Showroom My Second 2DOF+TL Sim with 200W Worm Drives G200-12

Having built and learnt a lot from my first racing sim (An El cheapo 2DOF Motion Sim with Arduino UNO + Wiper Motor2 + IBT_2 Bridge), I am now embarking on my second 2DOF+TL with a more powerful 200W motor from Motion Dynamics.

I have bought most of the parts from ebay as listed here under. All prices are in Aus $.

1. Motion Dynamics Worm Drive G200-12 + 200 mm Shaft x 3 $361.48
2. Lazy Susan Bearing - 12 inch (305 mm) Load - 455 kg. 12C *Made in USA Genuine* $24.25
3. BTS7960B DC 43A Motor Driver H-Bridge x 3 $45.05
4. Arduino UNO $29.95
5. Server PSU (12V, 39A) x 3. Got them free from an IT friend!
6. DC 5V Angle Sensor Hall Effect Potentiometer Analog Non-Contact Instrument x 3 $77.97
7. Heim Joint M10 (10T/K) SI/Female x 6 $49.20
8. Uni Joint $38.00
9. M12 Threaded Rod 3 m $18.00
10. 3/4'' Threaded rod 24" $12.00
11. 75mm Wheels, nuts & bolts, paints $100.00

This time I will be using the 25 mm Square Hollow Section (SHS) mild steel tubes for the base frame and the motion platform.

I will keep posting my build as it progresses over the next few months.

Today on my Dining table, I carried out testing the Plugins for all my Steam car racing games, AC, CCD, R3RE and non Steam games, LFS & FM7 via the Virtual axis of the SimTools Game Engine. Beauty! It all worked. Awaiting to download the DirtRally 2 Plugin and test it on the Steam version of DirtRally 2 as well as Dirt?and DirtRally? Then I can move the PC to my 2DOF+TC Sim and test all of them live.

I had to relocate my temporary Plugin test setup from the Dining table to the Study (domestic issue!!). Here are photos of what I have been doing. I think I need to work on the CCD with the Tuning Centre. Once the hot weather goes away, I will move to the garage, where my Motion sims are housed.

I am progressing well with the testing of the "Engine". All the motors were driven fully with the SMC3Utils v1.01 and found to be working well; however it was noticed that some stray movement of motors not selected to run happened sporadically. Finally, it turned out that the 5V power for the IBT_ 2 and the Hall Effect Potentiometers sourced from the Arduino UNO was inadequate. I didn't have this problem with my earlier El Cheapo sim where I used an ordinary Potentiometer. Looks like the Hall Effect Potentiometer (See picture) must be drawing too much current thus pulling down the UNO's 5V. So, I rewired the 5V supply to the IBT_2 and the Hall Effect Potentiometers to a separate 5V source and tied all the GND together. Problem solved. Now, everything ready for testing on the Motion Sim.

Hi, @noorbeast, I am using the same motor (Motiondynamics.com.au/worm-drive-motor-12v-24v-200w-180-rpm-20nm-torque) in my new motion sim, but it does not hold the seat in position when not powered. But with the wiper motor on my El Cheapo sim, I don't have such problem. Did you have similar problem?

Hi, @noorbeast, I wish I knew this important info well before I bought the motors. How true is the saying that "Haste makes waste!" Anyway, for the time being I have propped up the seat with a car jack. I will remove the jack while ever the motors are powered up.

Hi, @noorbeast, I tested my new motion sim and the damn thing (sorry for the expletive) almost threw me out. Response was very fast. So I went back to the SMC3Utils and wound down the Kp from 600 to 150. It was ok but still fast. Looks like I have to change the worm gear from 25:1 to 60:1. I will talk to the guy at MotionDynamics on Monday and see what he can do about it.

I still use these motors/gearbox and have never found them to be too fast, it's more likely that you just need to tone down the setting in Simtools.

Hi SeatTime, thanks for your suggestion. These are my settings as attached. The only place I can tone down the speed is at the SMC3Utils, Kp and Kd. But it didn't help. I may change the gear box from 25:1 to 60:1 as suggested by @noorbeast. Any further suggestion will be very much appreciated.

You don't need the change the gearbox for this issue, there is no such thing as a servo that is too fast. The only reason for changing the gearbox is to get more torque if that is a issue. You need to look at the settings in 'Tuning Center' for the game that you are trying to run. Increasing the number will reduce the sensitivity of that DOF.

Thanks mate. Before I received your reply, I reduced the PWMax in the SMC3Utils from 100 to 70. It slowed it down. Now I will go into the Tuning centre and do what you suggested. Much appreciate your help.

To clarify: Fast servos are good for simulation, as it allows accurate tracking of the telemetry data from the Game. If you are just sitting in the sim and moving the sliders left and right quickly and it is trying (and has the power) to throw you out of your seat then that is a good thing. Note that once you are actually in a game these over reactions are not normal (unless you crash or something) and are set via the Tuning Center.

Keep the power up in SMC3 at least over 200.

SMC3 Utils is only used to ensure the servo is set to accurately track the required data and not overshooting etc. Once set it should not be touched. Select the 'Sine Wave' or 'Motion' in SMC3 Utils, this is a more realistic representation of what will happen in a game. Don't drop the power, as this will cause all sorts of other issues.

Thank you guys. I will religiously follow your advise.

Hi, on the topic of Tuning Center, I found that in Page 82 of the SimTools USER MANUAL v2.4 "If you want to start over, you can re-install the original plugin and start again."

Couldn't I just edit the file LiveforSpeed_MaxMin.cfg, located under ,
C:\Users\your name\AppData\Local\SimTools\GameEngine\MaxMinProfiles.

<?xml version="1.0" encoding="utf-16"?>
<GameMaxMin xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<_GameName>LiveforSpeed</_GameName>
<_RollMax>3.81742796807532</_RollMax>
<_RollMin>-3.81742796807532</_RollMin>
<_PitchMax>2.60873361972098</_PitchMax>
<_PitchMin>-2.60873361972098</_PitchMin>
<_HeaveMax>0.932457143384532</_HeaveMax>
<_HeaveMin>-0.932457143384532</_HeaveMin>
<_YawMax>64.5452328926197</_YawMax>
<_YawMin>-64.5452328926197</_YawMin>
<_SwayMax>5</_SwayMax>
<_SwayMin>-7</_SwayMin>
<_SurgeMax>8</_SurgeMax>
<_SurgeMin>-10</_SurgeMin>
<_Extra1Max>0.0889381317930061</_Extra1Max>
<_Extra1Min>-1.755236168832</_Extra1Min>
<_Extra2Max>0</_Extra2Max>
<_Extra2Min>0</_Extra2Min>
<_Extra3Max>0</_Extra3Max>
<_Extra3Min>0</_Extra3Min>
</GameMaxMin>

If I do edit with say Notepad++ and save it, will it work?

Shortened the motor arm by 30 mm and now the motors are able to hold the seat in position when not powered. Launched the SMC3Utils and carried out the testing. Have also replaced the previous Server PSU (12V, 39A) with a 12V, 200A Server PSU. This power supply is really good, much quieter. Now Sim is ready for testing with Simtools.