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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 10:58 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 04:59 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 06:40 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
http://www.netbikes.com.au/roadtests/BMWR100RS.htm

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 07:39 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 08:13 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 06:16 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 11:35 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 11:47 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 01:08 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 04:57 PM

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

hobbipro 01-27-2002 06:36 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 06:45 PM

hobbipro,

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 07:21 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 07:34 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 07:45 PM

41,42
 
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.

Potato 01-27-2002 07:45 PM

DOH! You're right about the 30-33T pinions. I just checked my tool box, it's 34T, my bad, sorry. But, Tamiya DOES make larger than 39T pinion gears. They go up to 51T ! http://www.tamiya.com/english/rc/rci...ts/mini163.htm

TRF-Powered 01-27-2002 07:50 PM

Potato,

Thanks
so what's the reason not to get Evo geared up more than 41???

hobbipro 01-27-2002 08:10 PM

lem2, according to my Evo II manual I would suggest trying 88spur/35 pinion to get a 6.5 ratio. You said you wanted to run stock only, so that is a great starting piont, It should be within 1-2 teeth depending on what track you run on.
I run the .04 pitch myself since my 04R uses them, and I have a F103, I want to use them on it as well.

Anyone have some spring suggestions, suspension experience with the Evo I?

TRF-Powered 01-27-2002 08:16 PM

I run evo 1 myself.

I put 70wt assoicate suspension oil all around, and blue spring at front and white at back. also, use inner most hole for the suspension at front. it runs very stable this way for me.

However, Evo II use TRF414M's suspension geometry, so you might wanna check out TAmiya's site and see how they pro set up their 414M and apply it to your Evo II

P.S. I took out the front stablizer bar

lem2 01-28-2002 12:22 AM

TBevo set up???
 
I was just wondering cause when I got the 41,42 pinion in the packet there was a warning for using these pinion with the TB01??

I was just wondering why? Thanks

And TRF!!!!! the spring set up that you have are you running mod motors there?? or I can use it also even if I am running Stock???

How low can I go with the TBevo???

TRF-Powered 01-28-2002 12:23 AM

I run that with stock. Never run mod on that set up yet.

lem2 01-28-2002 12:39 AM

TRF
 
were you able to install the aluminum bell cranks for the TB01 to the TBevo???

could you possible help my cousin get a secong hand millenium or millenium pro charger??? he is going home here in manila this march, its a bit cheaper there. A brand new will be much better but he doesnt have any idea which stores in Ca sell it the lowest.
I know that is a ig favor to ask but I am "desperate"


hehehehehe

Thanks

Lem

TRF-Powered 01-28-2002 01:00 AM

Yes I was able to assemble the AL steering set in my EVO after 8 black spacer and two 3x15 screws later and it steers like dream now.

I don't own a millenium charger so I never thought of researching for the cheapest price for it. I personally use a integy 16x9 charger and love it. but a lot of people hated it since it trickles after a full charge.

If you really want it I would ask around the people I race with see if they have used one for sale. A new one is no problem too. Just post a message on this board and ask people who live in CA to find you a cheap one. There are tons of hobby shops here in CA hard to say who has the cheapest. I will ask someone I know tomorrow and give you answer asap.

lem2 01-28-2002 01:14 AM

Thanks!!!!!
 
Thanks TRF!!!!

Dragon 01-28-2002 04:14 AM

counteracting the leaning with weights?
...but this leaning is to the left during accelearation and to the right during braking....how to use weights?

i think it should be like what potato said...a lighter carbon shaft....

and btw, does the stabalizers help balance it as well?...i mean when the car wants to lean left or right, the stabalizers will like prevent that or somthing?.....

the back stabalizers of my evo 1 works well, but the front doesent seem to do anything.....i think its because of the design.....thats y in evo 2 its different....anyone else have the same problem?

Dragon 01-28-2002 04:24 AM

woops....wait a min...is the carbon or aluminium shaft lighter?

TRF-Powered 01-28-2002 09:25 AM

carbon is lighter, however, I have seen in many posts and personal RC websites that the carbon shaft strips in the gear case when you hit something head on.

lem2 01-28-2002 07:33 PM

re: carbon shaft!!!!
 
I have seen it break into pieces after it hit a barier and then accelerated!!!!! thats with a 10x3 motor!!!!!!

But maybe its okay for stock racing!!!!

since I had a carbon shaft with my tl01!!!

but if you weight the shaft in your hand of the carbon and the shaft that came with the TBevo there is just a small difference!!!!

I just do not know what the masters of the TBevo would say about this: That's all of you here!!!! hehehehehe

Dragon 01-30-2002 08:09 AM

wah so jia lat ar....no wonder no one buys them...haha...

anyway, does anyone with an evo whose front stabalizers actually do somthing?

hobbipro 01-31-2002 07:44 AM

I had a good chance last night to really burn a few packs in the EVO II. I made a few suspension changes that really worked good for me.

Front: Stock mounting positions
Yellow (medium spring)
60wt oil
2 hole pistons

Rear: Stock as well
White (Ex hard spring)
40wt oil
2 hole pistons

Adding a stiffer rear spring gives the front end more traction, and livens up the streering considerably. It does make the car twitchy, but manageable. I did notice the car wanting to wander to the right when excelerating hard, must be the shaft drive bias everyones been talking about. I'm planning on getting rid of the front one-way since I couldnt stop hard without spinning out, other drivers could out brake me, and cut underneath me. Also I'm going to try the Ta04R front C hub with the torque bar that attaches to the top of the steering posts to see if stiffening the front hub area will help any.
Otherwise car has handled a few run ins with the boards, and no broken parts yet. :)

Dragon 01-31-2002 08:34 AM

if the cars wander to the right during high acceleration due to the shaft being bias to roll to the right, wont the stabalizers prevent that from happening?...some people even call it anti-roll bars right?

i wonder if i can get the front stabalizers of the evo2 to fit on my evo 1....hmmmm....

Potato 01-31-2002 11:48 AM

I don't know if stabilizers will help... you can't eliminate the shaft torque. There will always be a larger force on one side than the other created by the shaft during acceleration or deceleration. Stabilizers are meant for reducing body roll, not really for counteracting the shaft torque.

TRF-Powered 01-31-2002 04:25 PM

Hobbipro,

How much did you pay for your EVo 2 shipping all the way from Hong Kong?

i am thinking getting an EVO2 too. However as a owner of Evo1, I am really worried about the ball diff come with any Evo. The diff has been a pain to get to. and it is so hard to get it just right. Does Evo 2 has the same problem?

The problem I have with the ball diff is that it's hard to get it just right. It's either too tight that locks up the rear when let go the throttle, or too loose. But once get it right it seems to be very smooth. but tearing the whole car down just to fix a diff is really annoying job.

imataquito 01-31-2002 07:26 PM

dragon .....
try using harder springs and harder damping so the torque of the shaft wont effect ur car ... or make the effect slower / less noticable or alltogether elimating it

hobbipro 01-31-2002 07:29 PM

TRF, I ordered my EVO II from stellamodels in HK. I found him on Ebay. HE sells them for $245 + $28 S&H, Not a bad price at all seeing as tower is going to sell it for $489 once it hits the states. It took 7 days to reach me via air mail. Good service if you ask me. If you want to see if he has any type in "Tamiya Evolution" on ebays item bar.
Secondly, yes the ball diff is almost impossible to get to once its in the car. The key is to get it adjusted right before you stick it in the car. I have built many cars over the years, and have a good feel for adjusting a diff. Simply take 2 allen keys or something to hold both outdrives, and try to turn the diff gear while holding on tightly. The gear should not be able to turn whatsoever! I played with the EVO diff for hours to find a good set point, and 1/4 turn from all the way tight works good. Especially if your using a hot mod like I am. Anything over 1/2 turn from tight, and it starts to slip. So basically no more than 1/2 turn. Dont worry if it feels notchy at first, after a few runs it breaks in and feels nice and free.
I ordered a front ball diff today, so we shall see next week how it runs. I've never been a fan of front one-ways in my other cars since my tracks are outside on asphault, and not always the cleanest.

Dragon 01-31-2002 07:55 PM

this shaft torque, does it also affect the TC3, MTR4TC or other shaft cars? do they have anything special on them to fix it?

Potato 01-31-2002 08:07 PM

I believe the MR4 is belt drive, and I think the TC3 has asymmetric suspension parts to supposedly counteract the forces. I'm not sure how effective it is, since I don't own one myself.

Dragon 01-31-2002 08:20 PM

OMG...whats Asymmetric suspension?...anywhere i can look it up?

hobbipro 01-31-2002 08:27 PM

Dragon, The TC3 has the same torque effect. A friend of mine had one that I was able to drive on a few occasions. While it handled great it still had that little tedency bias to the right. He now has jumped to the schumacher mission, and I must say it is much nicer than his TC3 was.
I had a Yokomo MR4- Special a few months ago, it is belt drive, so no torque bias on that one. The only other cars to have a shaft are the MRC cars.

TRF-Powered 01-31-2002 10:07 PM

Hey Hobbipro,

1/4 is exactly what I use now. just like you said, it locks a little at first, but is super smooth now.

Also, Does Evo 2 still use +2 offset wheels?

Yeah I saw stellamodels on Ebay too. the price is really good.

by the way, does it come shrink-wrapped?


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