Thrustmaster Tx/t 300 repair and brake upgrade

Discussion in 'Sim Racing Hardware' started by Chili P, Apr 9, 2016.

  1. Chili P

    Chili P

    Thrustmaster throttle cable repair.
    Some time ago I bought a second hand Thrustmaster TX Racing Wheel Ferrari 458 Italia Edition for peanuts because it was missing all cables, in addition the control cable from the pedal set had been cut leaving about eighteen inches of cable from the pedals base.
    I ordered new cables from Thrustmaster (took approximately two weeks to arrive) and bought a set of Tx pedals second hand on an auction site, again for peanuts understandably as they are not renowned for being the best pedals and I was up and running, happy days.
    I knew at the time I would need/want better pedals but finances are tight and good pedals seem to be sky high cost wise, so I decided to try and repair and possibly upgrade the Tx pedal set with the cut cable, here is the result.

    I used the cable linked below, I simply cut off the center retention clip on the RJ12 plug, glued it on the correct side of the plug and it fitted into the Tx wheelbase fine, the clip later came adrift from the plug but this seems to have no detrimental effects with its retention or connection to the wheelbase.
    The pin out of the cable matches the Thrustmaster pedal cable so I just cut one of the plugs off the replacement cable and soldered the two cables together matching each individual wire color to color, connected every thing up and it all works fine.

    As a word of caution do not be tempted to use Lego Mindstorms NXT cable, I have seen this suggested elsewhere because it has the retention clip on the side of the plug (just like Thrustmaster) only thing is, its on the wrong side of the plug!! and you will end up having to cut the clip off to get it to fit and it will cost at least double the price of the standard Rj12 linked below.

    Tx brake modification.
    This is a load cell modification using these parts apologies for the poor quality pictures (old phone) the parts needed are :-
    5Kg load cell, this has M5 threads
    (You could use a 20Kg load cell but unless you are seriously into bodybuilding, avoid it due to the lack of leverage compared to other load cell brake mods.)
    Available here
    or here
    The load cell is mounted by screwing it down onto a piece of scrap wood cut at an angle to match the brake pedal arm angle as it is compressed, the wood block is held to the Tx pedal base by four small self tapping screws and some hot glue.

    Load cell amplifier
    Available here
    There are other load cell amplifiers available for around half the cost of the DSD one or there are also indestructible to build your own , I chose the DSD amp due to it having the addition of a gain control (recommended) his website also has some helpful instructions and wiring diagrams.

    The load cell amplifier amplifier is simply hot glued into position on the inside to the upper case of the pedals. A three or four mm hole is also drilled through the upper case just in front of the brake pedal to mount the gain control with an additional one or smaller mm hole adjacent to it for a locking pin that is on the gain control, once bolted on I hot glued it in place, additionally there is a plastic rib that is a part of the Tx pedal case and this could damage the wires leading from the gain control to the amplifier, just cut a grove in this rib so that the wires cant get squashed and hot glue them in place.
    Next I cut the wires that are attached to the old brake potentiometer, there are five wires on it, other load cell mods that I have seen there are only three wires but this has five and you need to connect them all or it will not work.

    Conical bump stop
    I used this, they come with M6 thread so a friend ground off the old stud, drilled and tapped the base plate for a M5 bolt screwed it in and spot welded it in place.
    I would not recommend these because the rubber is a bit too firm for me, giving roughly 15mm of compression or so, maybe a little more.

    I removed the Rs bump stop and put the original brake spring back by bolting it to the load cell with a spare M5 bolt and washer that was lying around. This had the effect of pre-compressing the brake spring by the load cells hight (about 10mm) making it stiffer but I also added some neoprene foam inserted inside the base of the spring to add a progressive stiffness to the brake action. As soon as pressure is applied to the brake pedal the spring immediately starts to activate the brakes (gain control helps here) once the spring is about halfway compressed it comes up against the neoprene rubber and begins to require significantly more pressure to increase the brakes effectiveness, this has worked well so far and feels good.

    Here are some pics, I know it helps a lot to be able to actually see the stuff.
    pedal mod complete 20160407_134933.jpg The inside
    conical bump stop
    The spring version

    Does it work?
    So far it works just fine, it is a definite improvement in performance and feel, to test this mod I used time trial on F1 2015 as I find that out of the games that I have, this one locks up the easiest with the old pedals.
    In the time trail I used Australia as both my son and I had been trying for months to pass this one guy but the best we could manage was (try not to laugh too much) in the 1.28s bracket using TC and ABS, attempts were also made without ABS and TC and we could almost match the times
    After the load cell modification and without using ABS within ten laps I was down to the 1.26s (eat my dust Boki) , I had to use TC as I need to reset the throttle calibration within the pedals. The brakes still lock up but I would say that it is much easier to control.
    Malaysia with TC and ABS 1.42.030, after the mod without using ABS, 3rd lap 1.39.780 and by the 10th lap I got 1.39.249
    spa/belg with TC and ABS 1.49.963, after the mod without using ABS, 5th lap 1.48.934 and on the 9th lap 1.48.890

    So there you have it, £35 to £40 for a good lap time improvement over the stock pedals, I suspect that the times may even improve further as I get used to the new feel of the brake pedal.

    This is still a WIP and there are a couple of things to be mindful of if you intend to try this mod out, the plastic pedal base can flex when extreme pressure is applied to the brake pedal, this is one of the reasons for using the wood block for mounting the load cell and it is also advisable to provide some support to the underneath of the base plate to help eliminate flex.
    On first testing out this mod I thought that I was overloading the load cell, it would reach peak load on the thrustmaster calibration and any further pressure would cause the brake load to drop off but by simply placing some packing material under the pedal base, between its support/grip feet eliminated this flex and brake drop off. (ohh and you may need to cut some of the plastic away for clearances etc)

    If there I were to do a Mk 2, I would not bother with the wooden wedge, I would use MDF/PLY on the outside of the base plate (to cover quite a large % for stiffness) and Din rail inside laid flat with the load cell mounted on that and into the outer wood base reinforcement (I dont think the wedge angle really matters much)

    sorry for the wall of text etc but I hope this can help some people out that might like a cheapo upgrade, if you have any questions just ask.
    • Like Like x 2
  2. Chili P

    Chili P

    Ok, quick update.
    the brake pedal broke off!! I did think that it might which was one of the reasons for using the 5kg load cell instead of the 20kg one that I have as well. I had a hankering to retry the 20kg but knew that I would have to reinforce the pedal arm, now I have the incentive to try that once I repair and re inforce the pedal arm. heres a picture of the break.

    Luckily I have a couple of spare sets of stock pedals to carry on with, I have to say that the brake feels bad now, really Bad. So I as I cant afford the dosh for nice new set of good pedals, I`ll try some DIY and let you know the results again with both the 5kg and 20kg load cells. (may be a while tho)
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