desk mount, questions

[leffty]

Hello everyone,
Guys, please help me, I'm a bit confused.
I own the Simagic Alpha Ultimate, I use it at about 55 %, mounted on the desk, a pretty heavy desk.
I don't have space for a rig, right now. Maybe in the future
Thinking about buying some solid wheelbase stand.
I have some questions, maybe someone with experience can help me.
First question : what's the difference between the FFB details between the solid desk, Ultimate mounted, like I have now, and some good quality wheelbase stand?
Do I lose some FFB details, as I have it now, on the desk?
Second question : what about the noise, vibrations, desk mount vs wheelbase stand?
In some cases, for example, Rennsport ( beta tester ) when I press the brake, the speed is under 10 kmh, it makes weird noises, hard to explain.
The same happens for AMS2, rFactor 2, LMU, AAC, especially when I drive over chicanes....
Does this happen, with a solid wheel stand, too?
Or with a good / great quality rig?
My desk, with everything on it ( TV 65 inches, as well) is about 52 kg.
Solid, but not very very solid
Another, and last question : would it help If I replace the desk, with a heavier one?
Let's say 100 kg, with everything on it.
Thank you in advance, have a great day, everyone

 

[blekenbleu]

what's the difference between the FFB details between the solid desk, Ultimate mounted, like I have now, and some good quality wheelbase stand?

Probably negligible, since you can dial up nearly any amount of detail wanted.
"solid" wants quantification...

55% of 23Nm ~ 13Nm, which roughly matches my AccuForce, which
is mounted to a home brew wheel stand, about 25kg on front legs and 20kg on rears.
I sense no detail loss in the wheel stand, being reaction torque impulses
to wheel base impulses. AccuForce goes thru a famously violent calibration cycle,
which with a high mass rim attached did generate sensible reactions in an older wheel stand.

 

[stigs2cousin]

Another, and last question : would it help If I replace the desk, with a heavier one?
Let's say 100 kg, with everything on it.

That would be an easy test, put some heavy wheights on it and test drive.

I´d see the advantage of an wheel stand more in better located pedals which could not change position with regard to the wheel.

But if you have no problem with "wandering pedals" you need to solution for that.

 

[blekenbleu]

As a test, have someone else drive while you feel the desk for vibrations and movements.

 

[leffty]

Probably negligible, since you can dial up nearly any amount of detail wanted.
"solid" wants quantification...

55% of 23Nm ~ 13Nm, which roughly matches my AccuForce, which
is mounted to a home brew wheel stand, about 25kg on front legs and 20kg on rears.
I sense no detail loss in the wheel stand, being reaction torque impulses
to wheel base impulses. AccuForce goes thru a famously violent calibration cycle,
which with a high mass rim attached did generate sensible reactions in an older wheel stand.

Thanks for your replay. I watched the images with your desk. Does it shake / vibrate, when you brake, driving over chicanes, etc ??

 

[leffty]

That would be an easy test, put some heavy wheights on it and test drive.

I´d see the advantage of an wheel stand more in better located pedals which could not change position with regard to the wheel.

But if you have no problem with "wandering pedals" you need to solution for that.

I have no issue with the pedals.
" put some heavy wheights on it and test drive "
I was thinking about this, but don't know what I could put on the desk, that heavy

 

[leffty]

I could buy 2 x bumper plates, 35 kg each ( I can hide them, somehow)
Something like this one
Not sure if it's going to help.
I'd say " yes "
What do you think, guys ?!

 

[blekenbleu]

Does it shake / vibrate, when you brake, driving over chicanes, etc ??

No enough to audibly or visibly shake items resting on it:

• MIDI control surface,
• push-pull shifter removed when using wheels with paddle shifters,
• joystick,
• power controller,
• oscilloscope,
• fans,
• prototype electronic modules for pneumatic G-seat experiments

When driving, one normally grips both sides of rim,
applying nearly pure torque.
Properly evaluating wheel base mount stability,
wants someone else steering
while watching and feeling desk or stand for stability.
Resisting force feedback torque by gripping only one side of the rim
provokes atypical net vertical and lateral forces.
Also, detecting desk/stand flex and vibration by feel
is harder while also trying to steer with the other hand.

What do you think, guys ?!

You may be looking for issues that are not really concerning.
Try to isolate "weird noises" sources before attempting to mitigate them.
For example, remove everything else from the desk, including drawers.
Sympathetic vibrations can be provoke by otherwise imperceptible energy
that happens to match some object's resonant frequency.
Some drawer liner may cure them.

 

[leffty]

No enough to audibly or visibly shake items resting on it:

• MIDI control surface,
• push-pull shifter removed when using wheels with paddle shifters,
• joystick,
• power controller,
• oscilloscope,
• fans,
• prototype electronic modules for pneumatic G-seat experiments

When driving, one normally grips both sides of rim,
applying nearly pure torque.
Properly evaluating wheel base mount stability,
wants someone else steering
while watching and feeling desk or stand for stability.
Resisting force feedback torque by gripping only one side of the rim
provokes atypical net vertical and lateral forces.
Also, detecting desk/stand flex and vibration by feel
is harder while also trying to steer with the other hand.



You may be looking for issues that are not really concerning.
Try to isolate "weird noises" sources before attempting to mitigate them.
For example, remove everything else from the desk, including drawers.
Sympathetic vibrations can be provoke by otherwise imperceptible energy
that happens to match some object's resonant frequency.
Some drawer liner may cure them.

I'm trying to find a way to avoid all those shakes
Sometimes, the display, 65 inches, shakes like the buildings in Tokyo ( 9 Richter scale )

 

[blekenbleu]

Sometimes, the display, 65 inches, shakes like the buildings in Tokyo ( 9 Richter scale )

Desk legs wobble? Large displays are not perfectly rigid,
but this sounds like too much display mass relative to desk mass.
Do you push and pull on the rim while turning it?

 

[leffty]

My desk looks something like this one ( mine has a bit smaller sizes)
34 kg, the desk, alone. TV is 30 kg, Simagic Alpha Ultimate wheelbase + Simagic FX Pro wheel, about 11 kg, and some other minor stuff on the desk, I'd say, 78 kg.
More than I thought.
No, I don't push or pull on the rim, while turning it.
I'm not sure, but I guess, if I put those 2 bumper plates ( 30 or 35 kg, each) it's going to solve the problem
Thank you

 

[simracingfanatic]

turn down your ffb. you'll need a desk made of granite to be able to handle your direct drive wheel.

if you proceed with the bumper plates, you'll need to secure them tightly to your desk.

 

[Wreckoning]

I used an old desk for a while with a DD1.

It was from an office so a bit more heavy duty that your average home office desk. The wooden desk top was about 25mm thick but it was reinforced with a steel frame all the way round it and it has drawers built into it on either side. I think the steel frame did a lot of the work to prevent flexing then just the sheer weight of it kept the rest of it stable.

Looking at your desk if it had drawers at either end that were full height that would help to brace any movement. Your desktop even though it looks quite chunky at the moment is only supported at the ends.

I used a monitor arm to bring the screen out and it basically sat on the top of the DD1 about half way along. Because monitor arms are going to always have some degree of "flex" having it sitting on top of the DD1 just made any movements of the desk move together it was never bouncing about. It was perfectly happy with a 32" 4K monitor and the arm at full extension for a while.

Obviously your 65" screen is on a different level and anything that big it's going to be more obvious if it's moving especially if it's close to you. Are you using that 65" screen for anything other than Sim racing? I'd be tempted to try a smaller maybe an Ultra/Super Ultra wide on an arm bring it in closer to you when racing and let it rest on the top of the wheelbase.

 

[blekenbleu]

34 kg, the desk

That low mass suggest those 6 cm slabs are not solid.

Sometimes, the display, 65 inches, shakes like the buildings in Tokyo ( 9 Richter scale )

Increased mass would lower the frequency at which a rigid body would resonate,
but might actually increase your desk's resonant amplitude.

If that desk is just a horizontal slab with 2 vertical slabs supporting it with no braces,
- it probably moves laterally; adding 45 degree diagonal braces at the rear corners,
from about 2/3 down the verticals, should help more than adding mass
- if you can sense any vertical yielding when pressing down at the middle of the top surface,
then it wants a truss to help resist flexing.

 

[leffty]

turn down your ffb. you'll need a desk made of granite to be able to handle your direct drive wheel.

if you proceed with the bumper plates, you'll need to secure them tightly to your desk.

I don't use it at 100 %

 

[leffty]

Thank you so much for your reply, guys.
I think, I'm left with 2 options only
1 - I reduce the FFB, which I don't really want
2 - I buy another desk, much heavier, I found one, 90 kg the desk, alone
With everything on it, about 135 kg

 

[blekenbleu]

I found one

If you can, try before buy.
Weight is not the issue; rigidity is.

 

[leffty]

Thank you.
Can you, please, share a picture here, with a solid / rigid /desk? From the internet...
I'd like to improve mine, or maybe buy something else
Heavier and more rigid, as you said

 

[Elaphe]

Just use thicker sheets of wood and denser wood.

 

[blekenbleu]

Can you, please, share a picture here, with a solid / rigid /desk? From the internet...

A desk need not be massive to be rigid and sturdy.
For your application, I would consider a workbench, e.g.

Global Industrial Adjustable Height Maple Butcher Block Square Edge Work Bench, 60" W X 30" D, 1 3/4" Top​