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Old 08-08-2019, 07:20 AM
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Originally Posted by 30Tooth View Post
The sooner you get parts produced the sooner you can start real testing. That's more critical than iterating endlessly imo, not that you're doing that.
I know for you guys it must look as if I am sitting endless weeks in front of my computer drawing the car, but I assure you that is not the case. I am glad if I have two hours of creative time per week. And because of that the car grows and with that I have to change parts. For the most time I am not even sure if my ideas will work even in CAD. This is all in all a very complex suspension and want to take it slow to prevent stupid mistakes (see last paragraph )

Originally Posted by Bry195 View Post
If force is proportional to the pressure and area of the piston (damper) one side of the piston has less area than the other because of the rod displacement. The side of piston without the rod is called the blind side. In compression for arm damping the fluid travels from rod to blind side and blind side to rod side in rebound.
In my heave damper the oil will travel from blind side to rod side in compression.

Originally Posted by Bry195 View Post
Is there a spring on your damper?
Yes. I just was to lazy to draw it.

Originally Posted by Bry195 View Post
Which direction will compression and rebound be translated through the damper? It might be something to complicated to conceptualize and I’ll just have to wait.
You don't have to wait! Your contribution is very helpful! You just made me aware of a huge mistake in my reasoning! Thanks for your attentive reading Now that I see the mistake I feel completly stupid. The preload arms that also act as arms to compress the heave spring will just move 0.5mm to the middle of the car under full load (front of the car on the ground) . So the compression of the heave damper is nearly zero

...and that is the reason why I don't want to rush this version. Somehow I never saw an error here. Back to the drawing board...
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Old 08-08-2019, 02:45 PM
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Originally Posted by wtcc View Post
I know for you guys it must look as if I am sitting endless weeks in front of my computer drawing the car, but I assure you that is not the case. I am glad if I have two hours of creative time per week.
No need to explain yourself, a modern life is a busy one. I'm just glad for whatever you share of your creative process.

Let me share a personal thing I know we all have in common; it is a lack of spare time. Between everything I have to achieve as a husband and father, I might get a spare fifteen minutes a day to move my projects to the goals I have set.

You do you, take your time and enjoy your process.

Now back to work!
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Old 08-08-2019, 03:27 PM
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glad I could help even if it was only tangential. I have a better understanding of the motion now so a few of my questions were cleared up. my previous post was long to provide some basic background to some concepts that any further attempts for me to clarify could further confuse but I’ll try.

Begin re-explanation
a damper is a spring that only applies a force when there is velocity. the amount of force created is directly related to the area of the piston or flap, orifice (leaks), viscosity. Set leakage and viscosity equal and whatever value you choose because they are irrelevant to the concept Im talking about. with a rotary damper the area of the flap is the same clockwise as it is counter clockwise. thus the “velocity spring” or force that is applied is the same in both directions. lets call it 1lb of damper in both directions because both sides of the flap (area) is the same. so whether it has 1 large vane or 4 smaller vanes the summed area equals 1 pound or kg of force in either direction.

in a piston damper the area is different on the blind side versus the rod side. the rod subtracts from the area of the piston on one side and it does not on the other side. second concept-the force applied to the rod in compression and rebound creates an exact displacement. 1lb of compression force creates 6mm of travel. 1.1 lb of force in rebound creates 6mm of return travel. or 1 lb of return force creates 5.5mm of rebound travel. this inequality does not happen with a flap or rotary because the flap has equal area on both sides. a piston does not unless its a double rod. i touched on the same concept from 2 or 3 directions but its just 1 concept. your heave damper will travel a different distance for the same force in both directions. by the same logic the damping force will be different in both directions.
End re-explanation

WTCC you have a very nice flap design that if adapted to the revised heave system will create equal damping force in both directions.

as a side note a single flap will need the same area as a 4 flap rotary with the same leakage and flow. But you have lengthened the flap which will increase the torque through leverage. The other thing I was curious about... did you look at the area you needed at that new length? The advantage of the pure rotary is the surface area of 4 flaps shorter in length creating a smaller circle....Im guessing because im too lazy to run the math on the increased length that is required on a single flap minus the increase leverage you have from moving some force farther away creating more torque.

Last edited by Bry195; 08-08-2019 at 06:31 PM.
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Old 08-11-2019, 11:55 AM
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It is not just the torque, that will be interesting to see how it will make the car behave, but also the higher speed, because my flap will have a higher angle change than that of the Awesomatix in comparison. From my side it is all just fun and a big experiment. I am no engineer, I am not calculating with viscosity and flap length. I just try to make sure I have no collisions and it will move mechanically

I found time in the night to solve my heave damper problems. The front suspension has hardly any space left to fill with more components. With some skill and luck I could implement two more arms for the heave damper kinematic and drew a new damper end to have no heave damper effect if the suspension is unloaded or under load on one side only.







The damper end now is more complicated than I want it to be with one joint on the arm and another ball bearing assembly on a rail. Any ideas to reduce the complexity here are very welcome. I for myself couldn't come up with anything better

Other than that, I think I completed the car as I had imagined it on a functional view. Again I will let the arrangement sink in some more days...
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Old 08-11-2019, 07:36 PM
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Id hire you. You are doing this because you want to. In my book that is the best kind of Engineer.

im a little lost in the perspective you use but can you get to the preload adjustment on the leaf spring?
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Old 08-12-2019, 06:21 AM
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Default the spirit of our hobby!

Kevin, I readt the whole post and I think you're doing an awesome job.
Of course you have skills and time to do it, but anyway your passion is impressive.
Today, most of rc people prefer to spend a lot of money to buy the last kit, the last motor, the last esc, etc... "Buy", not build.
They are missing the point of rc car. Even if you are not an engineer (I suppose you are, btw :-D) you can build, test, "arrange", modify and play with parts in order to create YOUR rc car.
Look at the main events pics gallery: everything has same equipement, same layout, same option parts, same wiring scheme. No one "dares" anymore.
It's not a matter of money. Certain "crazy" projects are more expensive that a new fresh Yokomo or Xray kit, but that isn't the point.
I think you repesent the spirit of our hobby. Congrats!

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Old 08-12-2019, 08:27 AM
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@jakelamotta: Thank you for all the kind words! CAD and 3D print give new possibilities for "normal" R/C car hobbyists. I also wish the car sector would have more builders like we see with the plane guys.

@Bry195: Here you go -->

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Old 08-12-2019, 07:36 PM
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Originally Posted by wtcc View Post
@jakelamotta: Thank you for all the kind words! CAD and 3D print give new possibilities for "normal" R/C car hobbyists. I also wish the car sector would have more builders like we see with the plane guys.

@Bry195: Here you go -->
With all of the focus on spring progression maybe an adjustable cam shaped preload. Its hard to see but it looks like a screw in the vertical position could be blocked by the heave system. An adjustable cam with a horizontal screw might allow you to get to the adjuster from inside of the chassis.

I think they call it an eccentric hub. But use a progressive radius like an egg or a cycloid curve.
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