M Chassis Universals / Cardans...what's the difference?

[Juhunio]

In putting together parts for a couple of M chassis builds, I've managed to find three different types of Universal / Cardan shafts:

Can any one help me out with the differences / advantages? They all look to be the same shaft length (30mm)

Q1: what's the difference between 53205 and 53597? My initial thought was that 53597 was just an updated version of 53205 (both called Universals), but 53205 look more like Double Cardan joints than Universals. They certainly look more...permanent, in terms of their fixings

Q2. What's the benefit of DCs over Universals?

Thanks!

[svenb]

The 53205 are not rebuild able, or not very easily where as the 53597 are and come in kit form. 

The double cardans have in affect two joints on each shaft allowing for greater angles. You lose less power through drag with them. 

I put a set on my ta06 and the difference was massive, smoother and less chatter on lock. Only needed on the front obviously. 

If you can afford the double cardans I'd get them especially for a fwd chassis. 

But if its a period build and to sit on a shelf then it's what ever is correct at the time 👍

[Juhunio]

Perfect, thanks @svenb

52 minutes ago, svenb said:

The 53205 are not rebuild able, or not very easily where as the 53597 are and come in kit form. 

If you can afford the double cardans I'd get them especially for a fwd chassis. 

That makes sense; double cardans at the front of a FWD chassis where drive and steering are happening at the same time. Universals at the back on a RWD chassis, if you can afford it! Is that about right?

52 minutes ago, svenb said:

But if its a period build and to sit on a shelf then it's what ever is correct at the time 👍

I'm not that committed to period features, so 53597 / contemporary universals will do for me! 

I'll sell the 53205s on, thanks 

[rich_f]

8 hours ago, Juhunio said:

Q1: what's the difference between 53205 and 53597? My initial thought was that 53597 was just an updated version of 53205 (both called Universals), but 53205 look more like Double Cardan joints than Universals. They certainly look more...permanent, in terms of their fixings

Sven probably gave you as much information as you need, but what he didn't mention was that the double Cardans 42300 are the only constant velocity drives (CVDs*) out of those examples. This means that the rotational speed at the output (wheel end) is exactly the same as that at the input (diff end), no matter what angle they are bent through.  With universal joints (single Cardan joints), the output speed is sinusoidal with respect to a constant input speed, with an amplitude proportional to the bend amount. This is a cause of noise, vibration and chatter and is one reason why double Cardans are better. 

The universal joints 53205 are indeed only single Cardan joints. 

*The term CVD is, unfortunately, misused in the rc world and most times I see it mentioned are with reference to rebuildable universals. Here I use it in the correct sense.