****Official**** Corally Kronos/Shogun/XTR Thread

[horatio]

13 minutes ago, Tug said:

 

I use tights that the Mrs no longer needs. It will reduce airflow and cause higher temps, but it's never caused me an issue, and certainly no failures yet. 

 

 

Whatever method you choose, monitor temps for a few runs, all ESCs have built-in temperature protection, but it's worth checking temps yourself. 

Thanks for the tip! I wonder if my missus would notice if a black pair went missing..... 🤣

 

Well, I actually pulled the trigger on a chassis shroud by Dusty Motors. It came with some shock socks as well, so I thought I'd give them a go. With the tyres, it got me into the free postage zone, so happy days. 

[horatio]

47 minutes ago, BashingBrian said:

Please let us all know how they are..!! I've been eyeing them up for ages...

So far, I'm pleased with the quality and feel of the rubber. Seems sticky! 

 

Quite heavy though.... 

[horatio]

Alright, so I put my wheels together today and 'dressed' the tyres. 

 

The stock tyres on the Kronos XTR weigh 315g,

vs the belted JetKo Tyres at 441g -

that's a 28.5% heavier wheel/ tyre combo folks. 

 

But being belted means better stability, predictability, more contact patch and thus more traction on tarmac. Hopefully all these benefits will outweigh the additional rotating mass. 

 

A really neat idea are the removable hexes. Note the castellated shape here with hex still being tightened. 8 x M3 bolts hold the hexes in place and it's definitely worth doing these by hand. In theory you can remove the hex and change to a different size if you swap, say, from a Corally to a Traxass. 

 

It's not easy to tell how tight to take them, as the amount of torque required for the bolts to pass through the wheel feels just the same as it does when it enters into the hexes. Do the tightening order properly, tightening opposing bolts all the  way round until it looks like this. 

There's absolutely no need to over-do the torque on these, else the threads will strip out in the hexes and your wheels will be parting company from your truck very soon! 

The tyres come with nifty, zip lock bags - so easy tiger - no need to cut them like I started to do - they're actually pretty handy to store your stock tyres. 

 

Included are some stickers - one pair of tyres had a set of JetKo Cyotes, which is definitely going on the body.

 

The other pair had 'top best tyre' stickers - which I'm sure is quaint English but whatever - I'm preferring the coyotes! 

For Kronos and Kraton etc JetKo recommended the 1/2" offset wheels. They clear everything fine, but the truck is definitely wider now by about an inch. This is likely a good thing if you want to try some speed runs on-road. 

 

These road tyres are marginally smaller diameter, so this will lower the roll-out slightly, effectively lowering the gearing. 

 

Fitted, they look absolutely bang on. Unlike some smaller scale trucks, the proportions are just right with these for 1:8th.

 

These tyres are described as medium soft (green) compound. The rubber is sticky at room temperature and likely be even stickier when running. I have absolutely no doubt that these are going to grip like hell on smooth, hard surfaces. 

 

On dirty, loose or dusty areas, these tyres will just pick it all up like blutac and need to be scrubbed to get the traction back up again - just like full-size tyres. 

 

Obviously, I can't wait to try them out! I'll head down the local showground while it's quiet. I'm sure that I'll break my personal speed record with these fitted. 

 

The overall quality seems excellent. The fit and finish of the wheels, tyres and hexes are without fault. 

 

My Dusty Motors shroud looks just like the latest truggy bodies! Better in fact... 🤣

 

I haven't fitted the sock shocks yet, which came supplied with the shroud, but I'll give them a go. I use them on my Baja 5B SS and they definitely help prolong the life of the seals and shafts etc. 

 

I'm very pleased with the items, all of which arrived the next day from Modelsport via DPD - free postage! 

 

So, shout out to Modelsport. Couldn't have done it quicker or cheaper. 

 

 

Edited May 10, 2022 by horatio

[Stormbringer]

Tyres and wheels really look good 

[horatio]

On 10/05/2022 at 00:39, Stormbringer said:

Tyres and wheels really look good 

Thank you! Yep - I think they look awesome. Hopefully they'll perform as good as they look. 

[horatio]

Shout out to the ebay seller:

Demontraders-UK 
Who sent me this wrench - it got to me in less than 24 hours and the postage was free!!!! 

[horatio]

So, I have a whole 1/2 mile stretch of tarmac all to myself..... 😝

 

What's a guy to do? 

 

The tyres performed flawlessly. Consistent grip, progressive past the limit and made the car surprisingly agile for such a big machine. 

 

No dramas - yes, as you get to that >75% throttle mark, the car squirms like a F1 car, but it just lurches onwards never the less. 

 

Motor was warm after half a dozen runs, but this is hardly surprising for 75mph runs with 0-60 around the 2.0 second mark..... 👀

 

The truck sounded smooth, everything stayed together - a flawless performance by both tyres and Kronos XTR. 

[Kpowell911]

Did you get a speed reading?

[horatio]

7 minutes ago, Kpowell911 said:

Did you get a speed reading?

Actually, no - you got me.

 

But I know approximately how fast it was based on markers/distance and time. 

 

That being said, I think it must be time to get a Sky RC GPS. 

 

The truck is insanely fast. No wonder it's so manic off road on 6S!! 🤣

[Yrkoon]

On 09/05/2022 at 23:21, horatio said:

Alright, so I put my wheels together today and 'dressed' the tyres. 

 

The stock tyres on the Kronos XTR weigh 315g,

vs the belted JetKo Tyres at 441g -

that's a 28.5% heavier wheel/ tyre combo folks. 

 

But being belted means better stability, predictability, more contact patch and thus more traction on tarmac. Hopefully all these benefits will outweigh the additional rotating mass. 

 

A really neat idea are the removable hexes. Note the castellated shape here with hex still being tightened. 8 x M3 bolts hold the hexes in place and it's definitely worth doing these by hand. In theory you can remove the hex and change to a different size if you swap, say, from a Corally to a Traxass. 

 

It's not easy to tell how tight to take them, as the amount of torque required for the bolts to pass through the wheel feels just the same as it does when it enters into the hexes. Do the tightening order properly, tightening opposing bolts all the  way round until it looks like this. 

There's absolutely no need to over-do the torque on these, else the threads will strip out in the hexes and your wheels will be parting company from your truck very soon! 

The tyres come with nifty, zip lock bags - so easy tiger - no need to cut them like I started to do - they're actually pretty handy to store your stock tyres. 

 

Included are some stickers - one pair of tyres had a set of JetKo Cyotes, which is definitely going on the body.

 

The other pair had 'top best tyre' stickers - which I'm sure is quaint English but whatever - I'm preferring the coyotes! 

For Kronos and Kraton etc JetKo recommended the 1/2" offset wheels. They clear everything fine, but the truck is definitely wider now by about an inch. This is likely a good thing if you want to try some speed runs on-road. 

 

These road tyres are marginally smaller diameter, so this will lower the roll-out slightly, effectively lowering the gearing. 

 

Fitted, they look absolutely bang on. Unlike some smaller scale trucks, the proportions are just right with these for 1:8th.

 

These tyres are described as medium soft (green) compound. The rubber is sticky at room temperature and likely be even stickier when running. I have absolutely no doubt that these are going to grip like hell on smooth, hard surfaces. 

 

On dirty, loose or dusty areas, these tyres will just pick it all up like blutac and need to be scrubbed to get the traction back up again - just like full-size tyres. 

 

Obviously, I can't wait to try them out! I'll head down the local showground while it's quiet. I'm sure that I'll break my personal speed record with these fitted. 

 

The overall quality seems excellent. The fit and finish of the wheels, tyres and hexes are without fault. 

 

My Dusty Motors shroud looks just like the latest truggy bodies! Better in fact... 🤣

 

I haven't fitted the sock shocks yet, which came supplied with the shroud, but I'll give them a go. I use them on my Baja 5B SS and they definitely help prolong the life of the seals and shafts etc. 

 

I'm very pleased with the items, all of which arrived the next day from Modelsport via DPD - free postage! 

 

So, shout out to Modelsport. Couldn't have done it quicker or cheaper. 

 

 

wow that is one sweet looking kronos 😄

[horatio]

7 hours ago, Yrkoon said:

wow that is one sweet looking kronos 😄

 

Thank you! I'm pleased to say it goes as well as it looks. The Kronos XTR is an outrageous truck! 😁👍

[horatio]

So I thought I'd install a heatsink with twin fan. 

 

 

Rather than use the Yeah racing/Power Hobby heat sink, I found the exact same, unbranded item. 

 

Next, I utilised the fans from a  Surpass Hobby heatsink, with WCF covers. 

 

 

These were then mounted using 8 screws instead of the 4 screws and the 4 standoffs (which I think would be a terrible idea).

 

Careful positioning of the heatsink is required to ensure clearance of the centre driveline. 

 

 

Wires routed, it's a tight squeeze getting the y lead into the XTR's radio box, but it's possible to with tweezers. 

[horatio]

Well, took the XTR out for a blast this evening and crikey! This thing sure does shift at a fair rate of knots. 

 

The fans aren't powering up on the heatsink though, which is mildly disappointing. I tried channel 3 in the receiver but they just don't spin up. 

 

 

That being said, the motor Temps at the end of these speed runs were 120°F - so warm but not too bad. 

 

After this footage was shot, I ragged it around and goofed with it some more - much to the horses delight - but the Temps went up to 160°F for about 2 mins, so I left it cool down and gave the dobbins a mint. 

[Stormbringer]

The dobbins werent to sure at start but after couple of runs they were really curious about it 🤔 

By way nice speed runs 

[horatio]

@Stormbringer

 

The horses were funny! The first pass I did was very cautious - just to make sure they didn't spook. 

 

Mid session, they were literally chasing around after it like a couple of hounds! 🤣

 

I took the (very toasty) XTR over to them afterwards to sniff and explained to them what I was doing. I'm pretty sure they'll be cool with it for next time. 

 

Next run will be with a data logger and hopefully - power to the fans - they simply won't run off the receiver I've got. No idea why? Bizarre. 

 

Possibly the fans are duds, but I'll leave that for future me to sort out. 

 

Thanks! My speed runs are done without a Gyro for stability control. Coming towards the camera especially, the windy conditions were seriously affecting the XTR's ability to track in a straight line. 

 

In fact, one of my passes was perilously to wiping out my tripod and camera. 😝

 

 

Edited May 26, 2022 by horatio
Reasons!

[Stormbringer]

Yeh in the vid could see they were wanting to chase it 

Good luck next run mate 

[horatio]

Cheers! I want to pick a calmer day so I can do the speed runs both ways and average them. 

 

I have to get these fans working first, assuming they're not knackered. 

 

It wouldn't surprise me if I hit >70mph. The surface is perfect for it. 

 

I'm also aware that by modern standards, anything below 100mph is considered 'meh'. To me though, these speeds are completely bonkers compared to the stuff I've driven over the years. 🤯

[Stormbringer]

At end of day its what you get out of it that counts mate 

Good luck in future runs tho 

[horatio]

1 hour ago, Stormbringer said:

At end of day its what you get out of it that counts mate 

Good luck in future runs tho 

😂 Grief mainly! My missus thinks it's geeky. I wonder one day if my beloved collection will all be rounded up and sold while I'm out. 

 

I find it satisfying building them though. And brushless is taking me on a journey that's very different to the stuff I've done before. 

 

My FPV drones are insanely fast, but it's all relative. In the air with so much space, hitting 127.5mph up there is less of a deal than keeping a truck on the straight and narrow, line of sight, at 70mph.

 

I can't quite wrap my head around how people hit 200mph, just standing there as their car travels the length of a football pitch every second. How do you even see the car at those kind of  distances? Let alone trying to figure out what inputs the car needs, without a clear picture of the car and it's attitude etc. 

 

FPV will make it easier to go fast I reckon. And TBS radio modules give insane range. It's only a matter of time.... 

[horatio]

Alrighty then.... 

 

You'd like to think that hooking up 2 fans with a y-lead would be a pretty simple task - routine for anyone that's into rc. 

 

Well, not in this instance. 🙄

 

Firstly, my Surpass Hobby y-lead didn't work with the Surpass motors. 🤔

After some normal checks, trying different leads direct into a battery etc - no joy. It turns out there were 2 problems: 1 motor simply didn't work - it was DOA. The other problem was that the Y lead factory connected had 1 of the plugs connected the wrong way to the motor that (potentially) worked. 

 

What an omnishambles! 

 

Note: Arrow on plug indicates positive terminal. 

 

The one fan that worked sure did whizz at a fair rate!

 

So, the unbranded fans where fitted with the unbranded y-lead which was much better with  normal plugs and clearer positive/negative wires. 

 

These fans are chunkier and spool up slower but really, really whiz. Either way - at least they work thus should prevent the >160° nightmares. 🤞

 

A close look at the heatsink shows why these seem to work better. 

 

 

Heatsinks conduct heat from the heat source and release it over time. With adequate air flow, and fans assisting a rapid flow of air over the vanes, the time it takes to release this heat is significantly reduced.

 

Thus, the motor should be cooler at the end of a run.

With a bit of luck, hopefully I haven't already ruined the magnets! 

 

Does anyone still zap motors any more? 

[horatio]

So.... tested the cooling fans on the weekend. They sure do make a whizzing sound. Starting at a pleasant 68°F, I proceeded to thrash the truck around and did about a dozen speed runs, most of which were full throttle. Near the end of the pack, I checked the temps:-

 

162°F.

 

So, still pretty hot. 

 

However, given just 2 minutes of rest, with the little fans whizzing away, the temperature dropped to around 90°F. 

 

At this point, I started driving around again - but only for about 2 mins before I got the LVC. 

 

So all told, not a bad result. 😁👌

[horatio]

From here on in, I'll be monitoring the speed with the GSM 020.

 

It fits perfectly between the rear body posts. Dual Lock ensures it won't go anywhere (I can literally pick the car up by it!) . Plus, there's a dusty motors shroud over the top of that as well. 

[horatio]

Some while ago, I made some outrageous speed claims, purely by making a note of some markers and manually timing.....well:

Just goofing around, I had 62mph on standard gearing and Corally electronics on the outrageously heavy JetKo tyres. 

 

0-60mph

 

Drum roll please........ 

 

I'm very pleased with this performance. It's not fast by RC standards - it's fast by ANY standard! 

 

I did a run where the peak G was 0.8, but the 0-60 time was actually slower. 

 

 

I hope this makes up for my taking liberties before! 😜

[horatio]

Motor Temp at the end of the speed runs was 138°F which is pretty good considering how it's been before. 

 

What I feel I need to do now is buy a new motor - one which I will never cook - and some more 6S packs. 😁

 

I'm torn between larger capacity cells, which will give me more fun time, vs lighter packs which will likely let my XTR accelerate quicker and handle better. 

 

I want to see 0-60mph times into the 3 sec mark. 

 

Any one else here hitting these kind of times already? 

[Tug]

60C isn't hot, it'll only cook if you exceed 80C.