Just a bit concerned about the recent and seemingly numerous propshaft problems where the prop adapter has come adrift and flailed around causing lots of damage.

what is the best wat to design a prop catcher for if it does come adrift?

Cheers

Mark

Same thing that you need for eating hardcore curries - a ring of steel!

Seriously though, this does concern me so everything is tippex'ed up and checked regularily.

just a couple of steel hoops, made of some flat steel strip, maybe 52mm wide, welded to bottom tunnel rails, and looped over the top. i'd get a few photos of mine for you , but i don't think i can see them now the engine and gearbox etc is in

Where mine failed, Tippex wouldn't have helped - the nut is within the adapter, so only visible if you take the adapter off....

I am making a hoop that is welded onto the upright end of the prop tunnel - it is as close to the adapter as I can get it. It will be boltable, so I can still get the prop in and out....

That reminds me - I must ring D&F to see if they have repaired it!

I was going to put one in mine, as a bolt in stainless U shape tunnel within the tunnel.
But at chassis build stage then I think a load of extra uprights down the tunnel sides would be good? and tidy?

not particularly clear, but

Description

my tunnel is only made of (i guess) 0.5mm sheet steel, with no tubes at the top.
as a race chassis, they are happy enough with how mine is.

The problem with a broken shaft is that if it breaks at the front the wheels continue to drive the shaft around. As long as it's held in line thats not a major problem. Once the end gets out of line it starts to flail about and destroy things. Fuel lines, tunnel and your legs! All major hassle to say the least.
To be effective a prop catcher has to be able to keep the broken shaft in line... or as close as possible to in line. The closer the hoop to the prop then the more effective it'll be (and less strength required). You want something like Blake82's but with a hoop OVER the prop. If it's close enough it only needs to be 1"x1/8" steel strip.

adrian

mine does go over, its not a very clear photo though.

ideally i suppose you want something under the prop too, if it breaks at the fron't and digs into the road its going to be even messier might rivet something underneath, or ad something to the gearbox crossmember

if the prop breaks at the back i guess it'll just fall out and end up in the road, so no major promblem

[Edited on 8/10/09 by blakep82]

Mine is going to be a ring of 1/8 by 1" steel just about 1/2" clear all the way round the prop then four "legs" off it bolted or welded to the tunnel rails. This way if the prop lets go it should just spin in the steel ring and not try to escape from the tunnel

RD

Mine is a bit like Blake's but nipped in at the bottom just in case the shaft tries to drop down, dig into the road and somersault the whole car (and before anyone says that's overkill you obviously haven't seen a runaway milk-float inverted by exactly that happening).
Cheers, Pewe

Although pole-vaulting on the end of the prop' isn't desirable, its the prop flailing about that causes damage in most cases. Do a search and you'll see where prop's have come through the tunnel side and broken bones, cut fuel lines/ripped out looms and started fires, or just mangled chassis tubes and gearbox casings.

As yours is Blake, I think you'd have problems; Too much room for the prop' to move.

quote:

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Originally posted by adithorp

As yours is Blake, I think you'd have problems; Too much room for the prop' to move.

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sorry blake but i think its better you know.
i had my prop let go and the damage and forces involved are huge at the front.
you will need as said something circular and very close to the prop to keep it within the tunnel.

cheers guys

Is this where I get to try out my newly refurbed tube bender?

i never put mine in, it was there since it was racing. it was put in by the chassis manufacture, and yes i would prefer it to have been different. but i do think the actual reality is, no matter what you do, the prop is never going to break exactly where you expect it. the only proper real safew wayt is to run in through a steel tube from front to back.

anyway, only about 18" of my prop is in the tunnel, the rest is out the back