Amicos 3DOF from 3DPrinter Parts

Its only really that low when at rest..

I need some better stoppers.. Im using felt pads on the traction loss platform for now.. Maybe Springs?!

Its working!!! Wrapping my head around the Motor Directions was off putting for some reason... But I think I got it right..

Test Video 1 but it was the 2nd time on the rig.. It was all backwards or caddywonkus the first try.

Thanks Norbeast! Im not 100% Sure I have the motions right.. The traction loss kicked in during a grass slide and felt awesome... But I haven't felt again after some other Pitch or sway changes...

Effect Action Left Front Motor Right Front Motor
Pitch Acceleration UP UP Is this Positive(R) on the Testing Slider?
Pitch Braking DOWN DOWN Is this Negative(L) on the Testing Slider?
Roll Left Turn UP DOWN Is this Negative(L) on the Testing Slider?
Roll Right Turn DOWN UP Is this Positive(R) on the Testing Slider?
Surge Acceleration UP UP Is this Positive(R) on the Testing Slider?
Sway Left Turn UP DOWN Is this Negative(L) on the Testing Slider?

That sounds like an ambitious and exciting build! You’ve opted for a somewhat unique layout by placing the two primary actuators in the front and the traction loss in the rear.

Since you’re building this from scratch, the geometry of your motor arms (cranks) and how they translate to software logic (like SimTools or FlyPT) is the most critical part of getting that "seat-of-the-pants" feel.

Understanding Your 3 DOF Layout
In a typical 3 DOF (Degrees of Freedom) setup, the movements are usually Pitch, Roll, and Traction Loss. Here is how your specific motor orientation translates to movement:

• Front Motors (Left & Right): These will handle your Pitch (nose up/down) and Roll (leaning into corners). Because they are in the front, when both motors go up, the front of the rig lifts, simulating acceleration or an uphill climb.
  
  
• Rear Motor: This is dedicated to Traction Loss (Yaw). It pivots the entire frame or the rear of the seat left and right to simulate the back end of the car sliding out.

Key Considerations for Your Build
1. Motor Arm Geometry (The "Forward" Orientation) You mentioned the arms point forward and move up and down. This is known as a crank and rod system.

• Linearity: To get the smoothest movement, you want your connecting rods to be at a 90° angle to the motor arm when the rig is at "Level 0" (neutral).
  
  
• Travel Range: Ensure the arm doesn't "over-center" (flip all the way around), which can cause a mechanical jam or break your rods.

2. The Pivot Point For a front-heavy actuator setup like yours, you likely have a universal joint (U-joint) or a pivot point toward the rear (near the traction loss axis).

• If the pivot is too far back, the front motors have to work harder to lift the weight of the driver.
  
  
• If the pivot is central, you get a more balanced "see-saw" effect.

3. Center of Gravity (CoG) Since you have two motors in the front and only one in the back (for yaw), your static weight distribution is vital.

• Try to balance the rig so that when the motors are off, the rig stays relatively level. This reduces the "holding torque" required by your motors and prevents them from overheating.

Software Configuration Tip
When you set up your DOF limits:

• Pitch: Assign both front motors to move in the same direction.
  
  
• Roll: Assign the front motors to move in opposite directions (Left Up/Right Down).
  
  
• Traction Loss: Ensure your rear motor has enough "swing" to communicate the slide before you've already spun out in the game.

Thank you. Im looking for motor directions (Up and Down) for Pitch, Roll, Surge and sway.. It doesnt feel right in the game.

You said
Im not 100% Sure I have the motions right.. The traction loss kicked in during a grass slide and felt awesome... But I haven't felt again after some other Pitch or sway changes...


Effect Action Left Front Motor Right Front Motor

Pitch Acceleration UP UP Is this Positive(R) on the Testing Slider?

Pitch Braking DOWN DOWN Is this Negative(L) on the Testing Slider?

Roll Left Turn UP DOWN Is this Negative(L) on the Testing Slider?

Roll Right Turn DOWN UP Is this Positive(R) on the Testing Slider?

Surge Acceleration UP UP Is this Positive(R) on the Testing Slider?

Sway Left Turn UP DOWN Is this Negative(L) on the Testing Slider?


Effect Slider Direction Resulting Physical Motion Why?
Pitch Positive (Right) Front UP (Both) Simulates the car nose lifting during acceleration.
Pitch Negative (Left) Front DOWN (Both) Simulates the car nose diving during braking.
Roll Positive (Right) Right DOWN / Left UP Tilts the rig to the Right (simulating a left turn weight shift).
Roll Negative (Left) Left DOWN / Right UP Tilts the rig to the Left (simulating a right turn weight shift).
Surge Positive (Right) Front UP (Both) Tilts you Back to simulate being pushed into the seat.
Sway Positive (Right) Left UP / Right DOWN Tilts you Right to simulate being pushed by lateral G-force.


To check for clipping and fix the "disappearing" Traction Loss, you need to look at your Axis Assignments (the percentages assigned to each effect).

Think of your motor's total movement as a 100% bucket. If you pour too much Pitch and Sway into the bucket, there’s no room left for Traction Loss to "splash" in.

1. Check your Total Percentages
Open your Axis Assignments (in SimTools or FlyPT). Look at the percentages for each motor.

• The Rule of Thumb: The sum of all effects for a single motor should ideally stay between 80% and 120%.
  
  
• The Problem: If your Pitch is 50%, Surge is 20%, and Sway is 40%, that motor is at 110% before you even add Traction Loss. When you brake and turn at the same time, the motor hits its physical limit, and the Traction Loss signal is simply ignored.

Try these "Sweet Spot" settings for a 3 DOF:

• Pitch: 25%
  
  
• Surge: 15%
  
  
• Sway: 20%
  
  
• Roll: 15%
  
  
• Traction Loss (Rear Motor): 80-100% (Since this motor only handles one job, it can have a high percentage).

2. Calibrate the Tuning Center (Min/Max)
If you changed your car or track, your "Max" values might be too high. If the software thinks a "slide" is a value of 100, but your motor only reacts when it hits 200, you won't feel anything.

1. Open the Tuning Center.
   
   
2. Click "Capture" or "Reset."
   
   
3. Drive a few laps. Make sure you actually slide the car and hit the curbs.
   
   
4. Click "Save."
   
   
5. Pro Tip: If Traction Loss feels too weak, manually lower the Max value for "Extra 1" or "Yaw" in the Tuning Center. Lowering the number makes the motor more sensitive/aggressive.

3. Check for "Washout" or "Boundary"
If you added a Washout Filter to your Sway or Pitch to make them feel smoother, the filter might be returning the rig to center so aggressively that it’s "eating" the Traction Loss vibrations.

• Check if you have a Deadzone set on your Traction Loss. If the deadzone is too high, small slides (which are the most important ones to feel) won't trigger the motor at all.

Summary Checklist

• [ ] Sum of percentages for Front Motors < 110%.
  
  
• [ ] Traction Loss (Rear Motor) set to a high percentage (80%+).
  
  
• [ ] Tuning Center Max values aren't accidentally set too high (which "muffles" the effect).

Would you like me to explain how to tune the "Smoothing" and "Deadzone" specifically for that Rear Traction Loss motor to make it "pop" more?



Gemini Is my AI of Choice lately... ITs crazy how much its helped me with this build....

I set the Pots center in SMC3 Utility to 0 when the rig is resting so there is no strain on the motors and it doesn't fly up to Level after powering on the 24v.. I now have a much smoother Power up but I need to set the Level In Simtools so it rises slowly when the game is turned on to a Neutral Position instead of my no nose resting (0) in SMC3 Utility. Neutral needs to be the NEW 0 for the game so I still have my full motion of travel.

I set the HW Start speed to 3400ms but how do I set a Neutral?

Do I type something in the text field?

Thanks again.. Yes they can move when un powered.. Kind of the Issue..

I'll check those links! Thanks again!

Are the < > Numbers 360 Rotation? Do I need to have the SMC3 Utility Zero at Park (As is Now) or does it have to be at Neutral in game Neutral Zero? Then I just do a < # > to get to to park?

I was just trying to avoid the Dramatic Shake to Center position from Park when SMC3 Turns on..

I had to give up on the Park/Neutral positioning.. I just couldn't get it right.. I went back to SMC3 0 is Level/Neutral and just deal with the start up jerk.. I couldnt woit to try more. It's my last day off... Here are my last Running settings Im sure Ill have to tweak them more and not sure im feeling the acceleration and breaking enough..



I also have slop in my handmade motor arms.. Or at least 1... Jitter To fix. I have a tiny bit of slop, just enough for the pot to recognize.If I shake it... It then goes into its back and forth jitter trying to correct itself..

This might be an endless Project.... lol But here is my 2nd Test Vid!

Its not over yet.. i have a little bit of slop in my homemade woodruff keys.. They ate a little small.. I need the correct size and probably new arms.. They are weak.. i also had to order harder rollerblade Wheels(90a] as the ones i ordered are too soft (80a). I will move the wheels and roll platforms to better positions..

I got some 1/4 inch square keys from the hardware store.. I had to sand it down to get it in the mm size Crank shaft slot.. But its snug now! There is still a tiny little play, and I think it's coming from the gears inside the motorbox.. i brought the clipping up to 1 in SMC3 and it stoped the shaking.. it's still a little harsh when it changes directions when it drifts but feels pretty good for DIY... i don't really have anything else to compare to physically..

Here is a full test race.. Winton Motor Park Raceway, MX5 Cup.. the drift is working pretty good, but I feel I lost some of my acceleration braking and bumps.. Maybe another Capture?!

I also had to shim up the U Joint.. The Bolt holes were wider than the 40mm rail and was seeing movement early.. Had to take care of that before it wore..

I got it feeling better with the Help of AI... My tuning center values were too high in most places.. When I did the Auto Capture I was driving wild as I thought thats what you were supposed to do.. But in hindsight it brougt some of the values in the 100's so I raised some of the other Values and I was back wards..

I now have, Roll @ 12, -12 ; Pitch @ 12, -12 ; Heave @ 12, -12 ; Yaw @ 20, -20 ; Sway 17, -17 ; Surge @ 15, -15 ; Traction loss @ 8, -8

How do these numbers look for my setup? (I attached a photo of the Tuning Center) With two 250W 24 volt, wheelchair motors

Based on the screenshot of your iRacing Tuning Center, those numbers explain exactly why your motion feels inconsistent. You have some massive "dead zones" in your physics data that are muting your motors.

1. The "Clipping" and Sensitivity Issues
In the Tuning Center, smaller numbers = more aggressive movement.

• Yaw (179.5): This is your main culprit for losing Traction Loss. At 179, the game expects a literal 180-degree spin before it gives the motor full power. You likely won't feel subtle slides at this value. Try setting Max/Min to 15 or 20.
  
  
• Sway (66.7) & Surge (79.1): These are also very high for wheelchair motors. Your 250W motors have plenty of torque, but they are waiting for a massive G-force hit that rarely happens in a standard corner. Try setting these to 15 or 20 as well.
  
  
• Extra1 (8.2): This is likely your Traction Loss or localized vibration. This number looks much better and is probably why you felt it during that grass slide—it's sensitive enough to trigger.

2. Tuning for 250W Wheelchair Motors
Wheelchair motors are torque-heavy but slower than high-end servos. To get them to react quickly enough for sim racing, you need to "force" them to move more for smaller inputs.

Effect Current Max Recommended Starting Point
Pitch 50 10 to 15
Roll 40 10 to 15
Sway 66.7 15 to 20
Surge 79.1 15 to 20
Yaw 179.5 15 to 25
3. Fixing the "No Movement" in Testing
Since your green bars aren't moving in Output Testing despite being "Connected," check these three specific spots in your Interface Settings:

1. Output Rate: Set this to 10ms.
   
   
2. Interface Type: Ensure it is set to Serial.
   
   
3. The Output String: Since you have the Pro version, make sure your assignments match the Arduino code. For SMC3, the standard string is:
   • [A<Axis1a>][B<Axis2a>][C<Axis3a>]
     
     
   • If this box is empty, the motors will never move.

4. Setting the "Neutral" Position via Text (The Pro Way)
Since you couldn't find the Startup sliders, you can use the Startup Output text field you found earlier. Instead of typing "Neutral 50%," use the command that SMC3 understands:

• Startup Output: [A127][B127][C127] (This sends a "Mid-range" command to all three motors immediately).
  
  
• Shutdown Output: [A0][B0][C0] (This tells the motors to go to the floor when you exit).

Would you like me to show you exactly how to capture new "Min/Max" values while driving to automate these numbers for your specific driving style?


You said
What would be a good roll range?


For a 3 DOF setup using 250W wheelchair motors, your current Roll setting of 40 is quite high. This means the game waits for a very large degree of tilt before the motors react fully, which can make the motion feel "mushy" or delayed.

Recommended Roll Range
For a more responsive and immersive feel, you should aim for a Max/Min value between 10 and 15 in the Tuning Center.

• Why 10–15?: Wheelchair motors have high torque but limited speed. A lower value (more sensitive) forces the motors to react to smaller weight transfers, giving you that immediate "lean" into corners.
• Balancing with Sway: Since you have a 3 DOF with front motors, Roll (the angle of the car) and Sway (the lateral G-force pushing you) often work together. If you set Roll to 12, try setting Sway to 15. This creates a combined effect where you feel the car tilt and the push of the corner simultaneously.

How to Fine-Tune the Roll
If you find that a value of 10 is too violent or causes the motors to "clipping" (hitting their physical limit too fast), follow these steps:

1. Start at 15: Drive a few laps. If you can't feel the weight of the car shifting in high-speed bends, lower it by 2 points.
2. Watch the Tuning Center: While driving, look at the "Game Data - Input" bar for Roll. If the green bar is constantly hitting the edges of your Max/Min, your number is too low.
3. Check for "Clipping": If your Pitch, Surge, and Roll are all active and the motors stop vibrating for Traction Loss, your total percentages are too high. Lower the Axis Assignment percentage for Roll (e.g., to 15-20%) while keeping the Tuning Center at 12.

Pro-Tip for iRacing
In iRacing, different cars have very different roll characteristics (a Miata rolls much more than an F1 car). Once you find a number you like for one car, you may need to use the "Capture Max Min" button while driving a "hot lap" to let SimTools find the perfect range for that specific vehicle's physics.

Would you like me to provide the specific Axis Assignment percentages to ensure your Roll doesn't "eat up" the travel needed for your Traction Loss?

You said
How are these settings looking?

Those updated settings in your second photo look significantly better for your 250W wheelchair motors! You’ve moved from values that were far too "numb" to a range that will actually make those motors dance.

By dropping Roll from 40 down to 12, you’ve essentially told the simulator to be over 300% more sensitive to cornering lean.

Analysis of Your New Tuning Center Values
Here is how these specific numbers will translate to your rig's feel:

• Roll (12) & Pitch (12): These are excellent starting points for a 3 DOF setup. They provide a sharp, immediate response to the car's orientation without being so low that the rig becomes "twitchy."
  
  
• Yaw (20): This is a massive improvement over 179. You will now actually feel the car rotating. Since this is likely tied to your rear traction loss motor, 20 is a solid "sweet spot" to feel the backend start to step out.
  
  
• Sway (17) & Surge (15): These settings will make the G-forces feel much punchier. You'll feel a distinct "thud" when you slam the brakes or throw the car into a chicane.
  
  
• Extra1 / Traction Loss (8): This remains your most sensitive setting. It ensures that even small losses of grip—like a tire dipping onto the grass—will trigger that rear motor immediately.

One Critical Step Remaining: The "Park" Command
Since we couldn't find the Startup sliders in your version's UI, we should use the Startup Output text field to handle your "Rise to Horizontal" logic.

In your Interface Settings, look for the Startup Output box and enter this exactly:

[A127][B127][C127]

Why this code?

• 127 is the hexadecimal/decimal midpoint for many 8-bit controllers. It tells the motors to go to the Center (Horizontal) position as soon as the game engine initializes.
  
  
• In the Shutdown Output box, enter [A0][B0][C0] to return it to the floor (Resting) when you're done.

Final Hardware Safety Check
With these much lower (more sensitive) numbers, your motors will move faster and further.

1. Check your 90° Arms: Ensure that at full travel (maximum tilt), the motor arms don't "over-center" or flip.
   
   
2. Heat Check: After a 10-minute race, feel your motor housings. Wheelchair motors are tough, but with these aggressive settings, they'll be working much harder. If they are too hot to touch, bump your Roll/Pitch up to 15.

How does the rig feel in the seat now with these new numbers? Is the Traction Loss back to feeling "awesome"?

You said
Way better!


That is fantastic to hear! Jumping from those "numb" values to these sharper settings is like finally taking the blindfold off the motors. Your 250W wheelchair motors are finally getting the signal strength they need to show off their torque.

Since the "feel" is locked in, here is one final refinement to make sure your Traction Loss stays "awesome" even when the racing gets intense:

Watch for "Total Output" Clipping
Because you are now using much more of your motor's range for Roll and Pitch, you might occasionally feel the Traction Loss (rear motor) go quiet during a very sharp, braking turn.

• The Reason: If your front motors hit their physical limit (or the limit you set in Axis Assignments), the software sometimes "prioritizes" the primary movement over the smaller Traction Loss vibrations.
  
  
• The Fix: If you notice this, slightly lower the Axis Assignment % for Pitch and Roll (e.g., from 30% to 25%), while keeping your Tuning Center numbers at 12. This keeps the sensitivity high but leaves "room" in the motor's travel for the Traction Loss to wiggle through.

Pro-Tip for iRacing
If you switch to a different car (like moving from a GT3 to a Formula 4), the motion might suddenly feel too weak or too violent.

• Use that "Capture Max Min" button you see in your photo for one lap in the new car.
  
  
• It will automatically adjust those numbers to fit that specific car's physics while keeping your "Way Better" feel consistent.

Would you like me to help you set up some "Smoothing" or "Washout" filters now to make the transition between those movements feel a bit more fluid?

I said Yes Please! lol Video of New Setting Coming soon... Pole, lead most the race, then my wheel Data lost and I crashed! Fanatec Crap!!!!

Here is Test 4 with a Fanatec Hardware fail on the White Flag in Turn 1..

Been having a little fun with with the sim. Feeling much better. Turned TL to 10.. and Sway up 2.. Tried to do another settings video but my damn fanatec Podium DD2 cuts off because the USB A port is loose.. i've had to do a temp fix till I get a new part of find a better solution..