T3PA loadcell upgrade DIY guide (1 Viewer)

Hujkis

Well-Known Member
Member
Joined
Sep 27, 2017
Messages
295
Steam
View
Credit to u/Sector95, who brought the sensor and the amp to my attention here.

This could be useful for people with T3PA that don't want to spend 250€ for Elites LC.
EDIT: I should mention, there is no software work needed, thanks to the Leo Bodnar LC amp. I've ended up just tweaking in-game brake deadzone and sensitivity.

What you'll need:
IMG_20180915_171543.jpg


  • 20kg Load cell sensor - <5$ from China, but can be found on amazon.{de,com}. They usually come with the HX711 module, but we're not going to use that.
  • Leo Bodnar LC amp - unidirectional
  • M4 rubber - size depends on your preference, as long as it has M4 screw, you're good. I got these
  • Cable with JST XH 3-pin connector
    • here it is important not to be an idiot like me and buy the correct connector. I ended up with PH, and after searching my place, I had every concievable JST connector except the XH 3-pin, so I've ended up doing some dirty workarounds. Sorry for that :)
    • alternatively, you could cannibalise the connector+cables from the brake potenciometer, since you will not going to use it anymore. But, it will be hard to revert back. It will also be ugly.
IMG_20180915_171745.jpg


  • 2x M5 screw - anything over 2cm is fine
  • 2x M5 nut
  • M5 drill bit for metal
And some tools:
IMG_20180916_104427.jpg


  • screwdrivers
  • H2,5 hex
  • something for the nuts :)
optional:
IMG_20180915_171900.jpg
  • hot glue pistol for amp and wire mgmt ( in true thrustmaster fashion :) )
  • soldering equipment for the wires.


1.
Drill holes to the conical mod metal plate.
IMG_20180915_175824.jpg


2.
Attach the sensor
IMG_20180915_180331.jpg


3.
Attach amp to the sensor
IMG_20180915_175503.jpg

just use the small screwdriver for that. Leo Bodnar FTW.

4.
Prepare the wires for amp-pedals connection

This depends on what you bought and whether you'll willing to do some soldering. Hopefully, your solution will be better looking than mine :D
More about this wire below.

5.
Inside the pedal assembly:
  • unscrew all 4 milions screws from the bottom of the pedals
  • open the lid slowly and disconnect the JST connector
  • unscrew the brake pedal loose
    • without this, it is impossible to fit the metal plate with sensor attached - from this IMG_20180915_194707.jpg to this IMG_20180915_194821.jpg
    • now it's also a good time to think about where the sensor wires will go.
  • screw the pedal back
  • attach the amp - I used hot glue, but you should be able to screw it down somewhere
  • connect the amp to the pedals, where the potentiometer used to be.
IMG_20180915_182437.jpg

* don't connect it like this. More on that below.

6.
Assemble it back, you're done.
...or do some testing first :)

Now, my journey was not that smooth. After I connected everything, the brake pedal did not work. I've spent hours trying to figure out what was wrong, re-soldered everything, re-connected everything and finally, I found it was the wiring to the amp.
The solution is to switch +5V red wire with ground black wire. WTF Thrustmaster!
...so if you take a look at the picure above, you can either put the 3pin amp connector backwards or prepare the pedal connector so the black wire is on the right, red on the left.

This was my V1:
IMG_20180915_201216.jpg

Using 2x rubber stop and nuts as spacers.

I've done a few laps and the pedal felt way to hard. So I did a few modification:
IMG_20180916_103740.jpg

  • replaced the nuts with washers. This way there is still space between the plate and the sensor, but just nanometers...
  • removed the lower rubber stop.
  • put the brake pedal plate higher

...and that's it. I'm quite happy with the result. Pretty easy to get use to. Definitely feels more 'natural'. Can't compare it to other LC pedals, you decide if it's worth it or not.
I've spent ~30€ on it, but you can get all the stuff cheaper, especially if you order from China.

Hope it helps,
M.
 

Attachments

Last edited:

cheba

New Member
Probationer
Joined
Nov 8, 2018
Messages
2
Steam
View
Nice mod! Thinking of doing the same myself since I've tried out a load cell with Arduino as a separate device, but due to driver issues I would love to integrate it into the T3PA/T300 combo to get rid of a separate USB device.

However I have a question: Do you use the T3PA with a USB adapter instead of connected to a Thrustmaster wheel? I'm asking because at least with the T3PA connected to a T300, the voltage over the potentiometers is 3.3V. I assume this is too low for a Leo Bodnar amp to work properly, since the Leo Bodnar amp is rated for 5V +-20%.
 

Hujkis

Well-Known Member
Member
Joined
Sep 27, 2017
Messages
295
Steam
View
Good point. I didn't have the voltmeter on me, so I did't check, but yes, I'm using the wheel, not usb.
 

cheba

New Member
Probationer
Joined
Nov 8, 2018
Messages
2
Steam
View
I see. Apparently the amp you have works with 3.3V then. I'm thinking of ordering one and trying it out myself. If it doesn't work, I can splice a spare USB cable to get a 5V supply to it.
 

stewink

New Member
Probationer
Joined
Nov 20, 2018
Messages
3
Hi, this looks like a great upgrade fantastic work!!!

I will definitely be giving my T3PA pedals a Christmas upgrade with this

It is *ALMOST* exactly what I'm looking for. Just 2 questions...

1. If I wanted to fit a variable resistor into the circuit to adjust the 'gain' of the pedal (i.e. adjust how much force would produce 100% braking in game) where would I put it in the wiring? What value would you recommend? 0 - 1 KOhm?, 0 - 10 Ohm? etc...

2. I guess increasing the value of the variable resistor (I mentioned above) would lower the voltage input to the pedals - meaning the registered 'braking' value is lower for the same force on the pedal. This makes me think a 20kg Load Cell with a resistor added behaves more like a 40kg Load Cell? Is that right, so it will only ever get 'harder' to press the pedal, the more I dial it up?

I know I can adjust the dead-zone and linearity in game to get closer to what I want from the brake pedal, but I would still like some more flexibility and I noticed that Fanatec pedals have a dial mounted on the side of the load cell, was going to do the same thing (small bracket between loadcell and conical bracket, with resistor dial on it). Just not savvy enough with electronics to work it out!

Thanks in advance for any help you can give me

Steve W
 

Hujkis

Well-Known Member
Member
Joined
Sep 27, 2017
Messages
295
Steam
View
Hi Steve,
thanks!

First of all, I wouldn't call it a 'great' upgrade. After fiddling with in-game brake settings as best as I could, I'm still no better with trailbraking as I was without the LC. I think a softer rubber would work much better. That would probably mean mounting the LC further from the pedal, and that would mean modifying the metal original metal bracket even more, which I'm not willing to do. Anyway, if I'll have some time, I'll try to find softer rubber that would fit in the setup I have now and report back.

I like your idea! Unfortunately, I'm probably the last person to give advice about electrics. It should be quite easy to test though :)
As @cheba stated, we might actually be running on 3.3V, instead of 5V (without external usb power mod). The LC's operational voltage is 2.6-5.5V with 1.7 mA (I think). So, get a voltmeter and do the math :p

where would I put it in the wiring?
There is plenty of space inside the pedals, if that's what you're asking.
 

stewink

New Member
Probationer
Joined
Nov 20, 2018
Messages
3
Hi Steve,
thanks!

First of all, I wouldn't call it a 'great' upgrade. After fiddling with in-game brake settings as best as I could, I'm still no better with trailbraking as I was without the LC. I think a softer rubber would work much better. That would probably mean mounting the LC further from the pedal, and that would mean modifying the metal original metal bracket even more, which I'm not willing to do. Anyway, if I'll have some time, I'll try to find softer rubber that would fit in the setup I have now and report back.

I like your idea! Unfortunately, I'm probably the last person to give advice about electrics. It should be quite easy to test though :)
As @cheba stated, we might actually be running on 3.3V, instead of 5V (without external usb power mod). The LC's operational voltage is 2.6-5.5V with 1.7 mA (I think). So, get a voltmeter and do the math :p


There is plenty of space inside the pedals, if that's what you're asking.
To 'soften' the effect of the rubber stop you already have, you could try to cut it into a conical shape?
 

stewink

New Member
Probationer
Joined
Nov 20, 2018
Messages
3
I'm ashamed I didn't think of that! :) What tool would you recommend for the job?
Also i noticed you left the single rubber stop in the top hole?. If you put the rubber in the bottom hole, then you would get more leverage from pressing on the top of the brake pedal to squash it? So it would 'feel' softer?
 

Hujkis

Well-Known Member
Member
Joined
Sep 27, 2017
Messages
295
Steam
View
Also i noticed you left the single rubber stop in the top hole?. If you put the rubber in the bottom hole, then you would get more leverage from pressing on the top of the brake pedal to squash it? So it would 'feel' softer?
Good point. I think I used the top one, because there is 'more space' between the pedal and the LC.
 

Wallaby

New Member
Probationer
Joined
Feb 10, 2019
Messages
1
Steam
View
I didn't get mine to work, I order 2 load cells just in case. The first one I installed didn't react at all in the Thrustmaster control panel. The other one reacted to me pressing on the load cell, however it was like 1/20 of the whole bar in the control panel. Any ideas?
 

Angel

Junior Member
Member
Joined
Nov 6, 2018
Messages
37
This is probably off-topic, but I'm thinking of upgrading my brake pedal as well with a LC and don't have the know-how or time to get into doing it myself.

So I was thinking of getting one from loadcellmod.com, they offer two depending on whether you want it with 10Kg or 20Kg.

I know that this decision is mostly a personal preference, but I've also read that the stiffer it is (since this mod is not adjustable) the more difficult it is to sense how much you are braking.

What do you reckon? is one of those a good purchase? which one would you prefer and why 10 vs 20kg?

Thank you in advance!
 

Hujkis

Well-Known Member
Member
Joined
Sep 27, 2017
Messages
295
Steam
View
This is probably off-topic, but I'm thinking of upgrading my brake pedal as well with a LC and don't have the know-how or time to get into doing it myself.

So I was thinking of getting one from loadcellmod.com, they offer two depending on whether you want it with 10Kg or 20Kg.

I know that this decision is mostly a personal preference, but I've also read that the stiffer it is (since this mod is not adjustable) the more difficult it is to sense how much you are braking.

What do you reckon? is one of those a good purchase? which one would you prefer and why 10 vs 20kg?

Thank you in advance!
Hi,
honestly, €90 is not an adequate price for this thing. Don't do it. If you really want to improve your braking, get a Fanatec CSL LC new or used, or better pedals, otherwise you'll be disappointed.
There are better ways to spend €90 on your rig :)
 

Angel

Junior Member
Member
Joined
Nov 6, 2018
Messages
37
Thank you! I saw the Fanatec ones, they were in my mind too, however I was exploring the possibility to get an upgrade for less than half of their cost...

But I guess you are right, better to spend 250 and be satisfied than going around spending money on cheap half-measures...
 

Savyman

New Member
Probationer
Joined
Mar 13, 2019
Messages
2
Hi I just wanted to say thanks for the post regarding DIY load cell. I had been talking to a good friend of mine about my driving and suggested going for a load cell setup with my T3PA pro pedals. And he also sent me this link which I used to find and purchase the parts for my DIY setup.
I wont say I didn't have any issues but that was due to getting the pedals apart and there was no plug on the circuit board for the pro pedals. I also had to make my own bracket to hold the load cell but it's all fitted working well and very happy with the results.
 

Attachments

Verwend

New Member
Probationer
Joined
Mar 17, 2019
Messages
1
Hi I just wanted to say thanks for the post regarding DIY load cell. I had been talking to a good friend of mine about my driving and suggested going for a load cell setup with my T3PA pro pedals. And he also sent me this link which I used to find and purchase the parts for my DIY setup.
I wont say I didn't have any issues but that was due to getting the pedals apart and there was no plug on the circuit board for the pro pedals. I also had to make my own bracket to hold the load cell but it's all fitted working well and very happy with the results.
Nice job.
Please, excuse me for my level of english.

Would you mind posting more photos (mainly of the wiring between the leo-bodnar amp antes the t3pa-pro pedales)? Are your pedals working well with the leo-bodnar amp?

And, for everybody...has anyone tryed this mod with a PS4? How are you able to calibrate them in the games?

Thanks a lot, and congratulations forma this mod, it is amazing. I would tryed it in a few days.
 

mmarkotan

New Member
Probationer
Joined
Jun 10, 2019
Messages
1
hi, thank you for the guide. I´ve tried to build one myself and followed your instructions step by step with partial success :). The mod works but
1) when connected via t300 base after pressing down on the brake pedal the "brake value" rises evenly up to 30% and then spikes to 100% (this happens all the time when connected via t300)
2) when connect via USB adapter it works like it should for a while but then it goes back to "spike from 30 to 100" and I have to switch the adapter from pedals to rudder and back again.
Please if you have any idea what might be causing this let me know (I don´t know much about electronics). I am going to build everything from scratch but I doubt it´s gonna help because I am going to do everything just like I did last time.
 

Attachments

popo2993

New Member
Probationer
Joined
Sep 3, 2019
Messages
1
hey, guys, I am just writing about this mod as my potentiometer has seized up I was wanting to install a load cell mod to bypass the potentiometer all together
however when I have stripped down my pedals set and opened them up the wires are not socket fitted but are soldered to the board instead has anyone here had to solder to the board at all and does the load cell actually bypass the need of the potentiometer because this load cell will end up costing me what I paid for the pedal set.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top