Have you noticed...

[XLR8]

The box-art RC10's Protech body has the windshield removed and, as such, the back end of the body forms a very effective scoop to direct air onto the motor plate and motor. Or, without the windshield, air is directed onto the ESC if it's mounted on the shock tower.
The shock tower contains some very large holes and I'm wondering if this was done to promote air flow to the motor.

Or, maybe the windshield delete was just a scale detail and has nothing to do with air flow.

[Ruffy]

Windows were only removed for the Box art body to give it a realistic look for the photoshoot. That car may have never been run from what we know. But leaving the windows intact (uncut) gives the RC10 the best aerodynamic flow for running, and is what most every racer did.

[XLR8]

Thank you for chiming in Ruffy. It's great to hear from someone who actually raced for AE bitd.

"...But leaving the windows intact (uncut) gives the RC10 the best aerodynamic flow for running, and is what most every racer did."

And that applies to me; I never raced a buggy with the windows removed.

While it's certainly true that removing the windows will create additional aerodynamic drag (not to mention the amount of dirt that huge "scoop" would collect from the track) it's also true that not all RC10's found there way to a track. I'm recalling that brief scene from The Dead Pool with the inner city kids playing with their RC10 on the street. I think this scenario was common back then and these drivers would be more concerned about maximizing run time (stopping before the motor overheats) than aero drag.

Anyway, as you say, the window delete on the box-art car was just a scale detail done for aesthetic reasons. To the extent that the shock tower holes and the shape of the body over the motor plate promote additional motor cooling, it's probably just a coincidence and not a design consideration. Races were typically limited to 4 minutes back then so motor heat wasn't a big problem.

I bring this up because I just recently completed restoration on a very clean original short arm A stamp car. It's not as clean as yours but it's complete with original motor and vintage electronics and apart from the Novak T4 in place of the kit's MSC, the car is exactly as it came from the AE. Before they take up residence on a shelf, I like to give my resto projects a brief (easy) run on the concrete driveway (on worn tires of course) and running the car on a 5000mah NIMH battery, it is easy to run beyond 4 minutes and bring the motor temp up. I will typically use an old beater (track) body for these test runs except this time I pulled a box-art body off one of the shelfers. Wow, after looking at that body on static display for so many years, I can't tell you how exciting it was to see it in motion! Anyway, it was then that I noticed that having the windows removed might provide some additional air flow to the motor and ESC (my box-art body is a faithful tribute to the original with windows removed and nets in there place).

Anyway, I thought I would post a topic here and see what members have to say about it.

thanks again for commenting!

[duckhead]

Hi Doug,

I'd think the holes were more for some (albeit minimal) weight reduction, possibly.

Funny to think though in the context of motor heat, drilling holes in the motor plate takes away from the total surface area likely diminishing (slightly) the heat sinking capability.

I do however sit in awe of how much engineering did go into these cars back then, impressive nonetheless

->Mark

[XLR8]

I think you're probably right about the shock tower, Mark.

You've referenced an interesting feature on the motor plate. I've always found the presence, size and location of those two holes a bit of a mystery. Do you think they planned to attach something like an extruded aluminum heat sink then, after the production tooling was finished, decided it really wasn't necessary?

As I study parts from this and many other RC vehicles from an engineer's perspective, I imagine that there are a multitude of purposes for every feature. Many times, that's just not the case; the design is simply what it is, accomplishes a singular objective, and there is nothing more to it.

... but it's fun to imagine what might have been swirling around in the engineer's minds.

thanks for commenting!!

[KidAgain]

You've referenced an interesting feature on the motor plate. I've always found the presence, size and location of those two holes a bit of a mystery. Do you think they planned to attach something like an extruded aluminum heat sink then, after the production tooling was finished, decided it really wasn't necessary?

If I recall their was a company that made heat sinks that attached to the motor plate, I got some somewhere new in package just need to find them.................

[Ruffy]

I do believe the reason for the two holes in the motor plates backside is for tooling, to hold it in the jig while the press comes down to create the two bends.
Basically the two holes were for dowels to hold the plate firmly while the press comes down and bends the motor plate at 90 degrees and also forms the back curved surface, all in one motion. I think you can see a quick short clip of this in the "RC10 The Winning Edge with " Jammin ' " Jay Halsey " video...check youtube.

[duckhead]

I do believe the reason for the two holes in the motor plates backside is for tooling, to hold it in the jig while the press comes down to create the two bends.
Basically the two holes were for dowels to hold the plate firmly while the press comes down and bends the motor plate at 90 degrees and also forms the back curved surface, all in one motion. I think you can see a quick short clip of this in the "RC10 The Winning Edge with " Jammin ' " Jay Halsey " video...check youtube.

You nailed it Ruffy, good eye! I watched the whole video last night and took some screenshots of the process, those holes most definitely were used to hold the flat motor plate blank.

[XLR8]

Awesome stuff, thanks guys!!


I've always assumed that the part was fixed by the motor plate and the top and back were pushed and formed over it. Seeing the images from the video it's obvious they've chosen a simpler and much more efficient method.


For what it's worth, I have made a motor plate for one of the runner cars -- no access to special tools or a press. I just traced the part, cut a blank then clamped and formed it around a block, doing my best to emulate with crude hand tools the process I thought AE had used. Clearly, I was wrong. Thanks for setting me straight on this.

[duckhead]

For what it's worth, I have made a motor plate for one of the runner cars -- no access to special tools or a press. I just traced the part, cut a blank then clamped and formed it around a block, doing my best to emulate with crude hand tools the process I thought AE had used. Clearly, I was wrong. Thanks for setting me straight on this.

You did an awesome job on that plate Doug, looks great! Reminds me of the plate on the RC10 Prototype car, just need to light gold anodize it

While we are talking about motor plates and The Winning Edge video, I found this interesting too:

Notice the motor plate on the outside of the chassis versus the inside...

->Mark

[XLR8]

Thanks Mark. It's not pretty but it does the job.

I noticed the odd motor plate mounting as well and was about to post a still image but you beat me to it.
I've never seen a motor plate installed that way before. Roger Curtis refers to the car as a "final product" and the video is dated 1986 (roughly 2 years after the car was released) so it seems odd to see the motor plated assembled inconsistent with the manual on one of AE's own cars.

Anyway, it's an interesting video and it was good to see it again after so many years. ...makes want to take an RC10 to the beach.

[duckhead]

Well... now that we are in the rabbit hole... Here is another interesting observation:

Notice the upper ball stud location on the front block carrier, the hole appears to be offset from center to the outside of the carrier. If you look closely it looks as if the left and right block carrier is reversed on this car, either that or the early design had relief on the front edge versus the rear edge of where the steering block fits.

Compare with the hole on the 'production' block carriers as seen on this mid-Edinger, we see the ball stud is centered in the block carrier.

What is real interesting is I never noticed that for whatever reason the ball stud went back to offset for the re-release car.

[XLR8]

That's curious. The car Roger is holding appears to have very little castor angle (less than 30 degrees) so the castor blocks can't be reversed. Since the car has 30 degree kick angle, fitting a castor block backwards that was made to yield less than 30 degrees total will always yield greater than 30 degrees castor angle. If, for instance, a 20 degree block is reversed, it will yield 40 degrees total castor angle. I don't believe AE ever made a block with castor angle greater than 30 degrees total (30 degrees = hinge pin perpendicular to king pin) so it's impossible to reverse them and achieve less than 30 degrees. Anyway, I've gone around and looked at every block I have and all of them have steering stops so the block in the video is a mystery.

As for the ball stud location, looking at the blocks I have, it's really a mixed bag. For two of the cars that I've owned since new (mid to late Edinger) plus one Cadillac RC10 that I know is original, the blocks have centered studs. But many other cars in the collection have blocks with offset studs. I have a NIP set of 30 degree Cadillac blocks that are offset stud. Most of my 20 degree blocks are center but not all.

We may never solve the castor block mystery but it's interesting to consider how the car has changed over time.

[duckhead]

New one for today...

What is the consensus on what appears to be an aluminum bracket capturing the inner hinge pin on Jay's front a-arm?


Also, holy heck that is a lot of lightening holes...