Lets clear this up....

[suprapimp22]

Hey guys, im planning on putting a brushless in a XXX-T.

In september im buying the second charger for the lithium batteries......So i want to make sure all of this is going to work first.

I plan on getting a shulze U-Force 75 ESC and a hacker c40 8s.....Will these 2 work togethor? Do i need any special 'connectors' or bars or plugs?....? I also plan on using a JR servo that came with my XS-3 radio and a XS-3 synthesized RX.


Is all of this going to work togethor?


-Chad M

[TheSteve]

You will need battery connectors for the U-Force but it includes the 3 PP35 male motor plugs you need. So you'll want to take some 12 guage wire and extend the motor wires and then solder on the PP35 plugs(and insulate it all with heatshrink) Your Hacker c40 8s will then nicely plug into the U-Force. And yes, it will work great with the U-Force. The receiver and servo should be fine.
The only question I have is what voltage LiPo cells you'll be running. If you're doing a 2s pack (7.4 volts) then the low voltage cutout in the U-Force is already fine. If you are going higher voltage and want an "automagic" cutout you'll need the programming software to change the voltage(or when it slows down stop running...)

[suprapimp22]

Hey TheSteve,

I was just going to use deans plugs is that ok? I plan on running a TP 8000Mah 7.4v pack....


I cant decide on a 6s 7s or 8s......


I relize the runtimes will be less with a 6s, but it will still be plenty long with that TP 8000.....i just want all out speed and torque.....any adivce?

[suprapimp22]

BTW- You think a lhener basic would be faster than any of those hacker motors listed? Price doesnt matter...

[TheSteve]

I'd stick with the 8s or a higher wind for anything other then a touring car. You'll certainly have plenty of speed.
A Deans Ultraplug is a great connector.

Sounds like a great combo so far.

edit - I'm sure the Lehner would also perform great, but I haven't compared one directly to a Hacker c40 - so I can't say for certain which would be better in your application. Other people are running Lehner motors with great success.

I'm personally a big fan of the c40 series because of the excellent heatsinking.

[mtrsprt]

If you were to choose a Lehner motor for some reason, I would choose the Basic 4200 or 5300 and run 6-8 cells.

[bomb-proof]

Starluck also has some killer 1/10 truck motors, I have tried one in a T3 with lipos and ran a solid 20 minute main with the nitro guys. Speed was perfect, after 20 minutes it was still not hot. And the $70 price tag was easy to swallow.

[DaFF]

SupraPimp,

My advice would be to get 2 lipo pack 2S 7.4 volt 4000 mA and hook them up in series for 14.8 volt.

It will be roughly the same price as your 2S 7.4 volt 8000 mA, only will it send to your motor and esc more voltage which is what you want for better efficiency, more torque, more speed and less Amp through the controller.

DFF

[suprapimp22]

I would, but i dont know how many volts the U-Force can handle, craps also said with 7.4v it is uncontrollable.....I also want very long run times with the 8000Mah

[DaFF]

As a matter of fact, yes, the UF can handle 4S - 14.8 volt lipo.

That's DFF approved because that is the setup I did run the whole afternoon without a problem.

If you ever decide to go with 14.8 volt, you'll need a lower turn ( Kv ) motor.

By going lower turn motor, higher voltage, you will increase efficiency ( less power from batt wasting as "Joule effect", which is power from batt translating into heat on the esc & batt )

Increasing efficicency will translate into more run time...

With more voltage, your motor will turn faster ( in fact you should try to be close to the motor rpm limit, that's 65 000 rpm in my case ), thus meaning you'll be able to gear it lower, which will also mean even more run time.

DFF

[suprapimp22]

DFF....So if i ran say...11.1v.... Then which motor would i want 6 7 or 8s?


What speeds would i be looking at?I want screaming top end but bitchin torque :)

I just dont want it to have so much power to where its going to wheelie at 40MPH....

[suprapimp22]

I just want the fastest setup that will run decent temps and decent run times, i dont want to run more than 11.1v ....I am going to have to mod the car to get the 11.1v pack to fit anyways...

[starluckrc]

I ran my Feigao 540-8S on 6 cells for 40 mph. 11.1V would be overkill. Should be a good setup for the 10S when I get it in stock.

[MarNaDaKi]

The only question I have is what voltage LiPo cells you'll be running. If you're doing a 2s pack (7.4 volts) then the low voltage cutout in the U-Force is already fine. If you are going higher voltage and want an "automagic" cutout you'll need the programming software to change the voltage(or when it slows down stop running...)

TheSteve
Can you tell me for sure the exact cut-off voltage the UF is set at from the company ?

[TheSteve]

The factory default is 5.3 volts

[suprapimp22]

Daff can you answer my questions when you get a chance please? Thanks :)

[suprapimp22]

Would 50-55 be resonable on a c40 6 or 7s? On 7.4 ( really 8.4v) ?

[TheSteve]

I think you'll need more then 7.4 volts to get that kind of speed with a xxx-t. Or if you do get that kind of speed you'll be way overgeared to get it and everything will be getting pretty hot and battery life will suffer.

[suprapimp22]

The steve, what if i just ran a 6s on 7.4v....what speeds would you think i would hit? Thanks...

[suprapimp22]

I really am pushing for 7.4....Because i dont want to mod the battery and chassis to fit a 11.1.....plus the 11.1 is like 60$ more

[TheSteve]

I don't think the 6s is what you want in a truck, I wouldn't go below the 8s. If you really need that much power you may want to goto a 540 sized motor.

[DaFF]

Supra, I am not in the main timezone as you, that is the reason why we are not on the forum same time. ( In fact it was like one o'clock morning when I posted my previous message :D )

Anyway, if you are thinking at the 11.1 volt 8000 mA, it will be roughly 50% more run time than the 7.4 8000 batt.

I am sure it could mean way over half an hour run time :eek: with crazzy sick power.

But the price for that means HEAVY pack and it will become very difficult to fit this pack on your car. The 11.1 v versus the 7.4 v pack is like + 150 grams ( or 0.33 lb ) and that is a lot on a 1/10 car.

Quite frankly it would be way overkill if even possible.

What I was saying for exemple is shoot for the Thunder Power 11.1 volt 5700 mA. This baby has the same weight as a 7.4 volt 8000 mA, has roughly the same dimensions and is also in the same price range as the 7.4 v.

This 11.1 volt 5700 mA in conjunction with a milder motor ( read 10s for example ) would be to my opinion the ticket for less heat, more efficiency, more torque ../..

DFF

[suprapimp22]

Ok, i thank you lots for all of your advice, but would i have any problems if i just ran the 8000 7.4v with a 6s motor? What kinda speeds? Thanks......


If that didnt work well, i might just run a 6000 11.1v and a 8s motor....

[DaFF]

You should not have problem with the 7.4 v 8000 mA.

Only might the UF thermal if you gear it with a low ratio gearing, but I am not sure because I have never tried a hot motor like you plan to use.

Anyway, speed is very difficult to predict, but I would say 45/55 mph.

DFF

[suprapimp22]

Thanks DFF....i think i'll get the 6s or 7s then...thanks

[MarNaDaKi]

The factory default is 5.3 volts

5.3 volts is not too low for 2s (7.4 volts) Li-Po cut-off voltage ?

6.0 volts is not supposed to be the strict minimun ?

[TheSteve]

Technically you don't want to go below 3 volts per cell with lithium cells. However the battery voltage is going to sag under a heavy load so it may be fine. Or perhaps they decided on 5.3 volts as a default because 6 would be too high for a 6 cell NiMH pack. Also the U-Force has a 5 volt BEC output, chances are Schulze uses a low drop/loss regulator which will use about 0.3 volts under load, this means your radio gear should never see less then 5 volts.

[DaFF]

Just be carefull with the UF low voltage cut-off... I have to investigate further into this, but mine was setup at 12 volt and I founded my Lipo to be slightly under this limit.

Further tests needs to be done, but for those using UF + Lipo, you've been warned !

I guess for now, I would suggest to set-up a HIGHER cut-off voltage to be on the safe side...

DFF

[suprapimp22]

Daff.....Im a little confused.....Can you please be more detailed on the cut off voltage, or what i would set it for 7.4 v? Thanks...

[DaFF]

Lipo cell do not tolerate deep discharge.

If they are discharged below 3.0 volt per cell, they can be permanently damaged. I think at 2.85 volt they fail and will be a complete loss.

Because of that limitation, 7,4 volt or 2S lipos pack can not be drained under 6.0 volt.

The UF has a low voltage cut-off that you can adjust ( only with the pc link ) from 5.3 volt to 12 volt in 0.1 volt step.

In your case, with a 2S 7.4 volt batt, you should setup it up at 6.0 volt.

I was only telling that you might even want to set it up slighter higher to be on the safe side. I would suggest something like 6.2 volt so that you are sure that even under load it will never go under 6.0 volt.

Side note: I am not 100% sure of what caused my lipo failure. I only know the pack was toward the end when it failed...

DFF

[suprapimp22]

Ohhh yes i knew they fail at 6v......What is the UF set at from the factory? Can i just leave it at that? I dont want to have to buy a PC link if i dont have to! :mad:



Thanks! ;)

[MarNaDaKi]

Starluck also has some killer 1/10 truck motors, I have tried one in a T3 with lipos and ran a solid 20 minute main with the nitro guys. Speed was perfect, after 20 minutes it was still not hot. And the $70 price tag was easy to swallow.

bomb-proof
70$ :eek: Which motor series does he has at that so low price tag ?

[MarNaDaKi]

What I was saying for exemple is shoot for the Thunder Power 11.1 volt 5700 mA. This baby has the same weight as a 7.4 volt 8000 mA, has roughly the same dimensions and is also in the same price range as the 7.4 v.

This 11.1 volt 5700 mA in conjunction with a milder motor ( read 10s for example ) would be to my opinion the ticket for less heat, more efficiency, more torque ../..

DFF

Are you sure of this ? TP, Kokam or Tanic ? Because the 5700 TP ones are way too long. Which manufacturer then ?

[DaFF]

Yes, you are right, the Thunder Power 7.4 volt TP 5700 2S3P is 185 mm lg while the 7.4 volt TP 8000 is 125 mm lg ( regular Nimh pack is 136 mm lg ).

I think I mixed up lenght because if you watch the 11.1 volt TP 5700, it is the same lenght as the 11.1 volt TP 8000 ( both are 185 mm )

Sorry for the confusion :)

DFF

[MarNaDaKi]

:( I would have really liked to be proven wrong :(

It would have been nice, 11.1 Volt in a stick pack format :rolleyes: