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PostPosted: Sun Aug 12, 2018 8:28 pm 
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Joined: Sat Nov 12, 2005 10:46 pm
Posts: 2903
Location: Escondido
tonystott wrote:
Sorry, but I have difficulty sgreeing with your logic.

1. Pedal forces are concentrated on the FRONT lip.
Only if the front Drive tongue contacts it.
2. Building up the rear of the socket will INCREASE forces on the front lip.
Sorry, I don't follow you on this. I'm not sure wht the "rear of the socket" is.
3. In order to seal the leak, it appears necessary to build up the front lip during the repair.
Agreed.
4. This will result, if nothing else changes, in greater pressure on the front lip due to the retaining "axle"
If you shave off the underside of the Drive front tongue, space is created for the repair. There should be no static pressure at all.
5. Raising the "axle" by shimmimg the drive mount will lessen pressure on the front lip,
Raising the axle by shimming risks insufficient fin clearance under the hull, requires extra work and is not necessary considering the alternative you mention in the next line.
OR shaving off some of the front of the Miragedrive to accommodate the raised surface of the fron lip.

I see absolutely no benefit in raising the rear lip. Agreed.
Tony, perhaps I didn't communicate well. I agree there is no benefit of raising the rear lip. I simply meant to suggest the possibility of building it forward to close the gap (shown in the first pic above). I wouldn't do it that way unless there were alignment issues (where Drive nose is pointing too far down).

As you can clearly see in the second pic, the rear of the Drive is resting squarely against the drivewell. It is not touching the front lip at all -- nothing but air is touching the front of the drivewell, including the front lip. The Drive pivots around the drum axle. It is designed to make first contact with the "lip" at the front of the drivewell. If the front Drive tongue is too high , it will pivot against the rear "lip" as it rotates further (as pictured). I have a Drive that does this, so there is no logic involved.

I had occasion to work with another forum member with a PA who had this scenario and developed a leak in the rear of the drivewell where the blue arrow points (3rd pic). We applied the patch as I suggested here with the adhesive I suggested here and resolved the issue. So all the above recommendations were based on experience, not logic.

This is just my opinion as an option to attempting to repair the front lip. I wish SI every success however he decides to handle the problem! 8)


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PostPosted: Mon Aug 13, 2018 4:11 am 
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Joined: Wed May 11, 2016 1:27 am
Posts: 375
I am interested in this as I have an old 2006 adventure hull with the same issue. I haven't bothered to repair due to lack of faith in repair. However I am thinking of turning it into mainly a paddle yak, hence not stressing the repair. This mod would allow me to still use the drive as a secondary option for occasional use.


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PostPosted: Thu Aug 16, 2018 12:44 am 
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Joined: Mon Nov 10, 2014 6:20 pm
Posts: 111
Location: Pula - Sardinia
in this moment the leak is fixed with plastic welding but I am not using the rear pedal. i removed half of the lip of the pedal but the quantity of added plastic it too high and the drive still doesnt enter properly. Raising the click and go is therefore necessary. I am waiting from Amazon the proper tool cause here in europe we cannot find easily a 3/14 inch ball allen!
after i will raise the block I know that, as you said. there will always be a risk that the leak with come again.
I thought to create a sort of "shaped" glove with resin that should cover that area of the drivewell. this resin will not attach the drivewell but after shaped it could be glued there. with this sort of shaped glove i should get 2 results: 1. the mirage drive will not hit and damage the plastic but will hit the resin. 2. since the resin is shaped the front force when u pedal will not go all in that damn small point but will be distributed on a larger area of the front drivewell.
what do you think about it?


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PostPosted: Thu Aug 16, 2018 10:41 pm 
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Joined: Sat Nov 12, 2005 10:46 pm
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Location: Escondido
The best way to find out is to try it -- you really have nothing to lose. If you decide to shim the C&G levers, I would recommend a Stainless steel plate so there is no problems with corrosion. Plexiglass might work, but might crack under the load. You may need longer screws as well. Before beginning, if you put your Drive in the other drivewell and flip the fins against the hull, you can estimate how much free play you have. When you raise the Drive mounts,you will have that much less space for the fins underneath the hull.

I couldn't guess how the fiberglass glove would work out for you. It might be worth a try, but I'm not sure it would be any different than putting more plastic in -- the plastic would be more rigid. In any event, there is a limit as to how much you can raise the Drive!

If this doesn't work out, you still have the option to use the back of the Drivewell by cutting the front Drive tab off flush:

Image

By doing so, there won't be any pressure against the front shelf of the drivewell. The drive will pivot until it rests against the back shelf. 8)


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PostPosted: Fri Aug 24, 2018 5:39 pm 
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Joined: Sat Nov 05, 2011 1:58 am
Posts: 2819
Location: Forster, NSW, Australia
Roadrunner wrote:
tonystott wrote:
Sorry, but I have difficulty sgreeing with your logic.

1. Pedal forces are concentrated on the FRONT lip.
Only if the front Drive tongue contacts it.
2. Building up the rear of the socket will INCREASE forces on the front lip.
Sorry, I don't follow you on this. I'm not sure wht the "rear of the socket" is.
3. In order to seal the leak, it appears necessary to build up the front lip during the repair.
Agreed.
4. This will result, if nothing else changes, in greater pressure on the front lip due to the retaining "axle"
If you shave off the underside of the Drive front tongue, space is created for the repair. There should be no static pressure at all.
5. Raising the "axle" by shimmimg the drive mount will lessen pressure on the front lip,
Raising the axle by shimming risks insufficient fin clearance under the hull, requires extra work and is not necessary considering the alternative you mention in the next line.
OR shaving off some of the front of the Miragedrive to accommodate the raised surface of the fron lip.

I see absolutely no benefit in raising the rear lip. Agreed.
Tony, perhaps I didn't communicate well. I agree there is no benefit of raising the rear lip. I simply meant to suggest the possibility of building it forward to close the gap (shown in the first pic above). I wouldn't do it that way unless there were alignment issues (where Drive nose is pointing too far down).

As you can clearly see in the second pic, the rear of the Drive is resting squarely against the drivewell. It is not touching the front lip at all -- nothing but air is touching the front of the drivewell, including the front lip. The Drive pivots around the drum axle. It is designed to make first contact with the "lip" at the front of the drivewell. If the front Drive tongue is too high , it will pivot against the rear "lip" as it rotates further (as pictured). I have a Drive that does this, so there is no logic involved.

I had occasion to work with another forum member with a PA who had this scenario and developed a leak in the rear of the drivewell where the blue arrow points (3rd pic). We applied the patch as I suggested here with the adhesive I suggested here and resolved the issue. So all the above recommendations were based on experience, not logic.

This is just my opinion as an option to attempting to repair the front lip. I wish SI every success however he decides to handle the problem! 8)

Roadrunner, my comments (NB I have no engineering qualifications) reflected my belief that the only areas of the hull experiencing forces generated by forward pressure on the Miragedrive pedals are
1) Strong downward force from the drive on the front lip of the drivewell
2) After maximum load is on the front lip, there will be upward force on the drive axle.

There will be zero pedalling forces applied to the rear of the drivewell

_________________
Tony Stott
2012 Tandem Island "SIC EM" with Hobie spinnaker and Hangkai outboard
only cool people follow the (non-magnetic) titanium weight-loss program! lol.)


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PostPosted: Wed Aug 29, 2018 7:48 am 
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Site Rank - Captain

Joined: Mon Nov 10, 2014 6:20 pm
Posts: 111
Location: Pula - Sardinia
Roadrunner wrote:
The best way to find out is to try it -- you really have nothing to lose. If you decide to shim the C&G levers, I would recommend a Stainless steel plate so there is no problems with corrosion. Plexiglass might work, but might crack under the load. You may need longer screws as well. Before beginning, if you put your Drive in the other drivewell and flip the fins against the hull, you can estimate how much free play you have. When you raise the Drive mounts,you will have that much less space for the fins underneath the hull.

I couldn't guess how the fiberglass glove would work out for you. It might be worth a try, but I'm not sure it would be any different than putting more plastic in -- the plastic would be more rigid. In any event, there is a limit as to how much you can raise the Drive!

If this doesn't work out, you still have the option to use the back of the Drivewell by cutting the front Drive tab off flush:

Image

By doing so, there won't be any pressure against the front shelf of the drivewell. The drive will pivot until it rests against the back shelf. 8)


Roadrunner thank u and thanx to all the other partecipants in this thread. I didn't do all the changes because of no time and then I wanted to collect ideas before making some worst damage.
I have a question for u. if I remove completely the front lip as you say for sure i will not have any other problem of "hitting" but where will the pedalling forces go? how will the pedal work without that lip?

about the "fiber glove" I wanted to add that creating a shaped cointainer for the drive in that front point I should have spread the forces into a wider area reducing the pressure. now the force is applied only in that small point where the drive lip touch the drive well. if i want to have a shaped receiver for the drive front i need a material that can be modelled
does any of u have removed the screws? I'd like to know their sice vecause in europe we use the metric system and maybe I could have problems to find the same thinkness with lonnger lenght.

at last i didnt mention the very last solution that i could try if everything goes wrong. opening a new hatch in the hull on the front seat and working on the f...ing leak from the inside.


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