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

Lebois · Aug 8, 2019

Hi all ! I already own a 2dof sim motion rig based on two 12nm stepper motors.
I am struggling to make the motors work at their full potential.
I am interested by the opensfx build which seems compatible with my motors with little changes ( i currently use an arm system).
But I am surprised by the torque of the 90st motors : only 2.4Nm...
So :
1)How 2.4Nm can lift a rig ?
2)Would it be really interesting to use servo motors instead of my steppers ?

diablo2112 · Aug 8, 2019

The SFX servo motors plus 1605 ball screws are very, very powerful. More than enough to bounce your whole rig around. No way I can run this system using raw telemetry and 100% mapping to the full actuator stroke. It feels like a shopping cart at 180mph on a cobblestone road under such conditions, and would break my rig-mounted monitor in no time.

Like with every motion system, less is more. Careful tuning of motion parameters, and you get a fantastic, powerful, tactile full motion system with the SFX actuators capable of simulating the most minute road deviations and nuances (especially with laser-scanned tracks). Much like the OSW wheel setups, no-one runs these at full power. Huge overkill there.

HugoB · Aug 8, 2019

diablo2112 said:
The SFX servo motors plus 1605 ball screws are very, very powerful. More than enough to bounce your whole rig around. No way I can run this system using raw telemetry and 100% mapping to the full actuator stroke. It feels like a shopping cart at 180mph on a cobblestone road under such conditions, and would break my rig-mounted monitor in no time.

Like with every motion system, less is more. Careful tuning of motion parameters, and you get a fantastic, powerful, tactile full motion system with the SFX actuators capable of simulating the most minute road deviations and nuances (especially with laser-scanned tracks). Much like the OSW wheel setups, no-one runs these at full power. Huge overkill there.

Double agree.

The SFX100 system is overkill for its purpose. I always have to add smoothing and some acceleration dampening, otherwise I feel like my eyeballs will vibrate out of their sockets, especially in F1 cars.

I like equipment that is over engineered for its purpose though

just like the OSW motor. It gives me confidence that it will last a long time. Add to that the DIY nature, it means I will also be able to repair it myself. Combine these two characteristics and I get years and years of guaranteed fun!

And if in 10 years my motors stop working and they are no longer produced, I can redesign the 3D printed motor mounts to use different motors

NeedforSim · Aug 8, 2019

Ringorian said:
You need to play with the Servo Controller P98

You can try it without the Ball screw attached and count the rounds the Motor does .. For 10 cm you need 10 Rounds with a 1610 / 20 with a 1605

I didnt tried it since i have no 1610 or longer strokes .. just guessing

- Check what happens when you reduce the P98 to 10 .. i thinks you get half the stroke (~5cm)
- with a 1610 Ball Bearing reduce P98 to 10 with the standard stroke could do the job
- Stroke 150 mm could be P98 to 30 with 1605
be carefull and reduce speed when experimenting .. but the good thing is that the plastic parts are cheap to change with a printer

I agree, I said the same in this thread: https://www.racedepartment.com/thre...simulator-thread.159524/page-130#post-2917772. The problem with this approach is the loss of encoder's resolution that could affect cues's fidelity because Simfeedback software has burn into the code the SFX-100 actuator fisical specs. In other hand, you would need more stroke for flight sims. Actually Simfeedback just support some cues in DCS.

Lebois · Aug 8, 2019

diablo2112 said:
The SFX servo motors plus 1605 ball screws are very, very powerful. More than enough to bounce your whole rig around. No way I can run this system using raw telemetry and 100% mapping to the full actuator stroke. It feels like a shopping cart at 180mph on a cobblestone road under such conditions, and would break my rig-mounted monitor in no time.

Like with every motion system, less is more. Careful tuning of motion parameters, and you get a fantastic, powerful, tactile full motion system with the SFX actuators capable of simulating the most minute road deviations and nuances (especially with laser-scanned tracks). Much like the OSW wheel setups, no-one runs these at full power. Huge overkill there.

Thanks a lot for your Quick reply !
I only can agree with you ! Opensfx 100 seems really really awesome !
Otherwise you didn't reply directly to my questions IMO ^^.
2.5 nm isn't very tough so I wonder how it's possible (i own a direct drive wheel based on a 80st that output 4 Nm)...

Tronicgr_6DOF · Aug 8, 2019

Lebois said:
Thanks a lot for your Quick reply !
I only can agree with you ! Opensfx 100 seems really really awesome !
Otherwise you didn't reply directly to my questions IMO ^^.
2.5 nm isn't very tough so I wonder how it's possible (i own a direct drive wheel based on a 80st that output 4 Nm)...

You missed that the SFX100 uses a leadscrew 1605 pitch... its like a linear reduction gear. It not used direct like yours.

Lebois · Aug 8, 2019

Tronicgr_6DOF said:
You missed that the SFX100 uses a leadscrew 1605 pitch... its like a linear reduction gear. It not used direct like yours.

Ok that's what i was thinking. Any Idea of which ratio it gives ?

HugoB · Aug 8, 2019

Lebois said:
Thanks a lot for your Quick reply !
I only can agree with you ! Opensfx 100 seems really really awesome !
Otherwise you didn't reply directly to my questions IMO ^^.
2.5 nm isn't very tough so I wonder how it's possible (i own a direct drive wheel based on a 80st that output 4 Nm)...

The motor isn’t lifting your rig directly, it’s only turning a ball-screw type gear at 3000rpm, this lifts your rig. This way the gear ratio helps that 2.5Nm (which is continuous holding torque btw, it’s peak torque is 7.15Nm!), translate to a lifting weight of around 200-250Kg per actuator! Which has been confirmed many times, showing gigantic rig constructions with tripple screens, heavy tactile transducers everywhere, all kinds of stuff attached and you still need to limit the SFX100 power, it hasn’t changed it’s speed or raw power. So you will probably never realistically get to it’s limits, unless you plan to use a real car cockpit as rig?

diablo2112 · Aug 8, 2019

The ballscrew diameter is 16mm (the "16" in 1605, while the pitch is 5mm (2 threads/cm), the "05"). A 2.4 N-m motor, using a 0.15 coefficient of friction for steel/steel (greased or oiled, the range is 0.11 to 0.17), gives about 270 pounds of raising force. That's PER ACTUATOR.

You can confirm this result using a ballscrew torque calculator, like the one found here: https://www.daycounter.com/Calculators/Lead-Screw-Force-Torque-Calculator.phtml

A ball screw is an extremely effective torque multiplier. The SFX-100 system is capable of lifting about 1100 pounds continuously, and over 3000 pounds for brief periods, using the specified 2.4 N-m motors.

Lebois · Aug 8, 2019

diablo2112 said:
The ballscrew diameter is 16mm (the "16" in 1605, while the pitch is 5mm (2 threads/cm), the "05"). A 2.4 N-m motor, using a 0.15 coefficient of friction for steel/steel (greased or oiled, the range is 0.11 to 0.17), gives about 270 pounds of raising force. That's PER ACTUATOR.

You can confirm this result using a ballscrew torque calculator, like the one found here: https://www.daycounter.com/Calculators/Lead-Screw-Force-Torque-Calculator.phtml

A ball screw is an extremely effective torque multiplier. The SFX-100 system is capable of lifting about 1100 pounds continuously, and over 3000 pounds for brief periods, using the specified 2.4 N-m motors.

Oh thanks a lot !
I will think about it, an probably start by mounting my stepper motors on that système !

Stevie_007 · Aug 8, 2019

Has anyone extended their 25pin d cables, are they just standard parallel cables, thinking of extending mine

metalnwood · Aug 9, 2019

Lebois said:
Oh thanks a lot !
I will think about it, an probably start by mounting my stepper motors on that système !

I don't know what steppers you have but they do behave differently than servos. While you can certainly attach them to the sfx actuators there is no guarantee that the sfx software will work with them if that is your intention. The SFX can move the actuators at a speed similar to many commercial systems but that is at 3000rpm. A stepper generally loses torque at the high speeds. So it's a case of your milage may vary if you go that way. If you just plan to use the SFX actuators for the mechanical part of your project and other software to drive them then there no doubt other options.

Lebois · Aug 9, 2019

metalnwood said:
I don't know what steppers you have but they do behave differently than servos. While you can certainly attach them to the sfx actuators there is no guarantee that the sfx software will work with them if that is your intention. The SFX can move the actuators at a speed similar to many commercial systems but that is at 3000rpm. A stepper generally loses torque at the high speeds. So it's a case of your milage may vary if you go that way. If you just plan to use the SFX actuators for the mechanical part of your project and other software to drive them then there no doubt other options.

I am using simtools and an Arduino to drive the stepper motors. It's 12n.m so it has enough torque. It's slower than a servo motor but not that much...
I will do the test. If it doesn't work, i will upgrade to the servo motor and simfeedback software.

metalnwood · Aug 9, 2019

Thats fine then, the SFX actuators have proven themselves to be good so if you have another working way to drive them then they should stand up well

Mascot · Aug 9, 2019

I might finally find time this weekend to ditch the electric spaghetti and install my SFX-100 shield. It's been aaaaaages since I got it, so... anything I need to know (or will wish I'd known) before doing the swap?
Planning on relocating the drivers at the same time as they're still in the cooler box that I jerry-rigged in a failed attempt to reduce the coil whine.

ThugUK · Aug 9, 2019

The only thing that you need to know is that you will kick yourself for not doing it earlier.
Its now plug and play.

Dave_6 · Aug 9, 2019

Got the ball screws and bearings in yesterday, quicker than I expected to. Now I need to order the motors. Anyone know anywhere else I can get those D-25 D-Sub cables from other than Monoprice? I keep checking and they haven't had any for a while and no ETA either.

diablo2112 · Aug 9, 2019

Amazon has tons of venders with M/M DB25 cables. 3ft, 6ft, 10ft, whatever you want. Most are prime, 2-day delivery.

Here's just one. https://www.amazon.com/Feet-Parallel-Serial-Cable-Certified/dp/B00P2VJ09O/