Linear actuators?

[Timebender]

I was telling my son today about the neat work being done by Bttws with his door marker lights with the animated arrows that can be seen in the video below.


https://www.youtube.com/watch?v=NL8gkeKKttA
Anyway, he mentioned it's too bad the doors don't automatically open and close in sync with the respective animations - and then we both said "Linear actuators!"

So I'm wondering if this can be used instead of the struts (or something with more force):
https://www.firgelliauto.com/products/high-speed-actuator
http://dmctalk.org/attachment.php?attachmentid=47981&d=1482559949

The only drawback I can see off the top of my head, is if the battery is dead or we lose any power electrically, the doors would be stuck shut or open. We could however add a second battery in the cubby behind the driver or in the front trunk as a backup in case of a power failure of some sort.

Thoughts? How much force do the struts provide?

[vwdmc16]

In my experience, linear actuators are pretty slow, you would have to wait about 10 seconds for the the door to go one way. I know I couldn't put up with that.

[Timebender]

There are now linear actuators that move a lot faster - a number of R2 Builders use them for doing the 3 leg to 2 leg transition, and that happens in about 1 second. The one I posted here in the link at the beginning of the thread is high speed and has a 20 pound force.
From what I can tell, the lifts we use now are 15 points pounds of force.

[Patrick C]

At the DCS in Dayton, there was a car with linear actuators. The doors still open via door struts like a normal DeLorean, but a hidden cable goes into the pontoon that connects to a linear actuator that will pull the door shut. It did take about 10 seconds or more to close via remote. Alternatively, you can still close the door conventionally. There are videos somewhere.

The owner did tell me the Acura engine swap he did in that DeLorean was easier than installing the linear actuators.

EDIT: Photos added that I shot at DCS.

[rickjames8]

it's too bad the doors don't automatically open and close in sync with the respective animations - and then we both said "Linear actuators!"


So for a while I owned a kit car called a Sterling. It had a very heavy canopy top that was assisted by struts, just like our doors. Many owners opted to supplement the struts with actuators. The only way to get a decent amount of speed (think less than 20 seconds for the door to open) was to use hydraulics. Mine had that, and my top could open in ~8 seconds. The trick was getting it to stop gently at the top of the travel, otherwise you're putting a ton of wear on hinges, body, and other components as the actuators stop and the door tries to keep flying forward.

This gets really annoying when you're in the rain.
47996


The owner did tell me the Acura engine swap he did in that DeLorean...

Ooh, interesting. Any more details on this swap? I'm a big fan of Honda engines. Especially ones that are easier to install than actuators. ;-)

[tommyrich]

At the DCS in Dayton, there was a car with linear actuators. The doors still open via door struts like a normal DeLorean, but a hidden cable goes into the pontoon that connects to a linear actuator that will pull the door shut. It did take about 10 seconds or more to close via remote. Alternatively, you can still close the door conventionally. There are videos somewhere.

The owner did tell me the Acura engine swap he did in that DeLorean was easier than installing the linear actuators.

EDIT: Photos added that I shot at DCS.

Yes, that's my car! :smile:
I used linear actuator for door closers. The trick is the struts lift around 300 lbs. This requires very powerful actuators to overcome the force. So, in order to go faster, you would need stronger actuators (more power).
When I said the Acura swap was easier, I think I was referring to the fact that many people have done various engine swaps, and it was something that was sort of expected to (eventually) work. The door closer system was something entirely new and we weren't sure it was even possible (or at least practical). But with the help of some smart and persistent friends, we were able to do both.
Tom

[Timebender]

The struts lift 300 pounds? I must be a lot stronger than I thought, as I've had to lift DeLorean doors that had dead struts before and it seemed a lot lighter than that :).

[DMC-81]

The struts lift 300 pounds? I must be a lot stronger than I thought, as I've had to lift DeLorean doors that had dead struts before and it seemed a lot lighter than that :).

Yeah, me too. I imagine that we have more leverage lifting from the bottom edge of the door than where the strut has to lift from partway up the roof section of the door. :strongman:

[tommyrich]

Yeah, me too. I imagine that we have more leverage lifting from the bottom edge of the door than where the strut has to lift from partway up the roof section of the door. :strongman:

Leverage, plus the torsion bar is helping a lot. You get the most help on a fully closed door. That's why the door without a strut gets much heavier as you raise it. The Delorean struts are very powerful for their size (strongly charged). This may be one factor in why they only last a few years.
Tom