Spring chart - Unsure how accurate?
 

http://www.petitrc.com/setup/yokomo/...ringsChart.pdf

As per the above spring chart, i was a bit dubious about the rates of the kit rear green and front orange as they felt heavier than quoted.

My friend who measures springs checked them and got the following:

Green rear 2.78lbs
Orange front 4.56lbs

That is absolutely miles from the 2.05 and 3.17 quoted on that chart. Even more confusing is my manual states that the kit springs are both blue front and rear?

I am hoping the Yatabe springs on the chart are closer. Anyone else any similar experiences?

I have asked my friend who measured the rating to post his method here as I am sure you may want to analyse it.

EDIT: Could it be that the new kits now come with the Yatabe springs anodised in black as that would be far more accurate? The reason I never gave this any thought previously is that the kit springs are black and the yatabe springs are that bronze colour.

I think the spingchart is no good. With all respect to the makers.

I have a few sets of yokomo springs. I recently bought some Yatabe springs.
I noticed that the Yatabe springs are not an extension of the Yokomo spring set.

The Yatabe set is a set on its own.

For example, Front Yatabe Yellow is noticably softer than the front yokomo blue and even orange.

Same is for the rear sets.

PS i posted about this issue some time ago.

Some chat about this on another forum,they have found the same,someone does make a spring lb tester but I can't remember who :confused:

Spring Gauge tester

[Click link]

That's the badger :)

Sorry mate, I had a quick look but didn't spot anything. I am glad others have noticed this as well. It's just nice to have a gauge as with my old cars, I am used of knowing the ratings etc.

I'm waiting to get the gforce spring gauge, and will redo the data for the chart. The chart is calculated based on measurement and assumptions, and it is wrong.

Really do appreciate the effort that has gone in to making that chart, and the effort that its going to take to "fix" it. :thumbsup::thumbsup::thumbsup:

As do I :) :thumbsup:

If someome is able to measure all springs and provide me the value, the chart on petitrc will be corrected.

My G Force Spring rate Gauge has arrived :thumbsup:
http://courgette.jml.net/~neal/RC/gforce_rate_gauge.jpg

Now to begin measuring...

Looking forward to the results mate and appreciate the effort. :D

Do you have all Yokomo springs or should I send you mine?

Neil

Would testing the associated spring which have know lb rating, establish a good base line on how accurate the gauge is?

Kind Regards

Sammy

Hi Sammy, that's the first thing I've tried to do. Had no real time since i picked it up on Saturday afternoon, but every pair of associated springs I've tried had had different values. I've tried tried two pairs of ae blue springs, each was different from the others. I
I've tried another pair also, whites again different to each other and not close to the rated value. Either that means the ae springs are vastly inaccurate, or rated values change with use, or the gauge or procedure is inconsistent? I need more time with it and excel.

hmm sounds like the ae spring aren't matched and use a wide tolerance. Have you got an unused pair in your box? Just to eliminate fatigue causing inconsistent values.

Do Tamiya or Hpi X gears do a set of springs with a known rate on them.

The Japanese part should have better QC if they are made in Japan

Regards Sammy

This seems like the exact opposite of when I measured AE springs, they came out almost as consistent as the Xgears ... almost ... and WAY better than Losi or Durango.

I was using a £50k test machine at work by the way.

You need to make sure all springs are pre-compressed a little bit first and to the same amount, the program on my machine sets the starting point to the compression required to generate a load of around 0.0375N (about 368g ... roughly the corner weight of 10th buggy) - zero the reading then compress a further 5mm, 10mm, 15mm - plot the best fit line through the points and read off in N/mm - finally convert to Kg/cm 7 lb/in.

Try something similar.

double post, sorry

sure, like i said i was just playing it initially, not had a lot of time to get serious or consistent results . device allows for 5mm and 10mm compression testing.