Tuesday, June 15, 2021

737-800 Sim 6dof Motion Platform

Just wanted to highlight Mike's 6DOF platform project and share here his words about it:

Regarding the design of the 6dof Motion Platform:   There is nothing super complex about its design.  It is modeled after the typical hexapod type design.   What is critical however, is deciding on the orientation/layout of the hexapod components.  These factors largely determine the size, complexity, and cost of the Motion Platform system.

I decided to use a Gearbox/Lever system to drive the hexapod actuators.   The main reason for this was ease of construction and low cost.   In my case, I purchased a 160:1 dual-reduction gearbox made by Grove Gear.   This gearbox incorporates a 1st stage Helical reduction, followed by a 2nd stage Worm reduction.  The Worm reduction prevents any “back drive” movement for safety reasons.  These gearboxes are very robust, having about 10 times the needed torque requirement.

Both the Motion Platform structure and the upper Flight Deck structure are weldments made with steel tubing.   The six Actuators are made using thick wall steel tubing, with 1” size steel Rod Ends on each Actuator.   I decided to use a 6” radius for the Actuator Lever on the output shaft of the gearbox.

There are many ways to design a Hexapod, and the approach that I have taken represents just one way of accomplishing the design and construction of a 6dof Motion Platform.  My approach to the design challenge was mainly constrained by my personal resources to build such a system.  Fortunately, I have my own personal machine shop, so machining and welding, etc. was not a problem.  As far as cost is concerned, I have about $15,000 invested in the motion platform material and system components.   This is relatively inexpensive compared to buying a commercial 6dof Motion Platform.   My Motion Platform is more of an experiment to see if I could build such a motion system on a “beer budget” that would yield an incremental level of Sim immersion to give a realistic sense of motion for ground/air flight operations using the 737-800 flight model.   I am very pleased with the results thus far, and I consider the time and cost worth the investment.

The input drive to the gearboxes is accomplished with six Servo motors.  These are very powerful servo systems, with high resolution encoders.  Each Servo motto is rated at 2.2 KW.  The Servo system is controlled by the Thanos AASD-15A Servo Controller, which in my case, is fed by the BFF 6dof Motion Control-software for outputting motion cues from the P3D flight simulator.   The Servo system is so powerful that careful “tuning” of the motion cues are required to prevent radical platform movements and related jolts that can induce extreme shock and vibration into the motion platform and related structures.  

Because people ride in the Sim Cockpit, it is to be considered a “life support system”, with related precautions and safety measures applied anytime the Motion Platform is in a “Powered ON” mode.  This type of setup needs to be taken seriously to prevent injury or worse.  I never work under the Motion Platform when it is powered is applied to the Servo Systems.  When starting and/or shutting down the Motion Platform, I always use a Check List to ensure it is done correctly each time.

I should also mention that when I first started this 737-800 Sim Project, I knew from experience with other big projects, that I wanted to fast-track the Sim build as much as possible.  In that regard, I chose Flight Deck Solutions for all the main Panel instruments and MIP structure.   Flight Deck Solutions are known for their high quality Sim components and systems.  I am proud to be a FDS customer, and from my personal experience, FDS customer service and product reliability is outstanding.

I also purchase the FDS Nose Section and Interior Panels.  All this gave me a huge head start on the 737-00 Sim construction.  Then I got the bright idea to add a 6dof Motion Platform to the Sim.  Designing and fabricating the Motion Platform greatly complicated the Sim Project.  However, I am now in the final stages of building the Sim, and expect to have it fully completer this year 2020.   This has been a 4+ year project.

San Diego, 2021

Thursday, March 18, 2021

Sim Racing Garage PT-Actuator reviews video collection

 Here is a complete list of videos that Barry from Sim Racing Studio made reviewing PT-Actuator. 

PT Actuator 5DOF Motion System Review Part1 "The Build"

PT Actuator 5DOF Motion System Review Part 2 "Electronics/Wiring"

PT Actuator 5DOF Motion System Review Part 3 "Configuring/Testing"

Scorpion Actuators From PT Actuator Review

PT Actuator 6DOF Conversion Review

San Diego, 2021

EMI Filter Guide by John Spanos

 So I just wanted to drop in here and share my fix for EMI and ground loops on my SFX-100+Surge that was causing grey outs when touching my Pimax headset, and also causing my HE Sprints to completely disconnect:

STEP1: get everything you are powering that’s interconnected in a system (sfx drivers, pc, usb hub, etc.) on one outlet. I accomplished this buy putting everything on a 12 outlet power strip that goes back to ONE outlet. Once that’s done, all of your peripherals and drivers are sharing one ground (assuming the outlet you’re using is grounded.... make sure it is) which will reduce the chances of creating ground loops...

STEP2: Make sure you’re using shielded cable or shielded tape on your servo to driver power lines (data line doesn’t need shielding). Mine came shielded, but If yours didn’t, the Thanos AMC  user manual has a detailed procedure for doing it. 

STEP3: Buy yourself the in-line emi filter suggested by Thanos in his guide. Below is the link. It’s a very easy device to install (will explain next), and it will essentially eliminate a lot of the higher frequency noise that causes drop outs on yours system.


Installing the filter.... Basically, all you have to do is instal this device on your main power cable that feeds your drivers...My drivers power cables are all daisy chained, so all I did was disconnect the wires (green,white and black) from ONLY the FIRST driver in the series, and connect them to the LINE SIDE of the filter (see pictures). The top two prongs on the LINE side are for power and neutral (black and white for me in the US). They are bidirectional so it does NOT matter which one is black and which one is white, just stay consistent when you eventually wire in the LOAD side back to the driver. The bottom prong on the LINE side is a ground for your green wire. So far all you’ve done is remove the 3 wires from your first driver, and wired them to the LINE side of the filter...

NEXT, you want to get two pieces of wire to connect the LOAD side of the filter back to the driver where you removed the black and white wires before... I opted not to use color coded (black and white wires) as I had some red 12-gauge sitting there, so don’t panic and get confused. As long as the wire is as thick as the other power wires, it’s not a problem.... throw some spade connectors on them, and wire them into the LOAD side prongs of the filter.

So now you’ve wired in two wires to the LOAD side of the filter, and you’re ready to connect them back to the driver...


Make sure to take note of which of the two top prongs on the LINE side you made black, and which one you made white.... why? Because your about to connect the LOAD side back to the driver, and as we know, the driver has a specific spot for a black (power) wire and one for a white (neutral) wire... you can’t mix this up when connecting the load side to the driver.... So please take a look at my pictures. I made sure to connect the wire on the LOAD side that corresponds with the black wire on my LINE SIDE to the first attachment point on your driver....The second wire on the LOAD side corresponding with the white wire on the LINE side then goes to the spot right below the black wire on your driver. just like it was before you removed them. LASTLY, connect the GROUND on the LINE SIDE to the driver housing. That’s it!  So you’re done.... super simple....All you did was introduce a filter before your first driver. Now all your drivers and everything else on that power strip will have much less EMI. 


STEP4: ground your rig properly.... sand down the anodized finished or drill a fresh hole into your rig (anodized aluminum is a poor conductor), and attach a wire (I have multiple wires because of multiple layers in my rig with surge). Once that’s done, take the other end of that wire(s) and attach it/them to the green ground wire off a male 3-prong power plug you’ve just cut off from a power cable ... obviously you don’t want power (black and white), as your intention is to make a ground plug for your rig, so you’ll either need to cut the white/black out and tape the ends off with electrical tape, or just remove the prongs associated with those two wires from the plug entirely, and just leave the green wire/ground on the plug. Congratulations, you’ve just made yourself a ground plug you can literally plug into THE SAME POWER STRIP as all you’re other stuff, and ground your rig. Your rig is now grounded using the common ground from your outlet that all your other stuff is using. Do not ground your rig on the drivers! It’s a noisy ground and it’s not as good as the aforementioned method. 

You’re all done! Enjoy your rig without dropouts and grey outs...

By John Spanos



Confused a bit? Take a look on this video to see a bit more clear the wiring:

And see this video with results of the measured EMI after using the line filter:

Tuesday, April 28, 2020

Friday, March 20, 2020

Business continuity update regarding the COVID-19 situation

Hey guys, I'm not sure anyone takes it seriously, but the covid-19 is airborne, and unless everyone stays home in isolation for 15 days atleast, there is going to be millions getting infected if not already in the United States... I still see people out and about walking, jogging, taking their whole families for a stroll in the streets, despite the Shelter in Place mandate here in California by the Governor. Its going to get real ugly here... therefore I'll be unable to ship out any orders, and placed for now my Tindie store in vacation mode for a while. I hope you all understand this is serious. I'll be here to answer questions or further develop on firmware etc. Take care people!

Wednesday, December 4, 2019

Open-hardware 4DOF servo controller solution

If you have one of these SFX100 4DOF platforms but no way to connect them to Simtools or FlyPT mover motion software, here is solution I designed for a DIY 4DOF controller that matches the 100mm actuators hardware. Its free and its plug and play (once put together).

I only provide plans (gerber files) and firmware for the device, and no support. Don't ask me about it, I don't build it or sell it. You will have to collect the parts for it. Its totally DIY. This free controller has some limitations but still its plug and play, no need to setup anything, all settings are in the firmware. The only extra parameters needed in the AASD-15A drives are the following:
Pn24 = 100
Pn52 = 1
Pn60 = 2
Pn61 = 6

There is no restriction to use it or copy it or modify it to your needs. Feel free to improvise! Heck, you could probably use two of them, and use the second for Traction loss, or active seat belt , or a g-seat... A small modification of the electronic gear would allow such use if you need less turns of the motor etc. Simtools and FlyPT support multiple interfaces!

For more information on the open-hardware-servo-controller see the Github page here:

The limitations/features of the AMC-Open-Hardware-4DOF-Shield are:

  • 4DOF only
  • 100mm stroke
  • 45kHz pulse rate (max motor speed 2500RPM)
  • 800 times per second updates (3ms delay in Simtools or FlyPT).
  • No LCD or encoder for parameters adjustment
  • Only two manual move test buttons
  • Only e-stop that disables the servos
  • Supports automatic calibration of the actuator (No need to stand up feet together on your actuator, to make sure its positioned all the way down before power up!!!)

In contrast the AMC-AASD15A servo controller has:

  • Supports up to 7 servos (7DOF)
  • Fully detailed LCD menu system
  • up to 2500mm stroke support
  • adjustable stroke, leadscrew, actuator type inline/foldback
  • Belt ratio calculation option
  • Support for rotary actuators
  • 200kHz pulse updates
  • 2000 times per second updates (latency as low as 1ms in Simtools)
  • Platform Check safety option
  • E-stop, Park/Standby, Force Offline buttons and switches
  • Automatic calibration without limit switches
  • Remote parameters via PC software interface or Terminal.
  • Rolling Average Filter for anti-vibration pulses on the servomotor
  • Spike Filter to automatically eliminate jolts from non-linear motion cues 

San Diego, California
USA, 2019