Door poppers - modifying door latch

[rockdogz]

I'm having fun getting the door poppers to work with the stock latches on my '68. There seem to be two limitations with the door popper solenoid that I'm running into:
-they can't have a load on them - cable must be loose
-they only pull about 3/4"

So I think I may need to make some modifications to the door latch, and wanted to get some feedback.



In my pic of the door latch here, when you pull up on the door handle inside the car, it pulls in the direction of A. The lever in turn causes the part B to go down, and pushes on the lever C. However, this takes too much motion - much more than 3/4" to occur. Plus, you can't pre-load the cable on the solenoid and get it close to releasing the latch, because of the first limitation.

So my thought is to drill at D and put a pin in there to limit the upward travel of the lever C. This would make B then only have to travel a very small distance - say 1/2" - to release the latch. What do you think?



I know that the other way to trip the latch - the lever you push when pushing in the button on the outside of the door - takes less effort, but this lever travels 90 degrees opposite of the direction of A and I can't see how the solenoid could be mounted to make that work.

[Camaro Zach]

do the math and mount the cable (perferrably rod) from the solenoid inbetween the "A" cable and the pivot of the arm.

[rockdogz]

do the math and mount the cable (perferrably rod) from the solenoid inbetween the "A" cable and the pivot of the arm.

There is too much travel - the solenoid can only pull about 3/4".

[bretcopsey]

I think what Camaro Zach is suggesting is if you move the cable attaching point from it's current location of Point 'A' up the arm, closer to the pivot, the travle will decrease.

The yellow dot represents the new mounting point for the cable, the pivot is circled in green.

You just need to calculate where the yellow dot needs to be.

[rockdogz]

I think what Camaro Zach is suggesting is if you move the cable attaching point from it's current location of Point 'A' up the arm, closer to the pivot, the travle will decrease.

The yellow dot represents the new mounting point for the cable, the pivot is circled in green.

You just need to calculate where the yellow dot needs to be.

That would decrease the leverage, making it even harder to pull...

[black67ls1]

What about using a push-pull cable connected from the solenoid to
the top (thumb actuated) part of the latch? I was thinking of mounting the solenoid at the front of the door down low, then running a push-pull cable toward the back then up then a tight curve to the top of the door latch. I just don't know if the end of the cable will be flexible enough to make the curve at the top of the door.

A variant to the idea above is to use something I once on the internet. It's a metal part that would be mounted to the inside
of the door the same as the latch. The part pivots from 0 to -90 degrees thereby converting up and down motion to side to side.
Then the push pull cable would just pull down on the bottom of the pivot point and pull across on the thumb latch.

Has anyone done door solenoids reliably?

[bretcopsey]

Tom, you are correct, and that is where the calculations come into play. You need to calculate what your ratio is currently and how much force is required to actuate the latch. Once you have established that base, you can calculate what the new ratio is and determine if the soledoid can generate enough force to still actuate the latch.

[Camaro Zach]

That would decrease the leverage, making it even harder to pull...

how many lbs are your solenoids. I went outside and messed around with my car and a 35 lb solenoid would pull it with ease with the decreased leverage....

[rockdogz]

how many lbs are your solenoids. I went outside and messed around with my car and a 35 lb solenoid would pull it with ease with the decreased leverage....

I think they are 35 lb units

[rockdogz]

What about using a push-pull cable connected from the solenoid to
the top (thumb actuated) part of the latch? I was thinking of mounting the solenoid at the front of the door down low, then running a push-pull cable toward the back then up then a tight curve to the top of the door latch. I just don't know if the end of the cable will be flexible enough to make the curve at the top of the door.

A variant to the idea above is to use something I once on the internet. It's a metal part that would be mounted to the inside
of the door the same as the latch. The part pivots from 0 to -90 degrees thereby converting up and down motion to side to side.
Then the push pull cable would just pull down on the bottom of the pivot point and pull across on the thumb latch.

Has anyone done door solenoids reliably?

That may work, although I'm trying to keep it as simple as possible since I figure the more complex the contraption is inside the door the more failure points it has.

[rockdogz]

Tom, you are correct, and that is where the calculations come into play. You need to calculate what your ratio is currently and how much force is required to actuate the latch. Once you have established that base, you can calculate what the new ratio is and determine if the soledoid can generate enough force to still actuate the latch.

I don't doubt you are right, but I was just trying to help the situation by requiring much less distance/effort required to pop the latch, thus saving the solenoid from having to work so hard and stress itself plus the cable so much. I think it would make them last longer.

[rockdogz]

What about using a push-pull cable connected from the solenoid to
the top (thumb actuated) part of the latch? I was thinking of mounting the solenoid at the front of the door down low, then running a push-pull cable toward the back then up then a tight curve to the top of the door latch. I just don't know if the end of the cable will be flexible enough to make the curve at the top of the door.

A variant to the idea above is to use something I once on the internet. It's a metal part that would be mounted to the inside
of the door the same as the latch. The part pivots from 0 to -90 degrees thereby converting up and down motion to side to side.
Then the push pull cable would just pull down on the bottom of the pivot point and pull across on the thumb latch.

Has anyone done door solenoids reliably?

I think I will try this next! I got some brake line that I will bend and run the cable in to make the bend.

[John McIntire]

I'm in the process of doing the same thing on my Chevelle. I'm attaching the solenoid to the "A" lever in the picture above. There is just enough room there to mount the solenoid and have it pull directly on that latch

[mikey]

I would try to eliminate the cable and replace it with a rod made out of linkage from a donor door handle. We used to do it that way with power door lock actuators on street rods in the 80's.

[rockdogz]

Using a rod sounds like a good idea, I'll have to figure out how to make that work. I finally just got it working tonight by mounting the solenoid low in the door under the latch and running the cable through a 3/16 brake line bent to angle towards the top of the latch. I ended up drilling a hole in the very top of the latch (not in the picture) on the piece that the pushbutton on the outside door handle would normally hit.

It seems that when the solenoid is mounted in this position for some reason it was able to work with some tension on the cable - I was able to pull it so that the small amount of travel in the solenoid plunger was enough to trip the latch. At least a few times - I'm going to try it a bunch more before I'm satisfied... and that's only if i can't figure out how to make a rod work because that sounds more durable.

[r.friborg]

I'm having fun getting the door poppers to work with the stock latches on my '68. There seem to be two limitations with the door popper solenoid that I'm running into:
-they can't have a load on them - cable must be loose
-they only pull about 3/4"

So I think I may need to make some modifications to the door latch, and wanted to get some feedback.

In my pic of the door latch here, when you pull up on the door handle inside the car, it pulls in the direction of A. The lever in turn causes the part B to go down, and pushes on the lever C. However, this takes too much motion - much more than 3/4" to occur. Plus, you can't pre-load the cable on the solenoid and get it close to releasing the latch, because of the first limitation.

So my thought is to drill at D and put a pin in there to limit the upward travel of the lever C. This would make B then only have to travel a very small distance - say 1/2" - to release the latch. What do you think?



I know that the other way to trip the latch - the lever you push when pushing in the button on the outside of the door - takes less effort, but this lever travels 90 degrees opposite of the direction of A and I can't see how the solenoid could be mounted to make that work.

Hi I did some thing almost like this on the trunk opening but the look motor is loding the trunk look a littel. Its hard to explain I am not tha good at english.
Hoope ypu understand?
Ask If you don´t.

R.F