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

C64 · Sep 22, 2019

@Prototype_ centre of mass for these rigs is of no importance as long as it stays within the 4 actuators, I can’t imagine wear being a big issue either, the only likely items are the ballscrew and motor coupling - both very cheap items.

I think your minimalist design will work well and be more practical, you could use 120x40 for the uprights ( I do, as well as for my base ) which will support your wheelbase and monitor + monitor support structure. It would likely weigh less than additional uprights to support the monitor. The key thing for rigidity is having the base frame joining the 4 actuators securely fixed in the corners... this means 4 angle brackets at each corner ( 2 in front, 2 behind ) and the wheelbase/monitor uprights rigidly attached to the base ( you have done this well using the actuators as additional bracing ). I’ll take some photos of my rig, it’s quite a simple design but works well and I can adjust pedals, seat, DD wheel easily.

wrxawd123 · Sep 22, 2019

When you guys ordered your aluminum profiles from Kinetik, did your email receipt specify length? Mine only specifies per unit price. I hope they know that I requested 250mm since the unit price seems to fluctuate a bit.

Furnace Inferno · Sep 23, 2019

wrxawd123 said:
When you guys ordered your aluminum profiles from Kinetik, did your email receipt specify length? Mine only specifies per unit price. I hope they know that I requested 250mm since the unit price seems to fluctuate a bit.

It did not but it all came through fine. I also was worried I’d ordered too short based on what other people were quoting but it does go up and down enough to think you may have ordered the wrong length.

anton_Chez · Sep 23, 2019

On carpet if you use rubber feet the rig shouldn't walk at all. However, depending if it wants to walk or not, you may over time find that the rubber will pull on the carpet where it's fixed. So you may end up with stretching or tearing depending on how much it wants to move. I've found the more I pad underneath the feet, the less it wants to walk. However it could be down to lesser intense profiles. Although, I do run fairly decent settings now and find the chassis rarely moving from the markings I've laid out.

I used to have mine on a piece of carpet that wasn't installed into the floor. It just pulled and bubbled the carpet because it was easy to slide on the floorboard underneath. So just a little warning for going straight onto carpet. Probably best to just let the plastic feet sit directly on the carpet and allow it to slide if it really wants to.

Prototype_ · Sep 23, 2019

C64 said:
@Prototype_ centre of mass for these rigs is of no importance as long as it stays within the 4 actuators, I can’t imagine wear being a big issue either, the only likely items are the ballscrew and motor coupling - both very cheap items.

I think your minimalist design will work well and be more practical, you could use 120x40 for the uprights ( I do, as well as for my base ) which will support your wheelbase and monitor + monitor support structure. It would likely weigh less than additional uprights to support the monitor. The key thing for rigidity is having the base frame joining the 4 actuators securely fixed in the corners... this means 4 angle brackets at each corner ( 2 in front, 2 behind ) and the wheelbase/monitor uprights rigidly attached to the base ( you have done this well using the actuators as additional bracing ). I’ll take some photos of my rig, it’s quite a simple design but works well and I can adjust pedals, seat, DD wheel easily.

I think the Center of Mass is important.

My thinking is, if the Center of Mass of your body is positioned in the exact center of the 4 actuators you'll get the best "feeling" from the movement. The "feel" is not a dark art, its mathematical.
Thats why your suggestion of moving the actuators further back makes sense?

Regarding strength, once the design is closer to complete, Ill run a static stress analysis to check the strength yield on the current 80x40 and 40x40 profiles setup, and see if they need to be bolstered up to the next size. The 120x40 definitely look good from a visual perspective.

So current design: If we move the driver forward by 100 mm, we move the drivers Center of Mass into the center of the actuators. This will also mean some reshuffling of the the motor position, and moving teh pedal box further forward. This is next design revision Im working on.

A simpler "fix" would be to move the rear actuators back another 180mm, but to my mind this thing is then getting too long, and would definitely need to go up a size in profiles, so in order to keep it as compact as possible, Im working on the first idea initially.

Moving h-point 100 mm forward, places driver COM is in exact centre of actuators. ^^

Moving rear actuators back 180 mm forward, places driver COM is in exact centre of actuators. ^^

-------

And on a personal milestone note. Finished my 3d Prints!
Big thanks to @C64 for the ITEM mod! :-D

C64 · Sep 23, 2019

I think we are confusing "centre of mass" of the entire rig ( including driver ) with the drivers seating position relative to the actuators. You are of course right that the drivers seated position should be as close to the central point between the actuators as practical

regarding extending by another 180mm... you can always by the side rails and extra 180mm longer and try both positions. My gut feeling is you won't need the extra 180mm, but it is only a guess.

prints look good - looks like a high end printer !

Prototype_ · Sep 23, 2019

Quick, basic strength test analysis.

Prototype_ · Sep 23, 2019

Some more static stress analysis tests on the rig framework:
40 x 80 primary
40 x 40 secondary

^^^^
A 70kg force in the direction shown yields a safety factor of 6. We are safe at 3
It would move 0.8 mm at the point compared to the base of the frame.
This means that 140 kg force can still be placed at this point and we are still good.
(So this is over engineered)

^^^
Again - well within spec.

^^^^
We can apply a force of over 150kg in this direction, and we are still good.
Again, according to these results, we can go down on profile size.

-----------------------------------------
120 x 40 mm base profile.
The larger profile allows for a more rigid frame, with the frame twisting by 0.6 mm if you applied a load of 70 kg with no support under its entire length.

The 80 x 40 mm profile, which are used in the design displace 1.75 mm with the same force.
This gives us a MARGINAL situation, and its most likely engineered fairly optimally, as the test is extreme, based on the context. The 4 actuators would support the base frame way better than in this situation.

Conclusion:

I think an 80x40 base frame will do the job, however the 120 x 40 profiles definitely look more the part.
The wheel and screen system is over engineered currently, and could be optimized more.

Hees · Sep 23, 2019

Very strange Q but accept my lack of knowledge.
What difference will be if we place the two back actuators wider than the front ones?

Also by this design I assume that the seat and pedals are static and only suits you, right?

ThugUK · Sep 23, 2019

Not sure what the difference will be, but it may put extra strain from twisting on the rig itself due to not being parallel.

diablo2112 · Sep 24, 2019

How to print SFX parts in under 100 hours

I've been experimenting with settings to reduce the print time for SFX parts. [For those unaware, I've been printing many of these sets, see details in the marketplace section, as I've been doing this as a free service for the community].

Anyway, after literally thousands of hours of printing, I've found a way to use a 0.6mm nozzle to get gorgeous prints that are stronger than the original, and take half the time to print. Here's the final result. This piece normally takes about 11 hours to print with normal settings (0.4mm nozzle, 8 perimeters, 12 top/bottom layers, 20% infill). I printed this in less than 5 hours:

This part is stronger than the stock parts, a natural consequence of a thicker extrusion, larger layer height, and use of 25% (compared to 20%) infill. To achieve this you really have to know your printer and slicer. Here's details on how to get this result.

First, you need a well-calibrated printer. You want it square (no skew), a level bed, and a very well calibrated extruder. All of these things are outside the scope of this note; you can google to get all of these things tuned on your particular printer.

For the SFX parts, you have a few considerations. A big issue is warping. To prevent this, I print with a 5mm, single layer height brim. Also, I've found printing the first layer at half the height of subsequent layers dramatically improves bed adhesion, reduces warpage, and gives a nice, cosmetic result. Plus, the brim will be fairly thin and easy to remove at this setting.

Here's the basic settings for a 0.6mm nozzle. You'll have to find the places in your slicer program to update these:

0.6mm nozzle profile (be sure to change to the whole profile, not just the nozzle diameter)
0.4 mm layer height
0.2 mm minimum layer height (for variable layers, see below)
0.2 mm first layer height
5 perimeters
8 top/bottom layers
25% infill, grid pattern
solid infill every 20 layers
perimeter start point: random
0.5mm brim, single layer high
variable layer height for the top 3mm of the print down to 0.2mm

The last requirement here is optional. Your slicer may not support this. You want the ability to have variable layer height, and set the last (top) 3mm of your print back to a 0.2mm layer. This wil print a very nice edge on the linear bearing (see picture, below) as well as give a very smooth, cosmetic infill on the top that you can see in the pic as well. If you do use variable layer height, you may want to set the number of "top" layers to 12, to compensate for the thinner layers this will print. Variable layer height is an advanced feature, and you'll have to read your slicer manual for specifics. Once you have all these settings, slice your STL file, and print away.

A couple of other comments. I printed all my bumpstops and sliders with the 0.4mm nozzle. I've not tried these 0.6mm nozzles with the sliders; this is the most sensitive part to variation in dimensions, and once I dialed one of my printers for sliders, I've used that ever since. You can try a 0.6mm nozzle on the slider, but be prepared to have to tune things to get a good, tight fit in the extrusion.

These changes will reduce the printing time for a full set of parts from 220 to about 100 hours. Good luck, and let me know if you have any further questions.

Insert Coin · Sep 24, 2019

Just curious: are the threads of the bolt holes still OK with a 0.6 mm nozzle? Don't they get coarse?

diablo2112 · Sep 24, 2019

Insert Coin said:
Just curious: are the threads of the bolt holes still OK with a 0.6 mm nozzle? Don't they get coarse?

I haven’t noticed any problems and I’ve tested each thread size in the 0.4 mm layered parts.

papasqueeze · Sep 24, 2019

Has anyone ordered the item profile?

I've just tried to pay for it over phone via card and I've been sent a proform or something to pay bank?

I thought it would be a straight forward payment

RCR_Finn · Sep 24, 2019

papasqueeze said:
Has anyone ordered the item profile?

I've just tried to pay for it over phone via card and I've been sent a proform or something to pay bank?

I thought it would be a straight forward payment

Is the Item profile any cheaper or are people buying it just because of better availability in some areas?

papasqueeze · Sep 24, 2019

I just bought it because you can tap straight into it

Erik van Uijtert · Sep 25, 2019

I need some help here. A few weeks ago everything was running perfectly on my old laptop. I've bought a new laptop.

Now Simfeedback does not seem to get the Telemetry. When I start the rig goes up as usual. I then start a game, but nothing happens.

I have done:
- Run remove_blocking.bat
- Changed USB ports
- Removed all other USB devices, except oculus rift S
- Disabled Webroot & windows Firewall
- Tried 2 different games AC & PJ2 (configured)
- Tried SimHub, that does seem to get connected.

metalnwood · Sep 25, 2019

Hees said:
Very strange Q but accept my lack of knowledge.
What difference will be if we place the two back actuators wider than the front ones?

Also by this design I assume that the seat and pedals are static and only suits you, right?

Really depends by how much but lets say I have the two on the right side, right front and right rear. They both extend 300mm to roll the platform to the left. If you move one of those actuators farther out then that actuator will no longer have good contact with the floor or may have no contact at all. It all depends how much farther out it is and how much you roll the platform.

You will also have the same effect happening on the other side at the same time. It may not make for a stable platform

Hees · Sep 25, 2019

metalnwood said:
Really depends by how much but lets say I have the two on the right side, right front and right rear. They both extend 300mm to roll the platform to the left. If you move one of those actuators farther out then that actuator will no longer have good contact with the floor or may have no contact at all. It all depends how much farther out it is and how much you roll the platform.

You will also have the same effect happening on the other side at the same time. It may not make for a stable platform

thanks very informative and clear, well explained

Insert Coin · Sep 25, 2019

I have assembled my fourth actuator yesterday, it took me about 7 hours for all actuators (motors not mounted yet). The bolt holes in the slider (M5) and fixed bearing mount (M4) are a bit too small. As stated in the instructions the bolts do not go in easily. I almost stripped the threads when I drove the bolts in, at a very slow speed with my cordless drill. Later I tapped the M4 and M5 holes first before putting the bolts in: now I could turn the bolts by hand, it was that easy. If you tap them: remove the tap and clean it after tapping about 1 cm deep each time or your tap will be full of PLA and you'll ruin the thread if you keep tapping.