Jump to content




Photo

Mini Cooper dragster


  • Please log in to reply
88 replies to this topic

#1 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 07 October 2020 - 11:25 AM

Like (almost) everything at The Wolcott Ranch, this car will be "for sale".

But my intent is to make it run in the "World Challenge" proxy "Just for Fun" class - no rules.

 

Body is a Toytech, WB is 3", wheel widths front and rear are about 2 1/2", pan width is 2 3/8". Configuration will be anglewinder.

 

Motor is a Havlicek custom built "Peanut" motor - modified FK can, Pro Slot endbell, arm wind is Group 20. It was installed in a Pablo Go Kart for one (road course) race, had way too much power, baggied up and marked "H20, one race.  FAST. Gears too tall for The Dungeon with 36 spur".

 

Perfect powerplant for this build. Small, lightweight, very powerful.

This is going to be the fastest Mini Cooper I've ever built  :crazy:

 

IMG_7242.JPG

 

https://www.youtube....h?v=q5cgVbAYui8


  • Tim Neja, miko, Alchemist and 4 others like this

Paul Wolcott





#2 eshorer

eshorer

    Race Leader

  • Subscriber
  • PipPipPipPipPip
  • 794 posts
  • Joined: 25-August 07

Posted 07 October 2020 - 02:01 PM

Now if you can just figure out how to make it sound like that Mini in the youtube! Maybe a tiny piece of something hitting the gear, a la "bicycle card on the spoke" of our youth?

Cool project.

Eddie


  • Pablo likes this
Eddie (not so Fast anymore) Shorer
Team Boola (circa the '60s)

#3 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 07 October 2020 - 05:00 PM

Oh I guarantee you this G20 arm in the peanut setup will deliver a real sharp whistle  :D


  • Rotorranch likes this

Paul Wolcott


#4 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 07 October 2020 - 06:49 PM

Planning/Parts gathering begins. Peanut has a 9T 64P pinion already installed.

 

My gearing guessing says, if it was too violent for a road course motor at 9/36/.750 = 5.3,

it should be perfect for a straightaway launch at a similar FDR. I found a 46T alum. drag spur and a pair of .930" OD ProTrack wheels with fresh rubber in the fridge. 9/46/.93 = 5.4 something. Close enough.

 

Mocked up, it looks like it will work fine as an anglewinder  :)

 

IMG_7244.JPG

 

 

 

 


  • Alchemist likes this

Paul Wolcott


#5 Martin

Martin

    Posting Leader

  • Full Member
  • PipPipPipPipPipPipPip
  • 3,107 posts
  • Joined: 22-February 09
  • Gender:Male
  • Location:US

Posted 07 October 2020 - 11:19 PM

The body you have there is a Mini Sprint. A small co. in the U.K. chopped the roof and added flares 1/1.

My 1/24 Stock car 1969 was a Mini Sprint. Still have it. Great little slot car.


  • Pablo likes this
Martin Windmill

#6 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 08 October 2020 - 03:47 PM

Thanks Martin  :)

 

I trimmed a little rotating fat from the pinion then oiled and tested the Peanut, since it's been in a baggie for months.

Draws 1.8 amps at 5 volts, runs cool, sounds very potent  :aggressive:

 

IMG_7246.JPG

 

Ready to begin loading the jig, but haven't decided between Parma O-ring or Samson BB fronts yet. 

For now, I'll start with the rear axle tube. Right rail goes straight forward, left rail gets angled, and I'll go from there

 

IMG_7245.JPG  

 

No rules baby, running with scissors

 

OIP.jpg


  • Alchemist, Rotorranch and Tom Katsanis like this

Paul Wolcott


#7 Dan Searcy

Dan Searcy

    Mid-Pack Racer

  • Full Member
  • PipPipPip
  • 179 posts
  • Joined: 15-July 11
  • Gender:Male
  • Location:SoCal

Posted 08 October 2020 - 05:52 PM

I've had this for a few years now.  I put this Toytech body on it a year or so ago.  The previous owner soldered a wheelie bar onto a Womp chassis.  I put a super 16D in it, nothing exotic, and it's a hoot.  Runs in the high 7's on a 1/8 mile strip.  My favorite drag car by far!

 

Can't wait to see your finished product.

 

IMG_5661.JPG

 

IMG_5663.JPG


  • Pablo, Tim Neja, Alchemist and 1 other like this
Steadfastly refusing to grow up...
Dan Searcy

#8 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 08 October 2020 - 06:24 PM

Thanks Dan, I love flames and Mini Coopers, and I love your car  :heart:

 

I spent a lot of time mocking up the drivetrain. Everything is a trade-off. To get the motor closer to the axle I changed to a 10T pinion. Here is what I have so far

 

IMG_7249.JPG

 

A 10 pinion is going to really load the car hard off the line, but I will keep that in mind as I build the chassis  :dirol:


  • Alchemist, Rotorranch, Dan Searcy and 1 other like this

Paul Wolcott


#9 Alchemist

Alchemist

    Posting Leader

  • Full Member
  • PipPipPipPipPipPipPip
  • 2,473 posts
  • Joined: 11-November 09
  • Gender:Male
  • Location:Far Far Away

Posted 09 October 2020 - 12:51 AM

Looking real good Paul!

 

With that type of motor potency, I presume the wheelie bars will need to be longer than the car?!  LOL

 

Ernie


  • Pablo likes this

Ernie 


#10 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 09 October 2020 - 05:31 AM

Thanks Ernie  :)

 

I can write my understanding of slot car drag racing on the head of a pin with a Sharpie  :laugh2:

It's the "Just for Fun" class, so what can possibly go wrong?

 

My goal is to put the power to the ground and not de-slot, but it's hard to "unlearn" 55 years of road course mentality.

In an effort to get the motor even closer to the axle, I'm planning to "tip" the motor upright

 

IMG_7254.JPG

 

Similar to a Banshee build I did a while back. The car lives in Canada. Last I heard the owner said it was a rocket

 

post-91-0-95040000-1522875750.jpg

 

 

 

 

 


Paul Wolcott


#11 Bill from NH

Bill from NH

    Age scrubs away speed!

  • Full Member
  • PipPipPipPipPipPipPipPip
  • 13,220 posts
  • Joined: 02-August 07
  • Gender:Male
  • Location:New Boston, NH

Posted 09 October 2020 - 06:49 AM

Direct drive would get the weight even further rearward. Wheels for .078 axles are around. :)


Bill Fernald
 
I intend to live forever!  So far, so good.  :laugh2:  :laugh2: 

#12 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 09 October 2020 - 12:09 PM

It's not a weight issue. If it was I'd just put the motor in the trunk  :laugh2:


  • olescratch likes this

Paul Wolcott


#13 Bill from NH

Bill from NH

    Age scrubs away speed!

  • Full Member
  • PipPipPipPipPipPipPipPip
  • 13,220 posts
  • Joined: 02-August 07
  • Gender:Male
  • Location:New Boston, NH

Posted 09 October 2020 - 12:52 PM

Then is that the only way you can get the gears to mesh? It's common practice to tip inline drag motors on their side, but that raises the CoG. Not an issue for your application. I saw some neat 1:1 Mini drag cars on a FB video last night.


  • Pablo likes this
Bill Fernald
 
I intend to live forever!  So far, so good.  :laugh2:  :laugh2: 

#14 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 09 October 2020 - 01:01 PM

It's the only way to go full sidewinder. That way the initial "twist" of the motor gets applied evenly to the flag.

Or at least that's my "newbie theory"  :crazy:


Paul Wolcott


#15 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 09 October 2020 - 01:46 PM

Which wheels do y'all like, the O-rings or the BB retros?


Paul Wolcott


#16 Rotorranch

Rotorranch

    What's a title?

  • Subscriber
  • PipPipPipPipPipPip
  • 1,755 posts
  • Joined: 22-November 10
  • Gender:Male
  • Location:Atlanta, GA

Posted 09 October 2020 - 01:53 PM

I like the retro wheels myself.

 

Rotor


  • Pablo likes this
Jeff Chambers

Posted Image      Posted Image
                                         "Kinky Kar"

#17 Don Weaver

Don Weaver

    Checkered Flag in Hand

  • Subscriber
  • PipPipPipPipPipPip
  • 1,738 posts
  • Joined: 26-October 07
  • Gender:Male
  • Location:Lexington. SC

Posted 09 October 2020 - 03:48 PM

Pablo - Do the front wheels on dragsters touch and roll?  If not then ball bearings add nothing but weight to the party.

 

Don


Don Weaver

​A slot car racer who never grew up!

 

The supply of government exceeds demand.
L.H. Lapham
 
If the brain-eating amoeba invades Washington
it will starve to death...


#18 Rotorranch

Rotorranch

    What's a title?

  • Subscriber
  • PipPipPipPipPipPip
  • 1,755 posts
  • Joined: 22-November 10
  • Gender:Male
  • Location:Atlanta, GA

Posted 09 October 2020 - 03:57 PM

Nose weight matters.

 

Rotor


  • Pablo likes this
Jeff Chambers

Posted Image      Posted Image
                                         "Kinky Kar"

#19 Don Weaver

Don Weaver

    Checkered Flag in Hand

  • Subscriber
  • PipPipPipPipPipPip
  • 1,738 posts
  • Joined: 26-October 07
  • Gender:Male
  • Location:Lexington. SC

Posted 09 October 2020 - 04:43 PM

Jeff,

 

Thinking more of the cost of ball bearing fronts vs cheap Parma o-rings.  Weight can be added cheaper.  But then I'm a penny pincher from the good ole days!  :)


  • Pablo likes this

Don Weaver

​A slot car racer who never grew up!

 

The supply of government exceeds demand.
L.H. Lapham
 
If the brain-eating amoeba invades Washington
it will starve to death...


#20 Rotorranch

Rotorranch

    What's a title?

  • Subscriber
  • PipPipPipPipPipPip
  • 1,755 posts
  • Joined: 22-November 10
  • Gender:Male
  • Location:Atlanta, GA

Posted 09 October 2020 - 04:49 PM

And they look better!

 

Rotor


  • Pablo likes this
Jeff Chambers

Posted Image      Posted Image
                                         "Kinky Kar"

#21 Bud Greene

Bud Greene

    On The Lead Lap

  • Full Member
  • PipPipPipPip
  • 469 posts
  • Joined: 12-February 11
  • Gender:Male
  • Location:Saraland, AL

Posted 09 October 2020 - 06:26 PM

What are you going to make the rails out of



#22 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 10 October 2020 - 11:52 AM

Bud, main rails will be .055 single wires.

 

Don, in this proxy they give extra points for "Appearance". I think both types of wheels look cool.

Who knows what the judge will prefer? No rules for "touch and roll", so I can use what I want.

 

Still undecided on the front wheels, but thanks for your inputs Jeff and Don  :)

The Samson front wheels really are lightweight, but they require a 3/32 straight axle.

The Parmas use a 1/16 axle and it can be angled and hinged.

 

All I have for now is a rear axle tube with a drip hole and ProSlot BB's soldered home.

Will be laying the rails later today  :to_become_senile:

 

IMG_7262.JPG


  • Bud Greene likes this

Paul Wolcott


#23 Pablo

Pablo

    Builder

  • Administrator
  • PipPipPipPipPipPipPipPip
  • 18,018 posts
  • Joined: 20-February 06
  • Gender:Male
  • Location:Cleveland, Tennessee

Posted 10 October 2020 - 08:38 PM

Yes I know I've changed my mind many times, so I'm sorry for that.

But I'm not sorry for trying to nail it the best I can.

 

There is no test track. I have zero drag experience, other than the Caddy and two duckys.

That hardly makes me experienced. So I have one chance to make it right, and the car has one pass to perform.

 

I have to guess on a lot of things, which makes me nervous. Main rails are .055, motor is anglewinder, and I'm using JK retro .812 OD retro wheels as jig blocks. Strange, but it works. Anyway, one rail goes straight forward, the other is angled to parallel the can.

 

Motor is centered for left/right weight balance and axle tube with BB's is centered in the jig.

I have decided on the Parma O-ring front wheels.

 

Again, thanks for those who gave opinions and input. Onward  :dance3:

 

IMG_7289.JPG


  • Alchemist and Larry Horner like this

Paul Wolcott


#24 Larry Horner

Larry Horner

    On The Lead Lap

  • Full Member
  • PipPipPipPip
  • 257 posts
  • Joined: 18-March 17
  • Gender:Male
  • Location:San Francisco

Posted 11 October 2020 - 05:08 PM

Looking good Pablo and I think you made the right decision going back to an angle winder. I thought the rotated can sidewinder design look uber cool but my own experience with drag bikes (real ones) is that the lower your CG, the more effectively you can transfer the power to the ground.

 

And now for a ignorant question from someone with very little angle winder experience. Does the slightly improper gear mesh when the arm axis is below the axel have much effect on performance? I know this same debate has raged for years regarding offset inlines and my personal experience is that any performance loss there is very negligible and I suspect that is the case here as well. Still, I also suspect part of the reason for such small tires on angle winder road cars is to minimize this offset.


  • Pablo likes this

#25 SpeedyNH

SpeedyNH

    Old Engineer

  • Full Member
  • PipPipPipPipPip
  • 716 posts
  • Joined: 18-July 15
  • Gender:Male
  • Location:Cow Hampshire

Posted 11 October 2020 - 05:39 PM

in my experience, with a good set of properly angled gears you can minimize loss from the funny mesh. it works with cobalt anglewinders, which will quickly destroy a badly meshed gearset. of course nothing's perfect (like correctly-profiled straight spur gears), but you can come pretty close. 


  • Pablo likes this
Steve Lang





Electric Dreams Online Shop