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Door pin lengths

RandyAB

Well Known Member
I'm getting ready to cut the pushrods and tap them for the Plane Around angled door pins. For the length, should I be aiming to maximize the extended length whereby the tip of the pin just sits at the outer edge of the Delrin block on the door when the door handle is in the full open position?
 
I'm getting ready to cut the pushrods and tap them for the Plane Around angled door pins. For the length, should I be aiming to maximize the extended length whereby the tip of the pin just sits at the outer edge of the Delrin block on the door when the door handle is in the full open position?

Yes, or possibly further, depending upon the gap between blocks. However, be advised that once the strut is installed, the aft part of the door will be pushed another 1/8-3/16" aft. I ended up with custom block for the door frame to tighten the gap between the two blocks. Then the block ride on one another and move the door forward. Otherwise the edge of the door would be scraping on the cabin top edge.

I think the plane around guys make a thicker block.

As long as the pin goes fully through the aluminum frame on extension, you are good. Extra distance beyond fully in doesn't add anything.

Larry
 
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As long as the pin goes fully through the aluminum frame on extension, you are good. Extra distance beyond fully in doesn't add anything. Larry

How do you measure fully?

I am aware of one instance where a builder (who I won't name and it wasn't me) had the pins extend just through the frame. The door flexed and opened. Fortunately, the pilot didn't get rattled and there was no incident.

I would recommend 1/2" to an 1" to prevent any flexing of the door to be problematic.
 
Yes, or possibly further, depending upon the gap between blocks. However, be advised that once the strut is installed, the aft part of the door will be pushed another 1/8-3/16" aft. I ended up with custom block for the door frame to tighten the gap between the two blocks. Then the block ride on one another and move the door forward. Otherwise the edge of the door would be scraping on the cabin top edge.

I think the plane around guys make a thicker block.

As long as the pin goes fully through the aluminum frame on extension, you are good. Extra distance beyond fully in doesn't add anything.

Larry


Thanks Larry. I haven?t put the strut in yet. I wonder why it would cause the door to be pushed aft if everything is in proper plane.
 
How do you measure fully?

I am aware of one instance where a builder (who I won't name and it wasn't me) had the pins extend just through the frame. The door flexed and opened. Fortunately, the pilot didn't get rattled and there was no incident.

I would recommend 1/2" to an 1" to prevent any flexing of the door to be problematic.

By fully I meant that to a point that the full circumference of the rod/pin has passed through the hole. My pins are slash cut on a 45, so at that point there is another 1/2" of pin still past the opening. In my case the pins are SS and there is still an 1/8" of F/G and another 3/16" of delrin block to help prevent the above to happen. I also have a center latch that should help to minimize some of the flexiing.

I do see your point and thinking about it a bit more realize that my advice was probably not appropriate.

Larry
 
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Thanks Larry. I haven’t put the strut in yet. I wonder why it would cause the door to be pushed aft if everything is in proper plane.

The strut applies a strong pressure to only the aft portion of the door. This creates a force similar to pressing on the forward portion of the lower door backwards as it is being closed. The hinge pins flex a 1/2 degree or so allowing a slight angle to the door. this angle moves the bottom of the door aft, as I mentioned. I suspect this is why van's put a bevel on the door edges, to allow them to ride up in this interference. However, if you go with MC seals and more squared door edges, I believe this is an issue that will result in chipped paint. My door edges were definately rubbing in the lower portion of the door until I worked with the delrin blocks to control it. Now the two blocks bring the door into alignment just before it closes fully.

Not sure if this issue is unique to me or not. My hinges are well adjusted, as without the strut I have a clean and true door movement.

Larry
 
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Pin extension

Randy,

Having 180 degrees on the handle equates to around 2" of lateral movement on the pushrods. Vans' system allows for only 90-110 degrees and 1 to 1-1/4" of lateral movement.
That being said one of the advantages of having 180 and the cam is allowing the cam to do its job by pulling the door in before the pins exit the door. I have around 1-1/2" of extension out of the door and 1/2" retraction. This still allows for penetration through the Delrin guides and the fuselage bulkhead. It is about 20-30 degrees of handle movement for the cam to do its job.
The pins are 2" long so you can extend the pushrods and cut them off where you want the pins to extend, then cut off another 2".
The strut does flex the door but the Delrin blocks from PA are thick enough you can "capture" the door in place where you want so it doesn't move for nor aft. This is good because one pushrod will always have a little more friction than the other side and want to shift the door. If it is captured it won't allow it and it helps with the strut flexing the door. Just sand the bottom of the delrin guides until there is enough room for the door to fit.

Hope this helps. Feel free to call if you have more questions or VAF.
801-580-3737
 
Randy,

Having 180 degrees on the handle equates to around 2" of lateral movement on the pushrods. Vans' system allows for only 90-110 degrees and 1 to 1-1/4" of lateral movement.
That being said one of the advantages of having 180 and the cam is allowing the cam to do its job by pulling the door in before the pins exit the door. I have around 1-1/2" of extension out of the door and 1/2" retraction. This still allows for penetration through the Delrin guides and the fuselage bulkhead. It is about 20-30 degrees of handle movement for the cam to do its job.
The pins are 2" long so you can extend the pushrods and cut them off where you want the pins to extend, then cut off another 2".
The strut does flex the door but the Delrin blocks from PA are thick enough you can "capture" the door in place where you want so it doesn't move for nor aft. This is good because one pushrod will always have a little more friction than the other side and want to shift the door. If it is captured it won't allow it and it helps with the strut flexing the door. Just sand the bottom of the delrin guides until there is enough room for the door to fit.

Hope this helps. Feel free to call if you have more questions or VAF.
801-580-3737

Thanks Sean. That makes sense to make the pin short enough to allow the cam to work it?s magic before engaging the pins. I hadn?t realized that the Van?s stock system had less travel. I will aim for about 1/2? recess into the door block.
 
The strut applies a strong pressure to only the aft portion of the door. This creates a force similar to pressing on the forward portion of the lower door backwards as it is being closed. The hinge pins flex a 1/2 degree or so allowing a slight angle to the door. this angle moves the bottom of the door aft, as I mentioned. I suspect this is why van's put a bevel on the door edges, to allow them to ride up in this interference. However, if you go with MC seals and more squared door edges, I believe this is an issue that will result in chipped paint. My door edges were definately rubbing in the lower portion of the door until I worked with the delrin blocks to control it. Now the two blocks bring the door into alignment just before it closes fully.

Not sure if this issue is unique to me or not. My hinges are well adjusted, as without the strut I have a clean and true door movement.

Larry

Thanks for this Larry.
 
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