====== three point hitch receivers ======

^ Techniques infobox ^^
| image |  |
| designers | [[:user:tim|Timothy Schmidt]] |
| date | 2021 |
| vitamins |  |
| materials |  |
| transformations |  |
| lifecycles |  |
| tools | [[:wrenches|Wrenches]] |
| parts | [[:frames|Frames]], [[:nuts|Nuts]], [[:bolts|Bolts]], [[:end_caps|End caps]], [[:plates|Plates]] |
| techniques | [[:tri_joints|Tri joints]] |
| files |  |
| suppliers |  |
| git |  |
| reversible | true |

[[:category:techniques|Category:Techniques]]

==== Introduction ====

The three-point hitch is a widely used type of hitch for attaching [[:ploughs|ploughs]] and other implements to an agricultural or industrial [[:tractors|tractor]]. The three points resemble either a triangle, or the letter A. Three-point attachment is the simplest and the only statically determinate way of joining two bodies in engineering.

==== Challenges ====

==== Size categories ====

There are five different hitch sizes, called categories.  The higher category hitches have sturdier lift arms and larger connector pins.

^ Category ^  ^  ^  ^  ^
^ Tractor power ^  ^  ^  ^  ^
^ Top link pin diameter* ^  ^  ^  ^  ^
^ Lift arm pin diameter ^  ^  ^  ^  ^
^ Lower hitch spacing ^  ^  ^  ^  ^
| 0 | Up to 20hp | 5/8 in | 5/8 in | 20 in |
| 1 | 20 to 45hp | 3/4 in | 7/8 in | 28 in |
| 2 | 40 to 100hp | 1 in | 1+1/8 in | 34 in |
| 3 | 80 to 225hp | 1+1/4 in | 1+7/16 in | 40 in |
| 4 | More than 180hp | 1+3/4 in | 2 in | 48 in |

There are also variants to the above categories denoted by N, (narrow). These utilize the pin sizes of the listed category, but the width of a category one step lower. The N variations are common in "quick hitches" and allow larger tractors to easily hook onto smaller utility implements.

:* refers to implement end; tractor end not specified

==== Approaches ====

''{{:archive:plate-three-point-hitch.scad.png?600|Three point hitch plate adapts to 5/8 inch, 3/4 inch, 7/8 inch}}''

==== References ====

  * [[https://en.wikipedia.org/wiki/Three-point_hitch|Wikipedia: Three-point hitch]]

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[[https://github.com/timschmidt/replimat/blob/e0bc0b855bb946bab00c75ca0d8b002ae0dc0172/wiki/three_point_hitch_receivers.html|Original archived page]] — revision 8342, 2021-09-25T10:03:59+00:00, by Tim.