85 replies to this topic

[tonyp]

Actually the extra holes will kill the return path of the magnetic field and should free up the motor for more rpm.

[dc-65x]

I think that might be an added benefit Tony. Maybe I won't have to gear the thing 2.5:1 and it might run a little cooler too.

[dc-65x]

I've chosen a chassis design to pattern my car after. It's Ron Quintana's 4th place finisher in the second 1967 Car Model Magazine Race. I want to try this chassis with its 4 tightly spaced rails per side and heavy drop arm:

 

 

Here's the entire race report (click on the picture to enlarge):

 

 

 

 

 

I also needed to decide on what rear wheels to use so I could make the "korrect" length of rear bearing holder or "duffy". The wider the rear wheel, the shorter the duffy needs to be.

 

Like many of the Car Model racers I'm going with some Weldon wheels that only have a 1/2" of tire mounting surface. To get the legal maximum tire width of 5/8" I'll let the rubber hang over the back just like these well worn originals:

 

 

With that decided I made up a sketch and gathered up the material for the duffy's and the modifications needed for a Cobra 26D rear axle bracket:

 

 

Here the duffys are finished and a blank plate soldered to the motor bracket ready for it's new bearing and mounting holes:

 

 

Time to get this baby into my "Rick's Jig" and build that chassis:

 

[Tim Wilkins]

Blue "Silver Hornet"?  i like it

[dc-65x]

I didn't notice that blue effect the lighting caused in the picture until you mentioned it. I like it too! Maybe I should try some of that "cold bluing solution" on the motor to really turn it blue.   

[don.siegel]

Hey Rick, 

 

Nice chassis choice, but... given that the rewound Russkit probably weighs about half of the GE, shouldn't you add another rail or two to the chassis? No room to add anything on the drop arm, but a little more weight on the chassis might help. 

 

Of course, that's all theoretical, but these things have a LOT of torque... 

 

Don 

[Bill from NH]

If more weight is needed, it could be added as a 5th main rail, as multi-rod outriggers along  the body, or in both locations.

[Pablo]

Duffy is surely smiling from above

[dc-65x]

 

Duffy is surely smiling from above

 

I hope so too Pablo 

 

A pan type chassis like my Ram Boochie would probably handle best for this beast:

 

 

I decided to approach the build as an LA racer might in 1967. The motor itself adds lots of mass and I can always add as many rails as will fit in the 3" wide chassis if it comes to that......we'll see.

[dc-65x]

Rodney thought it would be interesting to compare the GE motors height and weight with the other common 1967 motors:

 

 

So the GE is a bit smaller than the giant 36D but it's still one big motor

 

So.......I'm going to change my mind on chassis design.   I'm not really changing the design because of the motor comparison above but because I saw this picture and I think a similar design would be fun to build (photo courtesy of Los Angeles Slot Car Museum):

 

 

 

This super cool Terry Schmidt chassis is going to be my inspiration for the build.

 

Here are the pieces for the first wave of chassis assembly including the brass rod and piano wire main rails, 1/4" brass strip "rails", motor bracket "L" braces, drop arm hinge tube and up stop plus 4 little square brass spacers:

 

 

I'm a believer in letting my Rick's chassis jig do as much of the parts alignment as possible. So I leave many chassis parts extra long so they can align with the jig pins. Here's the jig ready to begin:

 

 

The partial chassis and all the jig pieces drying after washing all the acid flux off:

 

 

Onward..........

[Pablo]

[dc-65x]

Hi Pablo,

 

I trimmed of excess crap-o-la and put the buff to the center section:

 

 

 

Body mounts are next......

[Horsepower]

THAT is an incredible piece of work! Not only beautiful, but it looks bullet proof. 

[dc-65x]

Thanks Gary

 

The big GE motor is tall and so are the 1" diameter tires it requires. The Mirage body is sitting a bit higher than the traditional body mounting pin tubes sitting on the frame rails will accommodate. So......I came up with another use for 1/4" brass strip:

 

 

I'm using these pieces to support the sides of the body and raise up the pin tube outrigger body mounts:

 

 

I decided since I'm following Terry Schmidt's build and using piano wire for the inside frame rail, I'm also going to use it for the outrigger mounts:

 

 

Brass pin tubes sit directly above the piano wire mounts:

 

 

Next up are the rest of the frame rails........

[Pablo]

Totally trick and very slick

[dc-65x]

More progress. The coolest looking part of Terry's chassis design........the angled outer rails:

 

 

 

I looked through the 1967 Car Model and ARCO race reports and found an evolution from arched brass to squared piano wire axle bracket braces. With the rest of the chassis using piano wire bits, I went with this:

 

 

Now it's time for some fun with a drop arm.......I hope!

[Bill from NH]

That chassis design always reminds me of a sunrise. Nice job, as usual Rick, on this chassis.

[Jairus]

Now that is a perfect car for "Nerfing" the competition. Bullet proof and beautiful Rick. 

[dc-65x]

Thanks Jairus, but I'd never nerf.....he! he! he! 

 

Here's the start of the drop arm. I tried to tie the drop arm "theme" with the main chassis by using a 1/4" brass strip. Here are the first pieces all lined up in my Rick's jig:

 

 

Next the Dynamic pillow block and its reinforcement goes on:

 

 

And some angled outer rails go on to mimic the outer rails on the frame to finish things off:

 

 

 

 

 

The finished chassis:

 

 

 

Time to get the roller assembled and onto the test track.....

[Pablo]

You made that drop arm look so easy

[dc-65x]

Hi Pablo,

 

It's my Rick's Jig that really makes lining things up easy.

 

The parts used to build up the mighty GE. Cox lead wire, drill blank axles, Boca ball bearings, a 35 and 30 tooth Weldun crown gears and a selection of 10 tooth pinions with different tooth forms:

 

 

Here's a closeup of the pinions and their different shaped teeth.

 

 

I've had problems with Weldun crown gears meshing smoothly. I tried the steel gears first to check for a smooth mesh. The pinion on the top left worked pretty well but when I tried the steel gear on the bottom right it was gear mesh heaven!

 

Here's my setup. I can quickly switch between  30 and 35 tooth crown gears for a 3:1 and 3.5:1 gear ration during testing:

 

 

I did change my mind on the Cox guide flag. I went with a Dynamic packaged and Riggen marked Dynamic Low-Profile guide flag. I also used shortened Cox braid clips and drilled the guide post for a Cox retaining screw and washer:

 

 

Wheels and tires are next............................

[don.siegel]

Great pinion shot Rick - fascinating how different the profiles are. 

 

Would definitely go with 3:1 - it's a torque monster (torquemada?). Something along those lines worked fine here, even on the short Bordo track. Unless of course your's revs a lot higher - be interesting to see in any case! 

 

Don 

[dc-65x]

Hi Don,

 

My "dewound" motor with the holes drilled in the can seems to rev quite freely..............and run HOT.      I thought I'd start with a bit lower gearing. Rodney's testing will tell the tale.

[dc-65x]

Wheels, tires and wheel inserts for this project:

 

 

I'm using these vintage Weldun's for rear wheels:

 

 

 

Below on the right is the stock wheel. On the left the modified wheel. The rear flange is removed as is most of the knurling and the front flange is thinned and chamfered:

 

 

 

The tires are mounted and trued front and rear. The rear wheel inserts needed a spacer made from styrene tubing to space them out "Korrectly":

 

 

 

Track testing time...................

[dc-65x]

It runs! Seems pretty fast too

 

 

It's got great brakes too. I don't have my track heavily glued and the handling is tail out, power oversteer. Perhaps with more glue it would tend to roll but not here. I hope to have Rodney test it on a commercial track.

 

 

Now the hard part, at least for me........the body.