26 replies to this topic

[Ecurie Martini]

Weight isn't really the issue, it's excess rotating mass. And it's high up.

Koford axles are the gold standard for racing, end of story.

 

 

The effect of rotational inertia is related to rotational rate squared X radius. I = ώ²R.  Thus, although the axle is much denser than the alloy wheel and the tire, the radius is so much smaller that its contribution to this effect is little more than rounding error

[Big_John]

There was a recommendation from a very credible source on a YouTube post that #42 drill blanks from Grainger would be fine 3/32 axles for slot cars. It's enticing to me because they're only $1.78 each if ordered in sets of 12. 

 

Grainger has two types of #42s: "drill blanks" and "reamer blanks"

 

Does anyone here have experience with these, and if so, is there a lick of difference between the two types as far as suitability for slot cars goes? Any concerns?

 

Thanks, and I hope you have/had a safe and nice Thanksgiving.

Since no one has answered your question of the difference between drill blanks and reamer blanks....

 

Drill blanks are made to a minus tolerance. In that size, the usual tolerance is +.0000" and -.0005". Reamer blanks are made to a plus tolerance. In this example, it would be +.0005" and -.0000"  These are usually expressed, for example, as +.0000/-.0005".

 

For use as an axle, the drill blank is the safer bet as it's usually better to have more clearance than less, but in reality, it probably doesn't mean squat in a slot car.  

 

They are often used as a gauge for drilled holes, with a lesser tolerance (and therefore cheaper) than, let's say, a class X tolerance gauge pin. 

 

I'm not going to get into the debate on what's better.