T3P3 Kossel Mini Kit

Assembly Instructions

Chapter 10 - Frame Assembly

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1001 Frame - Parts needed

Base assembly

Tower extrusions 600 long x 3

M3 x 8 socket capscrews x 6

M3 full nuts x 6

Top assembly

M3 x 35 socket capscrews x 3

M3 x 8 socket capscrews x 3

M3 full nuts x 6

M3 washers x 3

Carriage adaptor assemblies x 3

(the pictures still show the original carriage adapters with projecting tensioner bolts and without endstop trigger bolts - see Note Chapter 4)

Endstop assemblies x 3

Extruder bracket

M3 x 8 socket capscrews x 2

M3 full nuts x 2

M3 full nuts x 4 (optional - for future expansion)


1002 Fit towers to base


  1. First make sure that you have the frame the right way up. The underside is the shiny side of the printed parts.
  2. We have changed the design of motor brackets to remove projections preventing the addition of nuts once the extrusion is in place. Please ignore projections shown in some of the pictures below.


Insert a tower extrusion into one of the motor brackets and push/tap gently until it reaches the bottom.

Repeat for the other 2 corners.

Invert the frame ….

and push or gently tap the frame extrusions into alignment with the bottom of the printed motor bracket.

Turn the frame on its side. Insert a nut in the top nut channel of the extrusion and push it along  with the long leg of a hex key until it emerges on the other side of the bracket.  Fit a second nut…...


and push both nuts into the bracket until they align with the bolt-holes.


Insert an M3x8 socket capscrew in each hole and tighten.


Repeat for the other 2 frame base corners.

1003 Identify X Y and Z towers

From this point on in the assembly, we need to identify the 3 towers individually. As shown, the front left tower will be X, the front right tower Y and the rear tower Z. The motor brackets in the picture have been labelled accordingly and the extrusions joining them will be referred to as X-Y, Y-Z and X-Z.  X, Y and Z-stickers have been provided in the kit if you want to label your towers.

1004 Fit carriage adaptors

Note: These pictures show a previous design of adapter, but the procedure is exactly the same.

Ease a carriage adaptor assembly onto the top of a tower (plastic facing inwards). You may have to loosen off the tensioner bolt before it will go on.

The leg carrying the single V-roller will be slightly splayed out from the rest of the adaptor.

Tighten the tensioner bolt to apply a small amount of preload to the rollers, while ensuring the adaptor can run smoothly and easily up and down the tower extrusion.

Repeat for the other two towers.

1005 Fit endstops

Fit an endstop to the top of each tower above the carriage adaptors, facing inwards. For the moment, tighten it about 80 to 100 mm below the top of the tower.

Note:  The central endstop connector tab gets in the way when  tightening the capscrew. As it is not used, it can be bent slightly so the hex key can fit past it.

1006A Fit extruder bracket

Fit the 2 M3x8 socket capscrews to the extruder-mount flange and loosely fit 2 M3 nuts.

Fit the extruder-mount onto the outside channel of the Z-tower, slide it down about half-way and tighten the bolts.

1007 Fit top frame

You will need to place the frame base on a fairly low support to gain easy access to the top of the towers.

Fit the top bracket to the towers (nut hole facing down)


Once all 3 corners are fully onto the tower extrusions,....

...turn the frame on its side, fit an M3 nut into the channel, as you did for the base, and align it with the bolt-hole. Fit an M3x8 socket capscrew, but do not tighten it fully yet. Repeat for the other 2 top brackets.


Turn the frame upright again and push the top brackets down the towers until 12mm of extrusion is protruding above each bracket (picture shows 15mm). It is important that they are all the same.  Tighten the M3 x 8 socket capscrews that you fitted to the printed corners.

Fit an M3 x 35 bolt with washer into the angled belt tensioner hole in the top of each bracket.

Fit an M3 nut onto each bolt from underneath and tighten just enough to draw it into the nut trap without raising the bracket on the pillar.

Now go on to the next Chapter.