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Tekno ET48 Build - TP 4070

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Tekno ET48 Build - TP 4070

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Old 12-18-2014, 08:14 PM
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Originally Posted by tman4wdr View Post
Like a glove!

Are you going to brace or support the motor to relieve some stress on the motor mount?
I wasn't planning on it, the motor mount is pretty robust.

Originally Posted by Dr_T View Post
Awesome you'll be able to fit it 0verkill! I really like the ET48, but always assumed it was just too small for brute power set-ups, very cool you prove me wrong . This is gonna be fun!

FWIW, I run 20k/2000k/10k (F/C/R). Depending on how you use it, I'd expect the 300k CD is too light and will be running hot. Been thinking of upping my front and rear a bit (esp. the 10k rear, which is getting a bit leaky, which I suspect is because of the oil getting too hot) to something like 40k/20k (still "off-road-ish"), or 500k/40k (more "on-roadish"), but so far have been too lazy (I mean busy, obviously ) to get the diffs out.

Did you get the motor from the TP website? If so, then you can confirm whether the weight in their specs (think it's listed as 490 g or something, opposed to the ~586 g I got) is a typo or whether they changed something to the motor?



Or you just flash it with genuine Castle firmware, thanks to Lizard / Rodizio.

Edit:
Here, I'll throw in this pic about diff fluids from Bill de Long out of the Hudy set-up guide, maybe it's useful:
Yup, big motor + lightweight platform = fun. I ordered it directly from TP Power and it weighs 585g.

Did you find it necessary to run a steel spur? I ordered one to have as a backup. What kind of gearing do you think is appropriate with no fan? I only have a 23T pinion at the moment.

Diff Ratio - 4.44
Spur - 44T
Motor KV - 1440 (or it could be closer to 1740 based on your findings)
Tire Diameter - 5.85"
Battery - 6S

So, when are you going to try the Lehner 2280 (44x120mm)?
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Old 12-20-2014, 12:35 PM
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I picked up the lightweight motor mount insert and opened it up a little bit so it could fit the Kershaw Designs 8mm bore pinion gear. No shaft reducing for me.




Shaved off the receiver box.



The Mamba Monster fits.

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Old 12-21-2014, 06:21 AM
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Looking good!

Cool you confirmed the TP specs are off on the weight. I'm really curious about your kv, did you check it yet with the Torque Control motor test in the Castle Link software? Don't know if the Traxxas firmware has that option, but you could use one of your MMPs or just flash your MME if it doesn't have it - it's a very useful feature in the genuine Castle firmware anyway.

Great you can fit the 8 mm pinions. You could check aliexpress for some cheaper ones, if you want some more gearing options and not pay $20 per pinion. I don't have my computer with me, but I could check the gearing a bit later. I think xmod was running ~105 kph gearing without fan on ballooning tires.

I started out with a plastic spur too, but did strip it after a couple of times, and that was with the Leopard 4082 even. Hard to tell if it was a rock, stupid gear mesh, or whether Power was a factor. I think for off-road use steel makes more sense, because of all the debris flying through the gears. On-road you might get away with plastic longer, I mean XO-1 has plastic spur, so should be able to hold a bit of Power.

Cheers!
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Old 12-22-2014, 04:36 AM
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Originally Posted by Dr_T View Post
Looking good!

Cool you confirmed the TP specs are off on the weight. I'm really curious about your kv, did you check it yet with the Torque Control motor test in the Castle Link software? Don't know if the Traxxas firmware has that option, but you could use one of your MMPs or just flash your MME if it doesn't have it - it's a very useful feature in the genuine Castle firmware anyway.

Great you can fit the 8 mm pinions. You could check aliexpress for some cheaper ones, if you want some more gearing options and not pay $20 per pinion. I don't have my computer with me, but I could check the gearing a bit later. I think xmod was running ~105 kph gearing without fan on ballooning tires.

I started out with a plastic spur too, but did strip it after a couple of times, and that was with the Leopard 4082 even. Hard to tell if it was a rock, stupid gear mesh, or whether Power was a factor. I think for off-road use steel makes more sense, because of all the debris flying through the gears. On-road you might get away with plastic longer, I mean XO-1 has plastic spur, so should be able to hold a bit of Power.

Cheers!
I haven't soldered anything yet, I'll have to look into it.
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Old 12-30-2014, 04:36 PM
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I got a lot of things buttoned up today. This motor runs really strong on a half charged 4S battery. This thing will be an absolute monster on 6S.

Fully assembled weight with a 4S battery and track tires is 8.85 lbs.


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Old 12-30-2014, 05:21 PM
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Please let us know how the diffs hold up on 6s! I really like this truggy but I'm a basher. I know the race guys love it running 4s on the track with truggy tires. I'd like to know what it does with some Badlands or something similar that gets high traction in the grass. The design of the diffs doesn't look like anything special compared to other brands, but you never know!
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Old 12-30-2014, 06:48 PM
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how do you like those castle connectors compared to EC5s?
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Old 12-31-2014, 04:14 AM
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Originally Posted by Cain View Post
how do you like those castle connectors compared to EC5s?
I like them. I had only used Traxxas connectors before this. They took a little more effort to install. They handle up to 200 amps of continuous current and up to 6 awg wire, so it seemed obvious to use them.
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Old 12-31-2014, 08:46 AM
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cool, will give those a bit more look.
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Old 12-31-2014, 09:18 AM
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I'd like to see a video of that thing...
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Old 12-31-2014, 12:21 PM
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I thought the savage flux hp motor was big, but that motor is absolutely massive. That looks like it is going to provide endless fun as long as it holds up. I only run my savage on 4s and it seems like a lot of people expose the weak links on 6s. It will be interesting to see how it holds up for you. Nice build!
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Old 01-01-2015, 01:38 PM
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Happy new year man, looking good!

That's super light-weight, mine weighs over a kg more and I think xmods MP9 buggy even weighs more no? Wonder where Tekno gets those weight savings; chassis is less wide obviously, but that should not make such a huge difference. How much more does your 6S battery weigh compare to that 4S you weighed it with?

Did you decide on the diffs yet? FWIW, I'm going to run 40k rear and 80k front, center stays 2000k as is. Pulled my diffs and my 10k rear appeared to be completely empty, so I thought I'd up it all a bit. The gears did not look that bad at all, although the front ring/pinion have some more irregular wear pattern (more "chippy") compared to rears.

What was a bit more worrying was that 3 out of my 4 outdrives (1x rear, 2x front) had chips off the holes... not sure what to make of that yet. Got my truck used, so maybe they were just over their expiration date (not willing to accept the TP4070 on 6S is too much yet ); I'll try some new outdrives and see how it goes. Very interested in hearing your results!


Pulled diffs, rear (10k cSt) was almost empty...


Gears don't look too bad, front does have some more irregular wear though compared to rear.


Outdrives seem to be less happy: 3 out of 4 (1x rear, 2x front) had chipped-off holes.

Also gonna try some new gearing soon .



Cheers!
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Old 01-01-2015, 02:31 PM
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Do I see metal inserts in the diff cups holding the crosspins? If so that would be an upgrade over the associated diffs in my RC8t and TT MT4.
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Old 01-01-2015, 02:45 PM
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Originally Posted by Micah78 View Post
Do I see metal inserts in the diff cups holding the crosspins? If so that would be an upgrade over the associated diffs in my RC8t and TT MT4.
Yes, they're the LOSB3528 Heavy-Duty Differential Case: 8, 8T, LST2, XXL/2. Very clever design and eliminates the spider gear axles cutting into the plastic.

Hope 0verkill doesn't mind too much I'm polluting his thread, but here's the measurements of the stock Losi 8ight ones I took once for someone - HD ones should be same as it is drop-in replacement. All measurements below are in mm. I think the Durango DEX408(T) has metal insert diffs too, in case anyone's looking for alternatives.









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Old 01-02-2015, 02:20 AM
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So your truggy is a Losi 8ight t? I am considering making the Losi or Durango my next E truggy just because of the metal inserts in the diff cups. I've been having problems with the spider gears in my MT4 running 6s. If I'm easy on the throttle it's ok,but if I start stabbing the throttle to do rolling or standing backflips the spider gears can't handle it.
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