19 replies to this topic

[dc-65x]

This is my friend Rodney's build of a GP car for the 6th R&C race. The car will be tested at his home track, Eddie's Slot Car World in Vallejo, CA. Here is the text and pictures Rodney sent me:

 

This is going to be my F1 entry.

Grinding tires. They are Alpha Humongous Supernatural donuts.  As you suggested two from one donut:

 

 

For the chassis I started with the drop arm for the Cox Quick Change guide:

 

 

I made the BRM with more scale tires than the rules call for.  I like the scale look.

 

 

This chassis design is a favorite:

 

 

I'm going to use a Martin Windmill painted the BRM H-16 body. I have a few motors to try out:

 

 

The motor is a 16D Mabuchi endbell with a Hemi can.  Magnets were pretty strong with the Hemi motors. I Hated the Hemi round motor brushes and coil motor springs. Russkit wheels, front tires and a Cox gear:

 

 

 

Looking good Rodney! Next up will be getting the body on and testing at Eddie's...........

 

Onward!

 

[Hworth08]

That'll work! Real nice.

[SlotStox#53]

That is just perfect!! Awesome car & should go really well

[dc-65x]

Thanks guys

 

Rodney continues..............

 

This the Martin Windmill painted the BRM H-16 body:

 

 

I also put together a white BRM livery done by William Haull:

 

 

I tested at Eddie's, mainly on the road course.  I narrowed the tires to legal width on the green BRM.  My trick 16D with Hemi can was blazingly fast, literally.  After three laps, I thought the motor would catch on fire…..real fast though!

 

Well, the motor was good for drag racing.  Time to thrash.  Out came the nice rewound armature.  A ‘68 Mabuchi armature went in.  The temps. were down but so was the speed.  Out came the Hemi magnets, the shunted brushes and the hooded motor springs.  In went the stock ‘68 magnets springs and brushes.  Now the motor worked fine speed wise.  Temps. were down (down but still kinda hot).  I did notice that the ‘68 arms in early cans do run hotter than stock ‘68 motors.  I was able to run quite of few laps on Blue King without melting the endbell. 

 

I tried a pile of vintage rewound motors also.  Had to zap the magnets on some of them and replace brushes and springs on others.  None of them worked as good as the ‘68 Mabuchi armatured motor.

This is what I think is going in.  Eddie has battery power with lots of amps available and the usual 13.8 volts.  The charger is always running.  I think the old rewinds were made for about 16 to 18 volts of transformer/power pack power with low amps.

 

The green BRM handled fine but could use some tuning.  The main thing is the front end does not plow.  Could use more rear bite. 

 

The white BRM presently has a stock Russkit 23 installed.  Boy is it slow.  Eric remembers them being slow.

 

Rodney must have really got his green car handling. I've never gotten one to not plow like a pig and roll over like a dog doing ticks for treats with modern tires and he's looking for more bite  

 

And remember, rewind those Russkit 23's guys. This is Pro racing......1966 style
 

[SlotStox#53]

Sounds like a hugely successful track test for both ! Glad he didn't melt any endbells , nothing wrong with warm or hot as long as they don't go Chernobyl & melt down

 

Hmmm guess it's time to look at rewinding finally then for that "True" R&C experience  

[Steve Okeefe]

It's really interesting how Rodney got the tires on the green BRM to work.  I've had the same problem with "plowing" (understeer) and rollover on vintage cars running on modern tracks, but switching to blue SBR usually fixed that.

 

Notice that's still a fairly lightweight car, except for the drop arm (two brass weights!)  Also notice very little is concentrated towards the back.  It's all in the middle.  There's not a lot of direct downforce on the rear tires to make them grab and plow or flip the car.

 

Nevertheless it is surprizing behavior given the TALL tires!  That car IS 2-3/4" wide, right?

[Tex]

I'm not telling you guru's anything new, but in case someone "new" is just tuning in to threads like this, you can also reduce rear grip by narrowing the rear tires even more; you don't HAVE to have the rears at max width. You could also give the rear tires more radius which, in effect, is a form of narrowing(less contact patch). If you have spacers between the rear wheels and chassis, removing the spacers(narrowing the car's rear "track") also changes the grip level balance between front and rear.

[dc-65x]

Rodney reworked the white and blue BRM shown above. Here's what he had to say:

 

I have always been a big fan of the 1966 Movie Grand Prix starring James Garner.  My favorite racing movie. 

The white BRM body and driver have been partially repainted and renumbered to honor the movie and James Garner.  The vac. car body is painted on the outside.

 

I blue printed the chassis, wheels and tires. The car was set with a 3/16" ground clearance for a more scale appearance.  A 16D re-wound armature was epoxied, balanced and trued.  I found a strong pair of stock magnets.  All were inserted in a Russkit can and black endbell.  Ran in the metal gears.

 

Next, testing at Eddie's.

 

 

 

NEAT!

[SlotStox#53]

That chassis certainly looks tough!!! The main rails look sizeable tubing or solid rod? Love the suspension detailing Great job Rodney

[dc-65x]

Here are Rodney's track test results on the white BRM:

 

More ramblings:

 

The newly built motor in the white BRM sounded good on the power pack.  On the track, no torque and gets hot.

The motors in the sports car and the green BRM are breaking in well.  There are still re-canned 68' Mabuchi motors in these cars.

 

In thinking back in time to 1965, Bay Area cars where built as light as possible.  We ran stock magnets with soup can shims.  Remember my dissertation on torque, amps, volts and weight of slot cars and the evolution of slot cars?  The white BRM weighs a zillion ounces.  With the high ground clearance we wanted decent handling by making a heavy chassis.  The funny thing is a 36D motor could hall around this heavy car with no problem.  Probably need a 517 Champion type of motor (too new) to move around a heavy car.  Better magnets, thicker wind, more amps available, lower voltage better heat control came later. 

 

Eddie trued a couple of old armatures for me.  Time to try more period correct 16D motor combinations.

 

Rodney

[dc-65x]

Another update on getting Rodney's R&C GP cars tuned up:

 

"Rick,

 

Christmas party at Eddie's today.  Wish you where there. 

Tested the F1 cars.

Hope everyone likes the picture with the William Haull Ferrari leading the way.

The Eddie refreshed armatures worked great.  See second picture.  Got three period correct motors to work.

Changed to a seven tooth pinion (from eight tooth) on the white BRM.  This and a re-armatured motor did the trick.  The motor ran great and ran cool.  Took some lead weight off of the drop arm to get neutral handling.

 

Regards,

Rodney

 

 

 

I wish I could have been there at Eddie's too Rodney.

 

Thanks for the update!

 

Rick

[SlotStox#53]

Great news the re-arming sorted the motors out ! Nothing like a kewl running vintage/period Korrect motor ,especially in such great looking cars!!

They look great on the track

[dc-65x]

Another GP entree from Rodney. His comments:

 

"Back in the day, most of the slot cars seemed to be Dynamic chassis cars.  To honer the popularity of Dynamic cars, Eric and I will have two Dynamic cars for the event."

 

"Blue printed Dynamic chassis.  Original Taco motor.  Car is very easy to drive.  Neutral handling.   When pushed the car drifts beautifully.  Please share.  Will try some black foam tires next."

 

"The track was cleaner than it has been.  They had a race last Thursday night.  With a cleaner track the foam tires have an advantage over the urethane tires."

 

 

How about that vintage rewound Mabuchi......have you seen many "TACO" rewinds??? I found that motor in an ebay lot and passed it on to Rodney:

 

 

Now it has a new life where it belongs, on the track

 

[Pablo]

Sweeet !! I never heard of a Taco ?

[SlotStox#53]

Very nice Dynamic ride! I've heard of taco'ing a chassis but never of an actual "Taco" rewind/motor

[Rick]

I'm diggin' his HD Dynamic Guide Tongue! ..................

[SlotStox#53]

Looks very familiar Rick

[don.siegel]

Reminds me of my local Taco joint in the Mission district of SF.... yum! 

 

Yum for that car too Rick & Rodney. When I see how well a good Dynamic chassied car can run these days, it makes me appreciate all the more how good the SoCal scratchbuilt cars were... 

 

I don't think any of the Dynamic cars ever made it into a final in the R&C or Car Model races, but they either made a semi, or just missed one a few times - especially run by Jack Garcia and the other Team Dynamic members. 

 

That motor really is a teaser... There must have been a lot of local rewinds like that - do you remember where the lot came from Rick? (I've got a couple with Tracker labels - ring any bells?)

 

Don 

[dc-65x]

All I remember about the motor is that it came from an eBay lot....perhaps from the San Francisco Bay Area.

 

Yes R-Geo Rick make great stuff!

 

Oh, and that's not a Dynamic 16D motor bracket. They are set up for really small diameter tires. Rodney modified a bracket for a bigger motor that uses larger diameter tires. Looks like he scratch built the front axle bracket for larger diameter tires too......nice!

[dc-65x]

I confused the Taco motor with another obscure rewound 16D Mabuchi. Here's the scoop on the Taco from Rodney:

 

Rick,

 

The Taco motor was a gift to me from fellow slot car enthusiast Jerry.  I have restored slot cars at no charge for Jerry.  He lives in the Bay Area.  He got the Taco motor along with other mid 60's slot car parts from a yard sale in Fremont California.

 

Jerry always comes up with boxes of slot car stuff from antique shows and swap meets.  He has me review the new purchases and tell him what brands the cars and parts are and what goes with what and what is the relative value the newly found slot car stuff has.  He knows that I never ask him to sell or trade anything.  I told him how interesting the Taco motor was and how it could be a Team Dynamic motor.  I gave him some background on the Dynamic Team Captain and his Mexican heritage.  So one day Jerry insists I have the motor and put it to good use.  I showed him the completed car the other day.  He liked the overall car so much that he wants me to build him a Dynamic F1 car using one of his favorite painted bodies.  I completed a Chappy 2D for him about two month ago which he really likes.

 

The motor is all original except for a replacement endbell.

 

Rodney

 

More details on the Dynamic chassis:

 

Yes Rick, it's a Dynamic 36D bracket redrilled for a 16D and the endbell mounting surface angled. The front axle bracket is a four hole Dynamic bracket with two hole positions cut off.  A piece of scrap Dynamic brass tongue is used as a spacer to raise up the front axle bracket to allow for the larger tires.