors (10 pairs)
  * Few sets of RC power connectors - I recommend using EC5, as they are rated for >90 amps (how many? depends on desing of your electronics)

{% hint style="warning" %}
Check [Electronics overview](/hrftank/iii-build-manual-electronics/electronics-overview.md) for a better insight into the electronic component options available for installation.
{% endhint %}

{% hint style="danger" %}
If you want to use water cooling, make sure that you power set is waterproof and watercooling-compatible!
{% endhint %}

## Tools

* 3D printer with 250x200x200 mm build volume (like Prusa i3 MK3S)
* Hex key set (aim for long one)
* Set of Philllips and flat screwdrivers
* 5,5 and 10 mm wrench (for M3 and M6 nuts, ratchet wrench will assembly process easier)
* Pliers
* Needle file set
* Soldering iron (preferably with soldering tips for M3 & M6 heat set inserts)
* Drill or rotary tool with 1.8, 1.9 and 2.0 mm drill bits
* *Optional but highly recommended:* 
  * *electric screwdriver (if you don't have one yet, choose a model with higher torque – it will suit the project better)*
  * *5 mm diameter file for chainsaw sharpening (makes installation of the hull threaded rods much easier)*
  * *If you don't have access to cut-to-size threaded rods: metal hacksaw and external deburring chamfer tool*

[^1]: *Optional, mainly for track pads and mud flaps.* Basing on my experience, Shore 30D is good balance between durability and flexibility

[^2]: It doesn't really matter if they are "ZZ" or "2RS" type

[^3]: ![](https://673609632-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhmKl11OGPwbKiNEUvA5L%2Fuploads%2FWaAHSvuQM3JbsnrQN8S8%2F51qx1KaCUTL._AC_SX679_.jpg?alt=media\&token=48572b90-7e57-460d-bdcd-01e1081c9fb1)