My Brushless Micro-T lives!

[TheSteve]

I've been working on a Brushless Micro-T and today I drove it for the first time.


I have everything but my LiPo packs so I had to try it on the 4 cell nimh pack.
The Castle Creations PHX-10 controller can drive the truck slower then the stock speed control. It doesn't cog at all, it does have a very slight ramp up to full power though(I believe its the 4 volt LVC in the controller), keeps it from doing a wheelie - with the nimh pack anyway, based on the speed and torque it will be wheelie city with the LiPo pack. I am using the medium pinion gear, its obvious I can goto the largest pinion. The body fits with no rubbing, no sign of the motor warming up. The ESC is forward only and brakes when in the neutral setting so I disabled the brake, the slight drag of the gearbox and motor seems to be fine, I may add a slightly delayed light brake when I can fine tune it with the LiPo's.

Once again peace has been restored in the RC world, all of my cars are brushless powered!!! Now where are my LiPo's !!!

Equipment used:

Micro-T with ball bearing upgrade
Spektrum SR3500 receiver
Castle Creations PHX-10 brushless ESC
Feigao LPS 5250 brushless motor - 12x22mm 5250kv
Deans micro connectors

4 cell Nimh pack at the moment, soon to be a 2 cell 250ma 20C LiPo

I'll be doing a scale dragrace between a stock Micro-T and the brushless version once the LiPo's arrive. I have access to a full drag system including a 6 inch tree.
I will also post the weight differences between stock and brushless/LiPo, as well as the runtime differences.

[TheSteve]

With the body on:

[alfred]

Dude that is nice.......so how is it on the straight.:D

[Fajita Dave]

Are you insane?! That thing is to fast for its size stock. You have to post a video of that thing :D.

What steering servo did you use anyway?

[TheSteve]

I am using the stock servo, I added the electronics driver board out of an Airtronics 94091Z I had kicking around that had gear problems. So now it works like a regular servo.

[m18_racer]

now all you need... http://yourmicro.com/forums/showthread.php?threadid=19010

[Namuna]

That is a MEAN lookin Micro-T!

Nicely done TheSteve!

[andyvader]

With the body on:
were did you get the body? i have been looking all over.



thanks,
andy

[jaejw1]

I still think you should give the kans a try,,,,,, comparing the stock to my lipo to my kans,,, the kans win it..
stock 150mah with medium pinion
2 cell lipo 150mah with largest pinion w/ micro deans
kans 160mah with largest pinion with micro deans

-the kans has more torque than the stock with less run time but the power lasts longer ,, it will wheelIes on demand and ride it as long as I want on a hardwood floor
-the lipo is like running stock with largest pinion-no power and takes time to get to speed

for 7 bux you cant go wrong and you could do a COMPLETE test for those that dont have a lipo but would still lIke a bl

[alfred]

Listen to the man will ya......he know's his stuff.:D

[microRS4guy]

jaejew- you sorta have your thinking right, but not all the way.
when you mess with lipos its not just find a pack that will fit and you are done. you need to fint one that fits, has a goot c rating and has enought mah to get the desired discharge rating out of the pack to accually power the motor. if you dont take into consideration all of thoes you will have lipos that are doing what you explain (i have the same problem). for the micro t you need cells that are close to a 20c rating and have at minimum 150 mah for them to be better than the stock set up.

[alfred]

Hey buddy can you post any links to some good cells so other members here know what to get.:D

[microRS4guy]

http://www.bphobbies.com/view.asp?id=A2416227&pid=U351143 there is a god cell to use, just remeimber when soldering lipos, you need a alunimum based solder, and do this with caution!

[jaejw1]

well I was using that lil lipo pack that was made by wattage ,, the pneumonia used for that micro ind_r plane,,, the same that was first used and video'ed in the micro-t,,,,,, but I will give another try at the lipo

[TheSteve]

A good nimh will perform better then a poor LiPo pack.If you get good LiPo cells though they willout perform nimh cells.
The LiPo pack I have maintains voltage for the entire run. Its been tested with the stock DC motor as well as with my brushless system. I now have a mamba25 installed in my Micro-T and its even more insane then before.

If I punch it from a dead stop the truck will do an instant back flip. I can wheelie all day long for the entire pack. I raced against a stock truck today and the differences are staggering. The same LiPo in a stock Micro-T is equally impressive, its like a micro missile.

If anyone has tried a LiPo pack and not experienced insane power and speed then I can only conclude the pack just isn't of good quality.

I will have some video soon.

[jaejw1]

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXJCR0&P=7

this is the pack i used.. 2 of them

[mugmug]

The Steve,

Which lipo packs have you ordered and from what source? I couldn't find that size anywhere??
Thanks

[TheSteve]

I am currently using a 150ma 2S pack I got a from a guy at one of the local hobby shops near me. I will find out more about it and see if it can be ordered online anywhere. I have actually put more then 160ma into the pack so I think its really closer to 170 or 180ma. If you remove the shrinkwrap around it it fits easily into the stock battery compartment with no mods to the truck itself.

I have also ordered some 250ma cells but there may be some dremeling required to get them to fit.

[mugmug]

Thanks for the reply. By the way that brushless can has the dreamiest color I've seen in a while. Good stuff.

[jaejw1]

I am currently using a 150ma 2S pack I got a from a guy at one of the local hobby shops near me. I will find out more about it and see if it can be ordered online anywhere.
please do ,, I would like to have one for myself,,,,

[jaejw1]

http://www.bphobbies.com/view.asp?id=A2416227&pid=W928390

would that be a good option,, not too informed on ratings of cells.. and which offers best results..

[m18_racer]

10C for this size!:eek: im probally going to roll with two lithium AAAs that will fit my chassis perfect.

[m18_racer]

also you will need a pcb board or whatever

[jaejw1]

so is 10c good or bad?,,,,,,, also why would you ned a pcb board

[m18_racer]

i dont know i read it somewhere. :confused:

[jaejw1]

so what about the lipo being 10c is that good or bad...... also there have been many ppl that have used stock elects with the lipo cells.. including myself..

[microRS4guy]

thoes cells will be cutting it very close to being good cells . i know i would look for something with better specs. the way c rattings work is 10c means the battery can put out 10x its compasity. so that would be .1x150. to give you 1.5 amps continous.

one way you can tell if this is goo or not. is get a volt meter and see how many amps the motor pulls from the stock pack.

[TheSteve]

10C for this size!:eek: im probally going to roll with two lithium AAAs that will fit my chassis perfect.


Ouch, lithium-ion AAA's? Those type of cells are usually rated at 2C maximum.

I think a 10C LiPo is plenty for the Micro-T as long as its rated at atleast 150mah's of capacity. Mine remains punchy for the entire run. I asked the guy at the hobby shop to bring in a few so I may have a few extras early next week.

I one I have I've put more then 160mah into while charging so I am thinking they are closer to 170 or 180mah cells.

[jaejw1]

you should have a few packs made and sell them,,,, or do special order,,,, I know I would like one

[mugmug]

I am using the stock servo, I added the electronics driver board out of an Airtronics 94091Z I had kicking around that had gear problems. So now it works like a regular servo.

TheSteve,

I'd like to buy one these servos from you through paypal. I'll send you the money in advance if you need to buy parts and such for putting it together. Thank You.

[TheSteve]

Thats a great offer but I'd need more driver boards from 94091Z's. Buying that servo just to rip the board out certainly wouldn't be the way to go. I do believe you can mod a hitec HS50 or HS55(don't recall which) to work quite nicely in the Micro-T, you take the two final gears out of the stock servo and swap them into the Hitec servo which allows you to use the factory servo saver.

[mugmug]

It must be the HS 50 then, cause I bought the HS 55 and opened it to do what you mentioned and realized the gear work is pretty different looking which I guess brings me to the next question, do the gear work have to be the same in order for the final 2 to be swapped or some variation is ok??

[m18_racer]

Ouch, lithium-ion AAA's? Those type of cells are usually rated at 2C maximum.


while this is true i would like you to do 300mah x .02 .. thats right thats 6 amps continuous discharge.

[TheSteve]

while this is true i would like you to do 300mah x .02 .. thats right thats 6 amps continuous discharge.

If the cells are rated at 300mah each and you use two in parallel then the total discharge capacity is 600mah, they are 2C cells so the total safe current drain of the pack is 600mah multiplied by two, or 1200mah which is 1.2 amps.

[Namuna]

Here's the breakdown on Powering the Micro-T...

Note: All due credit for this info to LBRC from other Forums (if I'm misquoting anything, let me know).

Firstly, the Motor can draw up to 2.1A max. So if you want the absolute highest possible amount of power/torque from your Micro-T, you need to get a battery pack with a high enough discharge rate to put out that 2.1a.

In terms of Lipo, the "C" rating is a multiplier for the pack rating. A 250mah battery rated at 10C means you can safely discharge at a rate of 250ma x 10 = 2500ma = 2.5amps. Such a pack would be ideal for the Micro-T, but so far the ones that people have been reporting on (like the E-Tec 250mah) is a bit too wide to fit in the battery compartment of the Micro-T without some dremeling.

I'm on the hunt for a Lipo cell that'll fit the stock compartment and still put out at least the 2.1amp and I'm hoping to hear good news soon!

[TheSteve]

The 2S LiPo pack I am using is 160mah and seems to handle the load of the brushed or brushless motor just fine. It warms up just a little without getting anywhere near hot. I believe its 10C constant and 20C surge.

I have also ordered some 20C 250mah cells, they should be here anyday but may be a little tough to fit in the stock compartment, my 160mah cells fit no problem.

Ideally though I think a battery that can handle between 2 and 3 amps is what we want. I also expect I want a battery like the 20C 250mah cells for when my faster brushless motor arrives.

The E-tec cells people are trying are only rated at 5C which is why they aren't performing as well as expected. I recommend people avoid the E-tec cells for now unless they find some higher rated cells.

[Namuna]

...The E-tec cells people are trying are only rated at 5C which is why they aren't performing as well as expected...

Ahhhh, this explains a few things. Thanks for that info.

[Lostinturn3]

does anyone have a link to a "good" lipo pack to fit the micro-t?

also, will a 7.4v lipo pack work with the stock motor/esc/tx or will it fry the stock stuff?

[Al P]

Apparently this is a good pack and it fits the compartment.

https://www.unitedhobbies.com/UNITEDHOBBIES/store/comersus_viewItem.asp?idProduct=4069

I have not used it but am considering it.

[NitroRyda]

HOLY COW! That Micro-T Is nice! I never know that you could do that much with them!