Seem cheap for the potential damage that could be caused..
I've not herd of any prop failures with anyone who's fitted one of Dan's catchers yet... - but if you search for it you'll
find the old thread with the evolution of its design and some of the first customers for one
the trick is to have a fairly close fitting catcher (round inside for preference) to limit the how far the prop can fall - if it can't more far
its not actually that dangerous
the danger comes when its allowed to move enough that it can start whipping around
forget the fancy new joint they are selling (i.e. skip to about 6min) but this gives you a pretty good idea of the problem:
quote:Originally posted by dave r
this is also on my to do list....... what sort of clearance should i allow to the prop ?
On an IRS set up with a fixed diff and box you could get away with less than 10mm.
With a live axle you would obviously need to allow for more at the diff end.
A prop catcher is one thing but what can be done to prevent failure. I dont see prop catchers having to be fitted to rwd road cars and i dont see
many rwd road cars suffering from prop failures.
Surely it's better to stamp out the disease rather than the minimise the symptoms ?
1- It failed at the front.
2- It was a temporary prop with a rubber coupling which I do not like, but it was use that or miss the day.
3- I made it, but it wasn't my welding that failed but the rubber coupling. It's the seventh prop I've made over the years and
the first to ever let go.
4- It dented the tunnel tubes but only the lower ones, the upper ones escaped as the tunnel cover took the beating.
Punched a hole in the floor, you can see the newspaper undernbeath in the photo.
5- The wiring to the fuel pumps managed to get wrapped round the prop and pulled out from both ends.
But, hey, no damage to me , the car is easily fixed.
Time is an illusion. Lunchtime doubly so.................Douglas Adams.
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Building: Dax Rush - very, very slowly....
posted on 13/11/13 at 09:01 AM
quote:Originally posted by Not Anumber
I dont see prop catchers having to be fitted to rwd road cars and i dont see many rwd road cars suffering from prop failures.
you'd probably see more prop failures on tin-tops if everyone took them to the track for a good thrash every now and then
prop catchers aren't needed as much on tin-tops mainly because your less likely to get injured when they let go (i.e. your not sitting right
next to the thing with only a thin sheet of alloy and a few tubes to protect you
its more to do with the consequences of a failure than it is to do with the likelihood of failure
this says it all really
quote:Originally posted by Johneturbo
i had mine snap at the front as i accelerated from 40 zone to 60 zone thankfuly no injurys to me or lisa
but the car was a right off as it hit a fuel line and burt to the ground
home made / modified shafts that haven't been balanced will have more vibration and that could shorten there life, but even a brand new
manufactured prop needs to be checked when the car is serviced to look for signs of damage or even just worn bearings or a lack of grease....
but that wouldn't help much in this case as it was the rubber coupling thingy...
quote:Originally posted by Not Anumber
A prop catcher is one thing but what can be done to prevent failure. I dont see prop catchers having to be fitted to rwd road cars and i dont see
many rwd road cars suffering from prop failures.
Surely it's better to stamp out the disease rather than the minimise the symptoms ?
MSA requires them. Which as mentioned already, points to the 'using them in anger'
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Building: Finished MK Indy with Volvo T5 engine
posted on 13/11/13 at 02:29 PM
I should imagine the failures seen in many kits and modified cars is due to builders (and suppliers) not understanding the need for the transmission
output and diff input flanges to be (at least almost) perfectly parallel, not having the means to set this accurately, or not making the shaft with
the couplings correctly phased.
Fitting the engine under the bonnet or dealing with other engine mounting issues normall takes priority over a correctly angled gearbox output. The
result of this is cyclic loading of the shaft (leading to fatigue) and vibration which may or may not be noticeable to the driver.
quote:Originally posted by Not Anumber
I dont see prop catchers having to be fitted to rwd road cars and i dont see many rwd road cars suffering from prop failures.
you'd probably see more prop failures on tin-tops if everyone took them to the track for a good thrash every now and then
prop catchers aren't needed as much on tin-tops mainly because your less likely to get injured when they let go (i.e. your not sitting right
next to the thing with only a thin sheet of alloy and a few tubes to protect you
its more to do with the consequences of a failure than it is to do with the likelihood of failure
this says it all really
quote:Originally posted by Johneturbo
i had mine snap at the front as i accelerated from 40 zone to 60 zone thankfuly no injurys to me or lisa
but the car was a right off as it hit a fuel line and burt to the ground
home made / modified shafts that haven't been balanced will have more vibration and that could shorten there life, but even a brand new
manufactured prop needs to be checked when the car is serviced to look for signs of damage or even just worn bearings or a lack of grease....
but that wouldn't help much in this case as it was the rubber coupling thingy...
[Edited on 13/11/2013 by mcerd1]
[Edited on 13/11/2013 by mcerd1]
mine was a brand new 2 piece prop made for the job with a quaif reverse box
quote:Originally posted by Not Anumber
A prop catcher is one thing but what can be done to prevent failure. I dont see prop catchers having to be fitted to rwd road cars and i dont see
many rwd road cars suffering from prop failures.
Surely it's better to stamp out the disease rather than the minimise the symptoms ?
We didn't used to have them fitted on our trains,then one day one failed,dug in under the sleepers and the propshaft then pierced the floor of
the train and popped up in the passenger saloon between the seats!
I dont think it can happend if the prop is made on new parts welded as in the books says.
My prop was balanced with that rubber silencer a the front of the shaft (gearbox side)
Photo Archive
Building: Dax Rush - very, very slowly....
posted on 17/12/13 at 08:35 AM
quote:Originally posted by Darek32
I dont think it can happend if the prop is made on new parts welded as in the books says.
My prop was balanced with that rubber silencer a the front of the shaft (gearbox side)
^^ of course it can happen - even with all new parts !
all it takes is a small crack to form and grow or a bearing in one of the UJ's to fail or some minor thing like that that doesn't get
spotted before it fails
all new parts welded up by a pro and balanced will be less likely to fail - but it can't ever guarantee it
or in this case it was the stupid rubber donut thing - these are probably one of the most common failures and they don't even do anything useful
on our cars....
the UJ's are also quite a common failure on landrovers when people fail to regularly check and grease them and that with factory made parts with
full quality control...
the moral is: Fit Prop Catchers! they won't make the prop any more or less likely to fail, but they will contain the damage
plus they are cheaper than new legs
quote:Originally posted by scudderfish
Are they on your website? I couldn't find them
Hi, apologies for the slow response. No not yet - only reason being I've focused purely on the inlets on the website to date. I need to add a
'locost' section. In the meantime to order just drop me a U2U.
NEW danST WEBSITE NOW LIVE! Bike carbs, throttle bodies and more......
, the car is easily fixed.
