stan2004 posted:mike g. posted:...Stan if I just use a DPDT switch I would wire the limit switches just as before correct?I assume you are referring to your earlier thread about where/how to connect limit switches. Correct, nothing changes from before. From an electrical/wiring perspective the linear-actuator is just a DC motor as before.
Thanks Stan, when the actuator arrives next week I will post some updated pictures.
Hi Guys and Gals, Here is a little update. I have been working on the bridge and got my Linear-Activator installed. Here is the deal, I need some help to figure out placement of it so it will open to and 90 degree and still close all the way. here is a video of what I have sofar. Any help would be great!
Hi Stan, Your a SMART guy, was wondering if you had a chance to view my video? If so, any ideas?
The first thing I thought was "why did he put the actuator on that side of the pivot point?" So even if you could rotate the bridge to full vertical you'd have the actuator sticking out in the aisle which will catch on your belt, shirt, whatever as you walk by. So I guess my first question is to ask if there's some reason you can't (or don't want to) put the actuator on the right side of the pivot?
I know you forgot to write down the bridge weight, but let's just say it weighs 10 lbs and assume (for the sake of discussion) that this is evenly distributed across the bridge). From high school physics this is equivalent to a 10 lbs weight sitting about 24" from the pivot point. So if your actuator can drive 200 lbs, this means you can theoretically raise/lower the bridge by applying the actuator 200/10=20 times closer to the pivot point on the right side of the pivot...or just a few inches away from the pivot.
Since you "only" have a 10" linear travel, I think you need to use this 20x leverage to allow you to swing the bridge the full 90 degrees (ignoring whether or not real bridges swing to true vertical!).
Stan, are you saying that the actuator should pull the bridge up. In other words, it sounds like you want the actuator on the right side of the pivot point as viewed in the film.
No, the actuator can be attached to bridge close to the pivot point on the bottom. It has enough power to push it up from there and stay out of aisle.
That looks really slick, Mike!
Mount the actuator base on a cross member attached to the rear outside edge of the stand/base. That will move it back, mostly out of the aisle.
Then fit the height position with the actuator nearly fully extended and the bridge held in a 90° vertical position. Attach the bridge mount near the pivot and the base will mount where it's located/falls. That's where the mounting cross member will need to be.
I think the grandchildren will be playing with the bridge a lot.
Hi all,
Stan the reason I didn't put it on the right side to pull it down is I also made a counter weight for it and was going to mount it there. But it sounds like you and Carl are thinking the same thing.
Carl, I will try putting the actiuator a few inches from the pivot point and see how it goes. I will take some pictures as I go along and another video when I am done.
One thing to consider when you have the pivot point close to the hinge, there will be a lot more force on that point, so it has to be quite strong. This is where the counterweight comes in, it lessens the force needed to lift and lower the bridge, and thus the strain on the actuator and it's mounting points.
Hi John,
I poured a concrete block that weighs 10 1/2 pounds and it fits nicely on the right side of the bridge. I took it off till I can get the actuator mounted in the right place. I am trying to get the bridge as close to 90 degrees to give me better room when going threw the door.
Hi All, Thanks for everyone's help I think I have got it almost where I want it. Tomorrow I will adjust the up limit switch, wrap the wiring, and be happy!! I hope you all like it.
Special thanks to Elliot for the limit switches,
Stan for the wire diagram,
Carl for his idea of moving the pivot point.
Gunrunner John for the idea for a counter Balance, wish I could have used the one I poured. But it would hit the actuator.
I am always open for input and ideas!
Looks like you've accomplished what you set out to do. Isn't it nice when that happens ?
Thanks Dan, it sure is nice. I notice that you get a lot accomplished also, I fallow a lot of what you do and I am very impressed!
Mike,
Ok, so closer to the pivot point works. I was seeing the actuator base located between the legs of the bridge base or the end of the table, attached to the horizontal support. Then I believe it would be mostly out of the aisle when in the up position.
Thanks Carl,
I did try it on the back side and between the support legs, but when I raise the bridge the tail end would hit the actuator. The location where it is should be ok, as that part of the bridge support will be behind the wall on one side of the door entering the room. The Bridge is 40" long and my door opening is 32" so that means 8" will be out of the path entering the room.
Dumb question, why not put the counterweight here, it looks like there's space.
Hi John,
I had one there but it was to big, but I am thinking about making a system that will let it pivot out of the way as the bridge lowers. I just haven't got that far yet. But I still like the idea of a counter balance.
I think a counter balance will make the lowering smoother, which is why I mention it. Also, it'll take a lot of strain off the connect points of the actuator. Maybe you need to find a big chunk of lead for a smaller form factor. 
gunrunnerjohn posted:Maybe you need to find a big chunk of lead for a smaller form factor.
Depleted uranium, maybe? 
Not sure, but plumbing supply houses used to sell lead in five pound increments. I don't see any reason why they wouldn't still have the lead. Plumbers use the lead to seal pipe joints in cast iron pipe. For those not familiar with the method, it goes like this. Basically you have a propane tank, not too different from the barbecue type. On top of the tank there sits a burner mechanism with it's propane supply hose connected to the tank. On top of the burner sits a kettle. The lead ingot was placed in the kettle and heated until it is molten. Then the plumber dips a ladle into the molten lead and pours it into the pipe joint.
Bottom line here, Mike, is that the lead ingots are roughly a 3" square cube. It wouldn't be too difficult to drill holes into it for eye bolts. Then you could hang it from the bridge.
Avanti posted:gunrunnerjohn posted:Maybe you need to find a big chunk of lead for a smaller form factor.
Depleted uranium, maybe?
Maybe he can get someone to fire a shot from the M1A1 into the train room. Once the damage is repaired, he has the heavy chunk of material to build the counterweight.
This looks to be about the right size...
Certified Pure Lead Brick (99.9% Pure) 26.2 pounds
mike g. posted:Thanks Carl,
I did try it on the back side and between the support legs, but when I raise the bridge the tail end would hit the actuator. The location where it is should be ok, as that part of the bridge support will be behind the wall on one side of the door entering the room. The Bridge is 40" long and my door opening is 32" so that means 8" will be out of the path entering the room.
Sweet! Now you have the power lift bridge setup.
Ok Guys'
Today I adjusted the limit switch, I founds a old Boat heat transfer tube made of Brass and filled it with concrete, so now it matches the 10 1/2 lb weight I had before. Here are a couple of picture and one last video. Enjoy. Thanks again everyone!
Great work Mike. Next time you need a bridge in a hurry, call on us Seabees.....Can Do. The difficult we can do. The impossible will take a bit longer.
Our work here is done. 
Looks a lot smoother on the down swing, not as much bouncing as without the counterweight, nice work!
First off I would like to thank everyone for there comments!
Second I would like to thank Mark, Carl, Max, RTR12, Pete, Stan, Dan, and John! Without you guys I would still be in the dark over this darn thing. Also now that it work you all have made my wife happy! Now I can do some of the things she wants done. She is a good woman and lets me do train stuff to a point and I know I spend to much doing it.
Thank You again to you great group of guys!!
Now to think of a new project that doesn't take a lot of money ( Scratch Build)
Mike.....that is nicely done!
Peter
Not at all, Mike. It was a pleasure. Some of my best fun has been had in the dark! 
It looks great.
Well done!
get the SeaBees over for the train room!
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