BL motors for HUGE project truck... - RC-Monster Forums

mike597 · **BL motors for HUGE project truck... -** 05.11.2005, 05:00 PM

I recently started building from scratch a project vehicle that needs 2 brushless motors. The truck is going to be rather large, so I really need motors with gobs of torque. I am very impressed with the Faiego motors, just need some help picking one out. My other question is with the controllers. Are there any that can handle 2 motors or is this not a good idea with BL motors? I am pretty new to brushless and need as much guidance as I can get. Thanks for your time.

RC-Monster Mike · 05.11.2005, 05:27 PM

First off, I would like to welcome you to the RC-Monster forums! Now, on to the questions:
What size/weight is the vehicle in question? Are you absolutely SURE you need two motors? Two motors woud require two speed controllers (one controller could in theory run two motors, but it isn't a good idea and it wouldn't likely work as well as a single system or two single systems together). POerhaps you could give us some details on your project and we can discuss a few options or suggestions.

mike597 · 05.11.2005, 07:43 PM

I apologize for being as vague as I was, I was in a rush and should have waited to post until later. I finished the frame the other day and now am working on the driveshafts. The project vehicle is a 6x6 running on Jumbo Kong Swamper tires. I have built 6- 1/4 scale trucks so far and just want to try something different. I had a clod that ran The jumbo kongs (8.5" tall) and had a blast, it just wasnt fast enough for me. I dont expect this thing to be a rocket ship, I have other cars for that and I have a purpose built crawler as well. I would like this to have pretty good speed for its size and be able to accelerate quickly. I dont really know how much it will weigh, but I need 2 motors for the 2 twin force transmissions and 3 axles I am using. The truck is going to be about 30" long and roughly 19" wide or so. Like I mentioned, its really big and I need a good amount of torque. If the Emaxx trans would be a better choice, please say so. I think it would be cool to make this a two speed, although getting them to shift at the same time would be quite a challenge. Thanks for the help!!!

RC-Monster Mike · 05.11.2005, 07:52 PM

Is it necessary to use 2 transmissions? I haven't used a twin force tranny, so I can't comment on its abilities, but the e-max tranny is pretty tough. If one transmission is possible, one motor could accomplish your speed/power goals with enough cells and the proper gearing. No problems. If two trannies is an absolute must, then two motors, controllers, ad ideally two battery sources could quite easily power this rig. How many cells are you planning? any idea what your final gear ratio will be?

mike597 · 05.11.2005, 08:02 PM

I beleive 2 transmissions are needed, I need to get power to 3 axles. From the front to the rear axle is about 25", so the driveshaft would have to withstand a ton of torque being that long. I would also run into the problem of getting 3 outputs from one trans. Unless anyone has an idea that would work to only use one motor. Are brushless motors really that powerful where they could turn 6 jumbo kongs and get going pretty fast? I never would have guessed they were that strong, I was planning on using 3 or 4 brushled motors originally and 2 super roosters. I was thinking I would run 12 cells for each motor (2 seperate sources). I think gearing is going to be figured out through trial and error. I have a good idea where to start to gear for torque, but thats only with brushed motors, these BL motors are so different it makes me change everything I have learned.

supermaxx4190 · 05.11.2005, 08:10 PM

i run a single BL motor with 16 cells and cant find a wheel that will hold up to the power. 1 motor is more then enough!

mike597 · 05.11.2005, 08:17 PM

WOW, I really had no idea they are that powerful. I am going to spend this evening looking at my driveline and see if maybe I can find a way to run one transmission and use one motor. If that is the case, what motor would you reccomend? Being that I would only need one it would save me a lot of money, could put that into something else. I have no problem bumping it up to 16 cells if that would make the difference, it would also help with weight issues to run one motor and one set of batteries.

RC-Monster Mike · 05.11.2005, 08:29 PM

I was thinking the 7xl on 16 cells. With enough reduction, this combo would move that thing out in a hurry. A buddy of mine made a 6 wheeled e-maxx (and sold them/sells tham as kits). He has a website where he sells them, along with some info. He made a custom diff for the "middle" set of axles with an additional outdrive on the other side, which sends power via another driveshaft to the rear wheels. Perhaps this diff is available and may work for your project, or at least give you an idea on how to make it work. i will try to find his website for you.

RC-Monster Mike · 05.11.2005, 08:38 PM

http://www.gallimods.com/gallery/album01

here is a link to some pictures of this beast!

mike597 · 05.11.2005, 11:10 PM

Very cool link, thanks a bunch for the info. The 7xl seems like it has a lot of power, which controller do you recommend for this application? Thanks a lot for all of your help, I really appreciate it.

mike

RC-Monster Mike · 05.12.2005, 06:11 AM

The 9918 warrior or micro 18/120 should be plenty of controller for this application. The gearing will need to be determined for optimal operation (start with low gearing and work up).