PLENTY of Questions about my BL Savvy

[Zcrusher]

I'm building up a brushless savage, and I have some questions.

First, motor/controller... I'll definately be running a BK 9920. I want to run 14 cells. What is the BEST motor/gearing for this cell config, and will I be twisting diffs?

Second... Tranny- What should I do with the tranny? I was thinking of leaving it and using the mechanical brakes to save my diffs, i hope. If that idea calls through, what mods are you guys doing to your trannies so they're solid and dont spin in one direction? Can controllers be set with NO brakes at all?

Third- Dabid reccomended Kyosho battery cups. Can these be used with the mechanical brakes?

Fourth- How are you guys meshing your gears when the motor screws are practically up against the tranny housing? Where can I buy a motor mount/ would anyone sell me one?

Fifth- I plan on running the 4 AA battery holder to power my RX/ Servos. Can i plug this DIRECTLY into the RX? Must I do anything to the controller after this? Also, what is UBEC and how is it utilized?

That should be it. Thanks :)

Zcrusher

an 8 xl would do pretty good in your cavage i would think. as for the other questions ill let some of the savage experts handle those.

[Zcrusher]

Thanks for the quick reply. I've been told an 8xl is a good idea, I think i'll go for it.

[coolhandcountry]

The ubec will take the place of your 4 aa batteries. It is hooked the to wires going to the esc. It takes the 14 cell voltage and cuts it back to a 6v usable current. You won't need the 4aa batts and it is easier to mount and won't have to be recharged or replaced.

It would depend on how you mount the cups if you can keep the mechinacal brakes.

[Zcrusher]

Ok, so it is soldered directly into the wires from the controller to the battery? How much is one of these going to run me?

Do you think I could use spacers/standoffs to mount the battery cups directly over the tranny/mech. brakes?

Z

[coolhandcountry]

I am not sure crusher. I have not converted mine over yet. There is a converted one or two around. One guy put the motor on top of the tranny and batts in where the motor is. No cups required.

welcome to the forum btw

[Zcrusher]

Thanks. I was told you guys were the BL gurus.

I would prefer to mount the motor/controller where the engine usually is for protection.

Z

[HotnCold]

Welcome to the site Z - check this link for the info on the UBEC -

http://www.rc-monster.com/proddetail.php?prod=6vubec

Enjoy...

[Zcrusher]

Very interesting. Can I solder the wires directly to the controllers Deans plug? The price is a bit steep, but I think I would like it more than conventional AA's.

Should I decide to use AA's, can I simply unplug the BEC wire from the controller and plug the AA's into the RX? I would do this until I was situated with the system and everything was working.

Also, is the BK Wanderer 8XL the same as the Feiago 8xl? I would prefer the BK for the preinstalled connectors. How are the connectors fastened to the controller wires?


I know these are alot of questions, but I really want to be 100% before I spend my cash.

Thanks again, and thanks for the warm welcome.

Z

[MetalMan]

If you use the UBEC or AAs, you can either remove the red wire from the 9920's receiver cable or you can remove the black jumper that is slightly hidden by the heatshrink. Here is another LVC choice, and I use it for 4s Lipo (but it will work with higher cell counts):
http://www.xushobby.com/servlet/Detail?no=38

BK has made the Feigao 8XL motor blue, and supposedly has put in better bearings (although I have yet to see/hear verification of this). Besides that and the preinstalled connectors, it is the same as the Feigao 8XL.

[Jasper]

Question 1:

The 8XL is a good choice. I had a 7XL in my savage. I liked the speed, but the runtime was for me to short. 5-10 minutes. With GP3300 cells (wich I used one season for serious racing) So the runtime must be good with better cells.

Question 2

I used the mechinical brakes on my savage. The controller can be set with only forward driving.

Question 3

If you mount the battery cups under the mechinical brake. It can be done. I also should recommed that because of the lower cg.

Question 4

You can also make an motormount at yourself. I used 8mm aluminium. I cutted the plate in the right sizes. I drilled some holes for putting in the motor. At the left and right I drilled 3mm holes. I tapped screw thread in these m3 holes. I drilled one hole at each TVP for mounting the motormount.

Dang, that's a fat motor mount! I've got some 1/4" alum. that I think I'll use for my 9xl once I get it, but don't know if I'll make the design that elaborate.........or big. ;)

[Zcrusher]

Interesting.

Thanks!

Will the CFR buggy motor mount work on a savage? If anyone has an extra/old motor mount that will work with an 8XL, I would be willing to purchase it.


Z

[Serum]

Hi, Welcome to the forum.

I would take a 7XL or an 8xl for slightly better runtime on 14 cells and leave the 2 speed transmission in tact, but please get the heavy duty 2nd speed. (it comes standard with the K4,6) the stock 2nd speed won't live long.

about the diffs. You need to get an FLM bulkless or GPM/dynamite aluminum diffhousings (not the cups, the cups you want for a bulletproof drivetrain are the Hotbodies C8019, and you can use them with the 8x16 bearing that also fits your wheels.

I have got some old pride/glory, i made the plate from 10mm thick aluminum;



What a beauty it was.. Something i need to make as soon as i get me new toy...

here is a helpful calculator to do some gearing math.

whatever you do, you really don't want to run the 4 AA cells. Get something proper.. a 5cells humppack of nimh cells would do (GP1100 or something like that) you don't necessarily need the Ubec.

[Zcrusher]

That's a nice motor mount! Any chance you have a spare?

Could you link me to everything I need to beef up my tranny? Thanks.


Z