170 replies to this topic

[prplgeez]

Rick,

You're an absolute class act . . . keep up the GREAT work!

[Hworth08]

I've seen the term used three times so far in this thread so it may need to be clarified. Joel's front wheels have a lot of he is calling toe-out. The correct term is negative camber meaning the top of the wheel is closer to the frame than the bottom. I've read of Philippe's frames having toe-in, meaning the front of the wheels are closer together than the rear. Toe-in would have some effect on a slot car as even with o-ring tires the car would be trying to steer itself into a turn. Negative camber would have no effect on a slot car using o-ring tires. It doesn't matter which part of a circle is touching the track. As far as "coping" there is a great difference in the settings!

Joel and Philippe should have waited till SRT came out with their program to have ran this race. Then we could compare the times of EACH lap and know what happened! There's going to be a copy of each frame built, just re-run the race! We'll adjust for "driver aging".

[dc-65x]

Hi Don,

Both Joel's and the Dokk's cars had negative camber as shown here on the Diamond:



The Diamond's wheels also have toe in (which you correctly described above). Joel believed that in heavy glue conditions the front wheels had no affect on the cars handling so to prove his point he set his wheels up with toe out.

[prplgeez]

Don,

I think we're all on the same page with the terms. Both cars would have had negative camber although in somewhat different amounts. Phillipe's cars used "toe-in" where, like you say, the front of the wheels would be closer together than the back of the wheels. This particular car of mine had "toe-out" where the fronts of the tires were further apart than the rear.

At first blush it would make sense that toe-in would help turn the car but the track conditions of the time were such that the car was virtually yanked into the corner by the rear tires hitting the massive amounts of Stick-It Brown and once the car takes a set in the turn, the angle of the car is such that neither toe-in nor moderate amounts of toe-out are going to be directing the car anywhere near the direction/angle necessary to negotiate the corner. In my opinion, it just didn't matter.

[Hworth08]

Hi Joel,

Just doesn't matter is most likely correct! The fastest cars now have something "similiar" to a tire mounted straight up. Don't know what the "proper" term for that is! Best?

[Noose]

A spare.

[dc-65x]

It's "clicker" time. It's some brass sheet with .015" clearance with the drop arm hole both front to back and side to side. I need to know where to place the .047" piano wire "clicker" hangers. I could just "eyeball" it. I decided to measure their location in the picture and establish a ratio between that distance and a know distance, the length of the drop arm cut out.

DOGGIES, LOOK AT THAT BOY SYPHER! :shock: :mrgreen:



Next came my funky-dog "line 'em stuff up" fixture to hold the hanger wires straight during soldering:



Here's the finished "clicker" with its hangers installed:



And the "clicker" installed the the center section with its up stops installed:





Onward to "plumber" time.

[Maximo]

Rick,

Fantastic work! I have been following this thread from the beginning and it has had it all!

Great scratch re-bulding of a legendary chassis that was built and raced by a true legend to the win at the '73 Nationals, and intense dialogue between the two men telling the story of what was! Both of which I admire and will keep high atop a pedestal regardless.

History tends to only remember the winners and journelist often write their accounts based on the excitement and conclusion of what happened that day. To win you must first finish and then finish first!

I love this forum...where else can you get the recent words, thoughts, ideas and love from the legendary men and their screaming machines!

Great build and photos Rick!

"Live life to the Maximo!"

PS - I love the "clicker"!

[idare2bdul]

For all their beauty the early 70's chassis are more an exercise in how do we do the same thing better. In the late 70's when they finally started taking weight out of the chassis, they went faster by leaps and bounds. Our goal was to build a car that punched the corners. When we did it I found the hobby had become a builders war with driving less important.
Recently I was talking to Carlos Alosi and he said the key for him going fast was to loosen up his car. In watching the fingers of the group 7 racers it's sometimes hard to see much movement.I don't want to say that the group7 racers of today have no skill, that would be wrong, but they are different skills from what attracted me to the hobby.
Joel's car was more a step along the evolutionary path. PDL's car was a dead end, or at best a branching off, except for the use of steel.

[BWA]

Next came my funky-dog "line 'em stuff up" fixture to hold the hanger wires straight during soldering:

Except, that the front one at least ain't straight. :shock:

[Hworth08]

Continuing Mike B.'s post I wonder if the cars were built "heavy" in the '70s because the heavy cars were best in the heavy glue? When did the tracks gets more natural grip caused by, I'm guessing, being top coated with poly? Was it better tires, better tracks, and more aero bodies or some other things that lead to the lighter chassis?

[slotcarone]

8) Don, all of the things you mentioned are correct but if I remember correctly when we first started using glue way back when we used to put it on the outside tire track. I don't remember when but at some point gluing changed from the outside tire to the inside tire and I believe that allowed lighter chassis to be used. Just my own thoughts. Maybe someone else has some other thoughts on this subject.

[dc-65x]

Except, that the front one at least ain't straight. :shock:

I can't measure more than a few thousandths erior between the wire and the front edge of the part. :? You are looking at an angled close-up picture you know. Sorry, it's straight enough for me.

What I don't like in that picture is the little bit of extra solder I didn't sand off. I think it should be either all left on or all taken off, not done half way. I did't see it until I took the close-up picture. I'll fix it .

[Jairus]

It's fine, Rick. I think he's just playing with you . . .

[BWA]

[Horsepower]

Ah, pity the fool who mess with the best.! :evil:
Rick's work is beyond the best. :up: :mrgreen:

[dc-65x]

It's fine Rick, I think he's just playing with you . . .

Al is an expert machinist and fabricator. When says something I listen. I went back and measured that part every which way!

Thanks, Gary, but my work is really not the best (see the webmaster in my signatue below for that) . . . but it may be the shiniest! :mrgreen: If I blind you guys with glare you might not notice the boo-boos

[dc-65x]

Next are the plumber hinge tubes and braces. Joel simply used a single piece of wire behind the hinge tube and another wire running along the top of the guide tongue connecting both hinge tubes (that piece will show up in the finished picture). No "bumper" is used. Here are the pieces laid out in the jig:



By contrast here are the pieces of the Neat Things Diamond drop arm. The hinge tubes butt up directly against the drop arm. A piece of wire connects the back side of both hinge tubes with the top surface of the drop arm. A 3-piece bumper is used in front of the hinge tubes:



The Diamond's drop arm with the bumper still needing to be trimmed to length:



The Missile's drop arm with the top brace in place:



Next are the dual plumber rails . . .

[idare2bdul]

By the time I started racing Group 7 in 1974 you had a defined glue zone. It was called limited glue racing. The glue was mostly put on the inside lane. You might put a little on the outside to assist brakes but usually it was just a small dot. Several West coast guys experimented with getting the weight out of the car by motor or chassis mods. I'm sure similar stuff was happening on the East coast. Shrunken C-can motors (called Peanut motors by some) gave us the first lighter weight motors using a polymer cobalt magnet. Don Noon put togeter a four HO magnet square cobalt motor (Foamy might refresh my memory here) and the race to lighten was on. I believe The Pro Slot square can was the first light weight single magnet (one on each side) motor that was commercially available. At this point you started seeing hand-cut steel perimiter frames but I was out of racing by then so others will have to fill in the blanks. The lighter weight made the car much more influenced by the downforce of the airdams and amazingly they often survived crashes because they dissipated energy in flight. Reinforcement just slowed you down.

[Prof. Fate]

Hi,

I was racing in the middle states, mountain west mostly. I don't remember ever getting coverage by the mags. Was doing cobalts from '72 for various reasons. But the tracks, except in Denver, were pretty small.

What I am getting to, however, is that I was driving with Mike's "little movement", but what I was doing was watching the dams. I could tell when the optimum time was happening by watching how much dam I needed for FLAT OUT, less dam but still stuck meant faster through the corner.

Curiously, I find myself doing the same thing with magnet cars today. In this case, I am watching how much magnet over the rail is enough to be faster through the corner.

Fate

[tonyp]

Don, the Camen guys were the first to glue on the inside of the turns. I remember them coming to Nutley Raceway and starting to glue three feet from the turns and all the way around on the inside color stripe. The times dropped at least a .10 or more that day for just about every racer.

In full-glue racing the cars got heavier and stiffer to get through the glue. The full-glue rules allowed you to put glue anywhere on the track and as much as you wanted. We would just glue the deadman on a King as far back from the turn as it took to just single blip the turn. Mechanical grip gave way to glue grip and bodies became less important for overall handling. We mostly used styles with lots of front downforce to get through the glue and no added-on spoillers.

On the east coast we went to glue zones after Joel, Freddy, and I returned from the Western States race which was the worst glue race for conditions ever. The San Fran guys had built cars to run narrow tires so they could put down even more glue that no one else could get through.

The cars got lighter with the move to glue zones and really got light when the motors went from C-cans to the little black box style motors. We were already running full airdams at that time but the smaller motors lowered the CG and less weight was needed on chassis to get them to handle. Mechanical and aero grip became important once again as there was not all that glue to get the car to handle.

The smaller the motors became, the more aero grip replaced mechanical grip and those are the Group 7 missles we have today.

[prplgeez]

Tony nailed it with his rendition of the evolution to light weight. For us at Camen, the focus of weight reduction was in the rear of the car. Glue was still heavy even with the limits imposed and the tracks were WAY short of the modern punch bowls, so it was necessary to retain a bit of ballast up front. With the introduction of air dams we found we could substantially reduce motor and running gear weight and still maintain car balance. Our development in that regard was most successful while Steve Bogut and Jon Laster were at Camen and probably culminated in the '78 Worlds car at Gothenburg, Sweeden. I estimated that my motor/running gear mass was 2 grams less than the closest competitor. A guestimate at best but that was where we were going at the time. Testing suggested that a 1 gram reduction of motor weight, properly executed, had the potential for a tenth of a second reduction in lap time. Endless hours were spent machining and hand filing motor details . . . and that was "per motor". It was an INCREDIBLE era!

There was also substantial change is chassis design between '73 and about '77 when four-rail steel cars were developed completely independently both at Camen in Maryland and in Texas by Jim Honeycut. Post '77 Nats, Tony P further refined the notion by removing the rear chassis cross piece and closing the front slot forming what amounts to the modern motor box as we see in the current sub 1.5 second aluminum screamers.

Then cobalts changed everything. We had worked with them for a couple of years but with virtually no success. All brakes/torque and absolutely no driveability. Cobalts were a major focus for us because of the incredible potential for motor weight reduction but Foamy beat us to it. The first successful cobalt motor that I'm aware of was Foamy's MONSTER at the '78 Nats. A quad made of two HO segments per side. Then it was on!!!

[S.O. Watt]

Hi, Joel!