Corally SP12 project

[V12]

Thanks. Yes the old Corally cars with aluminium chassis are really cool.

Yesterday evening I was cleaning a few slightly used parts what will go on the car. I hope the bearings are arriving today so the build could continue.

[highwayracer]

This is probably THE car I regret getting rid of the most. I had 4 of them (1 was for racing and the other 3 were for parts). On mine, I cut the cross bar...giving it independent suspension.

The hardest thing with the car was getting the rear diff to work poperly. The diff rings would slip because it used an o-ring as the friction point. If you keep them from slipping, then the diff works really well.

Does anyone have one of these that they can part with?

Regards,
Roger

[V12]

On mine, I cut the cross bar...giving it independent suspension.....

There was an optional wishbone conversion kit for the SP12 what did exactly this. I have this but choose to use the original red frontbar for this car.

Bearings and some other parts came in today so build will continue. More pictures tomorrow.

[V12]

Frontend was completed. As you can see from the pictures the Corally cars use a liveaxle at the frontend, this means the bearings are not in the frontwheels but in the steeringblocks. So you can change wheels fast and easy without the need for removing the bearings and inserting at the next wheels.

[V12]

Also rear pod, bearing holders and rear axle bearings were added.

[V12]

Build goes on with assembling the rear axle/diff.
At the picture you can see the parts used on a Corally diff, it´s a little different than an US type diff. Diffballs are not shown in the picture. There are no hubs but driveplates what interact with the wheels without screws. At the picture you can see one of the notches at the driveplates doing the job.
Also as larger difference there is a large thrust bearing in use, nearly same pitch circle as the spur gear and enclosed inside the right wheel.

Using o-rings for fixing the diff plates was introduced by Corally but IRS used this system later also with their yellow fibreglass rear axles before the notched diffrings were used.

At the nect picture you can see one of the special Corally spur gears what are hard to find today. The diffballs are inserted from both sides so there is no wobble. Also it seems the spurs were moulded and machined afterwards. Available as 48DP and 0.5 module what is used here. You could use this also at an US type diff as the same bearing diameter is used here.

Finally the assembled rear axle/diff and wheels.

[V12]

Next step is building the rear damper. It´s a friction typ damper as used with the Associated cars but enclosed by two rubber grommets.

Picture with the damper parts.

Rear damper assembled.

[V12]

Rear axle and damper installed in the car, also the wheels.
This is the current state as seen in the last picture. What is left?

Some parts are missing as the radio plate and battery holders.
Also the body posts have to be added but this will be after I have a radioplate. I don´t have the special 48mm versions what have some sort of a foot and were used at the front of the early cars but I have the normal 50mm versions.

[highwayracer]

I'm really enjoying reading about this build.

As for the front body mount with the foot, there's also a rubber piece that slides over it. For the radio tray, there were 2 versions made by corrally that looked very similar...but not interchangable. One was for the SP12, while the other was for the SP II.

[uzzi]

Hey mate sweet project ( I have one too )....I have the radio plate and the battery holders if you still require them.

[a01butal]

This is a really sweet car and a great build project. This is the 2nd Corally SP12 I know about, other one is a very sweet car also but hasn't been displayed here.

[V12]

First thing to continue in the new year was the SP12 car. Finally I was getting such a rare radio plate NIB.
Also had an original set of standoffs for the radioplate even when it seems there were two different style standoffs.
From my old Corally cars in the past I had some of the special threaded bodyposts left and these also went on.

What is left now?
I still need some batteryholders for the saddlepackbatteries but there are some on the way what are on a used Corally chassis.
Have to wait if those are usable what means looking near new.
Also the round nut at the top of the rear damper isn´t really true. Actually there is an antennaholder located but again this is on the way.

But overall the SP12 isn´t that far away from finish now. That´s the current state.

[V12]

Long time gone since last stage of the SP12 project, but it´s not easy finding those parts today needed for a 100% correct build. Especially if you want to use new, unused parts. No foreign parts are used with this build, even screws are original old type Corally black Torx screws, newer screws are silver colour.

Finally got the correct front body posts what was the most difficult part of everything. Early Corally cars were using body posts with chassis protection, the SP12 was the last car using this type. Newer cars used the same type as rear bodyposts.
Also found new battery craddles and the special mount for rollover antenna.

battery craddle with metric aluminium nuts

[V12]

left new type body posts, right early body posts

[V12]

Final pictures of the SP12 in the next days.
Also working currently on rebuild of a SP10, big brother of the SP12.