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GooneyBird

The aftermath of racing for 275 km in 8 hard hours. (long post, many photos)

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"Dude, it's a TT01! Will that even hold up to that distance?" people asked.

Short answer, yes it is. But don't expect a functioning car after it's done. There are consequences!

In numbers:
- 275 km, spread out over 1000 laps.
- 3 guys in our team. Two drivers and one mechanic/marshal
- 20 minutes per battery
- 10 driver changes
- 23 battery changes
- 3 sets of tires completely gone
- 2 completely threadbare tires ("No, it still feels fine, I'm sure we can do at least 2 more stints on these tires!")
- 1 major breakdown
- Many, many buttpucker-moments
- A lot of fun!

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Long answer, incoming. Along with many, many photos.

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This weekend a track near to me held an endurance race. 1000 laps of the track, starting in the early afternoon and continuing into the night. I participated, along with a friend and my dad using my trusty TT01E Cup Racer. @Fuijo chipped in and made this gorgeous replica of the Flying Lizard Motorsport 911 GT3, using a Tamiya 911 GTS3 and a decal set from MCI. I then added my own touches to it (namely a light set) and prepped the car for the 8 grueling hours of racing that lay ahead.

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We started off in fifth position, but quickly made our way up to fourth, where we stayed put for the first couple of hours. We were comfortably fourth, with a 20 lap gap in either direction. We were on cruise mode. Then all of a sudden, we lost power. I was struggling to keep the car up to speed, and I was getting lapped left and right. Turns out the issue was two-fold.

First, the battery that came out looked like this:
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Yeah, that one's done.

Secondly, and far more seriously, the rear diff crown gear had shifted and locked up. I nursed the car back into the pit lane (any repair that made the car unable to go back to the pit was a DNF) and threw in on the bench. It turned out that the rear diff enclosure had split, causing the diff to move down (!) and so forcing the entire pinion shaft up and making everything go wonky downstream. But more on that later.

After 20 minutes of frantic wrenching, we were back on track. However, we were down to sixth!
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We drove on all-attack mode, and managed to crawl back to fifth after the guy in front of us suffered a failure. That meant we slid back into our original starting spot.

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As night fell the threat of rain emerged. We turned the lights on at 19:30, and maybe 30 minutes later the heavens opened up. I was doing a driving stint at the time, and was concerned with the traction falling off and of course water damage to the electronics. The speed controller is waterproof, and so should the servo be, but the receiver and the TLU01 controlling the lights aren't. I figured as long as I kept the car warm, meaning not slowing down, it'd keep most of the moisture from settling onto the electronics.

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Much to our surprise, most of our competitors either crashed, or slowed down to such an extend that I was able to make up two (!) positions in the 60 minutes that I had the wheel. We did 3 stints in the rain, and the car never missed a beat. My TT is set up to be a bit understeery. This makes it easy to drive, and in the rain, an easy to handle car is a fast car. Everyone spun out, and I was able to keep a decent speed (lap times were down maybe 10% from dry laps, and it was getting darker and darker). This meant we climbed from fifth into third as dusk turned into night.

In the nighttime we soldiered on. Battery changes were done with the assistance of a light on your forehead and sheer experience. At about 22:00 I started to feel fatigue setting in. During the day and the dusk we could manage 3 stints back to back. This meant 60 minutes of driving, and then handing it back over to the other. But in the complete darkness, with nothing but our (fading and failing) headlights to guide us, the best we could do was 2 stints followed by a driver change.

During the night we kept our third place, but number four was never far away. During the better part we were no more than 4 laps ahead of our competitor, and a couple of tangles with backmarkers getting frustrated and/or too caught up in their own fights meant that for the better part of 30 minutes we were actually on the same lap. My friend was running that session, and we had trouble keeping third. So we decided to undercut the other guy. I pulled the car in early, changed the tires and the battery, and went out about 15 laps before we were scheduled. I noticed the other guy slowing down as well, and he was due for a pit stop too. With fresh tires and a charged pack I soon blitzed by him and managed to pull a 3 lap lead as he had to pit after us and had a bit of trouble (I heard later).

The car was performing better in the cool night. It was getting loud and chattery, but she kept on ticking. Lap after lap after lap passed under her wheels, and with each fresh pack she felt eager. She wanted this as much as we did. However, all of the dust and dirt washed back on track meant that the headlights were fading. At the beginning of the night we had sharp yellow headlights, and by the end they sorta faded into this globby, no-real-definition, instant-MOT-failure mess. With the final 3 stints the rains came back. By now we were closing in on midnight. Fortunately it wasn't a downpour, but enough to dampen the track. Once again my little TT stepped up to the plate, and with others slowing down we started pulling in on number two. However, 20 minutes wasn't enough to make up the 20-ish lap gap, and we finished third. We did it. The car did it. Boy, we were exhausted!

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Right after I pulled her off the track. Notice the dirt and grime, as well as the basically-opague headlights.

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The body split in two places along the front splitter, but otherwise held up fine! A bolt fell out of the rear wing, but the thing stayed on regardless. Lucky!

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So how does that affect the longevity of a TT01E? Well, today I pulled her apart completely.
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What broke? Several things, in fact.
- The rear diff cover snapped off and caused all sorts of weirdness with the rear diff and spur. (Top right, next to the body posts is the broken housing)
- The spur-and-pinion cover melted to the chassis due to the heat (Top right, next to the rear wheel)
- The tub itself has damage from the heat from all of this.
- The front left bearing exploded, causing the wheel shaft to chatter and vibrate. We opted not to replace this during the race, as the car was fine with a vibrating wheel.
- The rear diff housing is damaged, along with the crown gear (as seen below)
- The spur gear itself is toast. The steel pinion, however, seems perfectly serviceable.
- The on/off switch has broken in half during a spirited battery change.
- The servo makes interesting (and expensive) sounds.
- The motor has very little brush life left.

As you might notice, I removed the front universals, opting to go for the dogbones. If a universal snaps they usually bind up. A dogbone will simply snap off and fall away. Reliability is the name of the game here. Also, there are no shocks. My team mate came to me during free practice with a set of TRF Big Bore dampers. We used those on the car, and I gave them back after the race. The shocks, btw, were fine and dry. (and really, really dirty)

A few highlights:
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The exploded bearing on the left. It pushed out all of the grease, and the stain was noticable on the front left wheel. Note how much the axle stub has worn down, and how much coating was taken off of the wheel hex.

IMG-5545.jpgThe broken battery switch. Yes, it was already broken when the rains started. Nails were bitten, anxiety was had.

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It's a little difficult to tell, but the brushes are down to their last mm. Also, the comm is a bit too chrome for my liking. This motor gets pulled out of race-rotation and into... I dunno, basher-mode?

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The spur is toast...

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...but the pinion seems fine.

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the rear diff and crown gear are mostly gone. Where did they go?

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There....

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... and there.

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Damage from the heat caused by the rear diff moving and pulling everything in and out of alignment. This tub is toast.

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As is the cover. This is supposed to be a flat surface, but the spur gear chopped out that ring.

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Whoops!

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And a bonus shot right after we finished and pulled off the body. Ugh, that dust went everywhere!

So what are my plans? I do need to replace a bunch of parts on the car, including the tub. And since I sorta consider the tub to be the base of the car, that kinda feels like buying a new car and changing everything over. So I might as well buy a whole new TT01E. But she's served me so well, I'd hate to part with her. I've had this car for almost 10 years, and had so many adventures. With this car I:
- Did about 6 races in the Tamiya Euro Cup
- raced in 2 Tamiya International M-chassis challenges
- Did about a million miles on our local home track (which no longer exists. Boo!)
- And of course this enduro!

I'll reply to this post with more pics as I tear down further. First up though, a good clean for both the car and my hands!

Credit for most of the on-track photography goes to my wife. She's getting better and better at this snappy-piccy thing.

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Time for two videos that just went up on Facebook. The first one is right when the rains started. It's still dusk and we're making progress. You can recognize the car by the yellow headlights. We were the only ones running non-white lights in front.

A few hours later, and the track was shrouded in complete darkness. This is where the issue with the dirty and opague headlights really became apparent.

(let me know if you can't see the videos. I'll grab them off of Facebook and host them somewhere else.)

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This is neat to see; @GooneyBird, can you talk about how the car was prepped prior to the enduro run?  For example, what sorts of lubricants did you use?  How much shimming was used for the pinion and ring gears for the diff?  Was the motor pinion's teeth polished at all?  The results are interesting and knowing the prep/setup context would be beneficial as well.

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1 hour ago, speedy_w_beans said:

This is neat to see; @GooneyBird, can you talk about how the car was prepped prior to the enduro run?  For example, what sorts of lubricants did you use?  How much shimming was used for the pinion and ring gears for the diff?  Was the motor pinion's teeth polished at all?  The results are interesting and knowing the prep/setup context would be beneficial as well.

Well, I actually didn't put that much prep into the car. The car is a seasoned racer and so it was already 90% there. The things I changed were either for ease of doing a pitstop, or reliability.

We changed batteries often, so every second saved did add up after a while. Therefor I tied the body clips with a bit of nylon wire to the body. Also, I made sure that the battery would be wedged in tight via foam pads, negating the use for the battery hold down strap. We found out we could change batteries without needing to take the body off, which was a definite bonus.

Lubricants: the car is mostly dry. Spur and pinion are 100% dry, as any kind of grease would attract dirt and turn into this grinding paste. The pinion is a Corally hardened steel item, that I run in carefully by doing about 10 laps at 1/3 speed. The spur is a stock Tamiya plastic one. The one that came off the car had been used to practice before this event, and I think that had the diff not shifted and throw everything out of wack I'm pretty sure it would have been fine.

I replaced the universals up front with dogbones. Why? The large outdoor track does not need a lot of steering lock, and when universals fail they tend to jam up the wheel, whereas a broken dog bone just falls out. They too were dry, for above reason. All had a little rubber O-ring in the back for cushioning. 3 out of 4 dogbones are fine, the fourth was the one that got hot when the bearing failed. In the front is a spool, and a fully open diff in the rear. The diff has a small amount of grease on the gears, but nothing crazy. I haven't opened the rear diff yet, but it sounds and feels fine.

I lightly shimmed out the front and rear diff pinions, but not much was required. I prefer to run them a bit loose, the teeth are large enough that they'll always sorta-kinda mesh, and there isn't enough power on tap to make them skip. Normally those things last forever, and I'm sure that had the rear stayed put it would have been fine. The front diff case is completely clean, and the front diff is 100% reusable. The rear diff casing is full of white fluff from the diff, but a lot of that would be from me limping the car back to the pit with a broken rear end.

The bearings all got a drop of light oil. The bearings around the spur gear shaft are damaged but still run true. All four outer bearings in the hubs are noisy, with the left front failed bearing being discolored and completely scrap. I'm pretty sure I can rescue about 3/4 of the bearings in the car.

Electronicwise not much has been done. I added a fan to the heat sink (defo needed with the high OOT we had at the start), and I made sure everything was in good working order. The body shell received 8 LEDs for rear- and headlights, and 2 more to light up the start number. All were powered by a single TLU01, running through a custom cable plugged into the main power line running in the car. (see my topic about the TT01 linked above). The TLU01 never skipped a beat, not even in the rain. All lights remained functional until the end. All the wiring was ducttaped to the body to make sure it wouldn't snag on anything.

Anything else you'd like to know?

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Good report sir !  

That thing hold up way better then expected i must say

 

** wished we had any form of track around here ;p **

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That is a fantastic story, and quite an accomplishment, both for you and the little TT01. Thanks for sharing!

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Nice. Thanks for sharing. Wish we had events like these. You must have been chuffed with the result. Well done!

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4 hours ago, GooneyBird said:

Anything else you'd like to know?

Nope, thanks for providing the details.  Seems like the rear end and a few bearings are the main sources of the extra wear and tear experienced.  If no bearings had failed, and the rear end had held together, maybe the car would have shown very little wear overall.  Frankly, putting 275 km on a RC car in one go is quite a feat; thanks for sharing all of this information!

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Fantastic write up @GooneyBird. Just shows that the old Le Man's saying of to finish first, first you must finish stand true. Amazed that one of the most simple chassis held up so well to that much constant use. Kinda makes you think if a higher end car would have actually lasted any longer, simplicity may have been key perhaps.. 

Don't replace anything, buy another one so that that you can show off the old warhorse like a famous Le Man's car with all wounds proudly on display. Retires with distinction 😎

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A superb write-up, with some beautiful pics.

That second video though, wow! How did you even manage to see where you were going?

It sounds like a very exciting race. Was that enough to stop you from dropping into a little heap on the floor with the extreme fatigue? 1000 laps is hard to get my head around. I was pretty tired after a 20 minute

stint at the old track, with sweaty and shaking hands. Amazing stuff! And congratulations on such a great result.

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This is a great write up. I think a club about 2 hours away does one of these, after reading this I really want to give it a go, but like @Fuijo says, I'm knackered after a 30min main in my nitro buggy, not sure I could manage an hour! Great achievement 

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What a great post about a great race. Love endurance racing 1:1 and you really captured the whole vibe. Congratulations.

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Great story and great writing, congrats for such an accomplishment!

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On 9/2/2019 at 8:23 AM, Fuijo said:

A superb write-up, with some beautiful pics.

That second video though, wow! How did you even manage to see where you were going?

It sounds like a very exciting race. Was that enough to stop you from dropping into a little heap on the floor with the extreme fatigue? 1000 laps is hard to get my head around. I was pretty tired after a 20 minute

stint at the old track, with sweaty and shaking hands. Amazing stuff! And congratulations on such a great result.

Thank you, it was a lot of fun.

Well, in real-life the track was slightly lighter than in the video. There was a bit of light reflected off of the clouds coming from a local airport which helped to see the contours of the track, but 80% of the light you had was coming from your car. Which is why the quickly-darkening with dirt of the headlights was a serious issue.

You have to keep in mind that 20 minutes at RcP is far more intense than 20 minutes here. Plus, there was hardly any direct fighting. Most people kept to their own pace and if you were coming up from behind they were eager to move over. Fortunately our car was quite recognizable, running yellow headlights.

Anyway, I did some further tearing into it today. I took all the good parts and gave them a clean. I'd say most of it is still usable, so I've gone and spent some money to get replacements for the worn-out bits. I have plans with the car, but I'll make a separate thread for that when the parts actually arrive.

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This is the rear diff internals. Dirty and a bit gunky, but otherwise perfectly serviceable. The ring gear however... It was cracked most of the way around, and the car was close to losing RWD altogether due to it. I'm not sure what caused it, but I suspect there was one major issue in the rear end that cascaded down in the car, causing all sorts of little issues to pop up.

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Issues like this. This is the spur gear stopper, and it's supposed to be white. All that black stuff is plastic from the spur gear itself. It was fused together, and I had to pry it apart in order to take it apart.

Schermafbeelding-2019-09-03-om-19-33-16.

Part GB2 is what we're looking at right now.

The electronics are all fine. I cleaned out all the dirt from the receiver and ESC today, and they function just fine. The servo was pristine inside (Go Savöx!) so I'm not touching that. The motor is actually a funny story. When I took it out it seemed to be rather gritty, and the brushes were invisible due to all of the dirt built up inside it.

But today I washed the motor (Yes, chucked it in a pot of water while running. This blew out every nook and cranny of the thing) and afterwards it came up great! The brushes are about 30%, but the rest seems a lot better. The comm is a bit on the shiny side, but it still spins well and true, without sparking so I'm calling this motor Officially Still Good!

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Great write-up and pics.  Actually I was only thinking of how an enduro like this would be great fun, but not sure we'd get the numbers to run it here.  Glad to see it happens somewhere in the world.  Who knows, maybe I'll get a team together and hop over the water for next year :p 

The longest enduro I did was a 3-hr buggy race.  We entered a re-re Buggy Champ in the SRB class and were officially the only SRB to finish, netting us first in class.  Even 3 hours was exhausting - there was no respite at all, we were either racing, marshalling or standing in the pits with tools ready to tighten up the UJ grub screws yet again.  By the end of the race we would only get 7-8 laps before we were down to 1-wheel drive and one wheel started to poke out sideways.  Handy for stopping people passing but awkward when clipping the barrier on corners.  Plus it was dark before the race even started, we'd already done an entire day's one-day race championship in changeable weather.

Anyhoo, it's interesting to see how bad the wear was and how close it all came to disaster.  My experience with RC breakdowns is they're either immediately fatal or they don't happen at all.  I'm fascinated by examples of 'wear and tear' in use and it's interesting to see how badly some things wore due to a partial failure without actually failing completely.  But equally would be interesting to see how well the car would have done if the back end had lost drive.

I will talk to some local people about running a similar event here...

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Hey Gooneybird, we where there first endurance for us ever with a TT-02.

Our car didn't make it to the end, broke down with the rear suspension broken. And didn't have replacement parts.

Great fun but very exhausting.

Now like you i have completely torn the car apart for servicing.

We experienced a broken down front diff because of one of the universals failing, Second front diff was on the go to because we didn't notice the universal was failing.

2 bearings are done, not to be revived anymore, 2 bearings a little rusty on the outside because of the rain and the heat of the rotation.

I don't trust the motor bearings from the carson 16 t brushless anymore, must replace them.

the bearings in the aluminium steering set up suffered a great deal, have to find a way to replace them as they are press fit.

Some plastic parts are need to be replaced as they soffered from failing universals.

Maybe, just by a new TT-02 to get the needed parts

Cheers

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12 hours ago, A3Baak said:

We experienced a broken down front diff because of one of the universals failing, Second front diff was on the go to because we didn't notice the universal was failing.

Which part of the universals gives up and fails? Were they tamiya universals?

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