calculating angle of simulator movement

Howdy all.
Heres a brain tester. And before I hear a its a brain trick in motion, I know that.

I can calculate the angle of lean of a simulator from pivot to motor connection, especially if the motors are mounted underneath, like 99% of my builds.

Foot motor sim is 650mm from centre of pivot to motor connection. Approximate angle up and down is 8 deg total. Based on a throw of 80mm.

Actuator sim is 400mm from centre of pivot to motor connection. Approximate angle up and down is 14 deg total. Based on a throw of 70mm.
Now the base of the sim is longer than the actual mounting of pivot.
Actuator sim base is total 120cm from memory. And the top of the seat is 90cm ish.
So, in that case, would the angle of the sim be more at the top of the seat or the end of the frame, as I am only measuring a small part of the base?

I am not sure how to calculate this as most online tools dont really allow for such things, unless I am looking at the wrong site.
Any ideas?

Not sure if being helpful or total noob

but...
Have you looked at the 'Motion Platform Designer' software?

I had a play a few weeks ago and it answered a few of my questions.

Hello st8smn !

Are you talking about this ? http://fly.elise-ng.net/motionplatformdesigner
licence 70€

>I had a play a few weeks ago
did you buy it ? or is it possible to have some tries as shareware ?

nope, havent seen it, is there a free version?
I dont particularly want to pay a heap for something I need to work out quickly.

That's the one guys, I didn't pay any money I found a free trial somewhere.

I have the free trial saved on my pc here but ill look into it and see if I can find it on the webz for ya's

I found it useful for me , it may or may not be for you ?


EDIT-- if you just click download on the page mentioned above it will d\l , unzip , install as per usual and ....BAM..... 30 day free trial

Ok, thanks, I will give it a look

OK, If we have a pivot to motors of say 400mm and a motor lever of 50mm, the angle would be about 7 deg.
But that’s at 400mm. If that measurement was at the full length of frame, say an extra 600mm as the very back of the frame is not on pivot, the lift from centre is about 110mm. And that’s the base.
So the head of the seat it leans about 130mm, and that’s one way so up and down the head of the seat would move about 260mm for back to forward. And that’s allowing for a seat height of about 850mm.
If that makes sense, a 100mm total lift from very bottom to very top give is a heck of a lot of movement at the head, where the feeling is.
I have done a quick sketch to explain.
14-15 deg total angle may not seem much, but at your head, it’s a lot more than you think, same at your feet. Hope this explains angle a bit better and the actual degeree of movement on a sim frame.
Its that the idea?

Ok my unit, Im running a 50 mm lever centre, and using 80mm of vertical travel, which equates to 108 deg of movement used.
Now when the levers all the way down it rocks the sim at the shoulder height down 32mm and when the lever is all the way to the top we actually move 48mm forward, this is due to the way the frame is built centre of rotation on the base is 70mm higher than the pivot. This will change this like this. In all its a 2.5deg pitch back and 4 deg pitch forwards, totalling 6.5 deg of total pitch. Now this can easily be changed by using longer levers but longer the lever the more torque the motor need to achieve the same speed as the shorter units, as in angle not distance. Now you might think that this is not much movement but at speeds between 500-650mm/sec this is can be very violent, fooling the brain in thinking you are being tossed about, For example (don't laugh), if I happen to be leaning forwards concerntrating of where I m driving, and pounce over a jump, the resulting movement of the chair throws me back and then the seat slaps me hard in the head and it returns before my body as actually stopped, ouch. In heave vibrations in software and pitch changes if the ground is rough I can not even manage to speak clearly due to the seat winding the breathe out of me. The movement is a real F*@kme what am I on, now imagine this at 40 -50 deg total , well you not going to be able to drive, or have any chance of being able to focus on a screen

Below pic is a side view showing my seat mover with motor arm centre shown, 50 mm lever using 108deg (40mm up, 40mm down)

Hi bsft,

Is this what you are trying to calculate?



If the seat is driven at point A. Let it be distance X from the pivot and it rotates distance A around the pivot.

Then another point on the seat (doesn't matter where) called B that is distance Y from the pivot will rotate distance B around the pivot.

Distance B is calculated: B = A * Y / X

Hello Rufus, I think I buggered up the question in the first place.
Yes, thats more what I am looking at of which I think I figured it out.
I know the actual travel of distance at the motor connection is not much, but the distance of travel, as your pic says in B , is more what I was trying to achieve. I think the angle is the same, just the travelling distance is greater making us driver think we are moving at a greater distance of throw.

I need more caffeine......

:?