Juhunio's Bits-A-Builds WIP: TA03F-TRF Calsonic Skyline R34

[Pylon80]

25 minutes ago, BuggyDad said:

Pleased you say that. In researching the other week I concluded that this set was reasonable value despite its fairly high price, because with the more basic options you need so much else on top (turnbuckles, maybe more). So I have one on the way. Also , even before considering the advantages of differently located ball joints for the tie rods, it very much seems to me that a key failing of the TT-02 steering is its layout, with slop being amplified through pivoting arm - across rear-mounted bridge - through other pivoting arm. Bridge at the front eliminates a lot of that.

So I also intend to use it as inspiration for some more homemade tinkering on a budget rally build (basically, find a way to make a bridge directly between the tie rods; hope that eliminates enough slop that I don't worry about much else).

This steering set is great because you can adjust Ackerman, something I played with all of last year and was new to me. Also unlike what Tamiya says you can use it on a regular (non type S) TT-02. You just have to shim it accordingly on the knuckles which you should always do anyway to cancel out or control bump steer.

I did make a home made steering upgrade for the TT-02 a couple years ago. I made a jig to redrill the stock steering arms to 6mm then I pressed in some tiny flanged bearings (6mm OD / 3mm ID). Then I had a turnbuckle to replace the steering bridge. The problem is I had to sand down the adjusters to make them thinner else they would bind. That made them very weak. My rally car now uses Tamiya aluminum arms and the stock plastic bridge but with flanged tubes (like in a Type SR kit). It works surprisingly well, so I think it confirms that the problem is really in the stock steering arms and not so much in the stock steering bridge.

[BuggyDad]

18 minutes ago, Pylon80 said:

... so I think it confirms that the problem is really in the stock steering arms and not so much in the stock steering bridge.

I think so, yes. The arms are where the play is but you rely on them much more if the bridge is at the back. Put it at the front and it bypasses them for slop between left and right wheel (albeit not for slop between servo and the rest of the system). The YR system has the layout of the TT-02 basic parts but in aluminium with bearings added, and is still fairly sloppy. Also notable that the YR arms still pivot on loose fitting sleeves - you can shim outside them but it might better if these were internally threaded for solid placement I think. 

[Pylon80]

37 minutes ago, BuggyDad said:

albeit not for slop between servo and the rest of the system

Hence why I went to the effort of re-boring the arms to accept flanged bearings

I find YR to be hit and miss. Certain hop-ups are similar performance for half the price while others are so bad one ends up paying twice...

[Juhunio]

5 hours ago, Pylon80 said:

For the front I highly recommend the Rebound Stopper 54638 to adjust droop. Droop is so important and setting it with internal shims on a Type S is a bit of a waste since the arms are ready for droop screws. For the rear, the THERCRACER carbon mount will work fine but I had to protect it with a tiny square of metal from a soda can else the droop screws quickly eat through the carbon. It damages them (obviously) and also makes your rear droop change which is annoying.

I have got the Rebound Stopper set but hadn't worked out how to use it with the rear suspension mount mod so was going to leave it out. Maybe I'll take a pause and order the proper Type S adjustable rear mount set (54967) instead of using the Racer mod...hmmm 🤔

[Juhunio]

4 hours ago, Pylon80 said:

This steering set is great because you can adjust Ackerman, something I played with all of last year and was new to me. 

 

4 hours ago, BuggyDad said:

I think so, yes. The arms are where the play is but you rely on them much more if the bridge is at the back. Put it at the front and it bypasses them for slop between left and right wheel (albeit not for slop between servo and the rest of the system).

This is really great info on the steering set, thanks for sharing the discussion chaps 👍

[Pylon80]

16 minutes ago, Juhunio said:

I have got the Rebound Stopper set but hadn't worked out how to use it with the rear suspension mount mod so was going to leave it out. Maybe I'll take a pause and order the proper Type S adjustable rear mount set (54967) instead of using the Racer mod...hmmm 🤔

You do not need it for the rear as the carbon fiber part is what the grub screw in the rear arms will be resting on. In my post above I was explaining how the carbon fiber can get marred/damaged by the grub screw so I glued a tiny square of metal to protect it. I think the RC Racer part is far superior to the Type S mount since you get the ability to adjust toe and anti-squat. You should stick with it!

[Juhunio]

On 2/13/2023 at 8:48 PM, Pylon80 said:

You do not need it for the rear as the carbon fiber part is what the grub screw in the rear arms will be resting on. In my post above I was explaining how the carbon fiber can get marred/damaged by the grub screw so I glued a tiny square of metal to protect it. I think the RC Racer part is far superior to the Type S mount since you get the ability to adjust toe and anti-squat. You should stick with it!

Cool, yeah I understood that, I was just umming and ahhhing over whether I want to glue metal to the carbon or just go ahead and order the correct part

But I would prefer to stick with the RCRacer mod...what type of glue did you use?

[Pylon80]

I didn't want to use CA glue as I was afraid of fumes making the shiny carbon foggy so I just used very thin double sided tape. Completely removable

Note that it's really OCD me who does not like to see a grub screws touch carbon though. This level of detail will make most people roll their eyes.

[Juhunio]

17 hours ago, Pylon80 said:

This level of detail will make most people roll their eyes.

No, I get it...the reason I'm debating what to do is that OCD me hates the idea of sticking bits of metal to that lovely carbon 😂 So we're sharing a similar pain here 😀

In reality this will spend all or most of its life on the shelf, so a little bit of some kind of heavy but clear tape beneath the rebound screw should be protection enough 👍

[M 800STD]

Could use helicopter tape for protection

[Juhunio]

A particularly hairy deadline on Friday meant there was no time for hobby fun last week, but a classically windy, wet and miserable Welsh Saturday provided the perfect opportunity for some more time with the Type S yesterday 

First up...front arms, including the rebound stopper / droop adjustment set

[Juhunio]

The rebound stopper is a pretty smart bit of problem solving from Tamiya. Because the tub doesn't extend far enough forwards to create a surface for the grub screws to sit on, they've engineered a piece of perfectly formed plastic that attaches to the base of the front suspension mount with a cap screw. The grub screws then thread through the lower arms as normal and sit on that plastic ledge...I've set the screws pretty much neutral for now until I get a body and wheels on

Neat, huh?

[Juhunio]

Then on with the rest of the front suspension, with the uprights and hub carriers being the recommended Hop Ups in the Type S manual, and some nice aluminium turnbuckles and low friction adjusters forming the upper arms. I had opened up the front damper stay packaging at some point, but all the bits and bobs were safe and sound 

First step being the Upper Arm Mounts, which attach to the diff covers replacing the original 10mm screws with new 15mm jobs. A hex ball stud then creates the anchor for the upper arms, replacing the lower ball nuts on the damper stay

[Juhunio]

The hub carriers need a 2.5mm hole drilling through them for the grub screw that anchors them to the suspension pin, so I had my first opportunity to open my new Pin Vise which I ordered from PJ a while back. It's a really well made piece of kit and did the job perfectly

 

[Juhunio]

The other challenge with the front was assembling a set of universals, more specifically working out the correct shaft length to go with the spool

The product page on the Tamiya website shows the spool fitted to a standard TT02 using the new 37mm swing shafts, whereas the usual Hop Up universal assembly set for the TT02 used 39mm shafts (53792). So, 2mm shorter for the spool then...

However, the recommended universal assembly Hop Up for the Type S was the XV-01 front set (54515) which uses 42mm shafts

So, based on the rule of thumb that shafts for the spool need to be 2mm shorter than standard, I needed 40mm shafts for the Type S. But as no such shafts exist, I went for 39mm...

And they fit just lovely

[Juhunio]

Front end now complete, and an altogether more satisfying thing to put together than a standard TT02

[Juhunio]

Next step is the rear arms, so it's time for the RCRacer adjustable suspension mod...

[TwistedxSlayer]

Looking great Matt

[Juhunio]

First up was the rear damper stay, again without the lower ball mounts which are replaced by the Type S Upper Arm mounts

Shockingly, I had run out of blue 5mm ball nuts 😱

So I had to use these black ones until I place my next PJ order

[Juhunio]

Then onto the rear suspension mount, first step is to mount it to the Fibre Lyte plate and select your bushings of choice

Now, the standard Type S steel mount is labelled as 3^o, so is either a fan of 60s Philly soul or creates 3^o of toe. I assume the latter

I want to use a set of TRF aluminium rear uprights on this build, which are 2^o. So that means I need the suspension mount to max out at 1^o

Unfortunately it doesn't seem like that's possible...according to the back of the SR manual (which uses the same bushings in a bespoke arm mount) the lowest toe achievable is 1.5^o, using the N3 bushing. So I've gone with that and we'll have to see what it looks like when the wheels are on

 

[Juhunio]

Replicating the rebound stopper on the rear is as simple as threading a couple of 10mm grub screws through the arms. 

I added a couple of squares of Gorilla Repair Tape to the carbon plate to protect it from the grub screws, thanks to the tips from @Pylon80 and @M 800STD 👍

[Juhunio]

For the rear axles and uprights I'm using the recommended XV01 universals but with the shafts switched out for lightweight blue ones, along with TRF uprights and blue turnbuckles for the upper arms which will once again be attached to the Type S aluminium mounts

I think the only kit-standard parts here are the diff cups!

[Juhunio]

As well as the kit-specified 1mm spacer on the rear side of the upright, these also needed a 0.2mm shim on the front side to take out a wee bit of slop. They're a nice fit now, moving easily on the hinge points without any lateral play

 

[M 800STD]

You will still need to be careful with those ride height grub screws.  I have aluminium chassis ruined by these screws.

I would suggest multiple layers of tape and Dremel flat the tips of the grub screw or replace them with M3x10 machine screws.

[Nicadraus]

That's a beautiful blued TT-02! I'm not usually a fan of the TT-02 but this is one of those builds that I really like aside from the KR version from Kevin/wtcc5. Intricate build, nice parts upgrades combination (carbon reinforced plastic, carbon fiber & aluminum) and of course, the blue bits that went very well with the main chassis. As they say in the RC world, "Blue is Better".