set up for BL revo.

hey guys im new on here. and my friend has made a bl hyper 7. so im going to try and convert my revo to bl. i was thinking of using a feiago 9xl for the motor, but the esc, i dont know to much about, but i want to spend and little money as possible, so cheapest is the best :). can i use the stock spur gear and tranny? do i need a mod 1 ( i think i do, but which one for stock spur). and any other info you can help me out on would be apreciated. (this will be my build thread also) .

[BrianG]

First of all, welcome to the forums!

The 9XL will be a good choice with 5s lipo or 16 cells NiMH. If you want to go with less voltage (like 12-14 NiMH cells or 4s lipo), go with the 8XL.

The ESC is possibly going to be expensive. If you go with 4s lipo/12 cells NiMH, you can use the Mamba Max controller. This will be the cheapest option. Some people successfully run this controller with more voltage, but it is running out of spec. You could get the BK Warrior 9920, but this controller does not have a cut-off for lipos, so you'll need an external on if you decide to do lipos. The Quark 125B is another choice (but pricey), but has a lot of programming options and will work with 5s lipo or 16-18 cells no problem.

You can use the stock tranny and gears (which are already Mod1) but you will either have to use a mechanical brake using a braking servo (and you will also not have reverse), or modify the tranny to use the BL motor for braking/reverse. To do this, you need to lock the tranny into second gear. Don't worry, BL power is more than sufficient even in second gear.

BTW: Your name says you are a Canadian RCist, but your location is GA? Is that Georgia or somewhere in Canada? Just curious. :)

yeh, im from canada originally, (thats my email, so i just decided to keep it the same. but i live in GA now . so yeah lol ) .

well the revo im getting has FOC (foward only) already installed, so will that do anything? i wasnt planning on running a lipo yet, there a little pricey, so nimh is good enough for me for now.


would Warrior 7020 Brushless Car Controller work as the esc? it says it can handle 20 cells, but i dont know what the motor is supposed to match up to O.o .

or would a Quark 65 amp Roadster Car controller work ? lol this is confusing me.

how big of a shaft on the motor should i get. and how many tooth on the mod 1 pinion ?

and does it help or not to run the rechargeable batt pack for the receiver ?

[BrianG]

First of all, what do you want this truck to do? Are you looking for high speeds comparable to the Nitro Revo (45mph+) or is this strictly for track use?

If you want super top speed with fewer cells and/or lower current ESC, I'd keep the two speed. A motor with high-enough torque to launch the Revo to high speeds in one gear will draw too much current IMO. This means you won't need to do anything with the tranny other than the FOC, but again, you won't have reverse due to the internal OWB. And you'll need the stock brake.

However, if you are looking for 30-35mph top speed for track use, then locking the tranny into second gear can be done. This will let you remove a couple other internal parts as well as the brake, brake servo, etc.

You can find a motor that will work with 18-20 cells, like the Wanderer 10XL, but I still think the current will be too high for a ~70A controller. The Revo is a heavier truck and needs some torque to get it going effectively, so I'd stick with the XL size motor.

An 8XL Wanderer motor, Mamba Max ESC, and 12-14 NiMH cells should do it for you relatively cheaply. The Mamba controller is rated for 100A and 14 cells (some say it can run 16 cells but I personally wouldn't). The 7020 can only handle 70A, and the quark only 65A. For a larger truck like the Revo, I'd stick to at least 100A like the BK 9920, Mamba Max ESC, or the Quark 125B. If it were me, I'd go with the Quark and the extra heatsink found in the store.

You'll also need a UBEC or receiver pack since 14 cells is too much for the Mamba Max ESC's built-in BEC to handle. You can use a receiver battery pack, but that's adding more weight and one more thing to charge. Better to use a UBEC.

i dont get the whole ubec part.

im looking for a fast revo, nothing about racing. something to compare to my friend BL hyper 7.

what if i got the Warrior 9920 Brushless Car Controller , ran two 7 cell packs to power it, and the stock reciever pack as the last 5 cells, so thats 19 cells. so thats 1 under its max. would that work? im looking for more speed, so would a 7,8, or 9 be the best for more of a speedy revo? and which mod 1 pinion works on the xl's which one in the store. (if you can show me, thanks. i need a budget ).

[BrianG]

First; don't count your receiver pack into the cell count for the ESC power, only the main batteries, which you have 14.

A UBEC is simply a switching voltage regulator that takes your main 14 cell pack voltage and converts it to 6v for the receiver. The fact that it's switching makes it very efficient and it is very light as small compared to a receiver pack. And since it uses your main batteries, you don't charge it.

More information: BEC/UBEC information

For a best match with 14 cells, I'd go with an 8XL.

Try this motor selector to get an idea of your options for the motor: Motor Selector Calculator

so a ubec, is a little device i that i connect to the battery pack set up, and plugs into the reciever? and i have to cut some wire on the esc that goes to the reciever?

where do i get a ubec? and how do i wire the bl set up properly?

which pinion should i use on the stock 40t spur, like tooth wise? 10,11,12 or w/e is recommended. ?

so a 8xl with 14cells, on a mamba max or 9920, which should i do ? what pinion tooth wise and how do i find the size of the shaft on the motor?

where can i find a 8xl, mike dosent have any on the site store. well not 3 wire ones, only 2 wire ones. ?

[BrianG]

Yup, a UBEC is simply a device with two wires in (goes to the main battery pack) and two wires out (goes to the ESC). Because most speed controllers have a built-in BEC, you have to disable it when using an external one. Some ESCs, like the Warriors, have a BEC disable jumper (black jumper). Others you hyave to cut ther red wire in the throttle cable. Or, just use a short servo extension with the red wire removed so you don't have to modify the ESC throttle cable.

You can get a UBEC here. It's a little on the large side, but works well. You can get a cheaper one here, but the support and customer service at RC-Monster is second to none, so I try to get everything I can here.

As far as pinions go, I's get a 14T and a 15T so you have a few options. Also get the three various Revo spurs (36T, 38T, and 40T) and you should be able to find the sweet spot between speed, runtime, and ideal temperature with one of those combos.

If you go with the Wanderer 8XL, you should also get this heatsink and clamp. The Wanderer end-bell tends to pop off from jump impacts and this heatsink also clamps it in place. Since there are none of those motors in stock, you could get a Feigao instead. It has a built-in heatsink and the end bell can be removed for bearing maintenance should it need it. Since the heatsink is built-in, it is cheaper. FYI: the Wanderer and Feigao have the same KV ratings so the Feigao 8XL will be a good choice.

AFAIK, the Wanderer and Feigaos both have a 5mm shaft, so you should get one of the "5mm bore, mod1 pitch" pinions on this page. Maybe someone here can verify that the Feigao really does have a 5mm shaft, but I think it does.

As far as ESCs go, the Mamba Max is a solid little performer. It is smaller, much more programmable (via a computer), can run brushed or brushless motors (with configuration changes), is easier to mount, has a built-in low-voltage-cutoff should you decide to go with lipos in the future, and is cheaper. I would definitely get a small 40-50mm fan to cool the heatsink though.

okay. but dosent http://www.rc-monster.com/proddetail...540C_XL&cat=20 that only have 2 wires coming from it , and the mamba max has 3 ?

so pretty much, i need ubec, mamba max, feiago/wanderer 8xl, plus 5mm bore mod 1 to have that set up.

for the stock 40t spur, would you go 14 or 15 t ?

[BrianG]

No, that motor does have three wires, the other one is just hidden. All current brushless motors have three main power wires since they are three phase A/C motors.

Yup, that's almost all the electronics you need; don't forget the radio. :)

Obviously, you'll also have to come up with a custom motor mount and a way to mount the batteries and the electronics.

If you onyl get one pinion, I'd get the 14T. I would still get the three different spurs so you have some gearing options.

ah okay, makes sense now with the motor, only thought it was 2. (i have the radio, i plan on the stock tq3.) motor mount i plan on cutting up and shapping some aluminum to make a mount. and battaries i dont know for sure yet, but ill work on that. okay, so i think ill do the 14t p with 40t spur, then maybe get the other spurs.

is there any thing else i need to mod to get this thing working?

[BrianG]

Honestly, you may have trouble with the stock AM radio. AM radios are sensitive to interference (compared to FM and digital) and brushless motors can put out quite a bit of noise. You can try it, and if it works, great. But don't be surprised to get glitchy response or limited range. You can help reduce this effect by keeping the antenna and receiver as far away from the motor wires as possible.

When you make the mount, don't be afraid to use thick material - like 5-8mm thick, and use good Aluminum; 6061 or 7075 grade. onlinemetals.com has some decent angle stock, but their angled pieces are not exactly 90 degrees, more like 89.5 degrees and it DOES make a difference. So you might have to shim the rear to get the exact angle to compensate. Any flexing in the mount, especially with jumps, will affect the spur/pinion mesh and you'll eat the spurs. I would also consider some way to either make a bracket for the rear of the motor or some other way to support the back somehow.

No matter what, expect the first build to have issues. Any weak spot will be noticeable and you'll have to come up with ways to address them. But once you get all the quirks worked out, you'll be extremely happy with the results.

Several members, myself included, have made conversions using the stock chassis and the stock tranny and each have used different approaches. Search around the Revo forum here and check out each one.

alrighty. i was thinking about like a "u" shaped motor mount . [_, like bigger in the front and lower in the rear to go under the motor to support it. but once i get and strip the revo, and order parts, then its thinking time :P

okay, got my revo. here are some pics the way i got it.



here it is now stipped of every thing i have got to so far (these parts (nitro stuff) will be for sale).

[ReDrUm_Racer]

I'd suggest taking off the motor mount, radio boxes, and all the other stuff that isnt needed, at least for now. By the way, I'm the friend with the hyper 7.