Is there a technique for popping TT02 dogbones back in?

[Exvee-Ohwan 105]

Went out for my semi-regular lunch time hot-lapping session and dropped a dogbone within 5 mins.  Typically today I didn't bring any tools, ordinarily I'd undo the upper arm so I can slot it back in.

I've heard of people popping the dogbone back in without taking anything apart, presumably flexing the plastic by force to get it in, which makes sense in principal since that must be the means by which it fell out. 

But I faffed around for a good 5 mins or so and couldn't work out how to get it back in without exerting what seemed like mechanically unsympathetic amounts of force.  Is there a trick I'm missing?

[skom25 1876]

I do not know answer, but I want to know something else:

Have you hit something or they just popped out during run?

[Exvee-Ohwan 105]

I think I clipped a kerb on this occasion.  In general this car has been pretty good in terms of retaining dogbones, think I can count on one hand the amount of times I've lost one.

[OnTheTrail 1170]

Personally I'd stick with using tools to fix this.   The more you stress the suspension parts to force it in the more likely they'll fall out next time.  

Oh, and avoid curbs too!   LOL  

[DTSCB 98]

I want to say that the dogbone can pop out if the control arms swing too high or too low.

If you disconnect the shock, you should be able to move it to where it can fall out/back in on its own.  From there, you can decide it the movement is natural enough for you to want to do it when the shock is in place. 

Also note that you may need to turn the wheels while it is in this sweet spot for it to actually happen. 

[Pylon80 3421]

5 hours ago, skom25 said:

I do not know answer, but I want to know something else:

Have you hit something or they just popped out during run?

They pop when you hit things only. Searching for a black dogbone on a black track while the other drivers are grumbling at you isn't fun! 😅

5 hours ago, Exvee-Ohwan said:

Is there a trick I'm missing?

I wouldn't pop them in without properly undoing the upper arm. There's already enough slop as it is. Also if you bend the plastic and one side ends up with more caster than the other, the car starts turning completely differently left and right.

[skom25 1876]

I will try to not hit anything. Last hit with TT-02B was bit... expensive

[Kowalski86 4075]

The main reason why dogbones pop out at the front is due to how the upper suspension arms are designed, they're narrow where they pivot in the chassis, and wide on the outside. Lots of slop in that area.

I'd personally wait and use tools myself, I have an old case dedicated to various tools and spare body clips for whenever I bring my RCs places.

[Rinskie 860]

Oh yea the process is to install universals on the front. Sure fire way to stop having to put them back in. 

[Exvee-Ohwan 105]

Thanks all, I will stick to tools for now.

 

[Juggular 5080]

Dog bones fall out easier at the front.  Steering angle makes more room.  

When the front tire flares out, hits something to widen the opening, and if the suspension is fully compressed (or fully extended), that's when dog bones fall out.  I would not force it in. But if you wanted to, that's where you could try.  But most chassis are made out of pliable plastic, you wouldn't want to train it to open easily where it shouldn't.  

When the dog bones have the least space is when the arms are horizontal.  It shouldn't be binding, but the dog bone shouldn't move in and out of either drive cups at this position.  When building an off roader, I compress the suspension halfway to see if the dog bones bind. Sometimes, Tamiya instructs us to use o-rings on both cups, but if you do, it might bind at the horizontal position.  Then I remove one.  (Not all chassis deviate from the instruction, but enough do. When it comes to o-rings in the cups, I ignore the instruction and go with what I see). 

If there is some slop at this horizontal position, there is a greater chance of it falling out when articulating. So I add more o-rings (or half a bagel of an o-ring) until there is very little slop.  (You can't decide how many o-rings to put in when the arms are up or down. If you set the o-rings to those points, the dog bone will bind when the arms are horizontal. I suspect binding dog bones can also fling out when the front steering angle is open by an impact. I think of it as being slingshot by the o-ring's pent up energy.) 

 

[skom25 1876]

I do not want to create new Topic, so I ask here. I hope @Exvee-Ohwan it is ok for you.

Are plastic cups/ dog bones good enough for almost stock TT-02? I am not worried about issue from Topic. I can live with that.

I have cups but no axles from TT-02B. I had a plan to buy 39 mm axles and use them in TT-02.

However, I am still not sure if they are necessary* in stock TT-02.

*Necessary means, that stock parts somehow limit suspension travel/ steering angle.

[markbt73 5697]

They are not necessary in a stock TT02. I've been gleefully beating the stuffing out of a stock-except-bearings TT02 for over a year now, including lots of big hits on the front (I tried it with drift tires for a while, it did not go well) and have never had a single part fail or dogbone pop out. It's almost boring in its reliability, sort of like a Toyota Corolla. I don't know, maybe I just haven't hit anything just right (or wrong). Of course, it still has the stock Torque Tuned motor in it as well...

[Exvee-Ohwan 105]

7 hours ago, skom25 said:

Necessary means, that stock parts somehow limit suspension travel/ steering angle.

I did wonder if the stock TT02's limited steering angle would be an issue for me (I was toying with the idea of deleting the D15 steering-limiter from the build, but in the end kept it), especially as my local race track is quite tight and ultimately caters to MTCs and GT12 cars, but can happily say I have zero issues getting round the track.  If I pick a bad line I might lose some time around a very tight corner and it can help at times to provoke some oversteer, but this is all just race craft and not TT02 specific.

Out in a car park or anywhere with open space it's a complete non-issue altogether.  I'd definitely say run it stock and see how you get on.  

 

 

[Exvee-Ohwan 105]

37 minutes ago, markbt73 said:

I've been gleefully beating the stuffing out of a stock-except-bearings TT02

Yep - me too!  I think I've put more packs through this car than anything else I've owned since building it.  In value for money terms it's the best RC I've ever bought.