View Full Version : Regular brush-motor & 3300 bat for WFRCC
GForce
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
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
05-20-2004, 05:56 AM
You guys crack me up with this brushed motor and nickel battery stuff!!! :D :D
Show up with nickel batteries and brushed motors and you will be toast before you even unload! :D :D
Can you say new technology is there and ready available?
Heeellllooo :D
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
05-20-2004, 07:54 AM
Can you say new technology is there and ready available?
Heeellllooo :D
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
05-20-2004, 09:07 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.
The last line should read...
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
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
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
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
05-21-2004, 07:45 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
details?
-Nick
Fastcar
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
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
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
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
05-22-2004, 02:29 AM
Sorry, they actually do 112. Still an incredible achievement on a 132 ft track.
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
05-22-2004, 12:52 PM
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
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
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
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
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
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
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$$ing match....and its getting old fast.
Both motor types have their advantages and disadvantages........the biggest problem with brushed is all you see are motors designed to work under a certain set of rules (ROAR)......I've got one in the works that ignores them all and works in our cars with no modifications....
Later EddieO
ElectricThunder
05-22-2004, 05:42 PM
Is anyone going to use larger graupner motors (700 size on up) on like, 24 or more NiMH or NiCd cells? That would be an interesting set up in a light chassis. Tons of power that rivals brushless motors for less than half the cost.
Fastcar
05-22-2004, 06:07 PM
Spoon, Who said anything about using a 5 or 6 turn mod motor? You guys forget that a few years back several brushed power cars topped 90+ mph on old, ineffiecient technology. Some of guys expect to have your brushless feelings hurt (in general) and that you can take to the bank.
Yep brushless feelings hurt.....
Kartrun, Come check us out at the tracks.
Chris LaPanse
05-22-2004, 06:53 PM
BTW-brushed are fast (a boat hit 76 on a 24 cell brushed), but BL can still put out more power due to their slightly greater efficiency and the lack of drag caused by brushes dragging on the commutator. Still, it will probably be amazing what brushed can do. Maybe we will see brushed cars topping 100mph. :D
kartrun
05-22-2004, 08:38 PM
It all depends on the car.....I know a lot of the drag cars use higher turn mods.....
This whole brushed vs brushless thing is turning into a ford vs chevy type pi$$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
Eddie, good to see you on here! You probably have no idea who I am but I do exactly what you do, me, I'm a bit of an old school motor guru type of guy. Have a motor buisness of my own thats going through a ton of changes due to poor management. Yeah, the car I'm referring to is powered by a motor I designed myself that will be released next year at the latest. It ignores the rules as well ;) Best of luck to you with your new buisness my friend! Later!
Fastcar
05-22-2004, 09:35 PM
Brushed cars on the east coast can top 100 no prob...
EddieO
05-23-2004, 03:06 AM
We've already seen brushed cars top 100 MPH....nothing new....
Effieciency doesn't mean a motor will make MORE overall power.....not sure where you get that. Efficiency will allow a motor to make more Output Power with LESS Input Power. At high RPMS, drag brake from the brushes is virtually non-exsistant....
Brushless motors make more power right now in the same size can because they have a BIGGER arm(in theory if understand how brushless work) and Rare Earth Mags(in most cases).
Just an example how big a difference Neo Mags make......we recently made a can with 4 neo mags on each side. These were very thin, so there was a HUGE air gap.
I put the arm in a regular can and ran it on my turbo dyno. At 5 volts and 40 amps, it produced 118 watts. Solid for a thrown together motor(I didn't adjust spring tension, timing, etc). I then took the SAME arm and put it in the new high output can with the Neo Mags.....at 40 amps in produced 148 watts.....
Doesn't take a brain surgeon to see how much of a difference neo mags will make. Just imagine this motor with the new oversize 5 segment arm in it......and remembers, its the standard 05 size.
Later EddieO
Spoon37
05-23-2004, 06:51 AM
also most of the BL systems I've seen also require more cells, so its not hard to see where big power figures come from if your running motors on 18+ cells....
I admit I am not a motor guru, but I still dont get why a low turn mod would be a bad idea? I run MT's so the reason I dont use em is cuz you lose alot of torque, plus it gets expensive on ESC's to run twin 6t motors.....lol
but I figure for a lightweight car geared for high speed a low turn mod would surely make more RPM and therefore attain a higher speed? or is there a point at which you would need a motor with more torque simply to pull the gearing?
;)
ElectricThunder
05-23-2004, 12:24 PM
The only problem with low turn brushed motors and many cells is that the risk of throwing a winding or magnet greatly increases. Also, at the higher RPMs the lower turn motor's comm and brush will be spent and not give the same performance the second time around. Worst thing also, the high cell count and high voltage could totally burn up your motor and melt stuff together. My two cents. :cool:
DualBL
05-23-2004, 12:29 PM
for speed, it's not all about rpm. it's about rpm and torque.
Cliff Lett said something along the lines of: you need 1hp to hit 100. you need 3hp to hit 120.
-Nick
crono man
05-23-2004, 01:59 PM
for speed, it's not all about rpm. it's about rpm and torque.
Cliff Lett said something along the lines of: you need 1hp to hit 100. you need 3hp to hit 120.
-Nick
Hit the nail on the head to hit the 130+mph is going to take HUGE amount of torque IMHO a standard sized 540 motor wont cut it!
Eddie.O
As for arm dia. BL have actually smaller arms then brushed motors
Also consider the thermal limit of a brushed motor which is lower then a bl motor.
The comm on a brush motor will ALWAYS be your weak point.
Ther are NO adavantages to brushed motors period ESPECIALLY in high speed runs
Spoon37
05-23-2004, 05:45 PM
ok so basically your saying the low turn mod wouldnt have enough torque to do it? that kinda makes sense....
well BL may be the way to go, problem is alot of peeps here already have alot invested in good brushed setups, I dont see a good reason to spend alot on a decent BL setup if you already have the gear that will get you there with brushed motors....ok one or two guys here are doing it just to prove the point but for most they wont go BL unless they were starting from scratch.
;)
crono man
05-23-2004, 07:51 PM
ok so basically your saying the low turn mod wouldnt have enough torque to do it? that kinda makes sense....
well BL may be the way to go, problem is alot of peeps here already have alot invested in good brushed setups, I dont see a good reason to spend alot on a decent BL setup if you already have the gear that will get you there with brushed motors....ok one or two guys here are doing it just to prove the point but for most they wont go BL unless they were starting from scratch.
;)
this is the bid for the WORLD fastest car budget will not be an issue for the dude gunning for 1 place...a brushed motor can most certainly get you in the top 5 spot but imho i dont think it will be the powerplant of choice..eventho an unofficial speed record was set by seiko motor owner and was clocked at 157kmh using a neo brushed motor
Also this event should have been done on a flat straight line...why add a curb?
GForce
05-23-2004, 10:55 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. :D
The current record is set by a brush motor. It is a dragster with 18 cells with G-Force motor within 310 feet.
Craps
05-23-2004, 11:13 PM
The current record is set by a brush motor. It is a dragster with 18 cells with G-Force motor within 310 feet.
Where is this listed?
I don't know if anybody paid attention, but Cliff Lett's run was with a 2 turn Avenox BL motor and the world record boat was also with a Lehner 8 turn BL motor.
DualBL
05-23-2004, 11:33 PM
maybe he's talking bout non-official?
there's been RC cars that have hit 130's, and many were brushed, but Cliff gets the credit as the fastest, cause he's the one that got Guiness to recognize.
-Nick
GForce
05-24-2004, 12:24 AM
Where is this listed?
I don't know if anybody paid attention, but Cliff Lett's run was with a 2 turn Avenox BL motor and the world record boat was also with a Lehner 8 turn BL motor.
It was in Rc car action mag few years back & RCCar mag also. This was done back in 97 by a guy name Chris Collins. Rail that ran 112.7Mph. The Rc drag racer held their speed run competition every year dating back from early 90's -98 & usually held @ MN & San Jose for 3 years.
Fast T3
05-24-2004, 10:47 AM
yes you right it is just stupid end it but the lith-pl fight ends with lith-pls are better
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
Fast T3
05-24-2004, 10:57 AM
ok you for get how much MORE torque a hight turn brushed has and well rmp does matter if you want to win you need torque if you want to know why E-mail me fast_t3@yahoo.com and if i had the money i know how to win and for you motor builders out there i would like to see your web sited and maybe buy one or 2 of your motors
racerrandy
05-28-2004, 12:38 AM
I am glad to see you on here EddieO. These guys obviously don't hang out on the right forums do they? :) There is no doudt in my mind what team is going to right at the front of the pack. Team BrOOd!!!! I thought about starting a thread on the other forum but wasn't sure it was the right place. The bummer about the whole thing is if you have a really good idea and might be able to compete you can't share it.
Good luck EddieO!
Randy