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[Doug D]

I've had my boat in the water for a week now. I try to sail her every evening if weather and the wind permits it.
The biggest problem I have encounters so far is the two brass shear pins keep coming out of the Universal Coupler.
I have learned that after about one hour of running time I have to bring the boat out of the water and check the shear pins to see if they are still in place.
More than once I've found them half way out, or one of them completely out and the other half way out.
It's a 15 minute fix each time and means I have to remove the universal coupler from the boat to put the pins back in.

I've considered switching to a different type of Universal Coupler but have not found any to date that are the appropriate size on the drive shaft end.
Part of the problem may be the heavy duty motor I have installed in my boat. Its got a lot of torque when its running at full speed and I've no doubt that's also a big part of the issue.
I'm dealing with a 7mm driveshaft diameter coming off the electric motor and a 4mm propeller shaft diameter.
Most of the universal couplers I've found are not large enough to accomodate that 7 mm drive shaft.

The brass shear pins came as a part of the Mobile Marine Models Heavy Duty Safety - Coupling kit.
From day one I've felt those shear pins were far to short and you have no way to secure them other than a friction fit. Within an hour of run time the pins are wanting to come out.

I was wondering if anyone else has run in to this same situation ?
I've got an idea on how to solve the problem but would appreciate knowing if anyone else has encountered my same probnlem
What was your solution ?

[Netleyned]

Have you spoke to Brian at MMM?

Ned

[Marks Model Bits]

Get some brass rod the right diameter and long enough to bend the ends over....... The pic below just about shows how I did it

[tugs62]

ive had the same problem now i just slide a piece of sillicon pipe over the coupling and i since ive not had it happen

[HS93 (RIP)]

Use two short lengths of heat shrink or the tube as in the last post , if you bend it over you could rip your hands to bits if you happen to get one in the way .


that is just my opinion

Peter

[Marks Model Bits]

if you bend it over you could rip your hands to bits if you happen to get one in the way.

True, but you would only do it once!!!! I tend not to put my hands (or any other part of my anatomy for that matter) too close to any rotating parts, also by this definition props are even more dangerous and would do far more damage!! 

[boatmadman]

You could replace the pins with new ones the right diameter and length. Put them inand then centre punch eac end. They wont come out then
You do need to remove the coupling to do this and place the end you are not punching on a solid lump of metal, a vice jaw for example.

Ian

[Brian Roberts]

Doug

I had this problem with my Imara, I just wound some insulating tape around the two shear pins and it's been fine ever since.

Brian

[nemesis]

Hi, Before you muck about with it get in touch with the people who sold it to you. They should replace the faulty item & maybe thank you for informing them of a possible manufacturing fault, Nemesis

[Norseman]

True, but you would only do it once!!!! I

An adult observation, but as kids also read these threads Peter's advice has to be the way to go.
Why deliberately build a nasty possibility into something when there are safe options available?
Then follow up it with exactly what you say - don't ever mix fingers and whirly bits.
Safety first time, every time Kids

Dave