JL-G27-Mod

Hi,

I'm new to this forum. I'm from Germany and living in the surroundings of Heilbronn.

In this thread I want to document my JL-G27-Mod. JL stands for Jo Lueg. JLVRH (Jo Lueg Virtual Racing Hardware) is no longer producing this wheel. The wheel consists of an excellent engineering mechanics. It's a belt drive wheel with the two parallel motors and the electronic board from the G27. The overall gear ratio is 1:25 (1:5 for the first gear and 1:5 for the second gear). The wheel is a D-shape MOMO (270 mm) with a SLI-PRO, eight buttons, two rotary switches (each with 12 positions) and two paddles. I've bought this wheel in 2012.

This is a documentation about what I have done. This is not a tutorial. My way is not a cheap way. My target was to realize the best available performance for this excellent wheel with a good reliability by minimizing the mechanical changes.

Starting in October 2015 I've replaced the original and weak motors by two BL42-63 motors from Granite Devices (peak torque = 0.6 Nm). The original board was thrown away and substituted by an IONICUBE 4X board with two IONI Pro drives from GD (after discussing with Tero). All Logitech G27 equipment is in my opinion scrap: the two toy motors, the damageable board, the simple optical encoder and the plastic mechanic - except the wheel.

Because of the power consumption it was necessary to invest in a SM-PSU from Mean Well: HRPG-600-36. For the logic circuit of the board a Mean Well RS-25-24 was sufficiently.

For the encoder I ordered an AMT 103-V from CUI. The normal encoder of the BL42-63 was demounted. Absolute necessary was the discovery board from STM - today in the version: STM32F407G-DISC1. During all the experiments I've killed three of them.
Question: Has anybody a wiring schematic for the Core407V with the STM32F407VGT6 MCU in combination with the MMos firmware and the IONICUBE 4X?
Perhaps: Beano? MMos? Dennis? Bernhard? RacingMat? or any other?

To optimize the speed of the wheel I changed both motor pulleys from 20 teeth to 52 teeth (from RRG). Changing the gear ratio will increase the speed but decrease the torque (but: max. 30 Nm are too much - in my opinion for a wheel with a diameter of 270 mm). The change of the motor pulleys included the change of the primary belt from 600 teeth to a Synchroflex 6 AT3-648. So the original gear ratio of the JL-G27 was changed from 1:25 to overall 1:9,615 (first gear is now 1:1,923; second gear remains to 1:5).

The result is a speed of a little bit more than 300 rpm and a maximum torque of round about 12 Nm at the wheel axis (based on max. current assumed as RMS). For my opinion this is absolute sufficiently for a wheel with a diameter of 270 mm. The outcome of this is a force of 80-90 N (single-hand) or 40-45 N (two-hand) at the wheel.

Additional features were implemented:
- killing switch,
- adjustment against unlimited and uncontrolled wheel spin,
- potentiometer for adjusting the torque 'on-the-fly',
- two push buttons for homing (for exact adjustment).

At this time it is necessary to thank:
- Bernhard for his innovation of OSW and the idea to try other solutions,
- MMos for his brilliant firmware for the discovery,
- Tero for his fruitful contributions to the project,
- Beano for his clear wiring schematics,
- Martin for his helpful tutorial of the OSW,
- Dennis for his practical contributions to the OSW-project.

New adapter plates for the motors must be designed and test versions must be printed. New couplings had to be tested. At least I used the couplings from RRG. The ECCI-paddles were substituted by the Logitech-paddles.

The whole wiring of the equipment was a challenge for me. I'm not really an electronic freak. I drive the two motors in a master & slave configuration. The upper motor is the master with the encoder. The lower motor is the slave (with no encoder) which receives the encoder signals from the master. So a triple split of the encoder signals was necessary: first split for the master (connector X6 for slot IONI_X), second split for the slave (connector X6 for slot IONI_Y) and the third split for the discovery (pin GND, PA1, PA0, PA2).

The encoder was adjusted by the dip switches to 512 PPR which means 512 PPR in the Granity software and 19692 CPR for the setup in the MMos software. The resolution of 512 PPR came from the former gear ratio of 1:25 (512PPR*4*25=51200 CPR). Because of this starting point the original encoders of the BL42-63 motors were demounted.

The synchronising of the two motors by separate and independent phasing is fundamentally. I did it in this way.

1. Lower motor (second motor)
the encoder is mounted to the motor
the screws of the coupling are loosened
only slot IONI_Y with IONI Pro
only the encoder is plugged in connector X6 (floor A)
start phasing by power on IONICUBE 4X
now the screws are tightened
the wheel is fixed after this procedure
power off

1. Upper motor (first motor):
the encoder is mounted to the motor
the screws of the coupling are loosened
only slot IONI_X with IONI Pro
only the encoder is plugged in connector X6 (floor B)
start phasing by power on IONICUBE 4X
now the screws are tightened
power off and the wheel is unfixed

All my calculations and settings are documented in the enclosed excel-file:

- calculations for the different gear ratios,

- wiring the whole equipment,

- settings inside Granity,

- settings for MMos firmware,

- web links,

- purchase list.

Now I have a powerful wheel with excellent reactivity. It is another world: with no oscillating, with minimal cogging, with no dead zone, no thermal problems. Everything is working fine!

Driving Nordschleife (rFactor1) and smiling every lap...!

In the moment I've no comparison to a Lenze-system (bought a complete Dennis-set as a backup, if I failed) which is now in standby-position and can be installed.

To-Do list:
- I've bought a 'KPCR Piez RIG Expert' with a 'Sparco Rennsitz Pro 2000 II LF' and 'Heusinkveld Sim Pedals Pro' (throttle and brake like carting),
- I've bought a 'Sony KD 43 X 8307'.
Both must be now implemented.

Next step will be to integrate motion - but this will need some discussions with Dennis and Henning.

Then I hope I am ready - or not.

There is always room for improvements.

Here are some pictures of the modified wheel.

JL-G27-Mod


Front view


Side view, left

Top view


Side view, right


The motors


The new pulleys


The old pulleys


The encoder


And the excel file

cool

nice work. very detailed.

Wow... really impressive!
You can know this transformation costs?

how is the felling? just as a real race car? is it a beast than can break you bone?

nice mod

fer