Brushed DC for drag racing- where do I start?

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CONSIDERABLE SHOUTING   1 W

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Brushed DC for drag racing- where do I start?

Post by CONSIDERABLE SHOUTING » Jan 08 2020 5:22pm

As the title says I've seen the Two Brother's drag car and LonestarEV's products, but I've always wondered how the hell a motor that can be picked up for literally free in working order can be made to push a drag car into sub-10 second quarter mile passes. Does anyone know of material I could start with to understand how? Is it literally a matter of crap-tons of amperage and a drivetrain that can handle it?

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Re: Brushed DC for drag racing- where do I start?

Post by amberwolf » Jan 08 2020 5:47pm

CONSIDERABLE SHOUTING wrote:
Jan 08 2020 5:22pm
As the title says I've seen the Two Brother's drag car and LonestarEV's products,
the title doesn't mention anything about what you've seen. it only says "Brushed DC for drag racing- where do I start?", just asking a question.
but I've always wondered how the hell a motor that can be picked up for literally free in working order
if you look at enough scrap forklifts and the like, with enough motor knowledge behind you to judge what you're looking at, eventually you might run into one that has what you want for free. but it's much more likley it won't be free, though it could certainly be cheap depending on the owner. you'll probably end up doign modifications to it to get what you want out of it, or to mount it, etc., though.
can be made to push a drag car into sub-10 second quarter mile passes. Does anyone know of material I could start with to understand how? Is it literally a matter of crap-tons of amperage and a drivetrain that can handle it?
never built a drag car, but have used brushed motor systems (motor, controller, batteries) outside their design limits to power drivetrains outside their design limits, and you can easily break things anwyhere in the system, up to and including the frame and wheels of the vehicle itself, if you haven't prepared everything to do this.

how to get the torque and speed you want out of a system depends on your budget (no money usually means not much power, unless you're really good at scrounging and begging and know what youre after and who to ask), your batteries (if they're not capable of supplying the power you need, it doesn't matter how good anything else you have is), your controlelr (if it can't suply te power, you might as well not have a motor), your motor (if it can't rpoduce the torque you need at the voltage you have with the current you have available, you won't go like you want), and the construction of the drivetrain and vehicle itself (if they can't handle the torque they'll break and you can crash, or worse).

there's a lot of details to how the interactions work, so i would recommend first going to http://ebikes.ca/simulator, reading the entire page to learn how it all works and how to use it, then experimenting with systems to see how each thing interacts with each other one. this can teach you some of what you need to look for to do what you're after.

but once you understand that part, you will also need to learn a bit about motros, batteries, etc., and ressistance, inductance, etc., so you can use the custom motor and battery and controller options to create a system with the power you are after, as there's nothing already in teh simulator that will do that in a car.


the best material to read for what you want to do is the pages and watch the videos of the various people that have built these things. diyelectriccar forums has many more large ev builds and conversions than endlesssphere forums, so you will rpobably find more info there than here about drag cars. similarly the evalbum site has a library of builds of various kinds, many of which link to their build pages. sometimes those build pages are gone, but archive.org may have copies you can find with a url search there.

but you can start with a search like this
https://www.google.com/search?q=Brushed ... rag+racing
using your exact title phrase, which has a fair number of sites on the first page that should get you started down the deep deep rabbithole you're heading for. ;)

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Re: Brushed DC for drag racing- where do I start?

Post by CONSIDERABLE SHOUTING » Jan 10 2020 10:26am

Sorry Amber, it's sometimes pretty hard to accurately describe what I'm looking for in relation to the technology presented. I'm just saying this to get it off my chest now- I've been on this forum reading through builds for months because people kept saying it was the best way to understand electricity in relation to transportation, but I've asked hordes of times how I can learn more about motors/controllers/physics of electricity ect. and I've received no answer for anything. I'm basically putting together a puzzle without knowing what the picture's supposed to be.
amberwolf wrote:
Jan 08 2020 5:47pm
if you look at enough scrap forklifts and the like, with enough motor knowledge behind you to judge what you're looking at, eventually you might run into one that has what you want for free. but it's much more likley it won't be free, though it could certainly be cheap depending on the owner. you'll probably end up doign modifications to it to get what you want out of it, or to mount it, etc., though.
Oh yeah, I definitely know that and I am prepared for it! It'll probably be a hell of a lot easier than doing a port n' polish job on a set of heads.
never built a drag car, but have used brushed motor systems (motor, controller, batteries) outside their design limits to power drivetrains outside their design limits, and you can easily break things anwyhere in the system, up to and including the frame and wheels of the vehicle itself, if you haven't prepared everything to do this.
I haven't yet built a drag car myself, but I have helped with several and I know enough to be ready for it. Things like the cage I will farm out to other professionals.
there's a lot of details to how the interactions work, so i would recommend first going to http://ebikes.ca/simulator, reading the entire page to learn how it all works and how to use it, then experimenting with systems to see how each thing interacts with each other one. this can teach you some of what you need to look for to do what you're after.

but once you understand that part, you will also need to learn a bit about motros, batteries, etc., and ressistance, inductance, etc., so you can use the custom motor and battery and controller options to create a system with the power you are after, as there's nothing already in teh simulator that will do that in a car.

the best material to read for what you want to do is the pages and watch the videos of the various people that have built these things. diyelectriccar forums has many more large ev builds and conversions than endlesssphere forums, so you will rpobably find more info there than here about drag cars. similarly the evalbum site has a library of builds of various kinds, many of which link to their build pages. sometimes those build pages are gone, but archive.org may have copies you can find with a url search there.
I'll take a look at the site- as for learning about resistance, inductance ect. I've already said my part.

I forgot about the DIYelectricCar site- probably because the damn thing looks like something I would have loaded up in Netscape when I was 8 :D. I'll head back there though, thanks for the tip.
but you can start with a search like this
https://www.google.com/search?q=Brushed ... rag+racing
using your exact title phrase, which has a fair number of sites on the first page that should get you started down the deep deep rabbithole you're heading for. ;)
I actually did, and I had saved a few threads to try and gleam more information- most of them were about using simple agricultural motors for other purposes than racing, like our Pakistani friend here who used alternators on his eBike. So far what I somewhat "understand" with DC motors in racing is, once you start shoveling tons of amps into these DC motors- aside from internal resistance- there's nothing for the motor to do but spin harder and faster because the electrons have to go somewhere, and most of the improvements these teams do to the motors is dense copper rewinding (field strength? not sure yet), active cooling and heavily improved bearings to deal with the turning forces. Again however, all of this is just words to me right now, because I simply have never learned the basics and nobody has ever pointed me to a "motors and electrics 101" book outside of my own research.

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Re: Brushed DC for drag racing- where do I start?

Post by amberwolf » Jan 10 2020 8:45pm

CONSIDERABLE SHOUTING wrote:
Jan 10 2020 10:26am
Sorry Amber, it's sometimes pretty hard to accurately describe what I'm looking for in relation to the technology presented. I'm just saying this to get it off my chest now- I've been on this forum reading through builds for months because people kept saying it was the best way to understand electricity in relation to transportation, but I've asked hordes of times how I can learn more about motors/controllers/physics of electricity ect. and I've received no answer for anything. I'm basically putting together a puzzle without knowing what the picture's supposed to be.
well, it depends on what you're trying to learn, and what you already know, and how you yourself learn things. so we have to know what puzzle you're trying to assemble before we can specifically help with that. ;)

Some filters you might consider, that may help you tell us what you' want to learn, helping us point you the right direction.

if you're trying to learn what stuff will do a particular job, a relativley easy way is to look at what others did that is like what you want to do, so you can do something similar, and so reading those kinds of threads works.

if you have a specific application for specific conditions, using things like http://ebikes.ca/simulator and the like willhelp you find the kind of system that will do the job.

that will also show you the interrelations between the various parts of the system, to show why you need x type of controller and y type of battery to power a motor of z type to perform a specific set of work.

if you want to know how specific technology works, that's a lot more general, and more or less helps to learn basic electrical first, basic electronics, then start learning about the specifc technology (controller, motor, battery, etc). which things to read depend on exactly what you want to know.

if you wnat to just know how one thing relates to another...the previous stuff is better.

if you want ot know in gneeral how a motor works, there's threads and wikipedia and gneeral internet pages about that, both for motors in general and for specific types of motors.

if you want to know in gneeral how a ocntroller works, same thing.

batteries, same thing.

if you want to know how to design these things from scratch, that gneerally requires a fair bit of technical background in that kind of technology, and then there are pages and threads about designing and building them, that will help learn what not to do (which is usually more important than just knwoing what *to* do).

and so on.

depending on wha tyou already know, and what you want ot learn, it may be more, or less, complicated than that. :(

I forgot about the DIYelectricCar site- probably because the damn thing looks like something I would have loaded up in Netscape when I was 8 :D. I'll head back there though, thanks for the tip.
i don't remmber what the forum looked like, but i do know it had a lot of good build info and also general explanations for all sorts of high power brushed stuff...just as much slogging thru things to find as there is here on es, but it's there. ;)

So far what I somewhat "understand" with DC motors in racing is, once you start shoveling tons of amps into these DC motors- aside from internal resistance- there's nothing for the motor to do but spin harder and faster because the electrons have to go somewhere, and most of the improvements these teams do to the motors is dense copper rewinding (field strength? not sure yet), active cooling and heavily improved bearings to deal with the turning forces. Again however, all of this is just words to me right now, because I simply have never learned the basics and nobody has ever pointed me to a "motors and electrics 101" book outside of my own research.
there isn't a single place i know of that talks about all of them becuase there are so many differnet kinds, different methods of explanation dependign on both level of previous knowledge and level of desired knowledge, etc.

so, for instance, if what you want is practical knowledge of how to make a specific kind and type of motor better, that's different than wanting to know the science behind why that motor does what it does. sometimes knowing hte latter will help with the former, and sometimes it's irrelevant because you can just do what osmeone else already did to do the smae thing. ;)


for a really basic thing you can simply start with basic electrical and electronic theory, at places like https://www.allaboutcircuits.com/education/
specifically
https://www.allaboutcircuits.com/educat ... r-control/
but you'l have to tell us if that is understandable, or over your head, or stuff you already know, to know if that is useful to you or if you need a different resource.

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Re: Brushed DC for drag racing- where do I start?

Post by Frank » Jan 10 2020 8:53pm

Go to Nedra . Com (National Electric Drag Racing Assoc.) to get some names, links, etc. or look up same on FB. FWIW, think of a brushed motor as a mechanical transformer : they will try to convert every volt and amp you send their way to rotary motion. The real power comes from the battery and controller, but the motor has to be able to handle it.

Sent from my SM-T380 using Tapatalk

Frank

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Re: Brushed DC for drag racing- where do I start?

Post by CONSIDERABLE SHOUTING » Jan 11 2020 6:03pm

amberwolf wrote:
Jan 10 2020 8:45pm
if you want to know how specific technology works, that's a lot more general, and more or less helps to learn basic electrical first, basic electronics, then start learning about the specifc technology (controller, motor, battery, etc). which things to read depend on exactly what you want to know.
Yep, what i've been needing are the basics for a jumping point. I just found http://www.bcae1.com/ from a GRM forum member that seems to finally fulfill that need, and DIYElectricCars is filling in some holes when it comes to how much larger motors work.
amberwolf wrote:
Jan 10 2020 8:45pm
i don't remmber what the forum looked like, but i do know it had a lot of good build info and also general explanations for all sorts of high power brushed stuff...just as much slogging thru things to find as there is here on es, but it's there. ;)
Yep, already found a few threads with some concepts on it I can follow!
amberwolf wrote:
Jan 10 2020 8:45pm
so, for instance, if what you want is practical knowledge of how to make a specific kind and type of motor better, that's different than wanting to know the science behind why that motor does what it does. sometimes knowing hte latter will help with the former, and sometimes it's irrelevant because you can just do what osmeone else already did to do the smae thing. ;)


for a really basic thing you can simply start with basic electrical and electronic theory, at places like https://www.allaboutcircuits.com/education/
specifically
https://www.allaboutcircuits.com/educat ... r-control/
but you'l have to tell us if that is understandable, or over your head, or stuff you already know, to know if that is useful to you or if you need a different resource.
Yeah, ain't that the worst? So far learning the physics behind motors is the same behind cams and valvetrain angles- you think it's a simple matter until you ask "how does this work?" and you're suddenly inundated with geometry. It's funny that I know tons of old-school car guys who don't shrug at breaking out degree wheels and calculators for complicated geometry on piston/valve clearance but shirk away at wiring ONE electric fan.

Thanks for the additional links. Hopefully I'll understand enough now to begin a project of my own.
Frank wrote:
Jan 10 2020 8:53pm
Go to Nedra . Com (National Electric Drag Racing Assoc.) to get some names, links, etc. or look up same on FB. FWIW, think of a brushed motor as a mechanical transformer : they will try to convert every volt and amp you send their way to rotary motion. The real power comes from the battery and controller, but the motor has to be able to handle it.

Sent from my SM-T380 using Tapatalk
That's kind of what I understand so far- I just don't yet understand the physics behind it, or the mindset behind the modifications yet.

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Re: Brushed DC for drag racing- where do I start?

Post by Frank » Jan 11 2020 6:25pm

Another resource is diyelectriccar.com, there's a Motor section, Controller section, etc. Lots of good posts there. Look for stuff by user "major" who knows quite a bit about motors.
Frank

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