Tt02b plasma edge II upgrade ?

[legau 8]

13 hours ago, Jonathon Gillham said:

Thats a pretty decent track for something that is just open to the public!

Yes it is, but pretty hard tough. Very dry at that moment, the clay is just rocks.

anyway it is very fun

[legau 8]

9 hours ago, nbTMM said:

Bounciness is caused by springs too stiff or shocks too soft. Try heavier weight shock oil, 1000cst 
Slapping the chassis on the ground is due to shocks too soft, or not enough ride height. Having the lower arms drooping down a bit is ok - they don't need to be completely straight.

Mounting the shocks to the inner holes on the lower suspension arms will give more range of suspension motion and it will be overall softer. The outer holes will give stiffer suspension and less range of movement.

Thanks for your advices. What is the viscosity of the stock tamiya oil ? 

I have 1130cst oil, team losi. I already filled the rear shocks. 

When you say too soft, you mean oil not thick enough or spring too soft ?

if I mount the shock to the inner holes, they will be softer, I can use spacers for the spring then, but they will have also more ground clearance  and with 1130cst oil, should be ok for that type of track no?

[nbTMM 433]

1 hour ago, legau said:

Thanks for your advices. What is the viscosity of the stock tamiya oil ? 

I have 1130cst oil, team losi. I already filled the rear shocks. 

When you say too soft, you mean oil not thick enough or spring too soft ?

if I mount the shock to the inner holes, they will be softer, I can use spacers for the spring then, but they will have also more ground clearance  and with 1130cst oil, should be ok for that type of track no?

The yellow oil in the kit is 400cst. Cst is a linear viscosity scale so 800cst is twice as thick as 400. You can also mix silicone oil to create an inbetween viscosity e.g. if you fill a shock halfway with 400cst, then the rest of the way with 1000cst you get (400+1000)/2 = 700cst. 

By the 'shock' I just mean the part with the oil, not the spring. So a soft shock is one with thin oil like the yellow kit oil. A stiff/hard shock is one with thick oil. Shocks provide resistance to suspension movement. The faster the suspension is moving, the more the shock tries to slow down that movement. The shock has two purposes, firstly to damp the springs so the car doesn't bounce out of control after the driving over a bump, and secondly to provide a resistance to hard impacts so the suspension doesn't bottom out when hitting sharp bumps or landing off a jump. If the shocks is too stiff (thick oil) they will restrict suspension movement too much and it'll be like having no suspension at all - the car will crash violently over rough ground and other things will act as the primary suspension like the deformation of the tyres and flex in the chassis. If the shock is too soft (thin oil) the suspension will bounce uncontrollably over rough ground, and bottom out easily. Most tamiya kits will have you setup the car under-damped (oil too thin).

The springs purpose is to control body roll and set the droop/compression ratio. Droop is how much the wheels can move downwards from the stationary ride height. E.g. when you pick up the car off the ground, the amount the wheels drop down when you pick it up - that's how much droop you've got.  Compression is the amount the suspension can compress (wheel cannot go any higher) from the stationary ride height. The softer the springs are, the more droop and less compression you'll have. A stiffer spring (or using the clip-on spacers/collars which pre-load the spring) results in less droop and more compression. If you have too much droop the wheels will drop down into deep ruts/holes and when you reach the other side of the hole, the bump may throw the car causing it to unsettle or flip. If you have not enough droop the car will skip over rough ground as it prevents the wheels dropping down into ruts/holes, which makes it easier to drive but results in low traction which is slow around a track. A general rule of thumb is to have about 30/70 droop/compression ratio. I.e. when you put the car on the ground the suspension compresses 30%, leaving another 70% of suspension travel to soak up bumps. Because the TT02B has so much suspension travel that can't be realised, because the chassis just hits the ground, I would aim for closer to 20/80. Most tamiya kits have you setup the car with almost no droop at all (springs too stiff and/or inappropriate mounting holes used).

Moving the mounting point of the shock (at either end) changes both the effective stiffness (at the wheels) of both shock and spring as well as the ride height, by changing the amount of leverage there is on the shock/spring assembly. If you're confused about the effect of moving to a different hole just ask this "when the wheel moves up and down by the same amount as before, how much does the length of the spring/shock assembly change?". If the answer is "more change in length than before", it's a stiffer setting. If the change in length is exactly the same, the stiffness is unchanged but the ride height may not be. 
If you change holes and then install a bunch of clip-on spring spacers/collars to readjust the ride height, you've stiffened the springs but not adjusted the shocks to suit, so you might want to go to a thicker oil too otherwise things might become bouncy. A stiffer spring requires a stiffer shock to keep it under control it.

[legau 8]

Thanks a lot for the explanations, really helpful.

anyhow, I set the shocks in the inner holes, rear and front, up and down (shock tower and suspension arm), I filled with 1130cst oil and use with spacer and no spacer at the rear.

the ground clearance is indeed improved but I still get ground impact when jumping more Than 50cm (more or less).

with the aluminium shocks of the df03, will It solve this problem or it is just the TT02b design that sucks on that point.

other than that, i’m Really happy with the car so far, the guys at the track were pretty impressed by the plasma edge, the performance With not so many hop ups, and the crash it can take before breaking. They all thought it was tamiya so just sh**t, diff not good with brushless etc... but I have demonstrated this was totally false beliefs, at least after more than 20 batteries without any problem. Anyway, my gpm steel gears are on the way, in case of... ;-) 

so last question, how to get a correct suspension on this car ? 

 

 

[nbTMM 433]

Trial and error, driver preference, type of track . Just try different spring/shock settings, ride heights and see what works best for you.

[legau 8]

8 hours ago, nbTMM said:

Trial and error, driver preference, type of track . Just try different spring/shock settings, ride heights and see what works best for you.

I don’t find the correct setting to avoid smashing it on the ground after every jump.

You said earlier the car should have a droop/compression ratio at about 20/80.

i have the impression that mine has 0/100. When I drop gently the car on the table, the shocks are not compressing at all. And I think I already had that with the stock oil. 

Even with no spacer. 

What am I doing wrong ?

[legau 8]

Look at these vid : https://youtu.be/j-gpxgySQ0k

it seems the upgrade is inevitable :-)

[Juls1 1661]

1 hour ago, legau said:

Look at these vid : https://youtu.be/j-gpxgySQ0k

it seems the upgrade is inevitable :-)

In that video he uses 3 racing oil shocks instead of Tamiya df03’s. I have both, the 3 racing units are junk compared to the Tamiya units. 

[legau 8]

20 hours ago, Juls1 said:

In that video he uses 3 racing oil shocks instead of Tamiya df03’s. I have both, the 3 racing units are junk compared to the Tamiya units. 

I just ordered the df03 :-)

what oil would you first test with these shocks ? 

[Juls1 1661]

4 hours ago, legau said:

I just ordered the df03 :-)

what oil would you first test with these shocks ? 

Start with 40wt (Tamiya yellow) use the smallest hole piston. See how that goes, if your not getting enough stability or pack then you can go up a little bit in oil weight, if the shocks are too slow you can drop weight a bit, but I highly doubt that would be the case. 

Feel free to have a look through my buggy damper thread. 

 

[legau 8]

4 hours ago, Juls1 said:

Start with 40wt (Tamiya yellow) use the smallest hole piston. See how that goes, if your not getting enough stability or pack then you can go up a little bit in oil weight, if the shocks are too slow you can drop weight a bit, but I highly doubt that would be the case. 

Feel free to have a look through my buggy damper thread. 

 

Thanks for the info, really helpful.

ok I will flll the df03 dampers with tamiya yellow and see how it goes. 

A dumb question but what tool do you use to maintain the shaft when you are screwing the little plastic support ?

i do like tamiya says, with something to protect the shaft but it always ends with some marks.

any tips ?

[Juls1 1661]

5 hours ago, legau said:

A dumb question but what tool do you use to maintain the shaft when you are screwing the little plastic support ?

I use these exact pliers, probably my favorite tool in my tool kit. 

 

http://www.rcmart.com/multi-shockclamp-version-black-p-58223.html?cPath=456_787

Tamiya also make a set but I don’t like them as the jaw is alloy not nylon so if you slip they mark the shaft. 

42276 for those that are interested.

[hanzo 9]

7 hours ago, legau said:

Thanks for the info, really helpful.

ok I will flll the df03 dampers with tamiya yellow and see how it goes. 

A dumb question but what tool do you use to maintain the shaft when you are screwing the little plastic support ?

i do like tamiya says, with something to protect the shaft but it always ends with some marks.

any tips ?

I used Tamiya non-scratch long nose pliers 74065.

[Wongataa 42]

11 hours ago, legau said:

A dumb question but what tool do you use to maintain the shaft when you are screwing the little plastic support ?

i do like tamiya says, with something to protect the shaft but it always ends with some marks.

I do it like in the manual - some needle nose pliers with paper towel around the shaft to protect it.  It works just fine and I haven't scratched a piston rod.

[TurnipJF 9192]

I use normal long nose pliers with pieces of fuel tubing over the ends of the jaws. 

[legau 8]

Thanks, i ordered the arrowmax in case of, but I received my df03 dampers this morning, along with a lot of hopups, so I didn’t want to wait and I use a heat shrink tube (several layers) around my little pliers and It went good.

I filled the front with tamiya yellow but added a little bit of 800cst oil. Il filled the rear with tamiya yellow only. I think the rear is really too soft but I can clearly see the difference between the standard shocks and these ones. 

I also installed the steering + turnbuckles, the reinforced lower arms and gear covers, the propeller shaft and joints, the fastrax motor mount with a pinion of 24T and the wheel alu hex. Not to forget a new savox servo with metal gears and the servo saver! A lot of work today! 

I also shimmed a lot of parts (lower arms, wheel axle, diff)

The spoiler has a lot of crashes as you can see in the picture  but that’s the buggy life!

i am now waiting for the front and rear aluminium wheel hub and I think she will be close to finish. 

Any other recommendations ?

i’m hesitating with the high speed gears and a larger pinion but it is already really nice like this. May be the universal shaft ? 

 

 

[hanzo 9]

8 hours ago, legau said:

I filled the front with tamiya yellow but added a little bit of 800cst oil. Il filled the rear with tamiya yellow only. I think the rear is really too soft but I can clearly see the difference between the standard shocks and these ones. 

If you do the 'drop test' by dropping the buggy on the bench say 10 or 20 centimetres, does it still bottom out/or bounce with the Tamiya yellow shock oil on the rear with the DF03 shocks?

I'm in the same situation and switched to 750 in the rears with the stock CVA's.  Higher than 10cm it bottoms out for me.  I also used the lower inner most mount point.

[ThunderDragonCy 7876]

I have the same shocks on my Thunder Dragon. I use 500wt rear 700 front with 2 hole postons. I use the stiff gold springs up front, but sone slightly softer rear springs. The softer rear setup is because the Thunder Dragon has a tendency to oversteer on turn in so the stiffer oil slows turn in and the softer rear spring increase rear roll and grip. 

[ThunderDragonCy 7876]

This is good quick look up table nowyou are tuning your chassis. 

https://www.rcscrapyard.net/uk/tips.html

As a tip, the kit springs for your tt02b are way softer than those gold df03 springs, so you can play with that for a start. If you want to get more into it, the df03 spring set 53927 is good. 

[legau 8]

4 hours ago, hanzo said:

If you do the 'drop test' by dropping the buggy on the bench say 10 or 20 centimetres, does it still bottom out/or bounce with the Tamiya yellow shock oil on the rear with the DF03 shocks?

I'm in the same situation and switched to 750 in the rears with the stock CVA's.  Higher than 10cm it bottoms out for me.  I also used the lower inner most mount point.

Yes it is still touching the ground :-(

i will post video

[legau 8]

1 hour ago, ThunderDragonCy said:

This is good quick look up table nowyou are tuning your chassis. 

https://www.rcscrapyard.net/uk/tips.html

As a tip, the kit springs for your tt02b are way softer than those gold df03 springs, so you can play with that for a start. If you want to get more into it, the df03 spring set 53927 is good. 

Thanks for the info :-)

[legau 8]

Some vid of the damper test :

https://youtu.be/3ziltAoJqDc

https://youtu.be/NVGG8659lZk

https://youtu.be/jY2YTdbSnEM

shoot your comments

[Juls1 1661]

1 minute ago, legau said:

Some vid of the damper test :

https://youtu.be/3ziltAoJqDc

https://youtu.be/NVGG8659lZk

https://youtu.be/jY2YTdbSnEM

shoot your comments

Rear shocks nearly look like there is no oil in them. Does seem like you have a lot of preload though. Usually you would setup the car with the droop set so the arms sit fairly level, the TT02b is a bit lower than normal and has little or no anti squat built in. 

In any case you want your suspension to sag till the arms are almost level. You might like to try the more outer position holes on the tower and arms. You can use the longer eyelets on the bottom so you can have about 8-10mm of sag (measured on the shock shaft) while still keeping that slightly above neutral ride height. Doing this might let you run less preload on the springs and alleviate that bouncing but it does seem you need to jump to probably 60 if not 70wt oil to get that nice pack to prevent bottoming from a 10-15cm drop and improve stability. I can see with its current setup it’d be a *** hole to drive. 

[legau 8]

31 minutes ago, Juls1 said:

Rear shocks nearly look like there is no oil in them. Does seem like you have a lot of preload though. Usually you would setup the car with the droop set so the arms sit fairly level, the TT02b is a bit lower than normal and has little or no anti squat built in. 

In any case you want your suspension to sag till the arms are almost level. You might like to try the more outer position holes on the tower and arms. You can use the longer eyelets on the bottom so you can have about 8-10mm of sag (measured on the shock shaft) while still keeping that slightly above neutral ride height. Doing this might let you run less preload on the springs and alleviate that bouncing but it does seem you need to jump to probably 60 if not 70wt oil to get that nice pack to prevent bottoming from a 10-15cm drop and improve stability. I can see with its current setup it’d be a *** hole to drive. 

Thanks a lot Juls1 for your analyse.

i notice if use the other holes (outer and middle), the ground clearance is less. 

May be I can use the middle hole with a 800cst oil and see how it goes ?

how do you set the droop? Just by turning the crown and stiffen or soften the spring ?

the longer eyelets ? What are they ? Included in the df03 kit ? 

Thanks again for all your inputs, really appreciate. I’ve learned a lot since i’m Here, but still a lot know!

[Juls1 1661]

13 minutes ago, legau said:

how do you set the droop? Just by turning the crown and stiffen or soften the spring ?

the longer eyelets ? What are they ? Included in the df03 kit ?

Your droop, it sag, while not specifically the same thing, in the case of the TT02B it essentially is. You want to reduce the spring preload until you reach the desirable 30% sag. Meaning 30% of your shock stroke should be inside the shock when the car is resting and fully laden (battery fitted, body on etc) you probably won’t need quite so much up front but it’s something you can play with. 

If you cannot achieve that sag without the spring becoming loose on the body you’ll need to use a softer spring, like the stock one. 

As for longer eyelets you might already be using them. But from the video it looked like you where not. Check the picture I’ve uploaded.