DDK - Die Deutschen Klassiker

Time for a small tinkering project before the big Xmas project, hands have been very clean for far too long.

As ever, I'm not sure if this subject will be of much interest, but at least it is a car (of sorts), I'll watch the 'views' numbers as I go along.

So, what is a 'tethered car'?

Over in the USA and later the UK (and many other countries) model cars, around 10 to 12" in length fitted with hot model aeroplane engines were raced tethered to a post by a thin wire and would scream around a round track at silly speeds.

Speed was everything and many models became quite techie in design and construction.

My effort here is to model something with what I have to be simply displayed in the garage, or even the house if i get permission.

I hope to DIY as much as possible.

This is a typical tethered car



I have already started the car, and this is a 'typical' update as i go along without a dead line but to be finished by the end of Spet or so when I get busy again on serious stuff.

First was a suitable old engine, about 5cc would do. Thought about using the 5cc diesel engine i made earlier in the year, but too big.

Settled on one from my small collection, make unknown but from the USA, about 1946 and spark ignition. I bought this engine at an autojumble about 48 years ago for £2 and it has sat on a shelf since until now.

I only have a vision of this car in my mind, no drawings etc so winging it as I go along using bits in the garage and getting the proportions right by eye (nothing new to that).

Chassis was made and left too long. It will be trimmed to length once the rear axle is in place. It will be drilled down the sides to reduce weight(!)

Next up was the front axle. It had to be a dropped beam and it had to be sprung, not simply welded/bolted on, too crude.

Some 8mm rod from B&Q and a some heat, welding and some careful filing followed, and then two spring hangers on the axle to take two leaf springs which will be made from an old hacksaw blade, spring modulus calcs showed it to be 'just-right...'
The rear axle will be bevel gear drive and solid to the chassis. Gears on order arriving early Sept.

Some pics so far:

That looks brilliant, back in the, well a good while ago there used to be a track in Leicester where I spent some time watching these cars. There is a delightful little program in the Look at Life series occasionally shown on Talking Pictures TV which is all about tethered car racing. I have also seen them at Brooklands before it was taken over. Great stuff, looking forward to the next update!!

Thanks for the reply, thought I was 'talking' to nobody out there!

Spent a little more time today on the car. Wife busy watching F1 Qualifying!

I wanted to get the rear axle sorted, so this was the task.
After a few loose sketches on the bench decided a simple cross tube will do. This will be brazed to the chassis rails and the center section then removed for the bevel drive gears awaited.

The axle is a length of 8MM dia BDMS as per the front but obviously straight...

Turned the retaining rings that will set the axle to the chassis and then machined the chassis rails for the tube in the lathe.

Ran out of oxygen for the brazing also...typical.

Bought a few packs of machined brass M4 cheese headed screws and brass full nuts and some grub screws.

The wheel discs shown are just dummies to make me smile.

Coming along nicely, what wheels are you going to use?

That’s a tricky bit…
They need to be 3 or 4 inches in diameter, so special.
Possibly make them on the lathe from nylon, but slim and alloy hubs.

That should cover the floor with lots of swarf!

Thanks for the interest.

R/C Model aircraft wheels a possibility??

Too plump, though some cars did use them. For the quick cars the slender 'knife-edge' design was more aerodynamic.

I might turn the wheels and use the black tyres off plane wheels, they are about 10mm section dia.

alternative is to use hard rubber section glues together to form a big thick 'O ring'.

Trying to kill cost here, so a good piece of nylon sheet may be the best and simplest way.

Has this thread REALLY had that many views? Maybe the counter is wrong..

Anyway, if true, nice to see.

Had a good quick go at the hillclimb Lola-Porsche today so all prepared for the races, and thus time on this little model.

Lots of parts arriving with the Post Man today and yesterday, the bonus was a bevel drive gearset for the rear diff. I'm trying to add some 'techie' things along the hap-hazzard way this car is 'designed' to (LOL!)

Lots of awkward machining to make things fit, more brazing (that did not go well) but progress.
The diff 'pinion gear' carrier is a repair washer now acting as the rear cross member until the body is done and needs mounting points.

Hoping my plastic discs for the basis of the wheels will arrive soon, that will be a challenge.
As ever, my 1922 Drummond lathe is invaluable and surprisingly versatile.

Still, pictures speak a 1000 words:







This bench has seen some stuff over the last 3 decades, I seem to have a working space now of about 800mm x 600mm

Love this on so many levels !!

https://www.youtube.com/watch?v=vkjnpgMjUac

That is seriously fast. I can’t see how they stopped it - when bobble-hat man picked it up it wasn’t going that fast - presumably they have to wait until it runs out of fuel?

Great aren't they?
When in short trousers I was modelling mad, but recall an article on these UK adventures in Aeromodeller magazine bought with my pocket money in the early 60's.

Amazing to me that a purpose built track was made here in the UK so many years ago.

It still continues today!

www.onthewire.co.uk

Some speeds were 200+ mph.

the internet is deffo tracking us all ... out of the blue yesterday I was fed some insta videos of modernist tethered cars going at 'speed of light' as they described it Nutty

After 4 days of acute PC security problems, it is time to update a bit on the car.

The discs arrived for the wheels so that is the topic of the post here. Glued 2 discs together to get the wider rear driven wheels and the skinny ones up front. Machined the 4 wheels with a taper to shape the wheels to an aerodynamic form using a bush off the one axle.
With gentle cuts this worked a treat, so all wheels the same diameter and form, but finish is a bit rough for now, though the pics shows the effect.

Talk about plastic swarf...the lather was covered, but all cleaned off ok for the next job.

Not yet pictured, but the engine is now coupled to the prop shaft and all bolted to the chassis.

I hope the brass screws will 'weather' quickly as they look too new.

Next step will be to find the material for the body which i hope will be a surprise.

Looks well engineered.

Do you know anywhere that you can run it?