SFX 100 question: lifting feet?

[Dutchlincoln]

Assembled the rig the day before yesterday. The longitudinal center-to-center distance between the actuators is 94 centimeters.
Start at 1200 rpm.
What is striking is that with vigorous movements the front feet regularly come off the floor, both left and right.
At 3000rpm it is the same.
I just saw that the rig was leaning back to the left (car was driving up a hill) and then the right front leg went off the ground, towards the ground, and off the ground again, while the rig itself was not moving. (was only half a second max. or something) It cannot be the case that the engine at the rear left was not powerful enough? If you want, it moves violently, so I guess it's not.
Anyone have an idea?

 

[ThugUK]

You have 4 independent actuators on a rigid frame.
Each of these actuators receive independent messages to rotate left/right (raise/lower), that corresponds with how the road surface is mapped.
So if the front left wheel goes over a bump, the front left actuator will raise.
Due to the frame being ridged it doesn't flex, so your front left actuator will raise off the ground whilst the other remain on the ground.
This is more likely to happen with the front, due to more weight being on the rear.

In a real car this isn't an issue as you have suspension making sure that all wheels are on the ground at all times.

Hope this makes sense.

 

[Dutchlincoln]

Hello Sarge,

What you explain here, makes sense indeed, but!!: as you say yourself, a car has suspention (and shock absorbers); this rig hasnt. My tiled floor isn't going to like this rude treatment in the end i guess.

I my only assume that the telemetry is sending sigals to move a "rig" in a certain direction, at a certain speed, and not just each wheel represents an actuator.

If this would be true, there would be a horrible issue when using a 6dof rig; the actuators mounted rigid on both sides would literally tear each other apart at the end...

Maybe you are right, as i have no clue how the programming has been put together, but mu logics would state it probably works a little bit different.

Actually, i think i need to put the ctuators a little further away from eachother, wich would result into a tad smaller diagonal angle, thus keeping the foot on the ground. It would slightly reduce the effect also, but thats the tradeoff.

Are there people who had this issue as well? How wide are your actuators placed from eachother?
Maybe some ppl that dont have this issue can merasure the front-rear distance of their rigs and share the info?

Thanks so far, really appreciate the input and thinking.

 

[ThugUK]

Mine are exactly 100cm between front and rear (middle to middle) which is recommended.
I still have one actuator leaving the floor every now and the , there is no avoiding it.
I don’t think yours would make that much of a difference.
I am sure the telemetry is taken from the road, so its bound to end up with one of the actuators leaving the floor a number of times.
You need to put it onto some rubber matting (I use gym matting triple thickness) to protect your floor.

 

[d69morpwr]

Assembled the rig the day before yesterday. The longitudinal center-to-center distance between the actuators is 94 centimeters.
Start at 1200 rpm.
What is striking is that with vigorous movements the front feet regularly come off the floor, both left and right.
At 3000rpm it is the same.
I just saw that the rig was leaning back to the left (car was driving up a hill) and then the right front leg went off the ground, towards the ground, and off the ground again, while the rig itself was not moving. (was only half a second max. or something) It cannot be the case that the engine at the rear left was not powerful enough? If you want, it moves violently, so I guess it's not.
Anyone have an idea?

View attachment 403983

Go back and double check all the motor driver settings. My guess is you missed one. I had the same thing happen.

 

[Dutchlincoln]

https://vimeo.com/user122795052/revi...438/1d5475314d

https://vimeo.com/user122795052/revi...819/d3f51eea29

https://imgur.com/a/hKPHhDa

 

[Dutchlincoln]

Go back and double check all the motor driver settings. My guess is you missed one. I had the same thing happen.

checked all settings, and missed one indeed, but even when corrected, the result is the same...

is there a way to restore to default?
maybe theres an other setting of which i have no knowledge, thats off? And there are so many, to check them all.... :-

 

[Dutchlincoln]

Mine are exactly 100cm between front and rear (middle to middle) which is recommended.
I still have one actuator leaving the floor every now and the , there is no avoiding it.
I don’t think yours would make that much of a difference.
I am sure the telemetry is taken from the road, so its bound to end up with one of the actuators leaving the floor a number of times.
You need to put it onto some rubber matting (I use gym matting triple thickness) to protect your floor.

thats a good advice, thanks. I will go look for it. At least now i know im not the only one.

still think it shouldnt though. Also helpful to know the with between center of actuators, thank you.

 

[mechsicko]

So far the only examples I've seen of sfx lifting a leg like this have been running SimFeedback unless I'm mistaken. Does anyone know if PTFlyer or SimTools does the same thing?

 

[d69morpwr]

So far the only examples I've seen of sfx lifting a leg like this have been running SimFeedback unless I'm mistaken. Does anyone know if PTFlyer or SimTools does the same thing?

I can tell you for sure simtools doesnt do that ever. Even running the roller coaster game at 100 percent it never lifted a leg.

 

[d69morpwr]

checked all settings, and missed one indeed, but even when corrected, the result is the same...

is there a way to restore to default?
maybe theres an other setting of which i have no knowledge, thats off? And there are so many, to check them all.... :-

Yeah its a pita but you need to check them all unfortunately. You can restore defaults on the motor drivers but i dont know about the arduino . I didnt use that for a few reasons.