Draught OZclassic rules

[hutch--]

This is an early draught of the suggested OZclassic rules. There has been input from both Lindsay Byron and Mark Fox on the front wheel size so I wrote 5/8 (0.625") into the front wheel size limit. The draught rules do not yet specify any rules about the bodies or the cutoff date and the area of aerodynamics is currently undefined as it needs to be specified in relation to the choice of bodies available.

The general concept of the rules are well defined limitations where they are required and completely delimiting and other consideration to maximise design freedom.

Your comments will be appreciated.

OZclassis Racing Rules

(1) Motor. The allowable motor is a Falcon 7 that must not be either modified or opened. Any mounting method is acceptable and the shaft may be cut down to match the pinion width. You may only use one (1) motor in the car.

(2) Chassis.
(a) Construction
The chassis may be constructed from high tensile steel wire (piano wire), any brass or copper based alloy wire, sheet brass or other copper based alloy or low carbon (mild) steel. Specific exclusions are high tensile steel as either components or complete chassis, aluminium or magnesium based alloys, any titanium parts whatsoever and any structural non-metallic chassis components (plastics, composites, carbon fibre etc ...). For non structural components, rubber, plastics and similar material is acceptable, primarily for damping purposes.

(b) Maximum Width
Chassis must be constructed so that the maximum car width including the body and the body mounting method do not exceed 3.250 inches.

(3) Rear Axle
(a) Rear axle must be solid and made of steel.
(b) Specific exclusions are hollow axles or axles made of any other material.

(4) Bearings
(a) All bearing in the car will be of the solid bush type, any bearing material is allowed.
(b) No other form of bearing is allowed including any form of ball or roller bearing in any part of the car.

(5) Wheels
(a) Rear wheel must measure .750 inches or greater.
(b) Front wheels must measure .625 inches or greater.
(c) Front wheels must be fully functional, touch the track, be able to support the weight of the car and be visible through the front wheel arch of the car.

(6) Tyres
(a) Any form of front tyre is acceptable as long as it is constructed of rubber or similar material, Neoprene and similar synthetic rubber are acceptable.
(b) Rear tyres will typically be black sponge rubber but minor colour variation is acceptable, dark grey, blue, green etc ...

(7) Ground Clearance
(a) Rear clearance at the axle and surrounding areas must be able to clear 0.047" wire.
(b) Front clearance at front wheel location must clear 0.025" wire.

(8) Bodies
[ not yet specified ]

(9) Aerodynamics
[ not yet specified ]

Rule definition Exclusions
There are no maximum or minimum tyre widths.
There are no maximum or minimum weight limits.
Any chassis/drive configuration is acceptable, you may design and run inlines, sidewinders, anglewinders, reduction gear systems, tooth belt, rubber band drive, roller chain or any other method you can get to work.

Regards,

hutch at movsd dot com

[Mark Fox]

(2) Chassis.

(a) Construction
Specific exclusions are high tensile steel as either components or complete chassis,

(7) Ground Clearance

(b) Front clearance at front wheel location must clear 0.025" wire.

Hi Hutch,

Like the rules so far however I think provision needs to be made for High Tensile Steel guide tongues of say a max of .875" (7/8") wide and 2.0" long.

This allows use of available steel tongues and chopped up flexi's or whatever as a component of the build.

Also would like to retain the current .015" as the front end clearance measured at the foremost part of the chassis (excluding the guide tongue of course).

[hutch--]

Thanks Mark,

Both of these make sense, the only one I am worried about is whether the track owners would be happy with a 0.015" clearance for these types of cars.

I would be interested in any comments from the older guys who raced back in the 70s as there were many more bodies available than what is now used in retro. While the TI is a reasonable body and the best of a very ordinary lot, there were others back then that usually worked better, my preference with the bodies available then for sports cars was the Maclaren MK6a which fitted both anglewinders and sidewinders better than a TI which tends to have its lumps in the wrong place.

The question here is, what if any cutoff do you apply to suitable bodies. The proposed class is not an "antique" class but a reconstruction of the VSCA and NSWMRRA rules for constructors. The whole idea is to use reasonable appearance bodies that look something like cars, not try and recreate the pre 1970 past.

The other factor is aerodynamics. Under retro you are allowed 0.500" rear spoilers across the back of the car with no side-dams at all. The original proposal I made with this proposed class was to make the size 0.750" in line with aerodynamic limits back in the 70s but to retain the "no side dams" rule so the cars don't end up looking like wing cars.

Comments here would certainly be welcome.

Regards,

hutch at movsd dot com

[bantamjack]

Gedday Hutch,

I have replied to your last post about proposed rules to include scratch built cars. You will find it on the Mobile Raceways forum as I could not get this one to work and had to re-register.

Bantamajck (from the era of steam powered slotcars)

[hutch--]

I have answered bantamjack's post at the URL

http://www.mrslotcar.com.au/race/showth ... 5#post5705

If anyone else has a comment, especially over the bodies it would be useful to hear it. The current leaning from various people is to not specify a date based cutoff but to ensure that only real car bodies are used, not slotcar thingies.

This would make it a lot easier for track owners in terms of stock in that cars built for this class could use bodies that they already have in stock without having to chase up and supply old body designs.

Commercially the idea with this proposed class is to be able to use existing wheels, tyres, gears and pinions, bodies, guides and if possible, a stock chassis for slot racers who don't have a constructor background so that the track owners are supported with their existing stock and don't have to make any special effort to obtain bits for one single class.

Whatever you do don't be shy, tell us what you think.

[John G]

Hi guys, thought I could add my 2 cents worth. I'm a slotter from the 70's and building a retro car at the moment. Bantamjack is an old adversary. I was one of Axton's 'proteges'.
Anyway, spring steel was a very common material starting from around 1975. In fact Bantamjack still has one of Kims old chassis which is a combo of spring steel, piano wire and brass. I think the use of spring steel helps visually differentiate more between the retros also. Any thoughts? John

[hutch--]

John,

Thanks for your comments. This is my take on the suggestion for steel chassis. I personally built and raced steel cars in 1970 as both anglewinders and sidewinders so there is a historical precedent for them if history in the criterion but it lends itself to a different technology and style of cars that were not available back them, EDM, Laser and similar technologies.

Keeping chassis designs to wire and sheet with no exotic bits avoids the cost and technology problems where anyone who is handy can build cars from piano wire and sheet without having to have access to very complicated and expensive technology.

RE steel bits, there appears to be support for commercially available high tensile guide tongues which is allowed in current retro so I will write this into the next draught of the rules.

The current thinking from asking around is that bodies should not be limited to any time period but they must still be based of real cars that were raced, not slot car thingies.

Kim is alive and well but marooned up in QLD with no retro racing. He came down at the end of last year to race retro at Hornsby and he has not lost the touch.

Regards and thanks for your 2 cents worth. Please add any other ideas as it makes it easier to find out what everyone else thinks.

[il cavalino]

Hi Hutch,

As an oldie who has been racing since the sixties it is great to see the interest generated by retro racing but one thing that puzzles me is we seem to have forgotten about one thing that has always been an integral part of slot cars and that is motor building.

The new generation of Plafit, JK and Slick 7 motors are great, but as I rememeber it we were racing opens in brass and piano wire chassis' in the 70's.

Sure using a stock motor is cost efficient but don't you miss the motor building side of slotting. Even using the little Proslot motors would help as you can at least change brushes and springs and give the com. a true.

Geoff

[hutch--]

Hi Geoff,

Thanks for your comment. I suffered the addiction back in the 60s/70s of winding and balancing motors but much of it can't be done any longer. Back then I had class H wire, facilities to true commutators, silver braze wire to commutators and Monsanto resins to bake the armatures. The other factor is you could get 007 Mura armature blanks without the green gunk on them, rip one apart and use the laminations to make longer armatures but you can't get the bits any longer and few would know what to do with them.

I retired before trasnformational metal magnets or ceramic cobalts became available which were a technical breakthrough but again few would know how to capitalise on this technology

In these economic times the cost factor is a big one, you can build a retro or probably a car for this proposed class for under $100 where tweakable motors start to cost a lot more and scare many people off for both financial and performance reasons.

I have occasionally watched opens up at HSC and they are impressive in speed terms but the motor setups and armatures cost a fortune and the race life is very short, even if you don't smash the car and its motor up.

I go for the sealed motors as it allows many people to stay within reach using the stock motors. The Cheetah II motors are as slow as a wet week and I even had to learn how to drive stuff that slow but the Falcon 7 motors should be a lot faster and allow you to design cars that handle properly instead of rolling inlines into corners like the current retros.

Its a pleasure to hear from you and thanks for your comments.

Regards,

hutch at movsd dot com