Project "SCYLLA"

[ColosTommy]

Well the first test run didn't last as long as i had hoped, but no mechanical failures and it didn't spontaneously combust, so that's a win in my book.
I definitely need more time behind the .....wheel (i guess, or maybe remote??), but from first impressions, the understeer is not as bad (as in not even noticeable) as i feared it might be, and it's not too sluggish.

Sorry about the non existent camera work, i was manning the fire extinguisher, infra red gun, timer, notepad and driving the damn thing, couldnt be messing around with a camera as well.

 

[pomplemus]

This project is awesome! Love the name too, I've always had a special appreciation for Greek mythology. The orange is a nice scheme, and the dual motors are a clever way to avoid a complicated middle diff case. I remember following a 6x6 nitro Savage build years ago, that was a beast.

I threw it on the scales today, no body, no batteries, and she weighed in at 9.1kg which is pretty much bang on 20lbs.
I would love to get some real world weights (I don't entirely trust Arrmas marketing department) for a stock 6s Kraton, a stock 8s Kraton and Heavily modified versions of each, all no body, no batteries. Just to see where they all come in.

I volunteer as the heavily modded Kraton 6S example!

Mine started out as an RTR V4, but is now up to and beyond V5/EXB spec, fully M2C'd out (chassis, towers, braces, etc), Castle MMX8S and 1717, 5mm front turnbuckles, wheelie bar, chunky TPU printed parts, etc. I recently upgraded to Fireteam springs due to the pudginess.

No body, batteries, or wheels/tires it comes in at 10.1 lbs / 4.6 kgs. I usually run 6S Backflips, which at 355 g each would bring the total no body/batteries weight to ~13.2 lbs / 6 kgs.

Looking forward to more updates!

 

[ColosTommy]

Thanks @pomplemus , appreciate the feedback and the weighing of your monster Kraton, looks a very nice rig

I'm guessing mine is going to weigh the around the same as a stock 8s (but would be good if any of you are able to throw one on a scale if you have one) but with the fragility of a 6s. I think it will be a while, if ever, before i build the confidence to launch this off of any jumps.

 

[ColosTommy]

I put together a temperature display to monitor the heat in both motors and esc's without having to get the body off and get the temp gun out.

Shoutout to @parcou and @RC-Dude , their posts on this https://www.arrmaforum.com/threads/those-expensive-fans-is-it-worth-it.62986/page-2 thread inspired me to order and make one of these for my rig....

I ordered two temperature displays off of amazon for £9.99 for the pair, then went about modeling up a holder which looked like this.

Printed it out of black PLA+ (it didnt come out perfect, but serviceable enough) then went about the worst bit of it the wiring.

I wasn't happy with how it was going to look with all the excess wire from the sensors bundled up under the mount. This picture shows the mass of wire from one sensor, so there was four times as much.

So i ordered a connector set off of amazon and went about cutting and re-pinning new plugs at a shorter length to tidy all the cable up.

After the shortening....

And the end result of how it looks on the chassis and with the body on powered up.

 

[Rizz1877]

U have my interest, hope it goes well.

 

[RC-Dude]

What would be helpful is a sensor mount that presses the sensor against the ESC. I find the temperature between the installed sensor and temp gun is not the same temp gun always higher.
What is the name of those connectors. I must confess I cut mine and soldered them.

 

[ColosTommy]

I find the temperature between the installed sensor and temp gun is not the same temp gun always higher.
What is the name of those connectors. I must confess I cut mine and soldered them.

JST XH2.54mm 2pin connector.

I found exactly the same issue, between the sensor reading and the temp gun.
I taped the sensor tight against my cup and left it there for a minute to get reading then used a temperature gun on the cup, got a difference of around 8 celcius. It will still give me a rough idea at a glance of where the temps are at.

 

[GamwToInsomnia.gr]

8 Celcius is a big difference :/

 

[ColosTommy]

It is, but if I'm aware it's reading 8 degrees low, and it isn't getting exponentially worse as the temperature goes up then I can account for it.
More testing is still required

 

[parcou]

JST XH2.54mm 2pin connector.

I found exactly the same issue, between the sensor reading and the temp gun.
I taped the sensor tight against my cup and left it there for a minute to get reading then used a temperature gun on the cup, got a difference of around 8 celcius. It will still give me a rough idea at a glance of where the temps are at.

It was never meant to give me the exact temp or what I discussed. Even with a heat gun it will be off depending on the area tested. In addition, we are getting outside temps, never the true internal with a gun.

Yes, I am 5-7deg off...yet still, if i want my device to be at xx temp and it hits it, I do add mentally add 5-7 more. What's worse, being off or not knowing at all... So far, I am well below readings on motor 140F and 160F motor plus adding the mental difference.

@GamwToInsomnia.gr is still a win vs having nothing or to keep taking the body off for a temp gun check, which is still outside surface temp.

 

[ColosTommy]

I had it out again today, and it did its first front flip!



Unfortunately not the kind of front flip i was hoping for, 40mph, about 4 foot in the air, and quite a few broken parts.
I took it out, aiming to get to a nice open flat field, i just had to go down a path which i did nice and sensibly, then pass through another field that had large grass tufts everywhere. Of course the little child in me couldn't wait to get to the nice flat field, "just floor it here, there's not that many mounds, I'm a good enough driver to dodge them" I was in fact not a good enough driver to dodge them, and this heavy lump flat out at 40mph isn't the most responsive in last minute direction changes, so chaos ensured.

I will begin the strip down later to assess the full extent of the damage and report back.

 

[ColosTommy]

Damage report:

1) Both front driveshafts came out
2) Front antiroll bar came out of its drop link on impact side
3) Pillow ball stripped out of upper front A arm
4) 3D printed side card cracked from the wheel impacting it
5) Steering turnbuckle buckled on impact side
6) Loss of drivetrain to rear axle
7) Suspected further issue with steering, possibly servo, to be investigated when rebuilt

Pictures.....

Issue 1 and 2 obviously just need reconnect/reseating so where easily solved, issue 3 will be solved with a spare RPM A-arm i have lying around. The 3d printed side guard will probably just be CA glued back together for now. I will need to source a new steering turnbuckle.
The loss of drive to the rear axle was entirely my fault (as if this isn't ALL my fault), when building up the Scorched locker insufficient locktite and torque were used and im guessing the impact was enough to finally free it all up.

A couple of questions i need advice/help with.

Theres no issue with me replacing one of the arms with a RPM while keeping the other side stock is there?

And if anyone can tell me the brand or part no for that red turnbuckle as when i looked on my usual supplier they only had steel turnbuckles and id like to replace with what is on there if possible.

Thanks..

 

[StephenSchandelmayer]

What I will say is my neighbor ran those GPM turnbuckles and he constantly bent or broke them. I would run stock ones

 

[ColosTommy]

those GPM turnbuckles

Is that what they are? I had assumed they weren't as i have a set of these GPM turnbuckles sitting on the side, but they are so heavy i wanted to avoid adding more weight. I hadn't even thought to check if GPM made more than one kind of turnbuckle.

Thanks for the info and advice.

I guess i just HAVE to buy some scorched titanium ones now, you forced me to!

 

[StephenSchandelmayer]

Is that what they are? I had assumed they weren't as i have a set of these GPM turnbuckles sitting on the side, but they are so heavy i wanted to avoid adding more weight. I hadn't even thought to check if GPM made more than one kind of turnbuckle.

Thanks for the info and advice.

View attachment 314415
I guess i just HAVE to buy some scorched titanium ones now, you forced me to!

Well I believe those are the old style gpm ones (on your truck) and then they started making them different. I have the newer style on my Goliath and they are pretty nice but they don't get put through much abuse

 

[ColosTommy]

I also found the front hinge pin holder had been ovaled as well as the lower front arm on the impact side, so they both had to be replaced as well.

As i was replacing the front turnbuckle i decided to replaace them all, there was excessive play/slop in the rear ones as well. While i was there I replaced all the hubs with new hubs with bigger bearings to try and cope with the weight better and tighten up the play/slop at the wheels. I ended up getting titanium turnbuckles all round, titanium ackerman plate with upgraded bearings, titanium steering stub plate, steering knuckle front hub and rear hub caarrier, all from Scorched RC.

It was only a matter of time i guess before i started throwing some upgrades at it.

 

[King blitz]

Looking good ..

 

[ColosTommy]

Little teaser of things to come. Will be a long while before i get around to fitting these.