KLP1 210 Dragon ACE/Rapido Beacon bowden toolhead

Overview:

This is a Bowden toolhead for the KLP1 210 that uses:

• Dragon ACE hotend, likely also Rapido/Rapido 2/Rapido ACE HF
• 4010 heatbreak fan (I use a Fabreeko Honeybadger)
• 5015 part cooling fan (I use a West3D Berserker Vindr)
• Beacon H with the standard connector, using the short screws from its kit
• BMG or Micro-Swiss bowden extruders (Micro-Swiss is greatly preferred)
• 9x M3x5x4 heat inserts
• 2x M4x6x6 heat inserts
• 2x M3x6 countersunk screws (top toolhead mounts)
• 1x M3x6 button head screw (bottom right toolhead mounts)
• 2x M3x12 countersunk screws (hotend clamp)
• 4x M3x12 button head screws (4010 mount)
• 2x M4x20 button head screws (5015 mount)

For mounting the extruder:

• 2x M3x10 or 12 socket cap or button head screws (attaching to the frame)
• 3x M3x40 socket cap screws (BMG extruder)
• 3x M3x12 countersunk screws (Micro-Swiss extruder)

This is the third toolhead I've used on my KLP1; I first replaced the original toolhead with a Smart Orbiter V3 to let me use a Beacon for bed probing and to avoid using the rp2040-based toolboard.

Then I replaced the SO3 because it had really bad heat creep in my 65C chamber, switching to a Dragon ACE for its good heatbreak performance.

You could use a Rapido or Rapido 2 or Rapido ACE HF as the lengths should match with the groove mount, though I haven't tried them. Other Dragon variants including UHF Mini and ACE Dragon are unlikely to fit and work for sure with the Beacon.

Bowden is known to be difficult to tune but if you use Kalico's bleeding-edge-v2 branch you can use nonlinear pressure advance that dramatically improves the quality. Additionally, many BMG clones come with bad fittings; the Micro-Swiss bowden extruder's compression fitting is much better quality. I strongly suggest you use a high speed motor roughly equivalent to the LDO 2504 to get enough motor speed to keep up with the Bowden pressure advance requirements.

Printing:

Print all parts from ABS, ASA, or better (temperature-wise) with 0.4mm nozzles and generous wall/top/bottom surface counts.

• Toolhead: add some tree supports inside the opening of the fan duct, in the bridge under the duct, in the opening of the heatbreak cooling fan duct, and for the top corners.
• Clamp: nothing special
• Micro-Swiss bowden extruder mount: nothing special
• BMG extruder mount: print it flat with supports for the cantilever.

Installation:

Firstly, raise the lid using https://www.printables.com/model/669892-minimalist-kingroon-klp1-lid-riser-and-kick-stand but modify it with a 25mm cutout on the rearmost portion of the left wall. See my photos for details. On my printer, I modified it physically with wire cutters, but if you are printing it fresh for this you can use a negative modifier in the slicer.

Secondly, you'll need to either replace all the electronics (I used an SKR Pico and Raspberry Pi 4), relocate the existing toolboard and adapt its connectors, or add an extra board connected over USB to free up a stepper driver for the extruder.

Completely remove the stock toolhead from the mounting plate the belts are attached to, and either cut or bend outward the bottom left mounting tab of the plate.

Replace the stock belt tensioners with these, but modify the design so that the tabs sit flush with the mounting plate instead of protruding: https://www.printables.com/model/562359-kingroon-klp1-belt-tensioner 

Insert the 9 M3 heat inserts into the toolhead, and the 2 M4 heat inserts into the toolhead and the clamp.

Install the Bowden fitting/groove mount adapter onto the hotend. For Dragon ACE, orient it when the adapter is in the toolhead, the heater is on the left side and the thermistor to be on the right side. (For Rapido I'm not sure but you probably want the wires going out the right, maaaaybe the back?)

Install the hotend into the toolhead with the clamp and two M3x12 countersunk screws. Make sure the M4 insert is on the left.

Install the 4010 fan on the left side with M3x12 button head screws, the 5015 blower on the front with M4x20 button head screws, and the Beacon on the bottom front with the the shorter of its included super low profile M3 screws.

Install the toolhead to the mounting plate with M3x6 countersunk screws near the top of each side, and one M3x6 button head screw on the bottom right of the rear side.

Install the Bowden extruder on the mount with its respective screws, and mount that to the rearmost two screws on the left side of the machine. Install 500mm of Capricorn XS tubing from the extruder to the hotend, making sure to fully seat them.

Use a split cable sleeve of around 10-15mm diameter to run the wires (heater, temp sensor, two fans, and Beacon USB) alongside the Bowden tubing, and put a cable clamp around it near the toolhead.

Kalico Configuration:

For the X axis, I have a motion range of 0 to 220, and use 0 as the endstop position.

For the Y axis, I have a motion range of 0 to 215, and use 215 as the endstop position (it homes at the back)

The printable range to set in your slicer is 0-220 in X and 0-205 in Y.

For the Beacon, the Y offset is -19.8mm and the home position is 110, 102.5. My bed mesh mesh_min is 20, 0 and mesh_max is 200, 190.

When you use the Beacon to measure the resonances, the Y axis will have a false peak where the Beacon and duct resonates but the hotend doesn't (you'll see a lot of Z motion for that false peak). I only need to correct the true peak; I use smooth_zvd_ei at 72 Hz for X and smooth_ei at 46 Hz for Y. Your machine may vary depending on your belts, whether you have the back right idler fix, and more.

For Pressure Advance, follow the instructions here: https://docs.kalico.gg/Nonlinear_Pressure_Advance.html My settings for Inland ASA at 250 C with a 0.4mm Bondtech CHT nozzle are as follows:

• linear_advance 0.45
• nonlinear_offset 0.6
• linearization_velocity 3
• smooth time 0.02
• pressure_advance_time_offset 0.004

This can and will vary dramatically with different filaments, temperatures, and nozzles, as well as different printing speeds.