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Open Motorsports WantedI am in need of multiple sets of 36mm id springs 4" long multiple rates needed for develoment project. Rates needed between 500 and 800 lbs/inch
I still need springs!
36mm id springs needed
I am in need of multiple sets of 36mm id springs 4" long multiple rates needed for develoment project. Rates needed between 500 and 800 lbs/inch
I still need springs!
Last edited by Jnovak; 10.01.18 at 6:48 PM.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
When I saw 36mm I thought now we have metric sizing on springs then realized that this is less than an inch and a half.
Kind of like really big valve springs.
they are small and light. Ther is a small body Oleins shock for them.Originally Posted by Steve Demeter
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
36/37mm springs are used in the in-line spring/damper arrangements - horrible for producing frictions in the damper.
why are they worse richard?
Will it help to get the spring ends reground?
How about needles thrust washers on both ends?
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
The issue is leverage of the spring side loads against the damper internals - the piston band and the bushing in the body end cap - this arrangement is the worst layout for amplifying the effect of those side loads.
The squareness of the end coils is not the problem, though they can actually be purposely ground un-square a certain number of degrees to center the spring forces at a particular load, but you need the special equipment necessary to determine the angle and direction of the regrind.
The needle roller bearings do indeed help, but are addressing a different friction problem.
Is it because the torsion rod is so short? Seems the spring itself should have less moment than a larger ID spring, thus producing less side loading of the damper mechanicals.
Chris Livengood, enjoying underpriced ferrous whizzy bits that I hacked out in my tool shed since 1999.
sound like the mounting faces on the shocks are not parallel?
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
Nothing to do with that. It is simply a case of leverage from where the loading is located.
the spring mounting ends are concentric with the shaft. So how are side loads imparted to the shock?
I must be missing something!
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
The spring wire is being twisted as the spring is being compressed, and the load is transferred up the coil at the wire center line. this is true of all coil springs.
On our typical closed and ground end springs, the spring load is first applied to the perch at the point that the wire touches the cut end of the end coil.
Some of that load is then transferred around the face of the endcoil by the wire being twisted up into it, but it is not enough to equalize the load fully around that face. It is only when the load on the endcoil face is equal around its face that that the spring force is centered along the spring centerline - when it isn't, the result is an offset force.
As a result, the load "pierce point" ( the center of the load at the plane of the end coil) is actually centered about 1 inch or so beyond the cut end of the coil, and a bit inwards of ID of the coil, making the load center offset from the center of the spring. That point will vary a bit with spring design and the load.
With the two cut ends of the spring generally being clocked differently from one another, the pierce points at either end describes a load line that can go diagonally across the spring from one end to the other, or, if the clocking of the ends is just right, the pierce points can describe a force line that is close to parallel to the spring center, but still will be offset.
The only way to centralize the load is to allow the endcoils to flex until the load about their face is equal at all points, which is what my hydraulic perches do.
The machine used to test the springs and analyze these forces is made by Instron. It has two platens with load cells arranged to measure both forces in line with the spring center ( total load) as well as load cells arranged to record lateral loading on the platen ( three cells in a triangular pattern), with which both the level of lateral load and its direction are determined.
Richard the springs i already have are ground flat and parallel on each end. I would agree that if the springs were not ground flat there would be serious side loads. They look just like 2" or 2.25" springs just smaller and shorter.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
Ground flat and square does NOT equalize the load around the face of the end coils - never has, and never will.
Sorry, but those are the facts of life with springs.
thanks Richsrd i guess my question is: why are these springs worse than 2" springs?
Do you have your special perches for the 36mm springs?
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
It isn't a case of being worse than 2" or 2.25" springs (they both have the same issues). It is simply a case of where the spring side loads are applied to the damper. Simple beam loading calculations will show you why.
had to make some custom perches for an Indy teams a ways back who had some custom in-line dampers on the front of their car. The idiots who did the design somehow thought that they could use linear ball bearings instead of a sleeve bearing in the top of the damper, and get rid of those frictions. Unfortunately, the side loads were so high that the shafts would last only one on-track session before the balls compressed grooves into the shaft. The perches got rid of most of that issue ( there was room for only one perch at only one end of the spring).
The same dampers on the rear of the car, but with the springs surrounding the damper body as is more traditional, could go 3 on-track sessions before the grooves destroyed the shafts.
Again, it is simple beam loading calculations that will show you why - as well as torque moments at the endeye perch.
We have done 36mm and 37mm perches many times over the years (including just last month for the electric car designed and run by one of the top F1 teams, and a damper manufacturer for that series - see the picture below), but except for those we did for the Koni dampers on the older Infinity Pro cars, they have all been custom runs, meaning that we do not stock them normally.
What are the advantages and disadvantages of torsion bars instead of springs? They would seem to solve this problem? I think most F1 teams use torsion bars at the front presumably because space is at a premium. Just curious.
Yes, that is a big reason why they went to torsion springs - zero side loading on sliding surfaces. Same reason that they went to flexures instead of continuing with rod ends. We supplied a lot of the F! teams with perches before they all switched over to torsion bars.
Of course, they have the benefit of budgets that allow replacement of some of those things that will last only a couple hours on track!
Sorry, I'm not up on all of the terminology - what is an 'inline damper' vs 'spring surrounding the damper' (which I do understand).
Thanks
Gary Tholl
#24 BlurredVisionRacing
For a time at Williams we used rotary dampers, but being in the aero dept I never got a good look at them. They looked pretty trick though. Maybe they were one of those fashionable things that came and went!
'In Line" - The spring sits on the end of the damper body. Done usually for packaging purposes.
Rotary dampers - If i remember correctly Ferrari also had them for a year or two - Spax, If I remember correctly. Again, most likely done for packaging purposes, and most likely abandoned because of unfavorable trade offs.
Actually I think it was Sachs rather than Spax.
Yup, you're right. I could only remember that the name started with a "s" !
This turned into a technical discussion but i still nedd 36 mm id x 4" long spring. BTT
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
I still need these springs! If you have some please get in touch!
Jay
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
36mm ID Springs
I had mine made by D Faulkner in the UK http://www.dfaulknersprings.com/
The price was reasonable and It didn't take very long to receive them.
John
thanks John .i just sent them an email.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
Or you could order them from Hyperco and have them Tuesday.
At least they had them available the last time I checked.
when was that Fred? Will call monday
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
A couple months ago
Call Kelly Falls (Hyperco) - he might be wiling to do you a special price ( especially if they have any over-runs from the customs they do). 260-490-9931
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