QL thruster shear pin

[Portland Billy]

Does anyone know where I can find a thruster shear pin part number 41100700?
Seems I can only find a full propeller kit for £66.
I only need a shear pin.

 

[vas]

If you cannot find it maybe you can make one up.
my QL thruster shear pin is just a piece of ss rod nothing fancy.
Stupidly never bothered to measure and keep the dia and length!

 

[Croftie]

Perhaps if Portland Billy either buys one or makes one from measuring the old bits he could post the size to help other in the future.

 

[Portland Billy]

I have one spare remaining.
Will measure up and cut some from SS rod.
Seems this yet another item discontinued by VP.

 

[Momac]

Do you have the broken pin for comparison?
Maybe a suitable shear pin can be found in one of those little Holt Marine packs sold in chandleries ?

 

[DavidJ]

I have one spare remaining.
Will measure up and cut some from SS rod.
Seems this yet another item discontinued by VP.

Kindly share the dimensions when you have them. Which QL unit do you have?

 

[Portofino]

Thing is shear pins are designed to SHEAR at a specific loading which is decided by a combination of pin material, cross sectional area, hardness/heat treatmant of the material.
If you can acurately duplicate all of these then fine. If not you could end up with a pin that is not strong enough to take the full torque of the motor .
Or worse still one that will not shear until after the prop has been damaged or something somewhere in between like teeth on the gearbox .
Starts to get a tad expensive from then onwards .

 

[Kawasaki]

Porto is correct
U can’t just stick a ‘piece’ in
It is more technical than that
I speak from experience
Tried ‘bodging ’ on three boats
Nimbus 27
Nimbus 365
Plus a Fairline
3 times further failure until I fitted ‘original equipment’
OE for short!
the Nimbus 365 was/ is where the problem of the incorrect shear pin really highlited to me the ‘not to bodge’ scenario
I stuck 3 homemade pins in
Correct diameter etc etc
All failed eventually
?

 

[penfold]

They're supposed to fail? How do you know they didn't do exactly what they're supposed to do and fail when an obstruction came through the tube?

 

[DavidJ]

They're supposed to fail? How do you know they didn't do exactly what they're supposed to do and fail when an obstruction came through the tube?

Yes there is a chance that Kawasaki had hit on the right material specification and the failure was due to an obstruction but my money is on failure due to material guesswork.

 

[Portland Billy]

I well understand the function of a shear pin.
But if spares are unavailable - what options do I have other than self engineered replacement ?

 

[plumbob]

I have the same thruster and bought 2 from DB marine at Cookham. Turns out they are mild steel as anything else wouldn't shear. I have the part number on the boat and can let you have it over the weekend if that helps? PM me if you want it.

 

[Portland Billy]

Thanks Plumbob.
I have the part number and will give DB a call.

 

[Portland Billy]

Gentleman at DB says cut some from similar diameter SS.
Non in stock and non on order.

 

[jamie langstone]

I having the same problem with a left hand prop for a QL thruster they don’t make them but there are right hand ones around . If any one has a left let me know.

 

[oldgit]

Club member had a bowthruster shaft fail where the shear pin goes throught shaft.
Chance of OEM replacement . NIL. Out of prduction.
Faced with purchase of complete new unit.
Local machine shop either welded old unit or turned up a new shaft for about £50.00.

 

[Momac]

Some debris was accidentally drawn into my bow thruster . The shear pin survived but the plastic prop was damaged by the shear pin.
So much for the shear pin being the weakest link.

 

[madabouttheboat]

I having the same problem with a left hand prop for a QL thruster they don’t make them but there are right hand ones around . If any one has a left let me know.

Am i being dumb, but couldn't you just fit a right handed prop and then swap teh wires around at the switch so that the prop direction is effectively reversed?

 

[jamie langstone]

Am i being dumb, but couldn't you just fit a right handed prop and then swap teh wires around at the switch so that the prop direction is effectively reversed?

My thruster has 2 props one RH and LH . If you put 2 the same props on it will counteract each other . Currently I just have 1 prop on that gives me some thrust .

 

[vas]

odd, my QL has one shaft bringing the thrust from the motor and a small gbox with two half shafts each one with an identical propeler contrarotating...