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BSCRA with brushless motor...motor is tiny so no need to angle it...and would it be any advantage? If so I'm sure they would have made it AW in the first place.
Those brushless motors have been used in both sidewinders and anglewinders

The championship winning motors in the BSCRA 1/32 sports class are all brush motors and all mounted at a few degree anglewinder. Larger diameter gear and rear tyres would be needed to get one of those in sidewinder. I think the builders of theses cars reckon smaller diameter gears/ rear wheels are an advantage.
These high reving motors need quite small pinions to get the right ratios. The brushless motors currently used are lower reving and have larger pinions. That helps getting the brushless motor further away from the back axles for sidewinders without larger diameter rear tyres.
 

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Bob Chapman
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Discussion Starter · #43 ·
It certainly is interesting about the different combinations.
I think that Honda back in the 60s or so actually had a transmounted engine in their F1 car.
Tire Wheel Vehicle Car Automotive tire
 

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Bob Chapman
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Discussion Starter · #44 ·
Lol Matt I'm in the same boat as you.
Bob
 

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Also, any chance you could give us a link to a reference for your description of the Gyroscopic effect (as per your post #11 in this thread.
I am particularly interested in understanding how the axis of rotation goes up or down depending on the change of direction.
The best way to understand it fully is to read up on Euler' equations.and do the maths.
I used the lecture notes and textbooks from my student days, sorry I don't know where or if it's to be found on the internet.
 

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Bob Chapman
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Discussion Starter · #46 ·
Well above my pay grade I'm afraid.
I still think principles are the schools head master.
 
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I am particularly interested in understanding how the axis of rotation goes up or down depending on the change of direction.
If a body is rotating (e.g. an armature in a sidewinder) and the car rotates about its vertical axis as per going through a corner, then a third force is generated tending to roll the car. With a sidewinder this force tries to hold down the inside wheel. As the car turns the opposite way, the roll couple reverses, again holding down the inside wheel. Thanks to 300SLR for explaining this to me some years ago! Try it with a spinning bicycle wheel held in the hands and you can feel the effect.

Re previous questions, I would always choose the A/W arrangement in 1/32nd scale as I think it has benefits with low polar moment of inertia. this reduces the pendulum effect that can make sidewinders a bit tricky whilst not sacrificing too much of the gyroscopic stabilisation or weight distribution benefits
 

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Bob Chapman
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Discussion Starter · #48 ·
Thanks GP. Makes sense ie the bicycle wheel example it can turn easily but harder to tilt.
A quick question if i may.
When using a long can vs an s can would the results be the same or would the long can having a longer and lower turning mass be more stable than the s can?
Bob
 

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At the same revs, the long can would have more gyro effect than the S can because the inertia of the armature is greater. The stack is longer. The height makes no difference to the gyro effects. It's only the speed and mass of the rotating parts that counts.
 

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Bob Chapman
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Discussion Starter · #50 ·
Thanks GP. Not what I was expecting to hear.
But I suppose its like comparing a spinning 26 inch bicycle wheel to a 12 inch one.
Cheers
Bob
 
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At the same revs, the long can would have more gyro effect than the S can because the inertia of the armature is greater. The stack is longer. The height makes no difference to the gyro effects. It's only the speed and mass of the rotating parts that counts.
Thanks GP. Not what I was expecting to hear.
But I suppose its like comparing a spinning 26 inch bicycle wheel to a 12 inch one.
[/QUOTE}
Not quite. I'll try and give a simplified description.
For similar types of motors rotating at he same speed, the gyro effect of the armature depends on it's diameter as well as it's mass.
The arms from S can and long can motors more or less the same diameter and similar enough in other ways, so it's a pretty close approximation to say the gyro effect just depends on he mass and speed.
However smaller diameter arm with the same mass will have less gyro effect because of the smaller diameter. So slim can motors produce less gyro effect than you might expect from the mass and speed.
If a 26 inch bicycle wheel had the same mass as a 12 inch one, the 26 inch one would produce much more gyro effect at the same revs. Also the mass of the rim makes a lot more difference to gyro effect than the same mass near the hub
 

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Autoavia
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As has been said already almost everyone in ECRA racing and at commercial raceways landed up running anglewinders màinly because they made it possible to use smaller gears and wheels. Any other benefit was regarded as secondary.
I have a Slotit Lola LMP which was supplied as an anglewinder and it is probably one of the poorest handling cars that I own. Same with an NSR Audi R8 which has never been good either so I suppose there is little benefit in running an anglewinder set up on modern plastic chassis cars.j
 

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Kevs Racing Bits
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There are plenty of in line cars with powerful motors and they are perfectly drivable.
Agreed, there are plenty of examples of that in hard body racing although powerful motors by hard body standards are not all that powerful compared to the quickest motors in BSCRA type cars.
However the fact remains BSCRA F1 class (inline) cars are undriveable with the more powerful motors that work very well in BSCRA sports class (anglewinder) cars
What reasons might there be for that?
Motor orientation isn't the only difference between BSCRA F1 and sports classes. The F1s have a wider track, smaller diameter rear tyres and more guide lead which might be expected to make them handle better. Set against that there are differences that might be expected to make the sports cars handle better including wider chassis and full width bodies which are widely believed to produce more downforce. It reality the sports cars advantages win out over their disadvantages. There doesn't seem to be a way to be sure how much of that is due to motor orientation and how much to other factors.
There are many differance between those and hard body cars - for example the tyres, the very much high reving motors in BSCRA cars (so the gyro effect is much larger), the much higher power used by BSCRA cars, etc.

The bottom line is what works best on some sorts of slot car isn't necessarily best on all sorts of slot car.
 

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Kevs Racing Bits
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BSCRA rely heavily on aero downforce, an F1 body doesn't generate as much as a full bodied car.
 

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The more aerodynamic bodies makes some difference in the BSCRA 1/32 sports class.
Swapping one of the far less aerodynamic 1/32 saloon bodies for one of those "high downforce" sports bodies on the same car makes some difference, but nowhere near the difference between F1 and 1/32 sports car speeds.
Aerodynamics make rather more difference in the 1/24 classes, for reasons that should be obvious.
 

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Slot King
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Agreed, there are plenty of examples of that in hard body racing although powerful motors by hard body standards are not all that powerful compared to the quickest motors in BSCRA type cars.
However the fact remains BSCRA F1 class (inline) cars are undriveable with the more powerful motors that work very well in BSCRA sports class (anglewinder) cars
Out of curiosity, where do you race your BSCRA cars?


Joel
 

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Bob Chapman
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Discussion Starter · #60 ·
Now I am starting to gain an understanding of the posts you lads have made. Things are starting to come together. This is really quite a complicated issue when considering the effect it can have on choices during a build.
Im very impressed and grateful for the experience and knowledge of our membership.
It takes building to a level I had never before considered..
Now to figure the effect of the type of motor within the configuration and its effect on
COG . It exposes a new rational on balance.
As we statically balance a car now but that changes with motor rotation obviously.
Taming the torque.
Cheers
Bobo
 
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