SimHawk's motion simulator

[SimHawk]

Yesterday I got my valves and ran a few tests with a single speed setup.

The sim works in a way! ,but I was a little bit disappointed as I could not get the sim to follow the target value properly. With low pressure (1 bar) it was not able to follow fast enough and felt too weak to toss around my body. With more pressure 2-3 bar it is strong enough, but overshoots wildly and the result is that i am thrown from end position to end postition.

I also tried an air flow choke to regulate the cylinder speed. I suspect that it has to do something with that X-sim think it has three speeds and I have mapped all to the same valve output so far since I do not have air flow choke's for all valve inputs. Profiler think it uses slow speed and can shut off the valve just before the target is reached but the sim is going far beyond do to its single speed setup. I see there are settings for how far before the target value profiler shut of the valve on each speed.

Anybody has experience in tuning a pneumatic setup and could give me some info? I will try more tuning this evening.

[egoexpress]

For 3 speeds with 5/3 valves you need 4 of them.

[SimHawk]

I know. I do have four 5/3 valves connected and wired up ready for 3 speed setup, but because I lack airflow chokes that should be on two of them it would not work like intended. I'll try to make some air hose squeezers today to realize the three speed setup.

Another question:
I see that profiler do not follow the target value continuosly, but needs a motion on the target value to enable the valves. Is that correct?

And a last some pneumatic thoughts.
When I realized that reducing the air pressure made the cylinders go slower but also weaker, it struck me that regulating air pressure is not the same as regulating the air flow. It should be possible to run the sim on relativly high pressure to make it strong but regulating the air flow to get the speeds slow enough.
Kind of similar to voltage/current in electronics. Am I on the wrong planet here or do this make sense?

EDIT:
I found this on the web explaining the best way to control an air cylinder:

As a result, air flow into the cylinder ports at either end of the cylinder is totally unencumbered providing high-force piston movement. The piston is trying to go fast and at full power, but since the exhaust flow of air is impeded by the cylinder flow control, the piston moves with full power, but at a controlled and desired rate.

You can read it here:
http://searchwarp.com/swa78890.htm

I see that I have a lot to learn!
If I understand it correcly to get an optimal setup I should restrict the exhaust air out of each cylinder instead of the inlet air and do it as close to the cylinder as posible. That means that the t-split used to join the two valves (for each speed) should be located close to the cylinder and have seperate air hoses down to the two valves. I think I need to buy some needle-check-valves!

[SimHawk]

Here is a link to a collection of pneumatic knowhow:
http://www.about-air-compressors.com/flow-controls.html

Here is the valve one should have to control cylinder speed:
[img]http://www.x-simulator.de/forum/uploader/pool/flow-controls.gif[/img]

[egoexpress]

I see that profiler do not follow the target value continuosly

You can adjust the sensivity in the Profiler (smoothness). As well as you can adjust the speed range of every speed related to the offset values.

imho you should apply the chokes on the air-intake side.

Btw, if you want a higher airflow with lower pressure you need a 3/8" system or higher.

[SimHawk]

@egoexpress - thanks for the tip, I found the settings in the profiler.
Actually I want higher pressure and lower airflow. Strong, but not catapult speed.

[SimHawk]

A video of the first tests of my SimForce :
For some reason DiRT worked alot better than LFS due to a update rate of only 2Hz on the data sent from Force Sender and LFS. Here is DiRT :




What you dont see is that it do not follow the target very closely. I will look more into using needle-check valves to control speed so I can realize the three speeds. The video is showing only a single speed setup.

[egoexpress]

Cool

*hint* Without chokes you can realise at least 2 speeds

[SimHawk]

Without chokes you can realise at least 2 speeds

If I do not misunderstand I cannot with my setup. It is not restricted by airflow so opening one or two valves makes no difference. I tested both, but without chokes it is unnoticable difference in speed.

But what the heck - it was great fun even if it was not perfect!

[egoexpress]

I see that profiler do not follow the target value continuosly, but needs a motion on the target value to enable the valves. Is that correct?

Please tell me some closer what you mean. If it would be follow the target at any time, your seat would not stop shaking even when you are driving straight forward. Please note that Thanos' interface has 1024 speeds, and your pneumatic setup just 3.

Could you please make a vid of the Profiler calibration process. Does it calibrate properly and does your seat return to center after calib?