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Old 02-24-2010, 07:41 AM   #901
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Hi Jilles

how is your salad and what have you orderd for main??
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Old 02-24-2010, 07:57 AM   #902
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jilles,

are progressive springs a myth or a fact? I've been playing around with one of those integy spring measuring devices and so far have found most springs to be near enough linear especially in the range from 0 to 5mm compression.
also I read around on the internet and have seen brands springs been called both.
so have you found any and if so which?
and what would be needed to make a spring progressive according to you?

oh good luck at the titc of course!

thanks
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Old 02-24-2010, 11:47 AM   #903
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Hi Jilles..

Do you have a good ground setup for the Tamiya TRF 416X car (rubber)


//Söberg
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Old 02-24-2010, 12:02 PM   #904
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Originally Posted by tomracing View Post
jilles,

are progressive springs a myth or a fact? I've been playing around with one of those integy spring measuring devices and so far have found most springs to be near enough linear especially in the range from 0 to 5mm compression.
also I read around on the internet and have seen brands springs been called both.
so have you found any and if so which?
and what would be needed to make a spring progressive according to you?

oh good luck at the titc of course!

thanks
A real progressive spring will typically have a set of normal coils, and a set of tightly packed coils. Tight coils function as normal in the first part of the spring stroke giving the spring a softer rate. These coils quickly bind up, leaving you with only the normal coils functioning. This in turn causes the spring rate to instantly rise. Sometimes you'll also see two different coils stacked on top of eachother, of varying thickness, which provides the same effect.

Typically you find progressive springs on passenger cars where a soft inital rate is desired for ride quality. The idea is that when the car turns, the springs will stiffen and support the car better through the turn allowing the driver to feel more confident. Unfortunately sudden spring rate changes also can also cause sudden loss of traction, which resulst in weird handeling characteristics. Typically on-road racing uses linear rate "race" springs (unless conditions demand otherwise).

Here are some progressive spring pictures:







What I find really interesting is what they refer to as a digressive spring setup. A digressive spring setup consist of two separate coils stacked on top of eachother (like shown above). The trick here is that the secondary spring has been preloaded and shackled to a predetermined weight. This causes the shackled spring to cease to function until it's preload is overcome by the suspension load. Once that happens, the spring rate will actually drop (because the secondary coils begin to function). The only time I've heard this setup was used was to allow DTM cars running on tight street courses to hop curbs without destroying the suspension or upsetting the handeling. Of course the real trick is to get everything setup just right so that the springs won't suddenly soften up during normal driving conditions.

Here is the only picture (from Eibach) of this setup in place that I've ever seen. It nicely illustrates the secondary spring shackle:

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Old 02-24-2010, 03:42 PM   #905
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Good, more evidence to prove that progressive springs in R/C are a myth.
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Old 02-25-2010, 03:50 PM   #906
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Hi Jilles,

How are you ?

What do you have to change on the setup on your car when the track is wet ?

Droop, camber, etc...

Regards,
Manu
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Old 02-25-2010, 03:59 PM   #907
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Good, more evidence to prove that progressive springs in R/C are a myth.
TBH, I wouldn't call them a myth... certainly they aren't true progressive springs (much like we aren't using true CVD's, mostly)... however I do have some charts that Ling Tong produced that do show a difference in the loading curves of different springs, and it's easy to spot that some are completely linear at inital load, whilst others have a distinct curve to them. It's not huge, but in the inital loading range is where the initial feel of the springs changes...

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Old 02-26-2010, 02:23 AM   #908
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I have some very old HPI Progressive Springs, I think they were available when the Pro 2 Came out.

And my Tenth Technology Predator DTM has the Digressive Spring Setup.

So the Mythical beasts do exist.
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Old 02-26-2010, 08:03 AM   #909
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Quote:
Originally Posted by Manu_05' View Post
Hi Jilles,

How are you ?

What do you have to change on the setup on your car when the track is wet ?

Droop, camber, etc...

Regards,
Manu
i think jilles is busy with TITC this weekend, so i doubt he will be posting anytime soon.
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Old 02-26-2010, 09:29 AM   #910
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hey jilles

Well done today at the TITC

what M chassis were you running ??

whats your set up ???
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Old 02-26-2010, 10:35 AM   #911
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Hey Jilles,

Well don in the mod and the mini.

I hope it will come on you tube so we can see it.

I think that he uses a M-05 chassis Phil.
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Old 02-26-2010, 12:30 PM   #912
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Quote:
Originally Posted by sidecarphil1 View Post
hey jilles

Well done today at the TITC

what M chassis were you running ??

whats your set up ???
one page back...

http://www.rctech.net/forum/7022348-post891.html
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Old 02-26-2010, 01:18 PM   #913
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thanks
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Old 02-27-2010, 12:11 AM   #914
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Hi Jilles,
a few companies are starting to make LiPo based chassis for the 416, any idea when tamiya will be bringing one out? cheers, thanks for taking the time to reply.
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Old 02-27-2010, 07:59 PM   #915
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i been asking the same on the lipo tray for tamiya long ago... but none of the tamiya agent can answer that...

to make things simple just tape it n put some bars for balancing.
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