Suspension program - Vsusp

[Rob7]

[quote="cheapracer"]Just a personal wish item, would like to be able to 'grab' a button that I could dynamically roll and bump together as one with my mouse.
Sounds cool, added to the list. This is for simulating the vehicle rolling around the RC instead of the center/bottom of the frame?

[Rob7]

........... Interestingly, Kogan, an Australian retailer, is now imposing a surcharge for orders placed through Internet Explorer 7. Because, as you've found out, it takes more effort to program things correctly for IE.

http://www.zdnet.com/blog/networking/au ... 7-tax/2496

Wait till Windows 8 and IE10 gets turned loose in the wild!

"Look maw, I've got a 30 lb [desktop] tablet with a 21" monitor!" And it has an on screen keyboard built in too.

hah, I do wonder about the usefulness of tablet PCs, especially for homebodies like myself. But it seems they're useful for taking pictures at rock concerts

IE7 definitely requires extra dev time. IE8 isn't too too bad. I'm thankful I don't have to support IE6 at my job - apparently IE7 was a big improvement over IE6 as far as following web standards.

[carguy123]

apparently IE7 was a big improvement over IE6 as far as following web standards.

Tee Hee, he said IE6, or any microsoft product for that matter, and following web standards in the same sentence.

[horizenjob]

Just a personal wish item, would like to be able to 'grab' a button that I could dynamically roll and bump together as one with my mouse.
Sounds cool, added to the list. This is for simulating the vehicle rolling around the RC instead of the center/bottom of the frame?

I think CheapRacer would like to watch the roll center move while a car is doing corner-entry/steady-state/corner-exit. So the car dives on entry, then maybe goes into a steady state and squats on corner exit.

This is what I am trying to study for the Car9 suspension. Let's leave discussion about why you might want different things for the suspension design threads and just say we would like it to be easy to use this tool for that here.

[horizenjob]

Here is an example of why I am uncomfortable using roll centers very much. It's sometimes convenient for conversation, but this type of result leaves with out much to say. This picture is a chart of Car9's front suspension roll center with about 2" of dive. So we are under heavy braking and about to turn in.

This chart would indicate odd things might befall us at this moment. It would probably be a bad time to be thinking about this anyway. In fact nothing extreme is about to happen.

[seattletom]

Rob, thanks for all your effort on Vsusp. Very impressive!
I've been using the Windows version of Wishbone for the last couple of months, and became interested in exploring Vsusp when this thread first appeared. I needed to change browsers, but got that done and Vsusp up and running.
I love Vsusp's graphical interface and its dynamic plots of multiple suspension settings. Making iterative runs using Wishbone and then plotting them is a huge PIA. Vsusp solves all of that but as you pointed out is limited to 2D calculations.

Steering/toe: To make the program show steering properly, I'd have to add a third dimension to the steering knuckle and also have the steering axis in 3D. It seemed like too much bad hacking to try to do that in 2D. The closest I could get would probably be to show how the tie rod end moves laterally in comparison to the steering axis during bump/roll .. hmm

So here's a wild thought for a 3D version of Vsusp: First, since you've been away from the forum for awhile, you may not be aware that the original DOS version of McDermott's Wishbone program viewtopic.php?f=5&t=1438&start=105 has been rewritten in visual Basic 6 by kf2qd and available here viewtopic.php?f=26&t=11985 I believe Peter has made his VB source available as well. Wishbone's strength is in its proven 3D math package that works out steering inputs and effects, anti-dive/anti-squat calculations and all the rest of the "normal" double a-arm geometry computations. And it's push-button quick for single iterations. But its one bump/roll/steer iteration at a time followed by manual data recording and plotting.

So here's my thought. What if the updated Wishbone math package were to be extracted and used as a 3D geometry engine behind an evolution of Vsusp's graphical interface to provide iterative 3D calculations from Vsusp inputs?
While I'm sure this would raise architectural and other issues, it would save you having to recreate a 3D math package and could shorten the flow to a fully funcitonal 3D Vsusp.
Just thinkin'...

Meanwhile, keep up the great work on the 2D package. It looks like a fantastic tool. And thanks again for sharing.

[cheapracer]

Sounds cool, added to the list. This is for simulating the vehicle rolling around the RC instead of the center/bottom of the frame?

Well presently you select how many degrees of roll, stop, leave it set at that, then go to jounce/bump and bounce it up and down at that set degrees.

I would like to shift the mouse left and right, stopping at any degree of roll and then shift the mouse up and down - all in one continuous motion.

I think your proggy is the first one that I can veiw some of my crazy ideas with

I wonder if people realise you can just save the website address to save your settings - that's probaly explained at the website but I don't read no steeekin manuals, dems for girly types!

[Rob7]

Here is an example of why I am uncomfortable using roll centers very much. It's sometimes convenient for conversation, but this type of result leaves with out much to say. This picture is a chart of Car9's front suspension roll center with about 2" of dive. So we are under heavy braking and about to turn in.

This chart would indicate odd things might befall us at this moment. It would probably be a bad time to be thinking about this anyway. In fact nothing extreme is about to happen.

Whoa, I don't recall ever seeing geometry that makes roll center height do that.

I'm midway through the fix for the 1mm roundoff problem. ETA is a couple days or or less

[Rob7]

I would like to shift the mouse left and right, stopping at any degree of roll and then shift the mouse up and down - all in one continuous motion.

I wonder if people realise you can just save the website address to save your settings - that's probaly explained at the website but I don't read no steeekin manuals, dems for girly types!

Good catch on saving the preferences using the url. I'm planning to update the project link box so it can optionally include the preferences there as well as include/exclude other parts of the project (control arms, knuckles, etc).

[Rob7]

Hi Tom, glad you're liking the app so far. Thanks for mentioning that Wishbone code I skimmed through it, and it looks useable and easy to understand. Kf2qd did a nice job. Yes, I think the math in that code would make it a lot more feasible to do a 3d vsusp. I'll look into the idea a bit later on, but that's pretty exciting. I didn't see any license on the code so far, but I'll ask before using

BTW, nice Ultima I've had Ultima-on-the-brain ever since I was lucky enough to get a ride in a GTR driven by Ted himself. Amazing car

-Rob

[horizenjob]

It would be nice if the graph settings were saved in the URL. We are using this to present our ideas and discuss problems in our suspensions. So having the chart settings in the URL would really help with that. Right now you can send or post the suspension easily, but then you have to describe the chart settings to use. I also don't bother to customize the scaling etc that much because I have to repeat it after I save it.

It's a good idea to make these things settable in the preferences too.

[seattletom]

Hi Tom, glad you're liking the app so far. Thanks for mentioning that Wishbone code I skimmed through it, and it looks useable and easy to understand. Kf2qd did a nice job. Yes, I think the math in that code would make it a lot more feasible to do a 3d vsusp. I'll look into the idea a bit later on, but that's pretty exciting. I didn't see any license on the code so far, but I'll ask before using

BTW, nice Ultima I've had Ultima-on-the-brain ever since I was lucky enough to get a ride in a GTR driven by Ted himself. Amazing car
-Rob

Rob, glad my idea wasn't too far off base. I've been doing some Wishbone crunching for Horizonjob on Car9 and have been envisioning a graphic front-end to the W/B math package for some time--passing input matrices with iterative roll/bump/steer settings to W/B and receiving output matrices back and then automatically displaying consolidated results graphically. I don't have the necessary programming skills, so have been doing lots of manual data transcription instead.
Hope the concept is useful to you at some point. I recall some (favorable) discussion of copyright issues re the original McDermott DOS code in the later pages of the original W/B thread. I recall kf2qd pursued this question a bit.

So you've met Ted Marlow. Yes, he also hooked me on Ultimas by drifting clockwise around those countryside roundabouts.
Mine was the second Ultima in the US. The first took a shortcut down the mountain during a Virginia City Hill Climb Driver walked away, the car didn't.
I still have my Ultima but want to do a "from scratch" build this time. An LS3 powered Car9 is where I'm headed. Then I'll have both beauty and the beast

[horizenjob]

Then I'll have both beauty and the beast

Some times it's coat and tie for the symphony and other times you just feel like putting on your leathers and swinging a chain around your head while your driving into town

What I think was done wrong on Wishbone is that the GUI and the math calculations are tied together. It would have been tremendously useful to me if the GUI ran a program to generate the results and then displayed them. Then people can write different GUIs.

What I want to be able to do is make 3D plots of the data that I request. This is like what CheapRacer is asking for too. A plot of wheel camber vs, bump vs, roll. Then you see the whole picture right away as a surface on the graph. The same with things like force angle vs. bump vs. roll.

I think to get the suspension right you want to be able to look at the second layer of effects. So how do things like camber, force angles, jacking weight transfer change when the chassis pitches from braking and accelerating while cornering.

I know I can plot these things on Linux/Unix systems. I'm not so sure about your web browser support package. If the browser can't do it perhaps there can be a chart option that was just a box of numbers I could cut and paste.

You're making good progress. I'm looking forward to the 1mm fix and some more accuracy for the measurements.

[cheapracer]

Just playing with it and I noticed my tyres went below ground when I moved the lower BJ closer to the hub - is it me or is there an issue?

[Rob7]

It's not you, it's related to a precision problem. Adding to the list of issues