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GooneyBird

Cup Racer 2.0, or the Ultimate TT01DR Type E-build.

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(Yeah, I said it. This is a TT01DRE. Kinda sounds like a dirt bike, doesn't it?)

As some of you might know, the Club Racer is no more. She gave her everything in an 8 hour endurance race at a local outdoor track. She made it home, but not necessarily in one piece. She was hurtin', and needed help. The more I dug in the more it became evident that this was no longer repairable. It was after I took her apart fully I decided it would be best to take her good bits, and discard the rest. She'd be giving her life for her younger sister.

You can read the whole story HERE.

Enter, a large stack of parts. Soon to become the best TT01E I can build. Since I had to replace many plastics it would make the most sense to replace them with the hop-up parts from a TT01D, or even an R. I have a couple of spares, but nowhere near enough to do a full rebuild. Assume 90% is new, and various bits and pieces come from either the spare parts bin or the Club Racer 1.0.

Things I've bought:

  • Tamiya Bathtub Chassis For TT01 #51001
  • Tamiya Spur Gear Set (55T/58T) For TT01 #53665
  • Tamiya TT01D B Parts (Suspension Arms) #51217
  • Tamiya Adjustable Upper Arm Set For TT01 & TGS #53674
  • Tamiya G Part (Gear) For TT01 #51004
  • Yeah Racing RC PTFE Bearing (5x11x4mm) 10pcs #YB6014B/S10
  • Tamiya Metal Motor Mount For TT01/DF02 #53666
  • Yeah Racing Titanium Screw Set w/FREE Mini Box for Tamiya TT-01E TS-TT01E (Totally useless, but it'd be nice to be able to use the same toolset for the TT as I do for the TRF and the M.Rage.)
  • Tamiya Drive Shaft Set (TT01) #51006
  • Tamiya TG10 long wheel shafts #50808
  • Tamiya Low Friction step screws #54409
  • Yeah Racing Diff Joint. (times 2, as it's a 4WD car)

And from the spare parts bin and taken off of the donor car there's:

 

 

  • Tamiya TT01 Aluminium Motor Heat Sink #53664
  • Tamiya Toe-in Rear upright (TT-01, TGS) #53673
  • Tamiya TT-01 Alu.Prop.Joint Shaft #54026
  • Tamiya TT02 Low Friction Suspension balls #54559
  • YEAH RACING Alum. Solid Axle For Tamiya TT02 TT02-069BU (in a TT02 diff housing. Long story...)
  • Various bits and pieces here and there.

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First up, sorting screws. The Yeah Racing-set comes with a nifty little box for all the hardware. I likey!
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Followed by the butchering of the chassis. I run square packs, but in order to make them fit in a TT01, some creativity (and a Dremel) is required. I cut out all the little triangle-pieces, and shaved the nubs flat..
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... this allows for a battery to fit, but it's not really in tight...
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... because you need foam tape for that. And lots of it. When applied correctly the battery will be so snug the holddown strap becomes superfluous.
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So snug!

Anyway, onto the actual build. The first step is to assemble the rear drive shaft and spur gear. I took a bit of time to remove all of the flashing from every part, making sure that they all rotated smoothly.
zx-Dpy-Zip-FDAHLp-Cx0-L4-F9ty-F-M1k-EISs

The next step is installing the propshaft and front drive shaft. Not very exciting, and I totally forgot to take pictures along the way. I skipped ahead a few steps and installed all of the bearings, just so I could check that the whole thing rotated smoothly. It was a bit rattly, so I added two miniscule pieces of foam in the cups to isolate the center shaft from vibrations. It sounded way better after that.

Next up, motor! Here we have our first hop-up, the metal motor mount. It feels substantial! I hope it does something for the cooling of the motor, but at the minimum it won't deform under heat like the plastic one did. (This caused excessive wear on the spur gear). I've also reshaped the heat sink as it was a bit wobbly.
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Right now it's going to run a Carson Cup Machine, as that's the standard for most races around here. Maybe at some point I'll go with a mild brushless setup (like a 17.5t or the 'other' racing motor, a Carson Dragster 16t)

4 more screws attach the motor cover. Since all the screws (technically bolts) are M3 and not self-tapping I ran a tap through all the holes. It feels like I'm turning the bolts into a nut, and not tapped plastic. I likey!
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That's how she sits right now. The new plastics combined with the titanium hex head hardware make it feel like a far more expensive and fancy car than it really is. Stay tuned for more updates!

 

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14 minutes ago, Superluminal said:

You still going to use the standard plastic moulded drive cups?

Yes, actually. During the enduro we found out that those are far more reliable than the universals, and with steering angles being not all that high at most outdoor tracks I think they'll be fine.

Also, I now have a set of long axles all-around, so the car is actually ~190mm wide instead of the ~182ish on a stretch like most TTs. And until I can find a set of longer axles for universals I'll keep running this.

Which reminds me, I may need to replace the plastic wheel hexes with alu ones too at some point.

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Wow, your parts list is nearly identical to the TT01R Type E I built for a Nissan Z-Tune shell.  I skipped the motor mount and went with a front one-way instead of a spool, but used the same ball bearings and screw set.  Anyhow, this should be fun.  Enjoy!

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On 9/11/2019 at 6:31 PM, Superluminal said:

You still going to use the standard plastic moulded drive cups?

Alright, I should have listened to you.

The plastic drive cups are fouling on the lower arms at anything more than arms level. So I DO need the smaller TB/TA-style drive cups, axle shafts and 39mm dogbones.

However, since I would like to retain the extra width given by the longer axle shafts, this means I have to go find a set of Tamiya 50808, the wider axles on the rear of a TB01/TG10, and for the fronts either the universal versions of those or a second set of 50808. And of course a set of drive cups that fit the TT-style diffs, but seeing as how Yeah Racing makes a decent set of hardened steel ones for not too much money I'll go for those. That's the easy part. 

IMG-20190911-203641206.jpg

Aww shucks. That means I got a set of longer TT-style wheel axles for nothing. :(

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Oooh I have another question if you dont mind - what do you usually run for the front diffrential on your TT01? I have been reading the thread on making a TT02 competitive and a poster there says the front diff should be almost fully locked and can be achieved by filling the standard diff unit with 1000000 cst oil (to avoid leaks) and the rear diff should be as loose/free as possible. Will the TT02 oil filled diff hopup work on the TT01 or do you prefer to use putty or similar?

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Loving the new build but can I make a suggestion. The cup racer was such a little warrior, I think rebuilding it with all the parts that went through the enduro (tyres and all) and giving it pride of place on the shelf, is something that it has certainly earned. In years to come, just looking at it will put a smile on your face every time. Just a thought.

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On 9/14/2019 at 11:04 AM, Superluminal said:

Oooh I have another question if you dont mind - what do you usually run for the front diffrential on your TT01? I have been reading the thread on making a TT02 competitive and a poster there says the front diff should be almost fully locked and can be achieved by filling the standard diff unit with 1000000 cst oil (to avoid leaks) and the rear diff should be as loose/free as possible. Will the TT02 oil filled diff hopup work on the TT01 or do you prefer to use putty or similar?

No worries, ask away!

I currently run a fully locked spool in the front. HERE are my musings on diffs for a TT. Indoors this helped a great deal with traction coming out of a corner. You could be on the throttle earlier and harder, and the nose would pull in instead of washing out. A bit weird at first, but once you get used to it you can actually use the throttle to get the car to rotate a lot sooner and quicker. There is a downside though, everything in the front drivetrain wears a LOT quicker with a spool versus a diff.

Outdoors I've found a spool to have less benefits. I ran one in the enduro, but I feel that if I'd run a 'heavy' diff, such as an oil-filled diff or a putty'd diff I'd have less tire wear for the same lap times. I'm currently debating putting the spool back in versus running a diff. I've found that the AW grease method works for maybe 10 packs, and then the grease simply flings out of the diff. Putty sounds like something I'd like to try, though the TT02RR oil filled diff is a rather appetizing hop-up. (If a bit expensive for what it is).

Oh, and the rear is 100% open all the time. TTs can be a bit tail-happy at the best of times, so anything to help that rear stay planted is welcome. My rear diff just as a small (SMALL!) dot of grease in there to keep the gears happy, but is otherwise completely dry. 

On 9/14/2019 at 12:15 PM, Scouser said:

Loving the new build but can I make a suggestion. The cup racer was such a little warrior, I think rebuilding it with all the parts that went through the enduro (tyres and all) and giving it pride of place on the shelf, is something that it has certainly earned. In years to come, just looking at it will put a smile on your face every time. Just a thought.

I'm just helping her be all she can be. There are enough Cup Racer parts in there to carry the spirit forward into the TT01DRE. 

Anyway, onto the things I did today. As I said before I couldn't run the standard 'fat' dogbones as they fouled on the lower arms. Too bad, as I'd finally manage to bag a set of wide axles extra so the car could be 190mm all around. Too bad. Today I bought a set of TG10 wide arms, along with diff outdrives to match. (And a set of low-friction step screws. @qatmix had great things to say about those in a TT02 build on his website so I got a set. Also, I'm trying to have the whole car be hex hardware, but that already failed. More on that later.

IMG-20190918-145327884.jpg

And here's the drivetrain in all its glory. Fronts are universals from the parts bin, and the rears are 39mm steel dogbones combined with TG10 wide axles. 

IMG-20190918-145816422.jpg

On the rear I'm running 2 degree toe-in blocks. I really really wanted to use e-clips and hinge pins on the rear, Tamiya makes a 3x22 hinge pin set for the DF02 that should fit, but I could not find 3x32 hinge pins to use in the lower holes. So alas, I had to break out the Tamiya screw driver, polish up the screw pins, and use those.... :(

IMG-20190918-154324292.jpg

Yeah....

Here are the front suspension arms laid out in bits. I'm using the TT02 steel low friction suspension balls, as the plastic ones tend to come apart if you look at them wrong. These are great little things, and I've yet to see any wear on them. 

IMG-20190918-155513685.jpg

The way these arms work is simple but ingenious. The turnbuckle goes in one hole to pull the halves apart or push them together, and a dowel pin goes in the other hole to prevent the whole thing from rotating itself out of alignment. Tamiya, anticipating numbnutses like me, helpfully placed an arrow on the hole where the pin goes.

IMG-20190918-160434581.jpg

When doing anything turnbuckle-related on a car it's always a good idea to have all four of them face the same way. That way, when you put a wrench on them when setting up camber it's the same direction on all four ends. In this case, forward (in travel direction) is longer, and backwards is shorter. However, this makes building a bit more involved, as you constantly check and double-check to make sure you've got everything the right way around, and that includes the rears already on the car. With the TRF this was way easier, as all you needed to make were 4 turnbuckles with ball connectors, and that's it. If you have one the wrong way around on that car, you pop it off, flip it around and put it back on. Not so much with the TT and its intricately molded suspension arms.

IMG-20190918-161004428.jpg

Remind me that this up is front, and down is back. So I don't go and install one backwards, because I totally see that happening. :D

 

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And after a week of being sick as a dog (I dunno, I felt a bit ruff!) I'm back at building stuff again. Progress has been slow as on the one hand I've fallen ill with a man-flu (Oh the horrors!) and on the other hand my job completely drains me of any energy to to anything at the end of the day. Long story and not for this thread. 

Anyway, I've gotten all the suspension arms on and shimmed out. As anticipated I'd put on one backwards. Because that's how amazing I am. With all those on the car is starting to look more and more car-ish. I've also assembled the front knuckles with the universals, shimmed them out, and popped them in.

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I'm running the Massive front bumper (as opposed to the Small-ish, Kinda-normal, Big-but-still-okay, and Really-Big ones) as it seems to fit the body I have in mind for it best. As this is going to be a racing car I'm going to run a PF LTCR2.0 on it, that it shares with the TRF. See how much handling I can get out of this beastie.

Time to assemble the steering! I've bought a set of Low-Friction step screws for the crosslink arm, and that really tightens up the whole assembly. It felt a bit sloppy, but that 99% due to the worn-out step screws in the arms. Good stuff! Underneath the step screws I'm running a small washer to prevent the plastics from eating into each-other. It's saved the arms so far, and there's no need to change something that just works.

IMG-5716.jpg

For a servo saver I've decided to go with the good ol' 51000 High Torque servo saver. Up until now I've been running the stock TT01 plastic servo saver, but after disassembly I've found hairline fractures in the plastic ring that acts as a spring. I could have probably dug up a new one of those, but I figured in the name of reliability I'd best go with a self-resetting servo saver and Tamiya's is one of the best.

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Much to my surprise the draglink is pretty much straight. As if this was meant to be! The geometry seems to work just fine, after a bit of careful trimming of the arm (a small bit off the back as it fouled on the tub) to allow for full lock.

IMG-5719.jpg

And with the servo installed you're halfway to installing all of the electronics, so that was a small step in further completing the car. I'd trimmed the excess wire off at some point and installed a Tamiya switch to the ESC when I first installed it in the previous incarnation of the car, so installation was nice and neat.

IMG-5720.jpg

I've deliberately left the wires of the motor long, as this thing changes motors frequently as required by various rulebooks. In fact, next summer I might run a brushless motor in it (Gasp!) to comply with 2020 club rules. 

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Glad to see it coming back together. I am paying attention as i might end up with one of these for the Tamiya Iconic class at my local club. The Iconic brushed motor is 17t. What kind of gearing do you run? 

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On 9/28/2019 at 12:32 PM, ThunderDragonCy said:

Glad to see it coming back together. I am paying attention as i might end up with one of these for the Tamiya Iconic class at my local club. The Iconic brushed motor is 17t. What kind of gearing do you run? 

I'm currently running a 25/55 ratio. This works for most outdoor tracks with a 25t Carson Cup Machine. I can imagine with a 17t you'd want to gear it a little lighter. What size tracks are you guys running?

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21 minutes ago, GooneyBird said:

I'm currently running a 25/55 ratio. This works for most outdoor tracks with a 25t Carson Cup Machine. I can imagine with a 17t you'd want to gear it a little lighter. What size tracks are you guys running?

For winter, tight indoor carpet. Summer is a large outdoor asphalt. 

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On 10/1/2019 at 8:36 PM, ThunderDragonCy said:

For winter, tight indoor carpet. Summer is a large outdoor asphalt. 

For the tight track I'd go with the 58t spur. That'll give you the widest range of FDRs to play with. Find one that keeps the motor temps under control. Alternatively, gear it so that it reaches peak RPM just before you start braking on the long straight. 

Outdoor just go as big as you dare. I'm running a 25/55 outdoors.

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@GooneyBird I'm thinking about a couple of upgrades on my TT01E racers. I currently have the big plastics driveshafts, and they work fine for what I need, but I noticed on re-reading this thread that if I upgrade to the TT01D arms the big outdrives will foul. Are the upgrade arms worth it in that case? If they are good, do you have any idea if some of those aftermarket aluminium gearbox outdrives for the plastic driveshafts would provide enough clearance? They look less bulky that the kit plastic outdrives. Would appreciate your thoughts. Thanks!

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@ThunderDragonCy, you're correct in thinking that they won't fit with the stock outdrives. What I did is switch to the 'smaller' style outdrives, in combination with TG10 axles in the rear, and 'normal' universals in the front. If the arms are worth it, that's entirely up to you. They give a couple more options for mounting the lower shock (yay!) and provide the means to install an anti-roll bar (does exactly diddly-squat on a TT IMHO). The real gain lies in the adjustable upper arms, and I'd focus on those over the lower arms. 

I don't know if aftermarket alu-outdrives will fit. The plastic ones foul quite badly, so they'd have to be a LOT smaller. 

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Another approach is to take a file to the plastic outdrives and remove some of the unnecessary material to make them smaller. Spinning them in a drill while holding the file against them works well to get a balanced result. They are very over engineered, so you can remove a lot of material without risk of weakening them unduly. 

This is a relatively mild trimming:

2021-05-02_04-11-15

You can take more off, making them more of a cone shape. You can't see them too well, but that is what I did with the ones on my rally car:

2021-05-02_04-08-25

They have held up to years of strenuous running with no issues. 

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Fantastic thread, and a compelling story! I had just finished reading through your excellent write-up of the car's 8-hour enduro, and look forward to seeing where this one will be headed!

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