Regular brush-motor & 3300 bat for WFRCC

GForce · #1 05-20-2004, 12:59 AM

Looking through all the thread in WFRCC.

I don't recall anybody mention any project with old coventional brush-motor & 3300 NI-MH or NI-CAD.

Is brushless system with LI-POLY the way to go for this event?
I'm still try to decide which system I should use.

Thank You!

sosidge · #2 05-20-2004, 03:36 AM

Brushed motors are less efficient than brushless - and RC brushed motors have more limits on the number of cells they can handle without burning up.

NiMH cells are heavier than LiPo, but NiMH can handle higher currents.

I can (almost) guarantee the record won't be set by a brushless, but I believe it could be set with NiMH cells.

Craps · #3 05-20-2004, 05:56 AM

You guys crack me up with this brushed motor and nickel battery stuff!!!

Show up with nickel batteries and brushed motors and you will be toast before you even unload!

DaFF · #4 05-20-2004, 07:00 AM

Can you say new technology is there and ready available?

Heeellllooo

It's just a question of seting-up the right bl+Lipo that's all ( but it is not that easy, I have to say)

DFF

Craps · #5 05-20-2004, 07:54 AM

Quote:

Originally Posted by DaFF

Can you say new technology is there and ready available?

Heeellllooo

It's just a question of seting-up the right bl+Lipo that's all ( but it is not that easy, I have to say)

You better add that this is all going to be very limited to the ESC used with the Li-Pos or as I learned the hard way, can use "BBQ" ESC using Li-Pos I thought were equal to nickel, but far exceeded them. This all new territory for us all and you better have deep pockets if you want to be in the record books.

sosidge · #6 05-20-2004, 09:07 AM

Quote:

Originally Posted by sosidge

Brushed motors are less efficient than brushless - and RC brushed motors have more limits on the number of cells they can handle without burning up.

NiMH cells are heavier than LiPo, but NiMH can handle higher currents.

I can (almost) guarantee the record won't be set by a brushless, but I believe it could be set with NiMH cells.

The last line should read...

Quote:

I can (almost) guarantee the record won't be set by a brushed motor, but I believe it could be set with NiMH cells.

glassdoctor · #7 05-20-2004, 09:58 AM

sosidge, I could tell that's what you meant to say (common sense and in context) but others didn't see where you were going.

I agree too... I can (almost) guarantee the record will be set by a BL... but the battery source is not a slam dunk.

I believe in the Lipo hype and I will have them soon myself... but we can't dismiss nickels. Just look at Lett's 111mph car. BL and Nimh. And I believe he ran that car around an oval race track at 111 mph, not just in a straight line.

I have a video showing his 96 mph run from back in 96-97. Keeping it pointed straight would be much easier than turning left every 0.8 seconds....

300 feet to get going will be an issue for sure though.

As for the Lipo/Nimh thing, I think the equalizer is the huge current that's likely when pushing a car to 120-140 mph. You need huge packs of lipo cells to pull huge current, like a minimum 8000mah pack... probably more like 10-12 Ah. The weight advantage disappears at these capacities... since runtime is a non-issue really.

Drag cars simply shave weight by going with 1/2 SC cells...

Craps · #8 05-20-2004, 10:21 AM

The big problem with quessing at what battery will be run with technology that is available today will probably by obsolete in the over a year from now contest.

Who knows where the Li-Po development will be then or will there be another battery technology that surpasses Li-Pos.

Besides you guys are probably talking about a run that will take less than a minute to run if not less than 30 seconds. 1/2 mile car track will take 30 seconds to go around at 100 mph.

kartrun · #9 05-21-2004, 05:23 PM

Well, I already know of one "brushed" powered car that is going to be there and she's already starting to pick up sponsorships from guys like Pro-line/Protoform.

lol

DualBL · #10 05-21-2004, 07:45 PM

Quote:

Originally Posted by kartrun

Well, I already know of one "brushed" powered car that is going to be there and she's already starting to pick up sponsorships from guys like Pro-line/Protoform.

lol

details?
-Nick

Fastcar · #11 05-21-2004, 08:15 PM

well we got guys here on the east coast... some are going some are not..... They say there gonna put a 6 cell car to 85MPH... and if another guy I know comes, he runs brushed motors and nicd's, if he goes, I think ya'll will see a 120-150 MPH run.

And don't even count out Nitro.... I know of nitro rails running 85MPh in just 132feet, quick gear change and theres 111 easy...

oh yea, a guy at my LHS had a 1/8 scale serpent car clocked...300 feet, it ran a 107MPH pass

kartrun · #12 05-21-2004, 08:30 PM

Nick, can't give specifics but I will say it is backed by a few manufacturers as of now. Fastcar, I'm from the East Coast as well. Durham,NC to be exact. I think i know of the guys you are talking about. Should be an interesting event indeed. Oh yeah, the car I'm refering to will feature a unique brushed powerplant. One the r/c car industry has never seen.

Chris LaPanse · #13 05-21-2004, 11:37 PM

BTW, Fastcar, there are 18 cell electric rails that can do 118 mph in 132 feet. The only reason that isn't the record is a lack of proper documentation.

Fastcar · #14 05-22-2004, 12:30 AM

118MPH in 132 feet???? you miss type that or what?..... highly impossible...

You race with us kartrun... at piedmont, 311, fuquay, or at clinton?

Chris LaPanse · #15 05-22-2004, 02:29 AM

Sorry, they actually do 112. Still an incredible achievement on a 132 ft track.

Quote:

And let’s not forget IEDA Champion, Chris Collins; his 18-cell Top fuel dragster was clocked at 112.7mph at Northstar Dragway in Minnesota

This is from the RC Car Action coverage of the current world speed record being set.

18 cells, BL, and an incredibly light custom chassis make that possible.

kartrun · #16 05-22-2004, 12:52 PM

Quote:

Originally Posted by Fastcar

118MPH in 132 feet???? you miss type that or what?..... highly impossible...

You race with us kartrun... at piedmont, 311, fuquay, or at clinton?

Neither Fastcar but I get around.

Spoon37 · #17 05-22-2004, 02:32 PM

a brushed car could go pretty fast but I reckon the only way it could be competitive is to use few cells like 7 max in a very very very lightweight chassis, then all it needs is the gearing done just right, I cant see it beating 110tho....

plus it would have to a one way trip for the motor if you had to do 2 passes like they have to for the guiness book of world records land speed record you'd have to change the motor in between cuz a 5 or 6 turn mod burns up pretty quick.....especially as it would essentially be overgeared.....

EddieO · #18 05-22-2004, 02:33 PM

There was a dragster that went 112 a years back, but since no guiness rep there, the record did not count. It had a brushed motor and nickel cells.....of course lipos weren't available in then for RC use......there was an article in RC Car Action about it.....

You can make brushed motors very efficient, but it takes special winds....and get even better with more segments and different magnet systems.

Not sure on what batteries I will be running, but I will mess with both. I am leaning towards lipos because of the weight......as I would like to make a bigger car for better stabability, so light components are needed.

I will show up with only brushed power though.....custom handmade motors though.....

Later EddieO

kartrun · #19 05-22-2004, 02:41 PM

Spoon, Who said anything about using a 5 or 6 turn mod motor? You guys forget that a few years back several brushed power cars topped 90+ mph on old, ineffiecient technology. Some of guys expect to have your brushless feelings hurt (in general) and that you can take to the bank.

Spoon37 · #20 05-22-2004, 02:44 PM

well ok they may not be the most efficient, but I am presuming you want very high RPM? if so surely the lowest turn mods would be best? or is this a misconception?

EddieO · #21 05-22-2004, 02:52 PM

I don't think people competing in this event will worry be worrying much about money.........I know I sure won't.

Later EddieO

EddieO · #22 05-22-2004, 02:59 PM

It all depends on the car.....I know a lot of the drag cars use higher turn mods.....

This whole brushed vs brushless thing is turning into a ford vs chevy type pi$$ing match....and its getting old fast.

Both motor types have their advantages and disadvantages........the biggest problem with brushed is all you see are motors designed to work under a certain set of rules (ROAR)......I've got one in the works that ignores them all and works in our cars with no modifications....

Later EddieO

ElectricThunder · #23 05-22-2004, 05:42 PM

Is anyone going to use larger graupner motors (700 size on up) on like, 24 or more NiMH or NiCd cells? That would be an interesting set up in a light chassis. Tons of power that rivals brushless motors for less than half the cost.

Fastcar · #24 05-22-2004, 06:07 PM

Quote:

Originally Posted by kartrun

Spoon, Who said anything about using a 5 or 6 turn mod motor? You guys forget that a few years back several brushed power cars topped 90+ mph on old, ineffiecient technology. Some of guys expect to have your brushless feelings hurt (in general) and that you can take to the bank.

Yep brushless feelings hurt.....

Kartrun, Come check us out at the tracks.

Chris LaPanse · #25 05-22-2004, 06:53 PM

BTW-brushed are fast (a boat hit 76 on a 24 cell brushed), but BL can still put out more power due to their slightly greater efficiency and the lack of drag caused by brushes dragging on the commutator. Still, it will probably be amazing what brushed can do. Maybe we will see brushed cars topping 100mph.