Spring rates yz2
 

Hi

Does anybody know the spring rates for these new springs that have come out ?

Yatabe spring rates

This table does not contain the YZ2 spring. Have a look here, update done minutes ago: http://www.petitrc.com/reglages/Univ...pringChart.htm

That spring chart Philim posted above is not quite right. It's a hard thing to do and Arn0 has done a great job compiling it for sure. Modulus of elasticity constant of the spring steel was guestimated (for the Yokomo ones), and is different for each spring set..

TeamYokomo.eu have just released this measured one:

http://courgette.jml.net/~neal/RC/Yo...ring-Chart.jpg

I was working on one similar myself with the Gforce spring rate gauge, but they beat me to it ;-)

I'll try complete the older Yokomo springs to complete the chart.

Now you need to help me out Neal. I only deal in springs rates at lbs/inch.

When I stuck n/cm to lbs/inch into google and tried conversions, I definitely wasn't getting the right figures. Anyone tell me how to convert them? :thumbsup:

Yeah I was getting silly numbers too, hence why I've not published my table...
One thing is for certain the AE pound "lb" rating of their springs is a bit nonsense. It's a weight, not a force. They do not mean lb/in either? I figured I'd start with "known" ratings, and calculate/convert back from metric force to the "lb" rating. silly numbers.

I just figured I'd go with the N/CM scale of the gauge, and refer them all back to that scale.
http://www.gforce-hobby.jp/images/products/G0132.jpg

If you are going to add the 'older' Yokomo springs, measure the YS and YAS as well, because you don't know HOW (Probably using a GForce thing, but nobody knows.) Bjorn did measure. If you get ~the same results, it should be OK.

Cheers Neil :thumbsup::thumbsup:

Only just started running Yokomo for the first time with the YZ2, what's the difference between the different sets? I'm guessing it's the length of the spring?

Cheers
Chris

Yeh the Carpet ones are shorter.

Neal, please carry on with your calculations. Would still be good to see how the old Yokomo and the Associated springs fit in with the newer Yokomo springs.

i think the chart needs decimal point moving so front purple are 72.8 n/cm as that = 6.44 lb

Do you mean lb/in?

You may be right about the decimal point, but those readings (on the yokomo.eu chart) are straight off the Gforce spring rate gauge. I bought one, and I was wondering the same after using it. Anyone got a gauge tester?

OK, I pulled out the AE Yellow front spring, rated at 3.75lb (lb/in or lbf?) by AE.
Measured on the gauge gives a value of 6.227N/cm. Using web based unit converters these convert to 0.551 ib/in.
Moving decimal as you suggest gives 62.27N/cm = 5.51lb/in.
Clearly not the AE rated value of 3.75lb!
AE front whites = 3.30lb, measured 5.450N/cm or 54.50 = 4.81lb/in

Something is not right.

I only have AE spring sets with their "known" values, plus the Yokomo springs sets rated by colour.
I'm not sure I trust the AE ratings, given they are lb (mass), not lb/in (torque). Unless they mean pound-force (lbf) (force)?
Either way you can't convert a unit of mass or force into a unit of torque. Related, but different things.

Maybe the AE ratings are arbitrary, just like the colours. so it matters not what the actual values are only that they are heavier or lighter compared to the others in the set. This ties you into a set, and makes conversion between brands difficult and a bit of guess work, which in turn makes you go out and buy the full set.

I guess then the point of the spring rate gauge is so you can check your own springs for match, and to measure them all yourself so you can compare against that scale.

I will, even to justify the cost of the spring gauge to myself ;-)
It's a bit of spreadsheet hell, and I'm super busy at work right now, but I'll get it done soon as.
I've got original Yokomo bmax set, Yatabe arena set and the new Yokomo YZ-2 set, plus AE big bore set. It's a bit of a task with them all set out on the bench :thumbsup:

a comparison between the ae big bores and the new springs would be very appreciative from my self. They're what im planning to use so any reference to what the team drivers will use would be beneficial.

Neal, N/cm to lb/in is simply a case of multiplying the N/cm number by 0.571401

If you do that with the AE whites in your example you get 3.11lb/in ... now if the displacement on your gauge was only an effective 95mm then that would be spot on.

By effective displacement I mean that it is entirely possible that the first few mm are just "settling" everything down and not actually compressing the spring, this will be amplified if there is any slop in the plunger at all or the springs aren't dead straight.

To get around this I suggest you pre-compress the spring by a few mm (5mm would be fine) and make sure that when you displace your gauges plunger by 1cm it achieves the full 1cm of travel.

That way the numbers will be much more consistent.

When I tested AE springs on my work's tensile/compressive tester (£50k worth) they were with in 1%

Hope that helps

You are an absolute top lad mate :). At least that lets me stick them in a spreadsheet and get close now. :thumbsup:

Hi Roger, yes I can convert from N/cm to LB/in, thats easy as you say...

My point being with AE springs, they give the rating in 'lb' not lb/in or lbf. Which do they mean, as there is a difference, one is a force, the other a torque?

The spring gauge travel is exactly 10.0mm, hence N/cm. There is no slop, it's very well machined.
I position the spring compressed a few mm, zero the gauge, compress 10mm then read of result.

As I described above the results are way off AE expected, so either the gauge is junk, or something else is wrong?

It's not so simple Allan I'm afraid. Please be my guest and try it, and report back the numbers you get.
Convert the numbers from this chart to lb/in, but you still can't compare them with the AE springs (with AE ratings), until I measure them on my gauge as well.


I'll probably have to do all the yok and ae springs, get the results into a table and show both N/cm and lb/in on that, ignoring the stamped ratings from ae.

Did you happen to tabulate your results when you tested? I'd be interested to see that spreadsheet. thanks.