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-   -   Tamiya TB-Evolution II (https://www.rctech.net/forum/electric-road/2656-tamiya-tb-evolution-ii.html)

Dragon 01-25-2002 09:58 AM

Tamiya TB-Evolution II
Ive just got one and built it up....its beautiful.....i love most of it,,,...the only thing i dont like is the new chasiss design....the upperdeck doesent feel so secure, and the cuntersunk screw holes under the lower deck is so close to the edges....i wonder will that be a problem in the long run....hmmm....but most of everything else is great.....

anyone else got the car?....care to share your views?

Potato 01-25-2002 03:59 PM

I don't have the car, but I'm just wondering, if you gun the throttle, will the car lean to one side? Like if you suddenly accelerate while holding the car in the air, does the car jerk to the left or right? Then, if you brake while the car is running (while you're holding it) does it jerk in the opposite direction? I'm curious about the shaft drive design.

Alvin 01-26-2002 05:40 PM

I have heard from my car crazy r/c kakis that shaft driven cars have an inherent problems - torque reaction. Meaning that the rotating mass of the shaft and motor has a tendency to pull the car to one side. I myself drive a tb01 and my driend driving another tb01 don't exactly feel it, unless of course you guys are running low turn mods. He ran up to 13x2 and I ran up to 14x2.

However, I have recently been reading up on 1:1 scale stuff and applying some of it to r/c - I found this little interesting bit - it could possibly affect shaft driven r/c vehicles too:-

Blipping the throttle at a standstill produces the famous BMW trait of the torque reaction tipping the bike to the rider's right. Any time the bike does tip to an angle of more than a few degrees, one has a struggle to keep it upright, the fairly

So in real life the bloody torque reaction thing does have an adverse effect. I was told that this problem is even more pronounced with drag racing cars. But I have not found any info on the web yet :confused:

In fact since the way belt drive cars have the rotating mass spin forward, won't you think it actually helps to stabilize the car somehow?

Dragon: congrat on your TBEVO2. I look forward to seeing u in the tamiya series :sneaky: i.e. if you are going. Hopefully by then I have acquired my final piece of equipment - a new servo to replace my S3003 :ha:

Hope you CA'd the carbon edges properly, my tb01's upperdeck has a blemish thanks me applying a bit too much CA :cry:

hobbipro 01-26-2002 06:39 PM

I received my Evo II from Hong Kong about a week ago. So far so good. I have a TA04-R, and 04 Pro, so I figured why not a Evo II. The only problems I found with the manual is with the rear diff setting, its way too loose. It says to tighten the diff screw till its tight, then back it off a revolution. When this was done to mine it slipped easily when holding both out drives. I ended up setting it at 1/4 turn from full tight. Anything over 1/6 to 1/2, and it starts to slip. I called Tamiya about this and they said it should not slip whatsoever, and to tighten it to where it wont burn up the diff. So pay special attention to this when building!

Also the rear joint cups are supposed to be glued in place with a synthetic rubber cement (not supplied). I first tried Elmers rubberized contact cement, but after 1 pack they came out of there sockets slightly. Now I'm going to try Weather Strip contact cement. If that doesnt hold, the only other thing left is JB weld, but then it will be impossible to get apart. Does any one have any other glue suggestions? I would think that a car of this quality would have a little better design than this.
I didnt really notice a right/left bias, but more runs will tell compared to my 04's. They claim they solved the left/right bias issues with this Evo II, We'll see.

Potato 01-26-2002 07:13 PM

Hobbipro, have you tried running it while holding it in the air? Punch the throttle and then the brakes, see if it torques to the side. I have some contact cement by Devco, I used it for my F1's tires. It works good, but I'm not sure how it will work for your application. Do you intend for it to be removed? You can try high quality CA glue. If you want to remove it, I think you can boil it in water or use CA remover. You can also try shoe goo, but it's probably not strong enough.

Is JB weld very thick like epoxy? It might cause vibration if not evenly distributed.

Dragon 01-27-2002 05:16 AM

waha...i dont really know if they solved it a not, coz i wont be running this evoII of mine yet....it will be on my self for display for collection...hehe....

but when i held up my evo I and full throttled from rest, it leaned to the left(Car facing towards me), and to the right when i applied the brake.... but it doesent happen if i progressively accelerate....anyway what can be done to prevent this from happening?

Fire 01-27-2002 10:35 AM

the tire's traction should be enough to keep the car straight~
unless the driver is like an on/off switch when driving or racing.

newracer 01-27-2002 10:47 AM

I used elmers rubber cementon my evo I for the drive cups and it worked great, just make sure you use enough

Potato 01-27-2002 12:08 PM

Ah, so it does lean. At constant speed, there won't be any problem though. It will only happen if you accelerate or brake. Supposedly the designers can compensate for this with unequal right and left suspension systems, but I'm not sure how well this works because the torque from the shaft is always changing. I don't think it can truly be compensated for. Ultimately, in some situations, you're going to have more force applied on one side than the other because of the shaft drive. I'm not sure it's noticeable, though. It seems most people drive shaft drives with no problems. I think they sometimes use weights to try to balance the shaft torque. Also, having a lighter shaft and a heavier car will reduce the problem (although I doubt many would want to make their car heavier on purpose).

PS Also if you're smooth on the throttle it won't be severe, like you said, when gradually accelerating the problem isn't as pronounced.

newracer 01-27-2002 03:57 PM

I never noticed any torque steer with my evo and I ran a 10x3 in mod.

hobbipro 01-27-2002 05:36 PM

I ran my EVO II today and to answer the question: Yes, it does lean a small amount to the right when tapping the throttle holding the car from the front. I was using a Ti 10x2, 88 spur/27 pinion the car didnt really didnt do anything abnormal on the track. The car seems super stable at speed, it has good cornering, but I would like to see it dive into corners more tightly like my 04R does. I think It needs a spring change since I was running bone stock red springs, and 400Wt oil all around. I dont see why it comes with red (soft) springs, when the 04R comes with yellow (medium) springs, when the EVO II is clearly 3-4oz heavier. I will do more testing.
One piece of advice I'd like to give is to make a small hole in the stock plastic antenna mount, and place a 3mm set screw (spares are given in the kit) in it to lock the antenna in place. The stock mount doesnt hold the antenna, and it easily pulls out.

TRF-Powered 01-27-2002 05:45 PM


I run a Evo I, and I never found any pinion that meshes well with the spur in the kit unless it's a Tamiya 04 pinion. Where did you get a 27 pinion?? I have pinions ranges from 34 to 39 since that's what tamiya makes. I have been looking around for a 33 or 32 pinion, do you know if tamiya makes it? or what brand of pinion meshes with tamiya spur?? Thanks

Potato 01-27-2002 06:21 PM

For 0.4 pitch tamiya makes them much lower than 33. I'm sure you can find them if you look. I have a 33 tooth in my toolbox, and I had a 32 tooth, but I gave it to someone. The lower teeth pinions are steel, while the larger ones are aluminum.

TRF-Powered 01-27-2002 06:34 PM

Just checked Tamiya's website.

They do not have pinions gears from 30 to 33T. the smallest 04pinion they have is 20T, and the highest is 39T.

lem2 01-27-2002 06:45 PM

Hi!! The web site of tamiya is not updated!!!

I just got 41,42 pinions for my TBevo but they said that I should be careful in using it in the TBevo, up to 41 only and no higher!

I just plan to race it stock!!

They said that if you hsould put lead weights to counter act the force of acceleraion in shaft driven cars I just experimented py taping coins and it seems to work with my car! during acceleration.

And I compared my evo to my friends fully hopped up tc3, which costs more here, and Yahooooo!!!! for me the evo performs better, i just wonder why it isnt used much or i do not see it a lot when there are races.

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