The SimFeedback-AC DIY Motion Simulator thread

sjb266 · Sep 17, 2018

Hey guys. Thought I’d create a thread for those taking the plunge into this brilliant DIY project..
I will be starting mine soon and I know there are others thinking about it.. so feel free to share your knowledge and experiences so we can all enjoy this platform to its full potential. A huge thanks to the developers who have really knocked this one out of the park!

Website: https://opensfx.com/2019/02/20/welcome-to-our-new-site/

Github: https://github.com/SimFeedback/SimFeedback-AC-Servo/wiki

For all the internals for the actuator contact Amy - skye@ntl-bearing.com
She can supply everything you need. Just remind her you want the ends of the shafts chamfered and make sure she sends the right sized ball screw - we have had a couple of issues reported. She is very helpful though and the cost is pretty good.

Huge thanks to @RowanH for writing a comprehensive user guide which can be accessed here - https://www.rowanhick.com/sfx-100-build-and-running-guide

In addition, @anton_Chez has contributed a list of post numbers for some of the important settings etc..
Post #320 SFX-100 thread
Post #327 SFX-100 thread for Discord correlation
Post #339 SFX-100 thread
Post #418 SFX-100 thread
Post #424 SFX-100 thread
Post #439 SFX-100 thread
Post #449 SFX-100 thread
Post #517 SFX-100 thread
Post #554 SFX-100 thread
Post #580 SFX-100 thread
Post #826 SFX-100 thread
Post #837 SFX-100 thread
Post #864,866,867,868,870,887,889,897 SFX-100 thread
Post #911,914 SFX-100 thread
Post #988,992,998 SFX-100 thread
Post #1147 SFX-100 thread
Post #1492 SFX-100 thread
Post #1511,1517 SFX-100 thread

I will try to keep this page updated with links to source the parts in other parts of the world. Just post whatever links you have and i'll add them here.

Please note: Not all the parts listed below are essential for the project. For the essential parts refer to the original shopping list.

Australia:

Thanks to @AussieSim for the following links:

10A power lead(s) * 4
https://www.jaycar.com.au/2m-black-mains-extension-lead/p/PS4152

Top quality wire stripper
https://sydneytools.com.au/product/boxo-cutws205-multifunction-wire-stripper

RCD/safety switch power block
https://www.bunnings.com.au/arlec-4-outlet-heavy-duty-portable-safety-switch_p4420028

WD-40 lithium grease for the ball screws
https://www.bunnings.com.au/wd-40-specialist-300g-high-performance-white-lithium-grease_p6100408

Vibration pads
https://www.bunnings.com.au/whites-on-site-100-x-12-5mm-rubber-anti-vibration-mat-4-pack_p3961547

WD-40 Dry PTFE spray for the slider (free shipping)
https://au.rs-online.com/mobile/p/lubricants/7577134/

Arduino Leonardo (free shipping + frequent 10-15% off discount)
https://www.arrow.com/en/products/a000057/arduino-corporation

DB25 cables * 4 (free shipping)
https://www.arrow.com/en/products/ak401-2/assmann-wsw-components-inc

PETG * 3 (free shipping)
https://www.arrow.com/en/products/petg17bk1/mg-chemicals

WAGO-like connectors to avoid a breadboard (perhaps use genuine ones if you are doing 240V AC)
https://www.aliexpress.com/item/32906719488.html

D-Sub breakout boards * 4
https://www.aliexpress.com/item/32297675967.html

3D printer Creality Ender-3 Pro
https://www.aliexpress.com/item/32918302452.html

Wires from Arduino to D-Sub breakout (remove black plastic from the WAGO end)
https://www.aliexpress.com/item/32887680826.html

Crimp connectors for AC wire leads
https://www.aliexpress.com/item/32813550981.html

acekrusty23 · Apr 11, 2019

Furnace Inferno said:
Well ****, I reprinted a slider with an adjusted deeper linear bearing hole mount to accommodate my longer one, everything now up and running and mounted fine.

Fire up my Accuforce, fire up the buttkickers, press start on the six profile rig lifts up to correct height, oh yes. USB disconnect sound , Accuforce wheel has disconnected .

Played it with an Xbox controller on the projector to my right but couldn’t really get a feel for it driving like that!

So what is the best way to resolve this I’ve seen on the previous page about ferrite cores, where and how many? What else can I do?! It only seemed to be the Accuforce having issues and the power/data cable from the motor goes right past the the front left actuator so perhaps that is th issue.

I was also having major issues with WiFi but not sure if that was the them or an internet issue at the time but it miraculously was fine once I turned off the servos at the plug.

Route the AF cables away from actuator, ground your rig and AF. I have grounded my 80/20 rig direct to power point, 4yrs ago no dramas at all. I’m using a xboxone x controller charger cable for usb, and again no disconnects.

Tim Palmgren · Apr 11, 2019

Quick question for anyone lurking in the thread at the moment...

Is the consensus a small server rack cabinet as the primary means for hiding away the Servo Drivers? I would ideally like to have them hidden away from any enquiring hands or paws, ideally with a key.

RowanH · Apr 11, 2019

Yep with a bit of airflow in it.

sberns · Apr 11, 2019

I was thinking of something like this:
https://www.amazon.ca/dp/B07BFRPWV5...1IDRNLKKUPSPQ&psc=1&ref_=lv_ov_lig_dp_it&th=1

And airflow will come from the holes I will cut for the cables

Tim Palmgren · Apr 11, 2019

@Steve Bernstein This was the type of thing I was considering https://www.trademe.co.nz/home-livi...70.htm?rsqid=6467f37704eb4cef9e9a430a3053974c

Flag Ghost · Apr 11, 2019

I'm just sticking all of my electronics including SFX controllers, OSW controller, 110>220v converter, PSU's, bass shaker amp, etc.. in this..
https://www.amazon.com/gp/product/B01I48EKR8/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

sberns · Apr 11, 2019

Tim Palmgren said:
@Steve Bernstein This was the type of thing I was considering https://www.trademe.co.nz/home-livi...70.htm?rsqid=6467f37704eb4cef9e9a430a3053974c

That looks like a great option as well.

Tim Palmgren · Apr 11, 2019

@Flag Ghost that was pretty much what I was thinking though the one I was looking at seems to lack the wheels.

Im thinking 12U should be enough. The other question is whether there is enough clearance to be able to line the inside panels with some damping material? Or based on opinions here it is unlikely you can deaden some of that 10KHZ noise? I am not too worried about it but I figure if I can line the inside of the panels it seems to make a difference on my computer cases so would expect it must make SOME difference for a rack case like this?

Mascot · Apr 11, 2019

saxxon66 said:
High Pitch Tone

It's a shame that you guys are going to help in this regard, but not having all the info, we found out about this before.

I think if someone is going to address this issue here, he is in charge to inform you about all what we (a lot of people tried helping before) did found out. This did not happen so I will do it now.

Sound level

This System produce a high pitch tone in the 10 kHz frequency.
We have proved this by using PC and mobile applications to record and analyze the spectrum and pressure. It shows the tone is spot on 10 kHz and about 30 db.
Most of us can hear the tone, but even it is not not comfortable, we can ignore it while using our motion simulator, because of the low sound pressure, sound coming from our games and the simulator mechanics.

I do know two (2) people (this is 1-2% overall) who can not stand this tone, and therefore can not use their simulator, as they like, because of this.

Sound origin

The Servo Controller is using a current control loop to control the torque in a servo motor by manipulating the pulse-width modulator (PWM) outputs that drive an inverter.
The motor currents are monitored and fed back to the current-loop controller and the controller updates the PWM outputs if necessary.
Typically the PWM carrier frequency is in the 10 kHz frequency range.
See: http://www.ti.com/lit/wp/swpy031/swpy031.pdf for more information about this subject.

This is the frequency you will hear if you enable the Servo Controller we use.

It is not related to the Arduino controller, because if you remove one variable out of the equation (Arduino) and the result (tone) is the same, you have proofed that it is not related to this one variable.
This is what we have done. By using the position control Jog method of the Servo Controller, you can hear this tone w/o any Arduino attached to the Servo Controller.
Btw. the Arduino uses PWM too but in a much higher frequency range (~200 kHz).

Sound emission

We opened the Servo Controller to find out what part is going to produce this tone.
View attachment 300744

By measuring the sound level by holding a mic near to the components, we found a relay to be the most likely cause of this tone. A quick test by wrapping this part with some tape for isolation showed a change in the tone.
View attachment 300745

The next step would have been to desolder this component and re-solder it via cables to prevent the transmission of vibrations.
At that point, we stopped further investigation because we exceeded a point that could lead to serious injury if anyone were to follow these steps.

We are of the opinion that even if we were to identify the component, it would not be a solution to change the internal structure of the servo controller for safety reasons.

Am I affected?

Like I said before, most of us can hear that tone.
People that are sensitive to higher pitch tones have stated that they can hear the sound even watching videos.
So try to watch videos showing the SFX in action, find a reference sound level (spoken words, ...) and tune the volume. By listing to the video you can estimate if you are effected or not.

Solutions

There is no real solution to stop the Servo Controller producing that tone.

Easiest solution: Use headphones

Other Solutions:

- Use in ear filters
https://www.racedepartment.com/thre...simulator-thread.159524/page-200#post-2948113

@saxxon66 I don't think it's quite that simple based on my own experiments. I put my drivers in a sealed cooler box to deaden the sound and it made no difference to the noise, but the volume was vastly reduced when playing a very similar-sounding 10kHz signal on my phone and putting that in the same box under the same conditions. This strongly indicated to me that the sound wasn't coming from the actual drivers in the box, but from a source outside the box. I posted about it a few weeks ago.

https://www.racedepartment.com/thre...simulator-thread.159524/page-192#post-2944068

PandaNL · Apr 11, 2019

@Tim Palmgren The other part was not on the picture, the fan needs 12v DC adapter and can be connected to this board with a 4 pin fan header. I want to use Noctua A14 3000rpm PWM fans for this.

Insert Coin · Apr 11, 2019

@PandaNL, FYI: an airflow straightener is highly recommended. See https://www.racedepartment.com/threads/easy-diy-wind-simulator-for-assetto-corsa.133999/

PandaNL · Apr 11, 2019

@Insert Coin: Yep I made one in fusion 360 to be 3D printed.

BrassEm · Apr 11, 2019

Does anyone have dimensions on their server rack installations? It is definitely the way I want to go to mount the servo drives and boards etc, but all the rack distributors I've contacted only have the outer dimensions and that is all. It would be nice to know the internal spacing to get a handle on fitting it all in.
(This would be another argument for having separate threads on the SimFeedback subject.)

anton_Chez · Apr 11, 2019

Had some weird issues last night and then tonight on a race night. My HE Seq Shifter gets knocked out of AC when there is a bump on a wall or another car while motion is running. NEVER had this before and now I have to muck around finding out what's causing it. I've ran this combo how many times now, I can't even remember, it's been a lot. It's very strange. The shifter is still recognised by the PC but I have to restart AC to get it back. It's super stupid.

Vantskruv · Apr 11, 2019

My USB-hub is comitting suicide when the motors starts running. Moved it to another place, of course an awkard place to make everything harder, and the problems disappeared.

I have ordered a netfilter and will go buy some ferrit-cores, and do some smart cable-placement.

anton_Chez · Apr 11, 2019

Yeah I just discovered that the ports that are getting knocked out are connected to the PCI hub I bought for more USB ports. I wonder if there is an issue with that? Might not even be related to the SFX-100. I have to do more testing.

HugoB · Apr 11, 2019

Vantskruv said:
My USB-hub is comitting suicide when the motors starts running. Moved it to another place, of course an awkard place to make everything harder, and the problems disappeared.

I have ordered a netfilter and will go buy some ferrit-cores, and do some smart cable-placement.

Some ideas that might help:

- Try installing Ferrite rings on all USB cables that are in the vicinity of your SFX100 actuators. Install them on both ends of the USB cable, as close to the plug as possible:

5mm diameter Ferrite rings are good for most USB cables and can be bought cheap on Amazon or Ebay. It might work or it might not, but they are designed to block airborne EMI signals (being received by your cables like an antenna) to enter your electronics.

- Install an EMI filter before your SFX100 actuator control boxes. Get a Schaffner FN2070-16-07 and wire it up like this:

- Get a proper externally powered USB hub with enough power to power everything

- Keep USB cables away from your SFX100 motor cables

- Ground your devices

- Try different USB cables, try different ports

- Try USB 3.0 cables or USB 2.0 cables, USB 3.0 hub, or USB 2.0 hub, mix everything up as much as you can, until it works.. But not before you have installed the EMI netfilter and the Ferrite rings, otherwise you'll never know if it was the cable or the position or the port or the vicinity to the actuators.

- Disable power management of USB ports in Windows power management

- Try a PCIe USB port card with it's own power supply from the PC's PSU.

- Pray to Undluchara, the god of USB (make an offering, sacrifice a virgin USB cable)

Vantskruv · Apr 11, 2019

I cannot find Undluchara on google.

saxxon66 · Apr 11, 2019

Mascot said:
@saxxon66 I don't think it's quite that simple based on my own experiments. I put my drivers in a sealed cooler box to deaden the sound and it made no difference to the noise, but the volume was vastly reduced when playing a very similar-sounding 10kHz signal on my phone and putting that in the same box under the same conditions. This strongly indicated to me that the sound wasn't coming from the actual drivers in the box, but from a source outside the box. I posted about it a few weeks ago.

https://www.racedepartment.com/thre...simulator-thread.159524/page-192#post-2944068

Simple, what do you mean by "not quite that simple"?

Like Pyronious said,

"... I would be surprised if that relay on the PCB is the only component responsible for the noise - it is simply the most noticeable. With this much power being switched, there are likely going to be sympathetic vibrations throughout the system, including the motors, cables/chokes, etc. Very difficult to isolate.
..."

It is likely that there are more components involved.
I described the cause and origin of the sound.
The vibrations will travel and will be emittied by connected components.

Like in the linked document from my post, and described by Pyronious, higher frequency drivers and FPGA will resolve this issue.
But it all comes at its cost.

"...
To increase the bandwidth, some drive systems
increase the carrier frequency to 30 kHz or higher,
which can increase the current loop’s bandwidth but
will also increase the inverter switching losses and
demand higher processing performance from the
digital control system. A higher switching frequency
requires increased gate-drive power, which then
increases the size and complexity of the system’s
power supply. Plus, the higher switching losses will
mean additional heat dissipation, necessitating more
extensive thermal-management strategies such as
larger, heavier and more expensive heat sinks, fans
or coolants.
..."

And not only technical costs even real $ costs.

ScottSonder · Apr 11, 2019

Furnace Inferno said:
Well ****, I reprinted a slider with an adjusted deeper linear bearing hole mount to accommodate my longer one, everything now up and running and mounted fine.

Fire up my Accuforce, fire up the buttkickers, press start on the six profile rig lifts up to correct height, oh yes. USB disconnect sound , Accuforce wheel has disconnected .

Played it with an Xbox controller on the projector to my right but couldn’t really get a feel for it driving like that!

So what is the best way to resolve this I’ve seen on the previous page about ferrite cores, where and how many? What else can I do?! It only seemed to be the Accuforce having issues and the power/data cable from the motor goes right past the the front left actuator so perhaps that is th issue.

I was also having major issues with WiFi but not sure if that was the them or an internet issue at the time but it miraculously was fine once I turned off the servos at the plug.

Well, glad you're running mate.. Your cable management probably isn't helping your situation at all. I had no EMI problems when I was using the AF with the SFX, and I hadn't done anything special with ferrites or anything.

Obviously our setups are entirely different and it could be a number of things, but if you clean up your cabling, you might not have any issues. Don't let your AF USB run over your servo motor wires, etc.

@ThugUK Don't worry about anything until it becomes a problem.