Corner Weight Scales

[Slipper man]

Does anyone know any corner weight scales near Caterham that I can use? I don't really need to pay someone to set it up, but it would be good to get the corner weights set up, and the geometry set up correctly.

[Shep7]

Have a look at PGM 's website,Andy will do this for you,at a price of course .

C7 EVN ,

Les S.

[Slipper man]

Who is PGM? Is that Andy Belcher?

[7 wonders of the world]

Get down vto B&Q and get 8 bathroom scales, 2 per wheel with a piece of ply bridging them,

Find a level place in the garage, correct with shims if necessary,

Ballast the car as required

Knock up a spreadsheet in excel and away you go.

Simply, cheap and repeatable

[Shep7]

PGM has an advert top right at the top of this page and in Low flying.

[Mark Durrant]

I can highly recommend Andy Jupp at Partridge Green Motorsport, Nr Horsham, West Sussex. He has set up my Busa Superlight including corner weighting, laser alignment, shimming the De Dion ears etc and the car handles perfectly

[Simon.Rogers]

No more excuses then 

By the way agreed just take it to Andy.  You know it will be right!

[Mark Durrant]

Simon

Given the result at Curbs are you visiting Andy on route to Gurston

[raydoc]

For the last 10 years, I have used 4 off 180kg bathroom scales to set up my hillclimb Supersprint  - 250 bhp Vx .

I created a flat floor by creating 4 epoxy cement square wheel pads c. 300 mm square and 4 more chassis height  measuring pads c.150 mm square on my concrete garage floor.  I used a long spirit level to get all 8 pads level to +/- 1mm. Suitable Salter scales can be sourced for c. £20 each which are ideal - thick glass top with digital readout. I also load the driver's side with a stack of plastic storage boxes filled with water and totaling 94 kg (my weight in racing kit + my foam seat).  I use a hydraulic jack on each corner in turn, letting the jack down slowly so the damper does not  temporarily support any of the car weight.

I use this set-up to measure corner weights and ride heights.  Perfect corner weighting is impossible with driver only in the car.  I find it best to go for the ride heights and a rake of 15 mm / m as Caterham recommend.  I find both fronts and rear left corner weights come out around 140 kg and rear right about 170 kg.  Currently, with lots of light-weighting, my car weighs 492 kg (ex driver and fuel) and around 590 kg on the start line.

If any of your corner weights exceed 180 kg, I believe that 250 kg digital bathroom scales are coming available!

[Ed White]

I used to use the bathroom scale route years ago. If you struggle getting ones with a high enough rating, try ebay for the USA  :)

[Roger Ford]

Amazon have loads of electronic scales which will go up to 180kg, but as I recall the problem with using electronic scales is that most automatically switch off after a short period. Does anyone have a recommendation for scales which don't do that, or a workaround for it?  Switching them back on would be OK, so long as they don't automatically zero themselves when switched on.

[Mankee]

These apparently have programmable auto-off features:

http://www.ebay.co.uk/itm/251855329150

http://www.ebay.co.uk/itm/141817300935

[ECR]

180kg would be uncomfortably close to max for my boat anchor ....

[Slipper man]

... but not for mine, unless I have been spending too much time eating Barbara's excellent food!

Still, booked in next week with Andy at PGM, so we will see how it feels after that. Oh yes, and a set of Meteor Moteorsports Nitrons...

[ECR]

Well I've got a new battery so there !

[Slipper man]

Does that offset the effect of the over indulgence in Barb's cooking then?

[ECR]

On a more serious note, I made a set of these to work with very cheap mechanical scales. They reduce the scale reading by 50% and remove any possibility of the scale mechanism jamming due to sideways thrust. The plate on which the tyre rests is mounted on a bar which is free to self align and the bar is exactly halfway between the scale contact point and the floor contact point .A gentleman by the name of Ruggles apparently concieved the idea ....

The scales don't need to be particularly accurate, as long as they are all equally inacurate (IYSWIM). That can be checked by placing the same weight on all 4 corners and adjusting ...

[Roger Ford]

Sounds interesting, but can't see a thing in that photo. Have you got a larger version?
 

[ECR]

Try that. I have some drawings I can forward if this is not clear

[Roger Ford]

Got it. That's pretty neat but beyond my welding skills - and no doubt having a set made up wouldn't be much cheaper than getting a full set of proper race scales.

[7 wonders of the world]

Making the scales less accurate kind of defeats the object of the excerise.......

I did mention previously I use simple salter analog scales two per wheel with a bridge, so they are working in the middle of their range.

As for slip plates simply slice a tesco plastic bag down the sides fold in half and ly on the bridge under the wheel and you have a very effective slip plate for a mere 5p.

Consistently repeatable readings can be obtained this way - and repeatability is the key to any set up kit.

 

[ECR]

Well, not really, The object of the excersise is a comparison between left weights and right . the absolute weights are not that important as long as the the percentages left to right/front to rear are very close.

The readings on the scales are interesting but not critical its the comparison left/right that's  critical

[Simon.Rogers]

Just use a tape measure and set the ride heights equal.

I have proper scales and always start off with a tape.  Very rarely need to adjust much after that.

[Dave J]

here's my method from way back in 2008 !!

http://www.lotus7.club/forum/techtalk/settin-adjustable-platforms-without-scales

 

[Mankee]

I used Simon's and Dave's tape measure methods (cheers lads) when I fitted the Nitrons a few weeks ago. And when I borrowed some scales to check it, it was 49.96%/50.04% across the diagonals. I'm no driving legend so I would never have noticed that 0.04% deviation. And it all gets knocked around when you start carrying passengers and have different fuel loads anyway.