72 replies to this topic

[dc-65x]

Time to scratch build another car.

I'm going to use a very interesting "how to" article by Mike Morrissey on building a 1970 "Pro" racer from Model Racing Journal (MRJ) as the basis for my build. I'm looking forward to following along and learning from how Mike built back in the day.

 

I'll be using some details from other 1970 pictures of cars from Pro builders like Gilbert and Steube that I find interesting too. I'll also be using MRJ articles on building a B-motor and period air control to build this car.

 

Click on the pictures to enlarge them. Take it away Mike:

 

 

 

 

Here is a close up picture of Mike's finished racer:

 

 

These are left to right 1970 Steube, Brady and Morrissey racer:

 

 

Here are the rules:

 

 

 

Next up will be the motor build MRJ article. I'm going to build the motor first so I can use it in the chassis build.....

[Bill from NH]

Should be an interesting build Rick.I built & raced my first anglewinder in 1971. 

[dc-65x]

Hi Bill,

 

Here's the motor build article for one of the later versions of the B-can:

 

 

Here are the parts I pulled for the build:

 

 

This a very cool and (for me) hard to find version of the B-can. This one was given to me by my buddy Rodney, Thanks Rodney! 

 

I'll be using the can on the left. It is the later version with the axle clearance cutout similar to what ended up on the Mura C-can. That seemingly ideal feature will come back to bite me.

 

The can on the right is a first generation B-can:

 

 

The later can on the left is also 20/40 ground. The top and bottom are thinned from .040" thick to .020" thick. It's also bored to gain some air gap with the armature:

 

 

[zipper]

"Circular Milled"  - but a dud was a dud...

[MSwiss]

The B gets a bad rap, but that looks like one in Joe Sullivan's podium car.

And mine was impressive enough, in early Saturday morning practice, at that same race, Mike Tango commented to PVA, "This kid's got hosspowa".

FWIW, I was also using the rectangular hole can, like Sullivan.

[zipper]

I did have one with rectangular hole - gosh how hot it did run; s24 bubble gum arm to blame...

[Bill from NH]

Mura sold short stack unbalanced arms for Grp.15 racing back in the day. I ran them weekly in rectangular hole B-cans from 1970-75 because they performed better in those cans than in the Mura Green C-can. Mura also sold complete B-can Grp 15  motors painted pink. The C-can version was their silver-gray color. I think the short magnets mentioned in Rick's B-can built article were Versitecs from Globe. I never did built open class motors with B-cans, but I had the parts for a couple.

[dc-65x]

Check this motor out from my old eBay Motors thread:
 

Thanks for all the input it is always much appreciated.

With this next pile, I mean vintage treasure, I'm going identify what I think I've found for a change :



Another non-floating pan chassis with a big B-motor installed on top of the half rail :



Here's a look at the motor, I wasn't to hopeful for anything good:



Another rust bucket . I started sanding the rust coating off the armatue stack and, oh my:



We have engraving . A single 24. And, what's this :



REHCO, so we have a nice Mura single 24 sold to REHco. It wasn't even broken in. Check out the brush wear:



This motor was a virgin. It was factory assembled and untouched. I got several of the Mura B's with 20/40 milled cans, Super B magnets and REHCO engraved S24 and D27/28 arms in another lot of motors a while back:



I'm going to restore the above original motor. I have a new chrome can and end bell for it. I want it to be stock so I can see how a stock S24 Super B a customer would buy ran back in the day . Sounds like fun to me .

 

My plan is to use everything but the can and end bell..................and the rust in my new motor.

 

Here's a link to the thread with lots of old period motors and cars from a single eBay lot:

eBay Motors

 

 

[Steve Okeefe]

Left side endbell drive...

 

or right side can drive...

 

Builder's choice!

 

 

[dc-65x]

That's right but this builder went even further. It's hard to tell from the pictures but he's running a CCW timed arm backwards!

 

Maybe that's why the brushes never even got broken in. The motor was a dog running the wrong direction.

[Steve Okeefe]

This is what happens when we run our dog backwards...

 

 

Okay, left-side can drive; now the comm-cooler in the "box-o-parts" makes more sense. 

[dc-65x]

Here are the magnet bits and pieces. Super B magnets, .005" steel shims for behind the magnets, .016" brass strips for the top and bottom of the magnets and clips to hold the magnets in place while the JB weld cures:

 

[dc-65x]

The magnets and shims glued in place, bearing soldered in and all mounting holes tapped and countersunk:

 

 

I couldn't help myself and took advantage of modern slot car tools to hone the magnets to .525" diameter:

 

 

The end bell is next.......

[Pablo]

That's a tight airgap all right, Lee Gilbert would approve. What's the arm OD?

[dc-65x]

Hi Pablo,

 

The arm is .513 OD so .006" air gap. Rodney suggested I try a tighter air gap for the vintage arms and setups. I can always open it up.

[Pablo]

Hoo boy howdy, that is tight

 

 

 

[dc-65x]

The stock B end bell on the right (red) gets lots of cutting on to end up like the modified on the left (white):

 

 

Comm inspection and cooling holes top and bottom, brush cooling slots on both sides, half rail clearance cut on the bottom and a buss bar clearance slot on the top:

 

 

All the pieces that make up the end bell. Thick aluminum Super Proofers, silver plated buss bars, brush plates and hoods, stainless steel machine screw fasteners and fiber board spring post insulators:

 

 

Here's everything assembled:

 

 

 

I love all the polished silver plated and stainless steel goodies:

 

 

 

That's as far as I'm going with the motor. Just bolting it together temporarily to use to build the frame around it.

[Bill from NH]

Airgaps that tight generate extra heat & the motors will drive punchy. We tried  .525 holes in C-cans with .513 arms over 15 years ago in CASRA & ANEAMCA  racing series. We never did get them to run right on most tracks. Lee Gilbert may have used a .525 hole, but all arms in those days were .510.

 

Rick, are you going to install a brass goop shield on this endbell, per the B-can build article?

[Pablo]

Bill, I wouldn't pass judgement on it until it's tested. If the motor needs more gap, like the man said, he can open it up more. It's a big wire arm, it may like a tight gap. Let the motor decide. Everything else is just theory.

 

I love the EB assembly

[Geary Carrier]

Excellent Endbell...

[W. J. Dougherty]

On the Engelman at Queen City/Need for Speed, during the ANEAMCA Series we ran the track backwards. You had to climb the banking and rocket down the straight into the lead on. Jim Stinnets motors were .513 arms with a .520 hole. He built 12s, SWs, and Contenders all the same. They were ballistic. I never saw one blow...

[Bill from NH]

Running the Engleman backwards was like racing on a big roadcourse. Unfortunately, I think that Ogilvie 185' track was thrown out when Peter Adamo, the U.S Raceways' distributor passed away. Bill. most all of Jim's motors were fast, but he quickly dumped his .525 motor program because he didn't like how they drove. His motors, & Lou Pirro's too, used JB Weld for magnet shims instead of steel shims. Do you recall Lou's rule that stated a small hole in each side of a can for "magnet adjustment" was legal? I still have have a new, never-used, .525 Koford diamond hone.

[MSwiss]

Air gaps with G7 arms and air gaps with restricted arms are 2 different thing

When I started at Koford, in 1985, we had .480 arms, and ran a .490 air gap.


In 1987, when we started with .459 arms, we ran .468 air gaps.

When we went back to .480 arms, in 1998, we went with a .492 air gap, partially because the magnets were taller/larger, and partially to provide more clearance, if the laminations swelled.

To say a motor is punchy and runs hot, is a contradiction of terms.

If it's punchy, it means it has good torque, and isn't stressed, pulling out of the turns.

A tight air gap, and less air moving through the motor, won't cause the motor to run hot.

[zipper]

Agree with Mike - my latest G7 (not brand new) are .490 in .500 gap.

[dc-65x]

Time to start the chassis.

 

I'm going to try to reference Mike's how to article pictures with my own struggle........... .......I mean construction. They won't necessarily be in the same order as Mike.

 

Mike's first picture (MRJ step 1) shows the tools and supplies he used. I needed a few more.     Actually that all my junk before I loaded into my workbench after we moved:

 

 

My chassis parts (MRJ step 2). That's my one and only Team Nutley drop arm:

 

 

We're lucky to have beautiful reproductions by Slotblogger "grooverunner" available. Thanks Ken! 

 

 

I'm going to use 1/8" axles although 3/32" were also in use at the time. Here's my 9/32" axle tube modified for motor clearance (MRJ step 10):

 

 

Next up is (MRJ step 6). Modifying the motor mount to properly center the big B-motor in the chassis........