[rob the elder]

I looked at a NIB flap. They have a black wear surface that appears to be glued to the bottom of the rear edge of the flap. The issue I have is this needs to be on the inside edge of both flaps to come into contact with the top mechanism. But thanks for the info, it suggests adding a wear surface to the bottom inside edge may be a viable solution. I am seeing the beginning of chipping where the top comes into contact with the flap that I want to prevent in future.

 

[kgschlosser]

The observation that decreasing the length of the arm decreases the force is important.

Yes and no. It's a double edged sword with this thing. Remember there is a spring that holds the thing closed. The cable pulls on the door and as the door moves the spring has to compress. By shortening the tab what is going to happen is the cable is going to loose some mechanical advantage against the spring so the cable is going to have to exert more force onto the tab in order to move the door. But because the tab is now shorter it is going to become stronger. Again it's mechanical advantage and a lever.... The unseen force which is the one I believe to be breaking the doors is when the top comes into contact with the door. It is supposed to do this by design. If you look at the top edge of the door there is a second kind of plastic bonded to that edge. It's probably nylon because of the slick properties of it.

So what I believe to be happening is with time the cable stretches and as that cable stretches the door opens up less and less. This lessens the entry angle when the top frame comes into contact with it. It gets to the point where the top frame is jamming the door laterally instead of the door sliding up. This force being applied to the door in a manner in which it is not designed I think is what is doing the doors in. The hing breaks and then the lock rod clip break probably the next time you drop the top into the trunk. Because of where those doors are when the top is up you would have no clue that something happened to it until you lower it and at that point it's too late and more damage has taken place. It's like one of those Jason Bourne maneuvers when he slams the book into the guys throat. the throat being the top frame and the book being the door.

 

[kgschlosser]

@rob the elder

I will take some photos tomorrow of the door and the angles at which the door comes into contact with the top fame.

 

[rob the elder]

The issue on both my cars is the top structure does NOT come into contact with the black piece on the bottom of the flap. Instead it comes into contact with the inside edge of the flap where there is no wear strip.

 

[joybill44]

The issue on both my cars is the top structure does NOT come into contact with the black piece on the bottom of the flap. Instead it comes into contact with the inside edge of the flap where there is no wear strip.

This brings us back to the bracket that holds the cable housing. To get maximum lift of the flap, the bracket has to be bent slightly down to remove excessive slack in the cable.

 

[rob the elder]

I understand the part that bracket playes in the start of motion and final travel. All my flaps are adjusted such that there is very slight tension in the cable when fully closed. I already did that adjustment. I check it every few months and have used this method on others cars to improve flap performance.

 

[joybill44]

I understand the part that bracket playes in the start of motion and final travel. All my flaps are adjusted such that there is very slight tension in the cable when fully closed. I already did that adjustment. I check it every few months and have used this method on others cars to improve flap performance.

One thing I have never seen is the other end of the cable housing. What is it attached to? is there any adjustment potential there?

 

[kgschlosser]

what needs to be done to remove the slack is to have a new end put on the cable.

This is the end you would want to use.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

It does away with the lock rod clip. The one above has to be crimped. I am sure it could be drilled and tapped to use a couple of set screws to grab the cable.

 

[kgschlosser]

even better. I finally found an example. This one is not crimped on It has a way of tightening onto the cable.

Swageless Fork Terminal for 3mm wire

That is for a 3mm cable which is too large their website says that can make other sizes. I think the cable in the Kappa is either 1.5mm or 1.6mm

 

[kgschlosser]

here is one that will fit the cables Not sure how much these things are tho.

15-FORK-6x12 - Griplock Systems, LLC

15-FORK-6x12. Fork Gripper with locking pin. For use with 3/64” – 1/16” 7x7 or 7x19 aircraft cable only. Cable Suspension Systems.

griplocksystems.com

 

[rob the elder]

The upper end of the cable is attached to the flap with the plastic clip. The upper cable housing is held in position by the metal arm or tab that we discussed above that can be moved up or down to increase or reduce tension on the cable. The cable then goes down and around the hinge and comes out basically parallel with the front edge of the top, pointed outward. The cable then curves to the rear and the housing is held in place by a fitting that is screwed in place to retain the housing. The cable travels to the rear, the curves up around the hinge ending up pointing forward again. The end is retained by a screw into the top of the hinge. When the top is rotated forward, the cable end rotates on the hinge forward which pulls on the wire. This motion is then translated to the end of the cable attached to the flap, which has the affect of pulling on the attachment point and rotating against the spring to open the flap aboug 20 degreese. This is where the flap is located when the top upper arm comes forward and into contact with the inside edge of the flap near the rear corner. The top upper arm then forces the flap up and forward rotating againsat the spring.

 

[joybill44]

The upper end of the cable is attached to the flap with the plastic clip. The upper cable housing is held in position by the metal arm or tab that we discussed above that can be moved up or down to increase or reduce tension on the cable. The cable then goes down and around the hinge and comes out basically parallel with the front edge of the top, pointed outward. The cable then curves to the rear and the housing is held in place by a fitting that is screwed in place to retain the housing. The cable travels to the rear, the curves up around the hinge ending up pointing forward again. The end is retained by a screw into the top of the hinge. When the top is rotated forward, the cable end rotates on the hinge forward which pulls on the wire. This motion is then translated to the end of the cable attached to the flap, which has the affect of pulling on the attachment point and rotating against the spring to open the flap aboug 20 degreese. This is where the flap is located when the top upper arm comes forward and into contact with the inside edge of the flap near the rear corner. The top upper arm then forces the flap up and forward rotating againsat the spring.

Am enclosing some photos to show exactly what my flaps are doing and when. It may help to explain why some cars have had no flap problems and others have. One photo shows where my top is by the time the flap is raised by the cable and before the top frame engages the edge of the flap. Another shows that my flap is open better than 65 degrees at this point. Another shows that my frame contacts the black plastic piece on the bottom of the flap and doesn't touch the flap itself. Another shows about how much slack I have adjusted into the cable by bending the cable bracket.

 

[rob the elder]

Was notified that the updated print file is done. They will do a test print and we will see how it turns out. More to come.