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New IRIS by AME

Old 11-18-2022, 12:33 PM
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The drive system should be more efficient if they can keep all the pulleys centered with as little offset as possible. Every 3 belt car I’ve seen had massive pulley offsets with some belts running down the side of the car.
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Old 11-18-2022, 01:00 PM
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Wouldn't a 3 belt system be more friction in the drive train, more rotating mass and more weight up higher in the car? Would a design like this really be more efficient?
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Old 11-18-2022, 03:42 PM
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Originally Posted by The Teacher View Post
Wouldn't a 3 belt system be more friction in the drive train, more rotating mass and more weight up higher in the car? Would a design like this really be more efficient?
Yep, no way this will be more efficient than a 2 belt car.
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Old 11-18-2022, 05:06 PM
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Hopefully IRIS can make a 3 pulley and the true mid motor position work. Other manufacturers could not. Interesting would be the suspension and the overall cg.
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Old 11-18-2022, 10:31 PM
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Originally Posted by rccartips View Post
Hopefully IRIS can make a 3 pulley and the true mid motor position work. Other manufacturers could not. Interesting would be the suspension and the overall cg.
I'm interested to know why a true mid mounted motor is important. I thought the current trend was more about equal length belts than putting the motor in the middle of the car.

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Old 11-19-2022, 02:39 AM
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Originally Posted by Scott_T View Post
I'm interested to know why a true mid mounted motor is important. I thought the current trend was more about equal length belts than putting the motor in the middle of the car.
I always thought it was all about front to rear weight distribution.
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Old 11-19-2022, 03:20 AM
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Originally Posted by glennhl View Post
I always thought it was all about front to rear weight distribution.
It's already easy to get a perfect 50:50 weight distribution with the equal length belt layouts. The motor isn't the only heavy component in the car.

The "true" definition of a mid motor layout is that the motor is somewhere between the front and rear axles. I'm not sure why the RC crowd think it needs to be exactly half way between the axles.
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Old 11-19-2022, 09:41 PM
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I'm thinking that the mid motor allows you to get 50/50 weight distribution easier, but more importantly it moves the weight to the middle of the car reducing its polar moment of inertia allowing it to rotate right and left quicker.
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Old 11-19-2022, 10:41 PM
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Originally Posted by glennhl View Post
I'm thinking that the mid motor allows you to get 50/50 weight distribution easier, but more importantly it moves the weight to the middle of the car reducing its polar moment of inertia allowing it to rotate right and left quicker.
My existing mid car is already slightly front heavy with the motor behind the spur and equal length belts. Moving the motor further forward will exacerbate this, requiring more weight added to the rear to maintain 50:50. That'll actually make the polar moment of inertia higher.
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Old 11-20-2022, 08:38 AM
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Originally Posted by gigaplex View Post
My existing mid car is already slightly front heavy with the motor behind the spur and equal length belts. Moving the motor further forward will exacerbate this, requiring more weight added to the rear to maintain 50:50. That'll actually make the polar moment of inertia higher.
Interesting, but I think moving large chunks of mass towards the middle of the car is always a good thing. My mid motor car is 49 front and 51 rear.
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Old 11-20-2022, 08:41 AM
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With most of the new cars way to light, I think there is no Problem with "balancing" the car.
Also different Electronic parts are different... Motors can be 10-20g different, ESC also, Servo 10g... I think you cann get 50g diffence only on the left side.. and when you drive 6000 or 8200 its aout 70g...
So you have anyway to balance it.
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Old 11-20-2022, 08:43 AM
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Going from an Mi7 to the Mi8 I noticed pros and cons of this.
The Mi7 felt like it had faster corner speed with mid motor.
The Mi8 with equal belts felt more efficient mid to exit with getting up to speed. But lacked that corner speed snap the 7 had.

I think both have their benefits with sacrifices.
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Old 11-22-2022, 07:02 AM
  #178  
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Release day tomorrow.


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Old 11-22-2022, 09:10 AM
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I'm probably not going to be able to resist buying one of these... especially since it's got some red anno. So where do I get one
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Old 11-22-2022, 09:20 AM
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Centering the motor in the car has more to do with the spinning mass the motor creates when operating at higher RPM's. This creates an offset torque that messes with the overall balance of the car even though car is statically balanced. Think bubble leveling a car tire to balance vs Dynamically balancing by spinning it.
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