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

RowanH · Mar 27, 2019

Buying a 3d printer was the best thing I ever did. Problem #34 solved with the 3d printer, went to mount screens to their VESA brackets... What do you know the brackets are too large to sit flush against the monitor. Solution - print spacers !

Mascot · Mar 27, 2019

Furnace Inferno said:
I would liken the the sound to being in a field with grasshoppers/crickets. Not overly annoying to me but it’s very distinctive, if I was watching a movie or just say in the room it would really annoy me but for its purpose meh not fussed.

Can anybody help with my question on how to detach the motor with the coupling from the ball screw side to tighten it, what’s the technique?

Not sure exactly what you mean, but the coupler just pulls apart with a little force if you want to separate the motor and the ball screw. There's a (red?) plastic 'joiner' (for want of a better word) that pulls apart/goes together with an interference fit. I can't remember if anything needs loosening for this to happen, but it surprised me when it happened during my assembly.
(This is with the 'official' DOLD couplers, not sure if others are the same).

Pyronious · Mar 27, 2019

Furnace Inferno said:
Can anybody help with my question on how to detach the motor with the coupling from the ball screw side to tighten it, what’s the technique?

I inserted a flathead screwdriver into the access slot and gently twisted to push the two halves of the coupling apart. This will get them partially separated, complete separation requires a little bit of wiggle, but not too much. Don't want to crack the plastic friction fitting.

Ringorian · Mar 27, 2019

sebna said:
Good to know I am sensitive to both 5k and 10k spikes - my other hobby is audio. I sell / return all audio gear which has spikes in those frequencies

No SFX-100 for me until it is resolved either with sound dampening or with proper addressing

Great find guys.

Its a difference if you watch TV with that spike (maybe 40db at 10000hz) or listen to calm music and have that spike or if you sit in your motion rig and have sound of the car on speakers or on headphones .. you will hardly realize .. not here to pull you over, just to make clear why the most can live with it in this case ..
as i wrote in some other thread .. i had a plasma tv doing this, it began to feep because of the psu and i bought a new tv .. 3 other people didnt even hear that feep ... but it was a tv and mostly i got crazy on calm tv shows ... If simracing would be a calm tv show i would go also crazy

HugoB · Mar 27, 2019

I don’t hear it anymore as soon as I put my Rift headphones on, even on very low volume. My wife is sitting 2 meters away watching TV and she hasn’t even mentioned it yet

But it is very clearly audible in a quiet room. I’d love to get rid of it, but since it’s so low dB it won’t do any harm and I can live with it. The fans of my Buttkicker amps are much louder, just a more pleasant whooosh

Furnace Inferno · Mar 27, 2019

Mascot said:
Not sure exactly what you mean, but the coupler just pulls apart with a little force if you want to separate the motor and the ball screw. There's a (red?) plastic 'joiner' (for want of a better word) that pulls apart/goes together with an interference fit. I can't remember if anything needs loosening for this to happen, but it surprised me when it happened during my assembly.
(This is with the 'official' DOLD couplers, not sure if others are the same).

Pyronious said:
I inserted a flathead screwdriver into the access slot and gently twisted to push the two halves of the coupling apart. This will get them partially separated, complete separation requires a little bit of wiggle, but not too much. Don't want to crack the plastic friction fitting.

Hmm, I was pulling quite hard and nothing happened other than pulling the motor off the coupling! I’ll give the screwdriver method a try.

HugoB · Mar 27, 2019

Furnace Inferno said:
Hmm, I was pulling quite hard and nothing happened other than pulling the motor off the coupling! I’ll give the screwdriver method a try.

It shouldn't be possible to pull off the coupling from the shafts! That means they are not tightened enough and you most probably will get slippage during use, so your motion will not work correctly...

How did you prepare the shafts and the couplers? Did you de-grease them and sandpaper them? The best is to also file slots along the length of the shafts and inside the couplers to get kind of teeth that clamp together... This way you should never get slippage.

When I lift up my motors for disassembly, I can just wiggle them up and the couplers will split. It feels a bit like pulling out a weed from the garden.

Pyronious · Mar 27, 2019

A few pics of the finished enclosure. The STL files for the enclosure are now available on the GitHub page along with the PCB design files.

o Tiger Feet o · Mar 27, 2019

I dont think splitting the coupler is necessarily required if youre struggling. You can tighten it up from the outside via the slot. If you want to get more purchase on the allen key, extend it with grips.

Mascot · Mar 27, 2019

I found gouging random furrows with the corner/edge/point of a small needle file along the length of the shafts (and inside the couplers) to be a good technique. Leave the rough edges for extra grippage. Sanding the surfaces might just make them smooth unless you use a really coarse grit.

The strength of this coupling is probably the weakest link in the whole assembly, but people have reportedly been using them for months without issues. But it's all in the prep work, and tightening the couplers as much as is humanly possible with such a tiny grub screw.

I'd certainly advocate some sort of appropriate loctite formulated exactly for this application.

HugoB · Mar 27, 2019

I did a bit of a remix on @jimbraj 's cable clamp.. hope you don't mind me posting it here?

Made it smaller so it fits the motor cables exactly, rounded off the tips and made it fit more tightly in the profile so it doesn't slide.

All credit goes to @jimbraj for the original design! This is merely a 'Darwinian baby'. I can share the STL if anyone is interested.

Jens Roos · Mar 27, 2019

Reading all comments on how to modify the coupling and/or axle/shaft to make it non-slip indicates something else is wrong. These couplings are for industrial use and I have never been doing any modifications or using cylindrical bound (loctite) thru years I have been mounting these on servos and similar applications.

Key slot are sometimes used but it is as common using clamping force only. With the correct tolerances and dimension of the coupling, slip should be a non issue.

Flag Ghost · Mar 27, 2019

Tried the 10khz test tone on YouTube. It is almost identical to my Tinnitus ! Surely there is some type of sound insulating material that will work as higher freqs don't travel through materials well.

saxxon66 · Mar 27, 2019

Steve Bernstein said:
Re: the coil whine - I have a DIY simwind setup running with an Arduino and Simtools. There was a terrible associated coil whine initially until someone suggested using inductors between the power and fans. I do not have an electronics background so forgive me if this makes no sense but I wonder if properly sized inductors could help reduce the whine...
https://www.xsimulator.net/communit...using-monstermoto-and-arduinouno.6876/page-14

NM, those are DC fans so this probably doesn’t apply.

Tl;dr; xsim thread, but I used the Arduino sketch as a blue print for my implementation.
First thing I noticed was a pwm noise.
Looking at the code I saw they use the standard pwm implementation by calling analogWrite. This will produce a pwm signal with 980 Hz.
I did some modification to the internal timer so the pwm signal is much faster.
End result no more pwm sound using sim wind.

Mascot · Mar 27, 2019

Flag Ghost said:
Tried the 10khz test tone on YouTube. It is almost identical to my Tinnitus ! Surely there is some type of sound insulating material that will work as higher freqs don't travel through materials well.

There was a discussion a few weeks ago:
https://www.racedepartment.com/thre...simulator-thread.159524/page-156#post-2929135

Furnace Inferno · Mar 27, 2019

HugoB said:
It shouldn't be possible to pull off the coupling from the shafts! That means they are not tightened enough and you most probably will get slippage during use, so your motion will not work correctly...

How did you prepare the shafts and the couplers? Did you de-grease them and sandpaper them? The best is to also file slots along the length of the shafts and inside the couplers to get kind of teeth that clamp together... This way you should never get slippage.

When I lift up my motors for disassembly, I can just wiggle them up and the couplers will split. It feels a bit like pulling out a weed from the garden.

Well that was at the point I was taking the motor off to tighten the screw more. The ball screw side didn’t come lose just the motor side that I tightened through the hole with the short end of the Allen key.

I bought some long T-handle Allen keys this morning so I’ll try those tonight. Just making sure if I pull it with pull force later the coupler won’t explode and break as I had a quick play with both fully tightened and no motor housing and wasn’t feeling confident something else wouldn’t have an issue after the whole ball nut issue. If it weren’t for that I’d be up and running tonight!

HugoB · Mar 27, 2019

Furnace Inferno said:
Well that was at the point I was taking the motor off to tighten the screw more. The ball screw side didn’t come lose just the motor side that I tightened through the hole with the short end of the Allen key.

I bought some long T-handle Allen keys this morning so I’ll try those tonight. Just making sure if I pull it with pull force later the coupler won’t explode and break as I had a quick play with both fully tightened and no motor housing and wasn’t feeling confident something else wouldn’t have an issue after the whole ball nut issue. If it weren’t for that I’d be up and running tonight!

Ah ok

I thought it was with fully assembled actuator, my bad.

Mr Latte · Mar 27, 2019

Flag Ghost said:
Tried the 10khz test tone on YouTube. It is almost identical to my Tinnitus ! Surely there is some type of sound insulating material that will work as higher freqs don't travel through materials well.

There are many many choices in materials for sound-deadening / sound absorption and vibrational control. Car Audio is one sector we find some solutions.

Mr Latte · Mar 27, 2019

HugoB said:
I did a bit of a remix on @jimbraj 's cable clamp.. hope you don't mind me posting it here? Made it smaller so it fits the motor cables exactly, rounded off the tips and made it fit more tightly in the profile so it doesn't slide.

All credit goes to @jimbraj for the original design! This is merely a 'Darwinian baby'. I can share the STL if anyone is interested.

What about making "wiring housing" or have any of you considered some form of plastic trunking to tidy cables?

EDIT
Just found this for those seeking to have tidier cable management...
Searches for "Closed Slot Trunking" should bring more results.

Ringorian · Mar 27, 2019

Jens Roos said:
Reading all comments on how to modify the coupling and/or axle/shaft not to make it non-slip indicates something else is wrong. These couplings are for industrial use and I have never been doing any modifications or using cylindrical bound (loctite) thru years I have been mounting these on servos and similar applications.

Key slot are sometimes used but it is as common using clamping force only. With the correct tolerances and dimension of the coupling, slip should be a non issue.

I for me didnt file one of em and everything is still in place ... you are completely right .. If everything done proper, you shouldnt need the file or sanding .. but sometimes people think some things help. there were a lot people in the beginning which would have changed several things with not even had one actuator build when we were driving with em for months .. with no problems ..
people forget that this is is mostly coming from cnc DIY stuff, and these machines are much more stressed i think then these servos turning a 1605 little up and down