hc625ma's cozy hangar

I am happy to show you yet another Simchair MKIV device – the Bell 206 style collective head. Its made from photos with measurements, so it should be almost exact 1:1 scale.

To make GOV RPM switch look scale, I’ve made a special adaptor for MTS-123 E1 switch. Another option is to use a regular 12mm spring-loaded SPDT switch for GOV RPM control. Small parts need to be printed at the highest possible quality and have built-in supports.

I will also be releasing a scale 206-style version of throttle frame part 1 with 104 degrees throttle grip travel range, as per information from an IRL 206 pilot.

This head is best to be used with MKIV collective with a physical throttle latch. Will release firmware for it in a few days =) You can find it in simchair4_models repo on GitHub.

Finally, after months of testing, all problems are addressed, and the new cyclic is here – and it feels great! Here’s the video which shows the new base up close – and then there’s a test ride in an epic freeware Hughes 500 for XPlane11 by Brett S – which is a pure joy to fly!

I have been able to calibrate my printer in a perfect way using a micrometer recently, and found that some clearances between certain parts may be too wide. That made me think that maybe we need to adjust models for a perfectly calibrated printer. Right now it seems that everything is tuned for a slight over extrusion.

There are a few problems that worry me:

1. How to reliably calibrate any printer? – We can use a method of calibration that assumes using a micrometer to measure the wall thickness of a calibration cube model printed in vase mode.
2. How will tuned extrusion affect durability? What needs to be changed in print settings? – This requires testing.
3. Is there a problem with an average factory-made printer at all?

So I decided to make a poll, if you’ve built something and used PLA for that, please select one of the options and write a comment about your experience. The comment part is important – because otherwise, I wouldn’t be able to distinguish real builders from bots.

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I am happy to tell that our nice documentation wiki grows every day. Our awesome DIY community helped me to port MKIII docs, so now we finally have MKIV collective build process completely documented! The first lever body added is the most advanced one – single collective body with a physical throttle latch. If you need other lever bodies, just use this one as a reference.

You can find all of supported (and planned for now) MKIV hardware modules on the modules list page of the wiki. If you’re here for the first time and want to know more about the project, please visit the start page.

I have adjusted MKIV menu on the site accordingly.

The first MKIV variant of this head is a generalized device – it has 8 spring-loaded switches in it. This means, with the mode switch, we can use 3 sets of 19 joystick buttons each!

The head itself was updated to MKIV standards – it features 2 Ethernet sockets and an MCU RST button for easier flashing. The former mode switch on the side of the head no longer works as one (we have it on the base now!) but is left in place for generic purposes (e.g. gear, floats, etc, why not!). The 2-pot version is now a default one. Expect an updated manual soon!

Joy button presses on middle positions of the switch and non-spring-loaded switches support are not yet implemented, will be adding those a bit later.

Do you guys use MKIII switch modes and non-spring-loaded switches in your heads, or do you prefer a more generic approach of having a lot of joystick buttons instead? Please let me know in comments =)

I have noticed a few bugs in DCS compat mode and fixed it. Also, I decided to pair it with “BUTTON_PRESS_ON_THROTTLE_CUTOFF” option, which from now on must be enabled for the Huey compat mode to work. Here are a few notes about it:

• IDLE REL joystick button (compact coll. head joystick button 5 by default) MUST be assigned to the corresponding button in the sim!
• connect your Simchair with closed throttle. In this case, no additional actions are necessary =)
• if you are not sure, before starting the helicopter, open the throttle past the detent mark, press and hold the IDLE REL button (red button on the compact collective head by default), and close the throttle. When you will turn the throttle grip to the left, the firmware will then send PgUp button press to open the throttle from “fully closed” position.
• DCS Huey compat mode only works in the middle position of the mode switch, this allows you to avoid sending PgUp / PgDn keys when you close the throttle in other sims, without disabling compat mode in the firmware each time.
• sadly, with the way it’s implemented in DCS, precise control of throttle below the idle stop detent is not possible. Therefore, for maximal realism, perform the startup with GPU connected. With external power supply connected, you can be sure that the battery won’t die during the startup and you will have enough power to open the solenoid driven throttle latch of the Huey. That allows you to perform startup at flight idle position of the throttle. Without GPU, the startup is usually performed with the throttle pushed slightly below the idle stop detent.
• Before closing the throttle, take a look at the state of the virtual IDLE REL button in the cockpit. If you have accidentally pressed it in flight and the virtual one is pushed in, just press it once more before shutting down the engine.

And a simple guide on how to use it:

1. open the throttle past the detent, press and hold IDLE REL, close the throttle.
2. perform the startup as described in the Flight Manual.
3. prior to shutting down the engine, check the virtual IDLE REL button state. If you see it pushed in, press the IDLE REL button once more to depress the virtual one.
4. to close the throttle completely, press and hold IDLE REL button on your collective and close the physical throttle. The virtual grip will follow.

Enjoy!

A couple of cool features have been ported to the compact collective:

• DCS Huey compatibility mode
• joystick button press on throttle cutoff
• secondary axis stabilizer – adjustable noise filter for potentiometer driven axes
• bug with incorrect button modifiers fixed for both pedestals

I think we can safely say, that with these features added, the compact collective is now complete. Here’s how it behaves by default at the moment:

• DCS Huey compatibility mode is turned on by default. That means, that when advancing throttle from full-right (closed) position, up to idle detent mark, keyboard button for throttle up key will be pressed (PgUp by default). After the mark, regular axis movement will be performed. To close the throttle completely (past the idle stop detent) you need to press the right push button on the compact collective head, which is set up as an IDLE REL button. This button won’t be pressing any joystick buttons when configured as IDLE REL button. If you don’t press the button before advancing the throttle past the idle stop mark, the virtual grip will stay at flight idle. You will have to move the grip back to the detent, press the IDLE REL button, and then close the throttle again.
• joy button press on throttle cutoff is turned on by default – that means that if IDLE REL button has been pressed before closing the throttle, a joystick button (3 by default) on the collective joystick (note that, not the head, but the collective!) will be pressed when the throttle will reach full-right position. This is very useful for XPlane helicopters (like DF 407, for example).
• secondary axis stabilizer is a very simple “digitizer” for potentiometer-driven axes. It allows for setting the minimal axis movement required to register a change in an axis. This kills the jitter completely and does not affect precision for stuff like throttles, zoom, and other secondary stuff where super precision is not really required. Can be set up on per-device basis depending on your potentiometer state =)

You can download the latest firmware from simchair4_software repo on GitHub.