New: 58660 1/18 Dynahead 6x6 (G6-01TR chassis) and more.

[taffer 948]

You need two b trees to offer the 4WS option, one b tree only had two steering hubs, Tamiya more likely to inc the whole tree?! Which will leave the door open for a standard g6-01 setup?

[taffer 948]

 

This unboxing seems to show you do receive all the parts to NOT fit portals if you so wish

(Plastic parts at least)

[Juggular 4961]

On 11/24/2018 at 5:39 AM, taffer said:

You need two b trees to offer the 4WS option, one b tree only had two steering hubs, Tamiya more likely to inc the whole tree?! Which will leave the door open for a standard g6-01 setup?

You were right, taffer! 

The unboxing showed 2 trees!  You can build G6-01.  

 

[Badcrumble 4201]

Manual!

http://www.tamiya.de/CommonFiles/Dickie-Tamiya/PDM_Products/Tamiya/300058660/300058660_Anleitung_Dynahead_6x6_G6-01TR.pdf

 

[Juggular 4961]

Thank you for posting the manual, Badrbumble! 

Two things jump at me.  

The first is how Tamiya is including Differential Clay.  I have never seen that before (even though I put it in my Konghead).  

Secondly, non-standard (uncommon) 950 bearings are included. 18 of them.  Yay!  (but... if portal gears are to be sold separately with 18 bearings, Tamiya would try to charge more. I hope they are not too prohibitive)  

All I'd have to get are 30 standard 1150 bearings, 2 standard 850 bearings and 24 non-standard 630 bearings. (56 Included bushings would give it a massive drag)  Add 18 included ones, Dynahead would use 74 bearings!  I love bearings.   

Thank goodness for cheap bearings.  Thirty (5x11x4mm) bearings would cost $6, thirty (3x6x2.5mm) bearings would cost another $6, and ten 5x8x2.5mm bearings would cost $1.  That's whopping $13.  That's much cheaper than one of those packaged deals.  

 

 

[taffer 948]

So.....how does the putty feel in the diff? I'm thinking just to stock to AW grease if the putty is too stiff, what does your kong diff now look like inside!?

[TWINSET 1793]

9 minutes ago, taffer said:

So.....how does the putty feel in the diff? I'm thinking just to stock to AW grease if the putty is too stiff

There's no instructions on diff lube in those pics - doesn't the putty just lock the diff solid?

 

KongHead manual shows diff lube;

[taffer 948]

if it locks it, I wont be using it!

[Nobbi1977 1793]

I use putty in most of my kits. It does not lock but it can be very stiff if you use to much

[Juggular 4961]

1 hour ago, taffer said:

So.....how does the putty feel in the diff? I'm thinking just to stock to AW grease if the putty is too stiff, what does your kong diff now look like inside!?

AW is too weak for heavy off-roaders.  For light on-road cars, AW grease is perfect. (AW is still okay for light off-roaders like the Frog, DT02, etc, but no good for heavier ones)  

I use putties for heavies.  My Wild Willy 2 used to lose traction on one wheel and the diff gets unloaded.  With putties, one wheel with traction gets ample power. (I used Bad Horsie Diff Lock grease for WW2, but even that is too weak for Konghead)  I also do a "wet tub test."  I make it as stiff as possible, but it should still work on a slippery wet surface.  (You'll be surprised how stiff it can be before it fails the wet tub test)  The Limited Slip Differential is best of both worlds.    

I put a bit more than what the Dynahead instruction shows.  I test out the diff with drive cups, dog bones, wheels and tires before I close the gearbox.  This is some other brand.  But it should work about the same.  The consistency is like Play-Doh, but a lot more clingy,  

 

[A bit less...  I put in 1 small ball of it, that got all smeared.  I wanted it stiffer, so 2 more small balls are shown here.  All 3 might be as much as Dynahead shows in 1 bigger ball of it]

[A bit more... With this much, it was very very hard to turn the drive cups by hand.  Any more than this would almost lock it.  The truck still turns fine--no traction lost due to locked diff because it's not locked]  

 

 

[taffer 948]

Hmmmm now do i want a slower version of not?

By the time I build it next year, hopefully someone will have run it at speed as well!

[smirk-racing 253]

7 hours ago, taffer said:

Hmmmm now do i want a slower version of not?

By the time I build it next year, hopefully someone will have run it at speed as well!

The range of kvs available with today’s  brushless motors, plus lots of options from 2-4s lipos (without even going crazy on the esc, although 6s is also pretty doable with a castle mamba x) makes it pretty easy to get past a 2x portal reduction with no problem at all. 

 

I did the opposite with a Tamiya dump truck - went to a 1200kv motor on 2s to slow it way down for a kid. Left the tires unglued to absorb excess torque.

 

 

[taffer 948]

I don't doubt it's possible, it's the durability aspect!

[taffer 948]

My 2x Dynahead's have had confirmed despatch emails! 

[Juggular 4961]

On 11/30/2018 at 1:30 AM, taffer said:

I don't doubt it's possible, it's the durability aspect!

On 3S, Teflon grease could be very useful (especially with so many gears!).  Along with full bearings, it should run for years.  

A bit of a concern is the kingpin holes on the portal gear.  If the portal gears encounter a bump at high speed, that's where the force would be transferred to. (I don't think there is any caster angle to help the matter)   Normally, the axle is on the same plane as the arms.  But by definition, the portal gears hang down from the arms.  At high speed, the king pins could get a lot of rear-facing torque from a bump.  If you run fast on a surface where there is no bump, then this time, roll-overs would give lateral stress on the kingpin holes. 

So 4S might be too hot... But 3S on a 3900KV motor would be 43,000 RPM. Which might still be faster than Konghead with a 23t brushed motor.  I'm thinking around there would be the limit?  

 

[taffer 948]

At this moment in time, I'm leaning towards a more crawler build, I will of course be monitoring YT to see if the portals hold up or what their breaking point is...

[taffer 948]

Arrived and on the homepage!

I haven't bought all the 76 Ball bearings yet, will be built after my honda city turbo in 2019

I'm hoping before I start the build some different coloured chassis parts are released, my king yellow has the smoke clear, would like white or normal clear????

[geniusanthony 361]

driving video posted, not me. looks fun. Want!

 

[taffer 948]

Drives well in above video, got everything now for mine except the esc, considering the Quicrun crawler esc......Waiting for matteo 's video!

[GTodd 1340]

Ok, seriously I know Tamiya isn't the pioneer but come on I can't believe Tamiya isn't getting some love for giving gear reduction axles finally.

[WillyChang 1814]

1 hour ago, GTodd said:

Ok, seriously I know Tamiya isn't the pioneer but come on I can't believe Tamiya isn't getting some love for giving gear reduction axles finally.

Tough crowd!

But they deserve some flack for still using 1150 plastic bushing in there 

 

T probably has a warehouse full of 950 bearings  after their disastrous efforts trying to introduce them on TRFs circa 2005  they tried putting them onto the then-new reversible arm suspension (TB Evo5 saw them first I think), but those itty bitty tiny little 1mm balls would never last long under the rigours of touringcar track stress. Some days they'd barely last a battery pack without going gritty, occasionally they'd simply explode.

They changed to 1050s not long after.

[Blista 1519]

Tamiya have a YouTube video about the PDC Designworks concept for the Dynahead (it's in Japanese).

They showed a few of their concept drawings for what could have been.  I would've voted for #4.

[taffer 948]

Just need to finish the body on my Dynahead build, I have installed cva oil shocks with blue (stiff) trf springs (which are slightly softer than stock).

There is a minor issue with the steering front and rear, the drive shafts when steering very slightly run on the drive cup producing a minor mark on the drive shaft, the wheels exhibit a small tremor as well which when actually driving seems to be when greater than 50% turning (a guess).

Has anyone else noticed this? It seems at the moment to avoid this the buggy would need to be lower while at rest and when driving so the drive shafts are straighter, which would mean possibly three hole pistons and soft springs instead??

Not an issue really with a stock 540 but unsure of how parts would hold up with anything faster

Edited January 12, 2019 by taffer
Pistons not pigeons!

[wolfdogstinkus 1893]

 

7 minutes ago, taffer said:

Just need to finish the body on my Dynahead build, I have installed cva oil shocks with blue (stiff) trf springs (which are slightly softer than stock).

There is a minor issue with the steering front and rear, the drive shafts when steering very slightly run on the drive cup producing a minor mark on the drive shaft, the wheels exhibit a small tremor as well which when actually driving seems to be when greater than 50% turning (a guess).

Has anyone else noticed this? It seems at the moment to avoid this the buggy would need to be lower while at rest and when driving so the drive shafts are straighter, which would mean possibly three hole pigeons and soft springs instead??

Not an issue really with a stock 540 but unsure of how parts would hold up with anything faster

It's almost definitely the pigeons.   

[taffer 948]

Lol **** spellcheck!