ARRMA Kraton EXB - Extreme Bash Roller Speed Truck

[Tony]

28 minutes ago, Skynet5 said:

Struggling to fine a servo instock at either modelsport or wheelspin.  Got all the stuff in my basket at wheelspin.  but I hear that some Savox don't fit without some dremmelling.

 

Ideas?

 

 

I have this for my Kraton EXB - fits perfectly. And it's in stock.

 

https://www.modelsport.co.uk/etronix-30-3kg-0-09s-standard-digital-servo-metal-gear-high-voltage-waterproof/rc-car-products/433049

[Skynet5]

Cool. Last bit is the pinion. I'm set on the max6 with 1650v...sounds like the stock pinion might not be usable. Motor might hit the drive shaft as well.

 

So what pinion do I need?  18-21+ by the sounds of it .

 

 

 

 

[Paul Busby]

2 minutes ago, Skynet5 said:

Cool. Last bit is the pinion. I'm set on the max6 with 1650v...sounds like the stock pinion might not be usable. Motor might hit the drive shaft as well.

 

So what pinion do I need?  18-21+ by the sounds of it .

 

 

 

 

Exactly. Get a 20t to get the overall speed similar to a stock Kraton (50-60mph)

[Skynet5]

14 minutes ago, Paul Busby said:

Exactly. Get a 20t to get the overall speed similar to a stock Kraton (50-60mph)

Cheers bud. Just got to find it in stock. 

 

This do? https://www.modelsport.co.uk/arrma-20t-mod1-safe-d5-pinion-gear/rc-car-products/444820

 

It isn't the optional part but neither stores (ms or was) have them in stock.

[Paul Busby]

1 minute ago, Skynet5 said:

Cheers bud. Just got to find it in stock. 

 

This do? https://www.modelsport.co.uk/arrma-20t-mod1-safe-d5-pinion-gear/rc-car-products/444820

 

It isn't the optional part but neither stores (ms or was) have them in stock.

Aye, that's the number.

[Paul Busby]

These are also the best pinions I have used:

https://www.rwracing.co.uk/product/cnc-1-module-steel-pinions-5mm-bore

 

Tekno ones are equally as good.

 

Nothing really wrong with Arrma pinions tbf.

[m4inbrain]

26 minutes ago, Paul Busby said:

Exactly. Get a 20t to get the overall speed similar to a stock Kraton (50-60mph)

 

Erm, that's not correct. 18t is 57mph bud (18/50 and 10/43 diff). Not sure if there's a difference between the EXB and v3/v4 in regards to crown/diff pinion, but yeah.

 

20t is 63, and the 4985 doesn't hold it thermally without fans.

 

edit: assuming we're talking the 4985, haven't actually read everything, so that's an assumption.

Edited December 24, 2020 by m4inbrain

[Paul Busby]

13 minutes ago, m4inbrain said:

 

Erm, that's not correct. 18t is 57mph bud. Not sure if there's a difference between the EXB and v3/v4 in regards to crown/diff pinion, but yeah.

 

20t is 63, and the 4985 doesn't hold it thermally without fans.

No it's identical... but you're right. I'm getting my "real speeds" and "gearing speeds" muddled up.

 

I'm curious, are you using an online calculator, because my spreadsheet has 20t @ 22.2v @ 65.85MPH "gearing speed".

 

TBH if you stick the speed pinion on it that came in the box, that gives you a good starting point, then you can go up a few teeth if you feel you need more (I reckon you will).

 

Edited December 24, 2020 by Paul Busby

[m4inbrain]

3 minutes ago, Paul Busby said:

No it's identical... but you're right. I'm getting my "real speeds" and "gearing speeds" muddled up.

 

I'm curious, are you using an online calculator, because my spreadsheet has 20t @ 22.2v @ 65.85MPH.

 

TBH if you stick the speed pinion on it that came in the box, that gives you a good starting point, then you can go up a few teeth if you feel you need more (I reckon you will).

 

 

Yeah, i suck at maths, so calculator it is.

 

To be fair: i'm not 100% certain what they use for voltage, i can only plonk "6s" in. Though 20t at 22v and 67mph doesn't sound right to me. What's the tyre diameter you're using in the spreadsheet?

 

edit: didn't realise you linked it. Copperhead 2 are 169mm. 

Edited December 24, 2020 by m4inbrain

[Skynet5]

Will 18t work fine ? WS have it in-stock at least.

[m4inbrain]

1 minute ago, Skynet5 said:

Will 18t work fine ? WS have it in-stock at least.

 

To be very honest, that's the maximum i'd use with a 4985 without fans. 

[Paul Busby]

1 minute ago, m4inbrain said:

 

Yeah, i suck at maths, so calculator it is.

 

To be fair: i'm not 100% certain what they use for voltage, i can only plonk "6s" in. Though 20t at 22v and 67mph doesn't sound right to me. What's the tyre diameter you're using in the spreadsheet?

165mm (Copperhead 2 6s). Have a look at my spreadsheet mate, it's pretty handy

 

Just now, Skynet5 said:

Will 18t work fine ? WS have it in-stock at least.

 

18T gears you for 59.27MPH, so a bit slower than the speed pinion with a stock Spektrum motor

[m4inbrain]

Just now, Paul Busby said:

165mm (Copperhead 2 6s). Have a look at my spreadsheet mate, it's pretty handy

 

 

 

 

 👍

[Paul Busby]

3 minutes ago, m4inbrain said:

 

 

 

 👍

Added to my spreadsheet. Appears you have spotted another clanger, and I was actually using copperhead 1

[m4inbrain]

See? 

 

63mph after drive train loss

 

Weird to watch that sheet being edited live lol.

[Paul Busby]

Just now, m4inbrain said:

See? 

 

63mph after drive train loss

 

Weird to watch that sheet being edited live lol.

The drive train loss is an arbitrary number I used to calibrate against the online calculator I found 😄

You should be able to download it and check my workings though.

[m4inbrain]

Just now, Paul Busby said:

Added to my spreadsheet. Appears you have spotted another clanger, and I was actually using copperhead 1

 

Happens bud, if someone's using CH1, the spreadsheet would've been  correct.

 

Either way, to be very honest, 5mph is hard to notice. Especially on a basher. I'd start 18t, and if contrary to my opinion and what i've read the motor holds it fine - just start increasing incrementally. Pinions don't go off, it's always good to have spares too.

[m4inbrain]

Just now, Paul Busby said:

The drive train loss is an arbitrary number I used to calibrate against the online calculator I found 😄

You should be able to download it and check my workings though.

 

lol

 

Well.. It appears that you correctly biased your outcome towards the outcome that i prefer. I can live with that.

 

Bookmarked it already, nothing to check at the moment since my RC stuff is in hibernation now - just today basically everything flooded around here, so if i want to drive something in front of the house, i need to get a boat.

[Skynet5]

 

Anything else?

 

 

[Paul Busby]

Looks good to me. I'd still recomend putting the 15T speed pinion on for your first drive before jumping up to 18T

 

My only suggestion, and this is completely optional, is to also get some heavier oils, especially if you want to run it in the winter in the mud and such. Stock oil is fine, but most people (myself included) find that the truck responds well to thicker oil all around. It can really help with tyre balooning when giving it the beans on the ground.

 

300-500k centre, 20k rear, 40k front... something like that. It's one of those things that's very much a personal preference though, I've gone up and down in weight a lot and find this to be the sweet spot.

[Skynet5]

4 minutes ago, Paul Busby said:

Looks good to me. I'd still recomend putting the 15T speed pinion on for your first drive before jumping up to 18T

 

My only suggestion, and this is completely optional, is to also get some heavier oils, especially if you want to run it in the winter in the mud and such. Stock oil is fine, but most people (myself included) find that the truck responds well to thicker oil all around. It can really help with tyre balooning when giving it the beans on the ground.

 

300-500k centre, 20k rear, 40k front... something like that. It's one of those things that's very much a personal preference though, I've gone up and down in weight a lot and find this to be the sweet spot.

Was unsure if the 15t pinion was big enough for the 4985 can to miss the drive shaft.  Is that pinion included?

 

[Paul Busby]

46 minutes ago, Skynet5 said:

Was unsure if the 15t pinion was big enough for the 4985 can to miss the drive shaft.  Is that pinion included?

 

It's included with the Kraton, yeah. You can always loosly put it on, then if it doesnt fit, just stick with the 18T.... just be prepared for that first throttle blip. Will be a hooligan.

[Kpowell911]

On 23/12/2020 at 11:45, Paul Busby said:

 

Posted my comments previously (quoted below). Bear in mind that the EXB doesn't do anything particularly special that a Kraton didn't do before, Arrma largely just included the parts that most folk have been adding to them for years.
There is slightly different geometry on the suspension, slightly modified A Arms, and LSD diffs... I can't say how much difference they make (yet) but that's it, for all intents and purposes it's the same car with the same driving experience, just tougher.
I'd probably argue my Titanium upgrades do a better job than the EXB ones, but that's up for debate.



Thinking about it again, I also think my feelings on the MT410 might be skewed by the fact I have a sensored electronics set up... Which does suit the platform for sure.

In terms of building, I've made no secret of my love for the Tekno build experience, and utter distain of the Arrma QC for spares (the gearbox replacements are utter turd), but I can guarantee you will have the Arrma in pieces and rebuilt from a bag of screws and plastic at some point
 

 

Excellent reply, thank you!

 

I had a (stock) ET48.3 and EB48.3, they were wonderful. They both had Tekin RX8 Sensored Combos, They were brilliant, almost too good for me. I didnt really like the lack of space for electrics however?

 

An MT410 is an itch Ive always wanted to scratch...... but?

[mydoddy69]

49 minutes ago, Paul Busby said:

It's included with the Kraton, yeah. You can always loosly put it on, then if it doesnt fit, just stick with the 18T.... just be prepared for that first throttle blip. Will be a hooligan.

 Might be in the rtr but it’s not in the roller you get a 12t only 

[mydoddy69]

20 minutes ago, Guns said:

Excellent reply, thank you!

 

I had a (stock) ET48.3 and EB48.3, they were wonderful. They both had Tekin RX8 Sensored Combos, They were brilliant, almost too good for me. I didnt really like the lack of space for electrics however?

 

An MT410 is an itch Ive always wanted to scratch...... but?

 
Space is tight there’s no denying that

 

What’s the But? 

 

Treat yourself it Christmas 😂😂