I was hoping the collective brain trust of the MR forums could help me figure out a way to animate the doors on my Walthers 2 stall engine house, the Cornerstone #933-3007. I would like to be able to open and close them without the help of the hand of God. Has anyone done this? I am open to either an electrically controlled option or a push/pull knob or a knob that turns On the fascia.
I have have a feeling that I might be able to take the twisting motion of a knob and turn that into lateral motion that can push/pull some throw bars underneath the layout.
If if anyone has tried this I would appreciate any advice.
I also plan plan on having a chain link fence that closed off a private siding, but I’m pretty confident that a push/pull knob will accomplish what I am looking for.
Greg’s mention of 'push-pull" rather than twist is far better for the lateral movement needed. One of the regular members on the forum, has done exactly what you are looking for, I don’t remember who offhand (drwayne, howmus etc). I do remember a past thresd on his explanation as to the workings. Basically a bronze rod was used from the bottom (hindges both doors) down through the surface, bent as a belcrank in opposite directions and linked together. The horizontal movement of a servo controlled the door movement. Any method of push/ pull as described will work (choke cable, music wire in tube, etc).
Rich, don’t see why a tortoise wouldn’t do the job. They are slow enough so door operation would seem more realistic. A bit of figuring as to setting the throw to a horizontally mounted one to the wire mounting of the bellcrank. Maybe drill a series of holes on the bellcrank to make final adjustments for the throw for the doors.
Since the engine house will be mounted perpendicular to the fascia I was thinking the twisting motion of a knob would be the easiest to translate into the side-side motion necessary to open the doors.
Though I suppose a flexible rod similar to the ones that Bullfrog uses could work as well.
you could also use a weight and lines (string). The weight could pull the doors shut. A line could be operated by twisting a knob aligned with a drum that the line(s) wrap around. Low-tech, reliable and cheap.
In addition to the Lance Mindheim article mentioned above, the March 1967 MR page 38 has a relatively simple mechanical means for opening and closing the chain link fence gate as you would see at an industry (David McLanahan author) and it would seem readily adaptable to the doors of an engine house.
It seems the greatest “challenge” is the wire/ belcrank mounting to the engine house doors themselves. To replace the lower hindge pin w/ the wire or mount close enough as not to bind (from eccentric movement). Is it better to just run a straight wire to below benchwork for ease of install and removal. Then worry about attachment of a lever to the wire. On a gate, the hindge side of the gate can just be built long enough to drop into the brass tube for pivot, a bit tougher to accomplish on a two stall (4 doors).
I have a five stall HO Roundhouse made from two Korber #104 Kits. I automated the doors to open and close using cheap gear motors. I use a 6-32 or 8-32 threaded rod extending out from the motor shaft. It is a very easy to do project. Couple the threaded rod to the motor shaft using either shrink tubing or fuel line and a short piece of K&S brass tubing as a bearing on the far end. Use a 6-32 or 8-32 nut fixed to a shaft so that it will move it up and down the threaded rod as it rotates. You can obtain slow realistic movements using this method.
Small low current low RPM gear motors are easily found on eBay. They are a cheap easy way to automate your railroad. My choice is 12 volt DC (reversible) 50 to 100 RPM. Using a threaded rod multiplies the working power too as well as slowing down the movement. The only limiting factor is your imagination.
I have some a long distance from the moving object using fishing line with a spring return in lieu of push rods. I don’t like long push rods.
I would love to see a picture if you have one available. Is there any sort of linkage at the “nut end”? I can understand how the nut travels up and down the rotating shaft, just not sure how the nut might be integrated into the door end of the works
I use this trick to move turnouts but could easily interpret to opening doors, I use homasote board and plywood base, but whatever you have…I use a brass tube, drill thru the boards just enough size to pass the tube thru but still a tight fit, usually gets hammered thru. I use piano wire for the throws, I bend the wire topside to connect to the turnout throw rod(outside of the track turnout), then underneath I bend the wire as needed makes a loop to attach the motor throwing mechanism (tortoise). For your door, you just make differrent bends topside to link to the door however way you do it, like just under the door with the wire having a U to slip under the door, have the tube just inside the door swing, the U will slip a little bit, then the usual underneath connections. Sounds very doable to me, there may be other techniques to suit also whatever you may dream up.
Unless you figure out a way to include an animated railroad employee opening the doors, it will still appear that they are being opened by “the hand of God”.
Unfortunately I didn’t take any pictures of the roundhouse door mechanism. That was one of my first automated projects about 8 years ago. I even did an overhaul of the roundhouse a couple of years ago and still didn’t take any pictures of the under layout stuff. I designed and built all my automated stuff for easy maintenance but the actual modules aren’t easy to remove without tearing up surrounding scenery or I would pull one out and take some pictures.
I got the idea from a Scale Shops turnout switch machine 1230. I made a quickie CAD drawing but I don’t know how to insert it.
Damon, MR had an article, 'way back in the '50s, for opening and closing roundhouse doors, involving a slotted sheet metal “t” mounted under each door. The top of the “t” had a hole for connecting it via a tie rod to a dual coil switch machine and another at the base of the “t” connected to a crank and vertical dash-pot (a loose piston in an oil-filled tube). The downstroke of the “t” was slotted, as was the cross stroke. Wood screw(s) in the long slot held the “t” to the bottom of the layout table and the slot in the cross-stroke was for the handles of wire cranks coming down through the table and up through the door hinges. Hold down a push-button to open them and the dashpot would slow the action; hold down the other button to close them. The guide screws kept the “t” in alignment and the crank handles would meet in the middle of the cross-stroke slot when the doors were closed. When the “t” moved away it would spread the handles of the door cranks.
I’m not sure if this was an actual installation or merely a theory, but I’ve always wondered just how well that sideways sliding motion of the door cranks would work—if it did. I bought a Heljan O scale 2-stall engine house kit and have wondered ever since if the “t” system would work with a motorized switch machine. Possibly a “Y” arm system would work on the crank ends, instead, but any way I look at it, it seems to rely on precise alignment of the mechanism. (Meanwhile, I’ve always wondered just how I’d attach the upper ends of the cranks to the doors for reliable movement.)
Back in the '80s, I used a similar idea to throw my turnouts. It worked very reliably for years. It used a crimp on ball sinker on the control board as a little pull handle, and 1 oz flat sinkers to hold the turnouts in one position, the ball pulled down and hooked over 2 small brads in the control panel to hold the points the other direction.
