would this be a good conversion for a direct drive? - RC-Monster Forums

BL_RV0 · **would this be a good conversion for a direct drive? -** 12.11.2007, 11:53 AM

http://www.hobbytron.com/GasPoweredR...rdGTJHCH5.html

with this outrunner
http://www.hobbycity.com/hobbycity/s...idProduct=5139

running on 2 of these
http://www.hobbycity.com/hobbycity/s...idProduct=4289

and this esc
http://www.hobbycity.com/hobbycity/s...idProduct=4691

would it work? what speed? btw, this will be a direct drive setup.

BL-Power · 01:48 PM

Quote:

Originally Posted by BL_RV0

http://www.hobbytron.com/GasPoweredR...rdGTJHCH5.html

with this outrunner
http://www.hobbycity.com/hobbycity/s...idProduct=5139

running on 2 of these
http://www.hobbycity.com/hobbycity/s...idProduct=4289

and this esc
http://www.hobbycity.com/hobbycity/s...idProduct=4691

would it work? what speed? btw, this will be a direct drive setup.

I would use another motor, i think 1500g are a bit heavy.

I would look for a motor with around 600g-800g

The Lipos are very nice, i have 2 packs of them and they are nearly as powerful as my Enerland (Polyquest) Lipos.

lincpimp · 12.11.2007, 01:51 PM

I have a feeling if you bought that vehicle you would leave gas powered as they are tons of fun. I do not do nitro anymore, but the actual gas powered large scale stuff is great and most get at least 30-40min on a tank. I am looking at getting a baja 5b ss kit, just looks like alot of fun!

What's_nitro? · 12.11.2007, 02:09 PM

Yeah that motor is a bit heavy. On the other hand, it is 3-4 times as powerful as the gas engine it's replacing!

Hakan_J · 12.11.2007, 02:23 PM

Hmm that page has alot of interesting ecs that I havent seen before, look at this one for instance:
http://www.hobbycity.com/hobbycity/s...idProduct=4316

Very cheap for a 3-6Lipo 120A esc?

BrianG · 12.11.2007, 02:38 PM

I think this project would be ideal for a dual brushless setup. A couple of largish size outrunners (so you won't need to gear down a whole lot) running on dual 6s lipos in parallel with dual ESCs. This would let you use relatively cheap ESCs for 5s or 6s operation and lower current. Even at 6s and say 60A each, that's over 3.5HP total. Then, something like the Nomadio radio in "tank mode" (where turning the wheel adjusts the throttle speed of each side) as a sort of differential.

zeropointbug · 12.11.2007, 05:50 PM

I agree, that motor is WAY overkill... it would be like someone putting a 1527 Neu in a Revo and expecting it to be controllable.

In fact, I would seriously consider a 1527 in this car. Or an outruner, such as THIS.

lincpimp · 12.11.2007, 06:07 PM

Quote:

Originally Posted by BrianG

I think this project would be ideal for a dual brushless setup. A couple of largish size outrunners (so you won't need to gear down a whole lot) running on dual 6s lipos in parallel with dual ESCs. This would let you use relatively cheap ESCs for 5s or 6s operation and lower current. Even at 6s and say 60A each, that's over 3.5HP total. Then, something like the Nomadio radio in "tank mode" (where turning the wheel adjusts the throttle speed of each side) as a sort of differential.

I like your idea of dual motors, but how about a pair of outrunners, each powering one diff. I have a hb lightning street, which is basically a stretched out 1/8 buggy with street tires. I was thinking another direct to diff drive, but use two outrunners and two cheap escs, both run on a pair or large lipos, 6s at least, maybe 10000mah total.

12.11.2007, 06:18 PM

Wow, disc brakes on each wheel!

The gas version looks slow. I would consider a Neu 2215/2.5Y powered by a PowerJazz on 14S lipo.

zeropointbug · 12.11.2007, 06:23 PM

The guy said the car weights 20 lbs... so when you take out that heavy engine, and all components not needed, your weight goes down significantly. WHen all said and done, the total weight could quite possibly be less than the gas version, RTR.

sikeston34m · 12.11.2007, 07:10 PM

I've read it somewhere that 700 watts of electric power equals 1 horsepower? Is this correct?

If so, the HXT 80-100-A 180Kv Brushless Outrunner is a 10 horse motor!

I just bought a HXT 80-100-A 180Kv Brushless Outrunner. It is HUGE. I'm thinking about doing an Electric Bicycle with it. Running the ESC that you have pictured and power it with 36 volt Dewalt packs.

You'll never get the diffs to hold up to that motor. Which btw, before you decide on a vehicle to do a Direct Drive to Diff conversion on, take a close look at the diffs and the gear ratios of those diffs. What's the diff ratio on this car? Are they upgradeable or tough already?

The dual outrunner thing might be pretty interesting, but the rear diff ALWAYS see the majority of the load. The rear is where you would see the most amp draw and is where the most useable power would find it way to the ground.

I think it would add another element of uncontrollability. The front being powered the same as the rear but not connected to each other, would make the front wheels spin their ass off, while the rear was getting under the load and doing the work.

The front tries to lift when you accelerate hard. This reduces traction there alot by itself. With actual tire speed not being equal, It would get out of hand pretty quick.

That's a cool looking car though.

lincpimp · 12.11.2007, 07:23 PM

Hey sike, I threw up a thread of my newest proposed project. If the dual out runners were connected by a center driveshaft, would that work better? I am sure that they would have to be timed together, and maybe that would not work either, or have a clutch to connect them at a certain speed.

sikeston34m · 12.11.2007, 07:27 PM

Quote:

Originally Posted by lincpimp

Hey sike, I threw up a thread of my newest proposed project. If the dual out runners were connected by a center driveshaft, would that work better? I am sure that they would have to be timed together, and maybe that would not work either, or have a clutch to connect them at a certain speed.

If they were connected and each had their own ESC, they wouldn't have to be timed any particuliar way. Each having their own ESC, each motor would have it's own EMF feedback to their respective ESC. Being independantly controlled like this, it would work without timing to each other.

It's when you try to control two motors with one ESC that timing is critical, and even then I hear of issues.

I think having them connected would probably work better. All theory at this point though.

lincpimp · 12.11.2007, 11:51 PM

Well, looks like I need to sell a few veehicles and buy up what I need. This may have to wait until I get my pair of LSP conversions done. One will have an 8xl on 5s thru a monster 125b. The other will have a kb45 9l on 5s thru and airmaster 125. With mech brakes and a solid center drive. The 1st will be an off road racer and the 2nd will be an on road drag truggy. Should be able to start them this weekend.

aqwut · 12:03 AM

that motor is over kill.. even for my 1/5th firehammer m/t... i'd get the 500-700 gram outrunner.....
it's pointless getting that outrunner and running off of those batteries and that ESC...
ESC can handle about 4400 watts.. and batteries could only output 2600 Watts... :) that's enough to make your car boogie.. batteries and ESC are good.. but I would get a different motor...
When I hooked that motor to a steel block (just for testing).. I ran it off of 6S 5000 mah 25C lipo, I couldn't even hold the outrunner... so for sure, it will chew your truck up on the first run... :)
Even a 12XL was able to chew up the center diff on my 20+Lbs truck.... imagine what that could do...