Cushion tester

[fierocious1]

I built this tester for testing cushion configurations. To test shapes, lengths and combinations of cushions to see what really happens during ramp up. I am currently using 3/4" long cone cushions instead of the standard SG .550 tall + cones. But wanted a way to compare in the ranges of resistance I skate in. Anyway, I am using a burned up electric motor for a stable rotating axis, a machined truck to attach cushions and a KP to. The arm is one foot long center to center for attaching a digital scale to. With the other tester, 25 degrees of lean is getting close to a usable limit. I have a degree wheel on there so cushions can be observed at specific lean angles.
Some pics,

https://www.flickr.com/photos/435057...posted-public/

https://www.flickr.com/photos/435057...posted-public/

https://www.flickr.com/photos/435057...posted-public/

https://www.flickr.com/photos/435057...posted-public/

A goal in this test is also to find a good amount of preload with extremely low ramp up. Awesome turning with stability at speed.
enjoy....

[quantoo]

your the only 1 experimenting with a cushion tester that i know of .
Is that an electric motor? and how do you adjust the amount of pressure/ rotation.
Is it synumeric?

[fierocious1]

Originally Posted by quantoo

your the only 1 experimenting with a cushion tester that i know of .
Is that an electric motor? and how do you adjust the amount of pressure/ rotation.
Is it synumeric?

The motor is non-funcioning. It is only used as the axis for the arm to rotate on. Soon as I get the tension arm made and installed, videos coming...
The arm is rotated, the truck moves with it, but the shaft(KingPin) and cushions resist rotation. A scale at the end of the arm will be used to measure the resistance. So I can move the arm, say 10 degrees, measure resistance in pounds or whatever. Move it another 5 degrees and check again. As the resistance ramps up, the poundage goes up. Surprisingly the yellows with cups just flat out gave up and were nearly crushed at 25 degrees. Give me a week or so and I'll have the tension-er/scale in place and working.

[quantoo]

Originally Posted by fierocious1

The motor is non-funcioning. It is only used as the axis for the arm to rotate on. Soon as I get the tension arm made and installed, videos coming...
The arm is rotated, the truck moves with it, but the shaft(KingPin) and cushions resist rotation. A scale at the end of the arm will be used to measure the resistance. So I can move the arm, say 10 degrees, measure resistance in pounds or whatever. Move it another 5 degrees and check again. As the resistance ramps up, the poundage goes up. Surprisingly the yellows with cups just flat out gave up and were nearly crushed at 25 degrees. Give me a week or so and I'll have the tension-er/scale in place and working.

Take your time im tying to merthfull.
The motor didnt seem to be connected up but it would be something i would use myself if it fit the bill quickly .not as if your selling a production run of these testers.

[fierocious1]

Originally Posted by quantoo

Take your time im tying to merthfull.
The motor didnt seem to be connected up but it would be something i would use myself if it fit the bill quickly .not as if your selling a production run of these testers.

Its like... hmmm I have low ramp up..... Yes but. Talking about it and proving it is rwo different things. In my spare time I'm building these tools. My friends that run cars a Bonnieville have a homebuilt waterbrake to test motor output. It sits in their shop, in a corner. When the time comes they put a motor on it to let the motor prove up modifications/changes to the already powerful engine. 700hp normally aspirated on an antique 6 cylinder truck motor is almost unbelievable.
Well, we can all talk about what our skates are capable of, but that doesn't necessarily mean that our mods are a good thing. So you chase a goal and then apply it in a test. Then apply it to the floor. Big difference.
A lot of cushion descriptions in the skate board industry are vague. What each type/shape is good for, strip away the unknowns.
Cushion shapes, heights and hardness help you control your skates, but not all skaters skate in the same places and types of skating.
I like carving through traffic and cranking up the speed sometimes. So Im out to find the limits of a well mannered cushion configuration for my application. So far I'm really liking tall cushion... so how far can I go cushion wise, where is my limit at?
Anyway. This tool will be able to actually show that binding can occur at much different plate angles. Then a person has better understanding because what you could not see while skating is now right in front of you.

[Tislord]

Following.

[fierocious1]

Radius plate mounted. It's function is to assure linear pulling force at the scale. Not shown is an arm that an eye bolt will used to put force to the scale. The eye bolt pulls the scale, the scale pulls a cable that runs around the radius plate, moving the arm. As the arm is moved toward the eye bolt mount, the cushions are compressed/distorted and trying to resist the movement. This resistance is measured on the scale. Since the center of the axis is app. 12 inches from the axis, the measurement will be in pound/ft.

https://www.flickr.com/photos/435057...posted-public/

Not long now! If I have enough time tomorrow, I could be finished....but my nice welding hood is at work.... not at home.... grrrr....!!! Maybe I can bear through it with a plain old backup hood... lol

On another project, I am already collecting parts for the wheel dyno. It will be a dyno, if I can configure the resistance to be read consistently. There are two ways to measure the roll of a wheel, timed or measure resistance. I was going for timed, but resistance measuring is only a step or two more involved.

[fierocious1]

Finally go it finished! Sorry for the mess around it, I am having to work indoors in a storage area we have. Using it right now for a makeshift work area.

This shows the completed mechanical linkage of the tester.
https://www.flickr.com/photos/435057...posted-public/

Tensioner arm and scale arrangement.
https://www.flickr.com/photos/435057...posted-public/

Radius arm and pull cable.
https://www.flickr.com/photos/435057...posted-public/

Truck/cushion/KP assembly. Kingpin rod is used as the fixed part that restricts and holds the cushions in place during the testing.
https://www.flickr.com/photos/435057...posted-public/

Indicator assembly. Photo is a little distorted for some reason. But as the cushion stack is assembled and compressed, I will be setting the arm to no slack movement. In other words no slop, snug with no flop in the arm assembly. Then the indicator is placed at zero, then everything lines up.
https://www.flickr.com/photos/435057...posted-public/
Thinking of putting a ball or something on the end for looking at the degree lines, but tired now and happy at least it works.

Interested in getting some readings in a few days. Going to gather up some various cushions to install into the tester, different shapes and sizes.

Anyway, just glad to have this one in working order now. I'm sure I could make a couple of mods but it is a working tester as is.

Ya'll enjoy!

[amohrfeld]

Now The real work starts. You'll have to take data for all the setups and plot them on a chart.

[fierocious1]

Originally Posted by amohrfeld

Now The real work starts. You'll have to take data for all the setups and plot them on a chart.

LOL, the suspense of it all!!! It won't take long to do it. I reworked the KP bolt from the first pic of it. The last pic shows it as pretty basic. Just unscrew the bolt on the end, just like a regular KP instead of reversed. I just don't have to lock it.
My goal is low ramp up with resistance in center position. Good control and not loose when centered up, easy low resistance lean over in the turns. Not going to be linear I don't think but lower pressures at 25 degrees will be nice. 25 is pretty far over but all the most used action happens at much less lean. So getting the sweet spot in between is really the goal. Also it has to be working in anyone's comfort level of hardness. If I can get my center up pressure to match my lean @ app 15 degrees, all will be well. My comfort level comes first!! LOL

The cushions should act similar on other than 30-46 degree kp plates.

But it's a combination, that is complicated. I still have one more thing to work with that has not been mentioned in a while. We were talking about the "floating caster axis" a while back. That needs to be proven as well. I change it on my skates during my tunes, but have yet to prove it with numbers. It is a minute shift. I think it can be proven but it will have to be done on the plate analyzer with a camera. Find the center point of between the cushions, fix an indicator to the truck or a mark, then set a needle at the mark to zero it. Swap cushions to see if the lean will move the truck off the needle setting. I can load the plates to any weight up to 600lbs. But 200lbs would work well I think.

This is about as far I think, as I need to go on plate and suspension testing. Any further would be just too much detail and the details that are like the difference between one bearing that is inexpensive and adequate vs a high dollar bearing.

Got to order more al bar....

[fierocious1]

Is clarifying why some people break trucks...... The fixed systems other than DA45-DA30s Just cannot take advantage of all this. Fixed system meaning that the KP angle never moves, has no curve to it. Yes you can average cushion hardnesses by using two different hardness cushions on a truck. No problem there, but you cannot take advantage of the floating caster tune, at all.

Using same physically sized cushions on top and bottom of the truck is a huge advantage in tuning(DA45).

[fierocious1]

As I stated the tester was done for cushion tests. I had some time to play this morning... :0

So a little test was done.
Issues, it is very hard to set up exactly the same for a cushion test so basically you have to look at a trend of values. Values being approximate. I repeated the pulls several times to clarify results. But it does show differences. I possibly will have to get a different scale in the future.
Values are approximate due to settling of the cushions and friction changes as they settle into place. Crazy to see the values change during the test.
Test1
Ok the setup, 1 yellow cone, 1 yellow barrel with cups, 1 small for the cone and 1 full size for the barrel.

5 degrees 26 oz
10degrees 55oz
15 degrees 96 oz
20 degrees 138 oz
25 degrees 212 oz

Test 2
Same as test one but with washers no cups other than built into the truck itself.
5 degrees 26 oz
10 degrees 55 oz
15 degrees 93 oz
20 degrees 122 oz
25 degrees 182 oz

Test 3
Triple cone set up. 2 yellow cones applied to the truck on both sides + a purple cone simulated against the plate. But actually a stack against the large nut, just as I had on my previous test skates the White Magnums. This amounts to a 1" stack between the truck and the plate. I feel that if I had ran a 3/4" cushion on bottom of the truck, the pressure results would have been even lower. Results....

5 degrees 21oz
10 degrees 48 oz
15 degrees 81 oz
20 degrees 117 oz
25 degrees 164 oz

There is more urethane to give way to displacement in the 3rd test but also the numbers are lower at the far end of the range. Usually we don't skate this deep in a turn, it's more like between 10 to 20 degrees of plate lean. Edit: depending on caster angle you may skate deeper or shallower in plate lean degrees.

Anyway there it is. A yellow vs triple cones. Enjoy

[Mort]

That's really cool man.

I find it interesting that 10 deg has little change and as you crank it over, the numbers really show a large difference.

Care to edit the above post and put down 2 full size barrels as well? With cups, and then with washers?

Maybe Mic the "compression" you are using by measuring the height of the total stack of the parts just held together by hand, and then with a snugged action(zero lash). Ya know just for reference. It would be good data to have.

Or using a small inch pound torque wrench to set the torque of how you tighten the kingpin nut.

Hey , now you can see the real numbers of the effect a lubricant(car suspension grease) makes. Ribs to the truck lol. I think the coefficient of friction between the truck and the cushions is important. It can prolong the life of cushions if kept low. Possibly allowing the skater to user slightly firmer cushions for better stability while keeping ramp up in check.

Very interested in future numbers from all the setups.

[fierocious1]

Originally Posted by Mort

That's really cool man.

I find it interesting that 10 deg has little change and as you crank it over, the numbers really show a large difference.

Care to edit the above post and put down 2 full size barrels as well? With cups, and then with washers?

Maybe Mic the "compression" you are using by measuring the height of the total stack of the parts just held together by hand, and then with a snugged action(zero lash). Ya know just for reference. It would be good data to have.

Or using a small inch pound torque wrench to set the torque of how you tighten the kingpin nut.

Hey , now you can see the real numbers of the effect a lubricant(car suspension grease) makes. Ribs to the truck lol. I think the coefficient of friction between the truck and the cushions is important. It can prolong the life of cushions if kept low. Possibly allowing the skater to user slightly firmer cushions for better stability while keeping ramp up in check.

Very interested in future numbers from all the setups.

There is so little difference at the starting point. Snug gets it done. But after 15 degrees things start happening. The nice thing about this set of tests is that I can put more pressure at centered, but not ramp up as much. Just like I had been indicating for several years. Now, there is the proof.
The stock with cups is fine for derby, they like v plows and need to be able to force the wheels to break loose. But triple cones, break an ankle....
More testing coming, but as I have time for it.

[wired]

Very nice!

It's a bit easier to follow if the pics show up here.

Originally Posted by fierocious1

Finally go it finished! Sorry for the mess around it, I am having to work indoors in a storage area we have. Using it right now for a makeshift work area.

This shows the completed mechanical linkage of the tester.
Truck putting pressure on the yellow set of cushions. Also shows radius arm in play. by fierocious1, on Flickr


Tensioner arm and scale arrangement.
Tension gauge and adjustable pull rod to set the angles. by fierocious1, on Flickr


Radius arm and pull cable.
Pull cable leaving the radius as the angle is increased. by fierocious1, on Flickr


Truck/cushion/KP assembly. Kingpin rod is used as the fixed part that restricts and holds the cushions in place during the testing.
Pull cable leaving the radius as the angle is increased. by fierocious1, on Flickr


Indicator assembly. Photo is a little distorted for some reason. But as the cushion stack is assembled and compressed, I will be setting the arm to no slack movement. In other words no slop, snug with no flop in the arm assembly. Then the indicator is placed at zero, then everything lines up.
Adjustable zero angle indicator. by fierocious1, on Flickr

Thinking of putting a ball or something on the end for looking at the degree lines, but tired now and happy at least it works.

Interested in getting some readings in a few days. Going to gather up some various cushions to install into the tester, different shapes and sizes.

Anyway, just glad to have this one in working order now. I'm sure I could make a couple of mods but it is a working tester as is.

Ya'll enjoy!

I am!

Flickr has a right pointing arrow at the bottom of their interface. Click on that and select the BBCode option and copy/paste the result in your text (no need for clicking the insert image icon here since all the wrapper code has been done by Flickr.

I'm looking forward to more pics and results!


.

[amohrfeld]

Lloyd,
First, this is great info.

It actually confirms my thought about the second cone: The cone closest to the truck does all the work - squishing against the king pin and not the second cone. Obviously the second cone squishes some but a lot less than originally thought.

Originally Posted by fierocious1

Usually we don't skate this deep in a turn, it's more like between 10 to 20 degrees of plate lean. Edit: depending on caster angle you may skate deeper or shallower in plate lean degrees.

Anyway there it is. A yellow vs triple cones. Enjoy

So what you are saying the the washer vs cup makes little difference. Don't tell Doc that.

[fierocious1]

Current setup
5 degrees 24oz
10 degrees 44 oz
15 degrees 72 oz
20 degrees 95 oz
25 degrees 130 oz

Stock yellows with cups
5 degrees 26 oz
10degrees 55oz
15 degrees 96 oz
20 degrees 138 oz
25 degrees 212 oz

[fierocious1]

Originally Posted by amohrfeld

Lloyd,
First, this is great info.

It actually confirms my thought about the second cone: The cone closest to the truck does all the work - squishing against the king pin and not the second cone. Obviously the second cone squishes some but a lot less than originally thought.



So what you are saying the the washer vs cup makes little difference. Don't tell Doc that.

The cups vs washers does, it's a small start in the right direction. I would never recommend any of this to beginner skaters. But to seasoned veteran skaters, I can make your day!

[amohrfeld]

Originally Posted by fierocious1

Current setup
5 degrees 24oz
10 degrees 44 oz
15 degrees 72 oz
20 degrees 95 oz
25 degrees 130 oz

Stock yellows with cups
5 degrees 26 oz
10degrees 55oz
15 degrees 96 oz
20 degrees 138 oz
25 degrees 212 oz

That is a more significant difference. If true in application, I'm sure you could feel the difference.

[fierocious1]

Originally Posted by amohrfeld

That is a more significant difference. If true in application, I'm sure you could feel the difference.

You can, the best part is stability at speed. The skates don't wander at all, but will break over in a heartbeat without the forced feeling. They respond. I always felt years ago when I started this that there was no reason for all this resistance as you cranked over. If you can handle soft cushions straight up, you should be able to handle them leaned over too. I just wanted things to work the way I wanted them too. 2 modified plates and one custom plate later, It shows. And you cannot rush testing, getting used to what you have done so you can prove to yourself that it is an actual improvement. Like I have a bit of preload now that I would not have ran before, but that's OK because I can break over the plates and not ramp up like crazy.
The other thing is, there are not two parts to tuning a DA45 but actually 3 parts to it. That is why it takes so long.