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Hi,

What are the advantages and disadvantages when comparing the two, or perceived differences?

Obviously there is a weight advantage, although small, it is a gain and we know that all sport can be about adding lots of small advantages up.

In karting a hollow axle, other than the weight advantage also affects the handling, is this true of a slot car too? if so how?

I am running 1/32 with plastic floors if that makes a difference

Any help is much appreciate as I am trying to get my head around all the variables.
 

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Apart from weight saving I cannot think of any advantage so will be following this thread.
 

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Kevs Racing Bits
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As you've only posted twice either you're new to racing slot cars or just a newcomer to the forum with lots of racing experience.

Assuming the former, I wouldn't bother wasting your time, there's umpteen other greater gains to be made elsewhere. Hollow axles probably won't be any advantage until you're racing at the top level of the sport, even then strength is more important in a deslot...a bent axle is game over.

As you're using plastic chassis you'd be better spending time working on all the other aspects of the car, tyres first, motor/gearing/driveability second, centre of gravity and balance next.

...have you got rid of the magnets in the chassis yet?
 

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I would use a hollow axle on the front wheels only and to my mind they are for weight saving but can be excellent as part of an independent front wheel setup using the slot.it kit.

I would never use on on the rear (driven) axle as they are much easier to bend, especially if you are putting grub screw wheels on and off,you tend to over-tighten and bring the axle out of true.
 

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Discussion Starter · #5 ·
As you've only posted twice either you're new to racing slot cars or just a newcomer to the forum with lots of racing experience.

Assuming the former, I wouldn't bother wasting your time, there's umpteen other greater gains to be made elsewhere. Hollow axles probably won't be any advantage until you're racing at the top level of the sport, even then strength is more important in a deslot...a bent axle is game over.

As you're using plastic chassis you'd be better spending time working on all the other aspects of the car, tyres first, motor/gearing/driveability second, centre of gravity and balance next.

...have you got rid of the magnets in the chassis yet?
Hi,

Thank you for the reply, I am relatively new to slot cars with my son as a father and son evening out. I have a few years racing experience in karting, hence knowing how a hollow axle can affect handling in that discipline.

I full appreciate that there are many areas I need to work on. I need to understand how to get my car as good as others as I know when I have borrowed one I can get their times or close to.

I have taken out or am in process of taking out the magnets in all my cars as we run on a wooden track and they perform no function other than some ballast.
 

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Discussion Starter · #6 ·
I would use a hollow axle on the front wheels only and to my mind they are for weight saving but can be excellent as part of an independent front wheel setup using the slot.it kit.

I would never use on on the rear (driven) axle as they are much easier to bend, especially if you are putting grub screw wheels on and off,you tend to over-tighten and bring the axle out of true.
Cheer for this, maybe something to look at for the front axle at a later date.
 

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I could be wrong but more rotating weight equals more torque? But also means more resistance off the mark?
Whats the weight difference anyone know? I should think 0.5g would be worth it to keen racers. Personally Im happy to use standard axles.
 

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All the mass is at the centre so minimal effect on torque. Its all about mass IMHO, so how quickly the car can accelerate, brake and corner.

I've raced for years and never thought of using hollow axles. Try reducing rolling resistance with ball race bearings, that makes a difference. And get a Trudy to get your tyres round if you are racing non-mag
 

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Discussion Starter · #9 ·
I could be wrong but more rotating weight equals more torque? But also means more resistance off the mark?
Whats the weight difference anyone know? I should think 0.5g would be worth it to keen racers. Personally Im happy to use standard axles.
I believe the heavier the axle, the slower to accelerate and slower to brake, although that said, the weight is very central so the affect is relatively minimal, unlike heavier wheels which are further from the centre and therefore require more energy to get off the mark.

I am happy with standard axles, but had 2 hollow ones and wondered if they offered a benefit that outweighed the negatives. From the above advice it would seem that any small gain is outweighed by the potential for an easy bend.

It was just something a knew from karting, where scaled up, the difference in weight was easier on the engine and also there was a handling difference with how the kart released out of the corner. Slot cars and karts are simiilar in that they dont have a diff, so wondered if there was a potential for a handling benefit.
 

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Discussion Starter · #10 ·
All the mass is at the centre so minimal effect on torque. Its all about mass IMHO, so how quickly the car can accelerate, brake and corner.

I've raced for years and never thought of using hollow axles. Try reducing rolling resistance with ball race bearings, that makes a difference. And get a Trudy to get your tyres round if you are racing non-mag
The Hudy has been a recent purchase and has being put into use in the last week, I have to say that my sons Grp 5 Porsche has a marked improvement in smoothness since.
 

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I always thought that if you had a rod and a tube of the same diameter, then the tube would be stronger/stiffer. You can Google this and it is pretty much supported wherever you look.

As for crushing with a grub screw, well between you and me, I wouldn't let Mcewan tighten my nuts, he's a big lad!
 
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I found that a hollow front axle (or axle bearing) is good for creating independely turning front wheels using self-tapping screws through the centre of each. Probably not really worth the bother but is kinda nice!
 

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This subject is as old as it is fascinating. For motor racing fans looking for answers, I wholeheartedly recommend a study of the front axle fitted by Ettore Bugatti to the front of the Type 35B.

It's only a personal view, but I rather admire the way Carrera tackle 'seating' of the wheels (front and rear). Quite how this company manages to accomplish what they do at such low retail prices is a different subject, but one worthy of attention just the same.
 

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I always thought that if you had a rod and a tube of the same diameter, then the tube would be stronger/stiffer. You can Google this and it is pretty much supported wherever you look.
No, for the SAME DIAMETER, the solid axle will always be stronger. But it obviously uses a greater amount of material. For the same amount of material you can have a hollow axle of greater diameter, which will be stronger in bending than a solid axle of the same mass.
 

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No, for the SAME DIAMETER, the solid axle will always be stronger. But it obviously uses a greater amount of material. For the same amount of material you can have a hollow axle of greater diameter, which will be stronger in bending than a solid axle of the same mass.
I probably over-generalised but I did try and cover this by putting stronger/stiffer and if a rod and a tube of the same diameter are compared, then the tube would be stiffer. However, you are correct when you say that for the same diameter the rod would be stronger. But for the same diameter, the tube would still be stiffer.

For the record, I have used both solid and hollow Slot.it axles on the front and rear of my 1/32 Slot cars with no ill effects or damage from grub screws although I could never say if there was an advantage to be gained from using either one.
 

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I probably over-generalised but I did try and cover this by putting stronger/stiffer and if a rod and a tube of the same diameter are compared, then the tube would be stiffer. However, you are correct when you say that for the same diameter the rod would be stronger. But for the same diameter, the tube would still be stiffer.
Nope: we will just have to agree to disagree. Again: for the SAME AMOUNT OF MATERIAL a tube would be better because you would end up with a greater diameter. For THE SAME OD (which is the case for slot car axles), a rod is better. I can go into the math but it is just too much and too complicated to go into for slot car axles. Suffice to say that for the same OD, a rod will always beat a tube: in tensile strength/stiffness, compressive strength/stiffness (both Euler and squash), and bending strength/stiffness.

But whatever: if it is that important to any individual, try an experiment with for instance a solid and hollow Slot.it axle. In my world I add 5 - 15g of weight to a car to get the no-mag handling I require. So saving <1g on an axle in a 70g car and then adding 15g to get it to 85g seems pointless.
 

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Sorry, Trudy is a girl at work...

+1 for SuperSlab's explanation. The air in the middle doesn't add strength. fill a tube with metal and it will be stiffer and stronger
 

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As for crushing with a grub screw, well between you and me, I wouldn't let Mcewan tighten my nuts, he's a big lad!
Let someone tightening your nuts!....what do you guys do in Wales instead of slotracing??? Shaking my head in disbelief.

Sorry I could not resist :D
 

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ParrotGod
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I use Black Arrow hollow axles (front and back) in my DiSCA racing and so far no issues.

In its latest outing in Suzuka, the sideways Lambo I built was pretty quick in the hands of the right drivers (Gary and Alex).

But again, we might got lucky...
 
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