
AW139 Heli Collective Grip
This page is split into three main sections:
Parts Guide
Print Guide
Build Guide
The ultimate printer I can recommend is the Bambu Labs X1 carbon with AMS or P1P if you have deep pockets. ($1200). It's a massive leap forward in 3D printing, with excellent quality and impressive speeds. It's pretty much press print and go as the software and hardware do the calibration before each print.

This has to be one of my favourite designs to date. After working on helicopters for over 28 years, I often wondered how to reproduce the controls to make them realistic. The hardest part that any Helipilot has tried is to replicate the magnetic clutch.
I have used a stepper motor (standard Nema 17) as the mag brake, Parallel actuator, Beep trim and later on the autopilot drive unit (series Actuator).
This is NOT a force-feedback unit because helicopters do not operate like that. The control rods/cables are typically connected to servos. Due to the astronomical forces required to move the controls (between 3-20 tonnes), there are no feedback forces through the servos/controls. This is usually done by linear force feel units (springs) acting on a parallel actuator which can reset the datum point at any position. This is the purpose of the Stepper motor in this case. Most modern twin-engined rotorcraft are uncontrollable if full hydraulic servo power is lost.
This system replicates the Bell 212 cyclic forces with force trim in. Most pilots I know on the 212 like to hover, take off and land with force trim off. This makes the cyclic go completely floppy and makes controlling the aircraft easier for more extended periods of time, such as winching.
To increase the force of the cyclic, stronger springs can be added to the force feel units for those preferring a more robust resistance feel. The forces this particular cyclic replicates is that of the Bell 212HP.
This unit comes with the following:
1) A trim release switch beep trim top hat.
2) A cargo release button (not used yet but is connected).
3) An ICS/Transmit dual point trigger (not connected)
4) AFCS release button (Connected but not used yet)
At the moment, The cyclic can be repositioned in any neutral position using the trim release. Once the button is released, the cyclic will hold that position and force feel is enabled. Fine-tuning the cyclic position electrically can be used by trimming the Beep switch top hat in the direction required.
I have included a highly detailed Bell 212 cyclic grip. If you have a resin printer, I recommend using this for a smooth finish. For those that do not have access to a resin printer, I might be able to produce them for you at a cost, but this will be a limited quantity due to the time they take.
Please note: I have made the cyclic fitting 25mm so it will fit most aircraft grips, both rotary and fixed-wing. So if you have another type, it should be interchangeable.
There is no complicated software involved, just Mobiflight, and I soon hope to issue the exact file, so you do not have to programme anything. This unit replicates a standard PC joystick, using a Leo Bodnar card to keep things simple. This means it can be used on XP, DCS, P3D and MSFS!
I hope this puts a smile on your face like it did so many at the EXPO in Lelystad, including real-life pilots!
Pre-release right now while I construct the Build/Print and parts guide, which will be added here (if you want to start printing:
The build guide and components list can be found here:
https://www.737diysim.com/build-guides-1/bell-212-heli-cyclic
General Information:

Build Guide

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STEP:
1
Insert the press button into the backplate AW14.

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STEP:
2
After securing the push button with its supplied locknut, place the 3d printed cap AW13 onto the end of the push button.

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STEP:
3
Place the push button assy into the Collective grip RHS AW16.

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STEP:
4
Secre the components with QTY2, M3 x 12mm screws.

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STEP:
5
Insert another push button into the back plate AW17, Secure it with the supplied lock nut.

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STEP:
6
Place the button cap AW12 onto the push button

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STEP:
7
Insert the assembly yinto the RH Coll grip

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STEP:
8
Secure the push button with QTY 2, M3 x 12mm screws.

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STEP:
9
Place the trigger into the RH Grip, Secure the trigger with an M4 x 14mm screw. Ensure the trigger is free to rotate and the screw is not too tight.

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STEP:
10
Place the ultra mini microswitch in position and secure it with QTY 2, m2 x 12mm.

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STEP:
11
Place the M3 brass insert into the orifice and glue into position.

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STEP:
12
Place the LH grip onto the RH grip

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STEP:
13
Insert an M3 x 12mm screw into the LH grip to secure the two halves.

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STEP:
14
The aft hole requires an M3 x 12mm screw, The forward hole requires an M3 x 20mm Screw

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STEP:
15
Insert Qty 3, M4 x 10mm Screws through the Collective end box into the grip assembly.

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STEP:
16
Insert a M4 x 8mm screw into the remaining hole.

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STEP:
17
Place two large toggle switches OFF/ON into the double backplate AW6

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STEP:
18
Place a large ON/OFF toggle switch into the single backplate AW10

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STEP:
19
Place te switch assemblies into position at the rear of the Baseplate AW3

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STEP:
20
Secure the switch assemblies with Qty 6, M3 x 8mm countersunk screws.

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STEP:
21
Insert a push button into the AW3 faceplate on the right lower orifice. Secure it from the rear with its locknut

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STEP:
22
Insert a further two pushbuttons into AW3 and secure them from the rear with their lock nuts.

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STEP:
23
Insert QTY 3, mini toggle switches (momentary)

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STEP:
24
Insert another push button in the upper LH corner orifice and secure it from the rear.

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STEP:
25
Repeat for the upper right orifice.

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STEP:
26
Place the Laser etched faceplate into AW3, available here in the webshop: https://www.737diysim.com/product-page/aw139-collective-faceplate-button-decals
Or please use the LINK button to download the DXF and create the part using your laser.

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STEP:
27
Insert Qty 2 navigation switches.

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STEP:
28
Place the braces over the switches and secure them with QTY 4, M3 x 6mm screws

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STEP:
29
Insert Qty 4, M2.5 x 5mm Screws. These are for aesthetics only.

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STEP:
30
Place the Top hats onto the navigation switches. Light grey to the LHS and Black one to the RHS.

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STEP:
31
Place the AW9 Caps onto the mini toggle switch shafts. Secure them with M3 x 4mm grub screws.

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STEP:
32
Use an M2.5 x 20mm screw to secure the cap on to RHS faceplate lugs.

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STEP:
33
Use a M2.5 x 20mm screw to secure the Hoist cap on the RHS faceplate lugs

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STEP:
34
Feed the wires through the coll boz and grip, lower the faceplate assembly into position and secure with Qty 3, M4 x 16 screws.
