A "Budget" TT-02 Build

[Kowalski86 1553]

After picking up a used TT02D, I debated on going for either a rally build or just a "budget" build. I decided on budget, hopefully any newcomer who reads this build will find it useful for their TT-02 build.

The Civic TT02D is probably the best kit to start with, you get two of the "big 3", just needing a steel pinion on top of the usual paint, servo, receiver, etc.

You also get a fairly simple shell that doesn't look half bad, though be weary of the extra dimples in the Civics shell, likely for an FF chassis. 

The wheels/tires are just a cheap $15 set, just something to get it drivable on the street.

[Kowalski86 1553]

One of the areas that some builders skimp over is their servo choice, I've seen $500 builds with all sorts of hop ups...yet they used one of those red no name servos. Keep in mind, when you sell or shelf your TT02 you can always migrate the electronics to something else. You can't really migrate hop-ups.

In this case I decided on a spare metal gear HiTec servo, with a medium Kimbrough servo saver. I did have to very carefully trim the edges, but it's still much more firm than the stock Tamiya part, and a good $13 cheaper than the hop up. 

 

[Kowalski86 1553]

So...things are being a bit delayed here, it turns out that both diffs were installed backwards, I had to take the car apart and fix that and lost a bearing, so I need to pick up a new one.

With the servo saver the steering is still a bit "acceptable", there's still some friction in the system. But we'll see how it plays out on the street.

[Kowalski86 1553]

Got around to trimming the body posts only to realize that my pipe tool matches the car.

So, steering....it's okay I guess? It doesn't center that well, but my biggest problem was the tires coming off since my silicone stuff didn't hold. That cut the drove short, but when the tires stayed on it wasn't too bad.

 

 

[Kowalski86 1553]

So...glue, and a "proper" test drive finally, here's some notes:

1. These cheap no name tires do not grip all that well, and already show some wear after not being used much.

2. The steering isn't bad beyond it not centering that well, likely because of the poor step screw bell cranks setup.

3. The handling is unsurprisingly not as sharp as my Type S, BUT unlike my Type S the TT02D doesn't get tossed around nearly as much, likely because it sits higher.

4. Sport Tuned motors run HOT! Is the heat sink preventing the motor from cooling off or is this just to be expected?

[skom25 457]

On my DT-03 I observed that Heat Sink works, but it is too small. Heat Sink was just warm, but bottom of motor was burning hot.

I expect it is the same with TT-02B. Heat Sink is much larger but bottom of motor is "closed" by chassis.

Maybe try fan as I did with my TT-02B?

 

[Kowalski86 1553]

10 hours ago, skom25 said:

On my DT-03 I observed that Heat Sink works, but it is too small. Heat Sink was just warm, but bottom of motor was burning hot.

I expect it is the same with TT-02B. Heat Sink is much larger but bottom of motor is "closed" by chassis.

Maybe try fan as I did with my TT-02B?

 

In my case, the heat sink was warm and the motor near burning hot! I might try a fan, I have one in my Type S that seems to help.

[Kowalski86 1553]

After fiddling with the servo saver I decided to install hop up number one, an aluminum servo mount! This servo mount was just $13 (vs $23 for Tamiyas), it grips the servo much better, but it does add some weight.

I also grabbed a cheap, $9 aluminum motor mount. Again the Tamiya part would be $20 while offering no extra adjustability.

Finally, I replaced the heat sink with a $15 Hot Racing fan/sink combo, the biggest drawback to all of these different manufacturers is that my hop ups are now three different shades of blue!

 

 

[Kowalski86 1553]

Drove it for a bit today, if the servo mount did any it helped balance the heavy NiMH that I use, had I used a LiPO I feel like the passengers side would have weighed more.

The steering was more "loose" after some adjustments, still doesn't center all that great but that's to be expected.

With the fan/heat sink and aluminium motor mount (and not running the fiber plate) the motor didn't get nearly as hot. So running a fan does make a noticeable difference over a regular heat sink.

Also, despite a few rolls and bumps the cheap motor mount didn't loose its mesh, not a bad cheap upgrade there.

[skom25 457]

If fan improves situation, maybe I will try ST in my TT-02B. Good to know.

[Kowalski86 1553]

2 hours ago, skom25 said:

If fan improves situation, maybe I will try ST in my TT-02B. Good to know.

It should breathe better in a TT02B over a DT-03. Thank you for the fan suggestion!

On a side note, adding a shim helped some of the centering issues I was having, but not entirely. I bring up my servo saver fiddling in this thread just to show how even little adjustments can make can make a difference.

[skom25 457]

You can totally improve steering, if you use flanged collars instead of step screws.

[Kowalski86 1553]

13 hours ago, skom25 said:

You can totally improve steering, if you use flanged collars instead of step screws.

I just tried that out, I used a spare set of Tamiya flanged collars that fit surprisingly well, and some spare machine screws with bolts on the underside of the chassis.

 

[Kowalski86 1553]

During testing I noticed that the steering response improved, centering still isn't perfect and it does wander a little bit. But my Type S exhibited some of this behavior despite it having "proper" Tamiya aluminum bellcranks.

Though on a more annoying note, one of my rear wheels broke on testing. That's a first!

[Kowalski86 1553]

No pictures, but more testing on a different set of wheels.

The steering simply won't center that well, I dunno if it's my servo, my servo saver setup, or just the TT02 doing its thing. The crooked servo arm (which you will see in all TT02s) really bugs me. I'll try loosening up some screws.

That being said it's been a good on-road basher, decent run time and nothing broken in all of the incidents it's had (other than the destroyed aftermarket wheel).

I...really can't justify hopping one of these up though, I did the aluminum servo mount because this car didn't arrive with a servo mount (and the hop up was just $2 more than the parts tree), and the motor mount was for cooling.

I'm always baffled when I see a TT02 with carbon and aluminum galore...screwed down to a chassis built from ABS. And that's why the Honda Civic shell suits the TT02 to a T, it's the "ricer" of the RC world.

[one_hit 913]

All of my TT-02s track straight. I think your servo is defective, or you might have overtightened the screws on the uprights. Did you check the steering with the servo disconnected to see if there is any binding? 
 

And just because the chassis is made from ABS, doesn’t mean it’s crap. My Type S has similar lap times compared to my newly built TA08. And if you really don’t like ABS, there’s always the glass reinforced hard lower deck. And did you know that the carbon reinforced TA08 tub has waaaaaaay more flex than an ABS TT-02 tub? It needs an aftermarket top deck to be competitive in high grip tracks. 
 

 

[Kowalski86 1553]

6 hours ago, one_hit said:

 And just because the chassis is made from ABS, doesn’t mean it’s crap.

My gripe with ABS isn't the flex (thats very desirable for a basher), it's that it's a cheap, not exactly durable material.

And I see that your TT02s all have aluminum steering posts, among many other mods. I'm certain that the screws on mine are too tight.

[one_hit 913]

24 minutes ago, Kowalski86 said:

My gripe with ABS isn't the flex (thats very desirable for a basher), it's that it's a cheap, not exactly durable material.

And I see that your TT02s all have aluminum steering posts, among many other mods. I'm certain that the screws on mine are too tight.

ABS being cheap is also one of the good things about it. It is very cheap to replace it. A stock ABS TT-02 tub from PJ costs less than $4, the hopup glass reinforced tub less than $5. Compare that to $40-50 for a TA08 tub that you can’t even find anywhere at the moment. The ABS tub on my TT-02 from 2015 is still fine, still no cracks. So I really can’t agree that it’s not durable especially since mine gets used on the track where crashes are inevitable.  
 

Regarding the steering, make sure the top and bottom screws on the front uprights are not too tight. You should be able to spin the plastic spacers on those screws by hand. Also check the servo saver if there is any play. Another thing to check is the tie rod screws. If they are screwed in too tight, it will bind. 

[Kowalski86 1553]

1 hour ago, one_hit said:

ABS being cheap is also one of the good things about it. It is very cheap to replace it. A stock ABS TT-02 tub from PJ costs less than $4, the hopup glass reinforced tub less than $5. Compare that to $40-50 for a TA08 tub that you can’t even find anywhere at the moment.
 

Regarding the steering, make sure the top and bottom screws on the front uprights are not too tight. You should be able to spin the plastic spacers on those screws by hand. Also check the servo saver if there is any play. Another thing to check is the tie rod screws. If they are screwed in too tight, it will bind. 

Good point on cheap replacement parts, I don't expect the chassis to crack. It's just one of those things I'll need to adjust to I guess.

I loosened everything up a tiny bit, the bellcrank screws were definitely much too tight. It centers much better but still needs work.

My biggest annoyance is how the servo arm rubs just a bit against the servo saver, if I could flip the saver around it'd fix that. The saver itself is very solid.

[Kowalski86 1553]

If you look closely you'll see where the servo arm had been rubbing against the bell cranks "bridge", common sense would say to buy a turn buckles set, but I had a different idea...

[Kowalski86 1553]

Ran it for quite a bit today, thanks to @skom25s suggestion and after loosening up some screws, the steering is halfway decent now. It's almost "point and punch".

The only gripe is due to my own mod, where the head of the screw in the arm rubs on the servo. This doesn't effect the steering, it's just cosmetic. I'll have to switch it with a flathead screw.

So for the price of a $7 servo, spare 3mm brass tubing, and troubleshooting any binding going on. You can have "decent" steering in a TT02.

Here's a picture after some additional battle scars and the new (used) wheels.

[one_hit 913]

Glad to hear you got the steering sorted out. Which screws did skom say to loosen up? Yes it’s a good idea to always check the steering for any binding. Just pop off the steering arm from the servo and wiggle the wheels by hand. They should be smooth and free. If not, something is binding. Just loosen one thing at a time until you find it. 

[Kowalski86 1553]

1 hour ago, one_hit said:

Glad to hear you got the steering sorted out. Which screws did skom say to loosen up? Yes it’s a good idea to always check the steering for any binding. Just pop off the steering arm from the servo and wiggle the wheels by hand. They should be smooth and free. If not, something is binding. Just loosen one thing at a time until you find it. 

Thanks, Skom suggested the brass tubing, you suggested that I loosen up the screws so I have everything about half a turn, more for the bellcrank screws.