Electric & Nitro Dragsters

[studysession]

Anyone using a dragster for their project?

If you go electric - 2wd has less drag. It is pleanty long enough to help with handling and there will be room for MANY cells with next to no mods.

Curious if anyone else using these or not.

[mgs9]

Mine is sorta like a dragster but shorter for handling reasons. I just barly started it. It will have duel eletric motors, and the rear part of the chassi is aluminum, but its not a pan. I dont know how to explain it but the the plates are vertical (2 parallel plates).
I have an auto cad drawing of it at my school, ill try to post them tomarrow. I dont have auto cad on this computer so ill save it to a floppy but in paint so i can open it on this computer.

[studysession]

Sounds cool.

I have been using touring cars so far for my testing. I am getting an electric dragster to play with and see what it can do. The wheel base is right about 14 inches. I will compare it to the touring cars in handling and performance.

I was talking to a guy who races them in the US. When doing RC drag racing they 135 feet which is 1/10 of a quarter mile. His was clocked 1.61 seconds doing 85MPh on the 135 ft strip that they race at. He was using a brushed motor on a micro switch.

For those who do not know, micro switches are just on off switches. They do not use an ESC. Just hard wire the batteries to the motor and use a servo for on or off. So it is full power ALL the time.

After listening to this guy back in the US, I figure there are most likely people out there that will use drag cars for the speed record attempt. I am curious how many dragsters will show up at this competition.

Good stuff!

[mgs9]

I didnt got to school of friday, so I dont have the auto cad pics.
I have been looking and i cant find what i need for the drive train. My drive shaft is perpendicular to my rear drive axle and i need somthing like a drive train like on the tc3 but i need it like a 1;1 ratio. Any help would be appreciated.

[studysession]

Are you thinking of using this in the Car Action challenge?

If so, I dont think a 1:1 ratio is what is needed. A lot will depend on the motor you use and if it will turn the gears fast enough at that high of a ratio.

I would like to see pics and might be able to give you some input.

[mgs9]

no sry i accendently posted it i wasnt finished with the post its actily like a 2.5:1 ratio.

[studysession]

A lot of those kinds of parts, I just make on the mill and lathe. I am taking a machining class to help me get better at it. I have made custom adaptors for different motors and drive shafts to allow those kinds of gear ratios on almost anything.

Problem is having the motor that will get it up to speed fast enough before it is out of range from the radio. So you need fast acceleration as well.

If you got that kind of low gear ratio, what kind of motor are you thinking about using?

[mgs9]

Im not sure.Probly these brushless motors that i saw for an air plane. The looked realy good though, 5500rpm Per volt i calculated it and if I run 12 volts on them i will get 66000 rpm. I forget what site it was on ill try to find it. I will also be running duel motors for added torque. Right know i have two realy crappy motors for testing and measuring, 2 scorpion 20turns. The only down side to the duel motors is the extra batteries im going to need, witch means more wait.
I dont know if ill make it to the FCC but ill try, if i do make it thats what ill run.

[studysession]

Brushless motors have a max RPM limit. You have to check the specs on the motors and see. Some of the plane motors only go upto 16 - 20 thousand RPMs no matter how many cells you hook up.

[mgs9]

I dont know much about brushless motors. It said 6-10 cells so i wounder if it will increas to 10 cells? With 10 cells it would still be 55,000 rpm. Here the site I realy have no clue if they would work or not. Never mind any way i just relized theye were 480's. :(

[studysession]

There are advantages of putting more cells. More cells will give it more starting power when under a heavy load. But once the maximum RPMs of the motor has been reached, it will not go any faster. The extra cells just gives it more power to push at that point.

[studysession]

Look at the Lehner motors -

They have the low end torque and the high RPM's. Best of both worlds.

[mgs9]

Do you know of any good brushless motor sites? Thoes plane ones were only 480's I need like 540 or bigger.

[studysession]

All your answers will be answered by searching here:
http://www.radiocontrolzone.com/forums/forumdisplay.php?f=335

Here is a resource for Lehner motors
http://www.bk-electronics.com/catalog/index.php?cPath=35&osCsid=99fa336f83885c56303475d867a76f44

[mgs9]

Hey thanx. Are you going to run in the FCC?

[studysession]

Yes - I was sponsored to try to break the world speed record before that was announced. That just pushes me to do it sooner.

[mgs9]

oh cool. who were you sponsored by? I think it would be hard to gat a sponsor. I asked my local hooby shop if they ever heard of the WFCC they didnt know.

[studysession]

By a few different manufactures.

It is not always easy getting sponsorships. A lot has to do with your experience.

[mgs9]

Do you race pro, my brother has a freind that races for team losi, they saw him racing at a track some how and thought he was realy good.
I was looking at that one site you sent me and how muck diffrece is there between the "LTM basic" and the "LTM series 2280"? Im a cheap a$$ so i would get the "LTM BASIC" if theres not to much differnce because there like $100 cheaper.

[studysession]

I have a 5300 basic - it is a great motor. It is fast and have loads of torque. Depends on application on which motor you want.

Now for beating the world speed record, you need the right motor for your car. Everyone's setup is different. So I cant say this motor will definately or a different motor will definately work. You and I can have same car and set them up so differently that we need completely different motors to run.

[mgs9]

true. I was on ebay to see if i could find any brushless motors for cheap but know body realy had any. I think mabey 4 things came up.

[jimbow]

that would not be the smartest thing to use a dragster.
1. dragsters are frickin huge. hugeness = heaviness.
2. everyone associate dragster spoilers with speed. not true. dragsters are made to haul ***** off the line. the spoilers only keep the thing planted. i think i would use a modded touring car chassis. since you can use as much space as u need to get movin, you dont need the hauliness off the line, and therefore you dont need as much downforce.

[Fastcar]

that would not be the smartest thing to use a dragster.
1. dragsters are frickin huge. hugeness = heaviness.
2. everyone associate dragster spoilers with speed. not true. dragsters are made to haul ***** off the line. the spoilers only keep the thing planted. i think i would use a modded touring car chassis. since you can use as much space as u need to get movin, you dont need the hauliness off the line, and therefore you dont need as much downforce.

All I can say is wrong!!!!

[studysession]

For the worlds fastest RC car - I don't think you would get a brushless motor good enough off EBay. Sorry.

As for dragsters - they are really light. Are they the right car for the job - that we will have to see. I really want to know who is trying to use a drag car in their project.

[cool head]

megatech has a new dragster, looks very easy to mod. and looks like it could reach triple digits fairly easy with a high end 21 and some custom gears.
http://www.megatech.com/product_detail_surface.php?ID=7810

[racinlosi]

Not so, this compatition isn't going to be won by slaping a .21 in a dragster. It's going to take some thinking, planing, and experamenting.

[studysession]

It is going to take a lot of experimenting. It is easy to get close to that 111MPh but to beat it, is an entire different story.

[Fastcar]

guys around here got serpent 835's with .21's going 100MPH....ain't to hard to do with a nitro dragster...just not that megatech one tho...oh and those 835's weigh more than 60ozs...

[mgs9]

I think a dragster could do the job, Yea they are meant to have a quick take off but the go realy fast in the process. Real life drag racers are some of the fastest vehicals around, some hitting well over 300mph in a quarter miles distance. Im sure its like that for rc dragsters too.

[Chris LaPanse]

There was one 18 cell BL dragster that hit an unofficial 118mph (anyone remember who that was?), so, I bet with a few more cells, you could see some really high speeds. You could probably borrow the setup from the 120mph RC electric boat: 32 cells powering a Lehner 2250 8T motor. It turned a 40mm+ prop at 48000 rpm. With the right gearing, that could probably break 130 or 140 in a dragster.

[studysession]

Chris - I am surprised that more people have not posted about that. The boat records are unreal and require loads of power. Put the same setup in a car and it will be extremely fast.

Problem is fitting some of the bigger Lehners into a 1/10 scale. The car would have to be bigger to fit that into.

[Chris LaPanse]

Yes-but the boats can put in lots more power for the weight. The boat used a single watercooled controller, wheras in a car, you would need 2 or 3 in parallel to do the same, because of cooling. You could also put in a mini radiator, but that would add too much weight. You also coulnt't just put it in and hope it's not running for long enough to overheat-the boats sometimes fry them with watercooling in just 2 330 foot passes. Also, it'll be interesting to see what happens in the LA SAWS this Nov.-they are shooting for 140MPH with 32 cell BL electric riggers.
Side note-check out these batts:
http://www.offshoreelectrics.com/images/record_breaking_120/setup.jpg
and this motor:
http://www.offshoreelectrics.com/images/record_breaking_120/setup2.jpg
all in this boat:
http://www.offshoreelectrics.com/images/record_breaking_120/setup3.jpg
THAT is what went 120.7 two way average, with best one way of over 122.

[mgs9]

Hey im kind of in a bind with my car. I need to find a beveled gear set up for the rear axle, I cant use somthing form like a tc3 set up because the ratio is too tall i think its like 3:1, in need somthing that is that is somthing like 1:1. I cant find anything along that line. If i cant find what im looking for I will have to change my motor positioning from series, to linear which I don't want to do.
Can you guys help me, input is appreciated.

Also what is a better dual set up Linear or series?

[jimbow]

All I can say is wrong!!!!
I was kidding.

[Speedtester]

I was kidding.

Sure you were :cool: :cool:

[mgs9]

Ok im lost now.

[studysession]

Me too. ;)

[mgs9]

hey can you buy blank sheets of carbon fiber? And if so where and how much is it?

[racinlosi]

Yes, you can. If you have to ask, to much for you to afford, lol.

Just kidding. Actually, just search on the net for raw materials, and you should be able to find some.

[mgs9]

Cool. Is it like $100+ for a sheet.
I have never messed arond with Carbon fiber before. Is it brittle, I would amagine it is fairly brittle. What can you cut it with i have only worked with aluminum. Lol I use a jigsaw with a Hacksaw style tip to cut aluminum it surprisingly works good.
Thanx

[BigJim1]

Hi Everyone

BIG JIM Greenemeyer here. I usually don't go on forums other than my own motor forum at www.rccars.com or the Integy Forum because I've had people impersonate me. They say stupid things and I get in trouble. If I just stay on the two then people know it's not me when it happens. But I'm making an exception today. I say this because someone else is registered on this forum as "Big Jim". I am bigjim1 here.

For those who don't know me let me give a little personal background.
I have been manufacturing, winding, tuning and designing electric motors for toy cars for more than 40 years now. I rewound my first slot car motor in 1964 while still in high-school. I later went into business manufacturing slot car motors. In 1978, I sold the equipment that couldn't be converted into making r/c car electric motors and started Team Checkpoint Racing, becoming incorporated in 1984.

During that period I desiged and manufactured the first ROAR approved electric motor completely made in the America called the Checkpoint Platinum. If I had to mention a "claim-to-fame" so to speak, it would be this motor which I feel was way ahead of it's time. Last year, one of my Platinum II motors made during that time period sold on EBay for almost $200.00 and it was nothing particularly special. Just a pristine example of a new production Platinum motor found in the stash of an old hobby shop. It had the original price still on the package of $75.00. Team Checkpoint Racing Inc., officially went out of business in 1990. But I stayed busy building motors and racing.

These days, I make the bulk of my income from consulting other motor companies on r/c car motor design. Associated Electrics and Trinity Products were two of my latest clients. I still build some motors and sell other r/c products and I do a lot of other forum work which is totally magnanomous. I don't mean to sound so grandious using that word. Let's just say I do a lot of work helping people with their motor questions for no monitary compensation at all. I feel it's just giving back a little that has given me so much in the 24 years I've been in the "biz". I can't think of a better way to support the hobby/sport of r/c car racing.
You can read a bit more about me in the December 1999 issue of Radio Controlled Car Action Magazine in the article, "The Century in RC".

I also have a published book about r/c car electric motor tuning and design titled, Big Jim's R/C Motor Black Book, printed by Trafford Publishing available from my website (www.bigjimracing.net) or by ordering on-line direct from the publisher.

Well, that's enough about me. I hate talking about myself because I always feel I'm sounding pretentious when I do.
I just wanted to post here on this forum that the official record for the World's Fastest R/C Car belongs to Chris Collins at 112.5 mph which was not exceeded by Cliff Lett's attempt, although it is a "Guinness" record. Chris's car and motor were made by Steve Saik, formally of Immortal Force Racing. The reason I am familiar with that record is the 13 turn quint armature in that brushed electric motor was made by me. The record was recorded and the race info was sent to and reported in RCCA magazine.

The record was made using a 300 foot-long straight-away and from a standing start. The speed was recorded at the end of that 300' finish line. Gas engines were allowed as were brushless motors of any size. Electric cars could use any number of batteries. The only restriction was the car had to be 1/10th scale. The car Chris used was a Top Fuel dragster of the type currently used at 1/10th scale drag meets using 20, 600mah cells, if my memory serves me correctly. I'm almost sure Steve Pond can find something in the archieves if anyone would like more info on the race.

The record has lasted a long time. But I believe cars can go much faster with the new Ni-Mh 3300mah cells we use now. The absolute speed record will probably fall next year but Chris and Steve will be there and I am already testing special Power Trix armatures that will be in some of the motors at that race. It's going to be a fun and historic race, I'm sure.

Good luck to everyone going.

Good Racing,
BIG JIM Greenemeyer
www.bigjimracing.net

[MT Dude]

wow, long post

welcome to RCCA, Jim

-Chris