Operating gates

This idea was published in MR May 2006 project illustrated

Pictures are linked to a larger view, click on them.

It was about 1990 when I build at my module “Naumburg” a furniture factory, called “MöbelFormAldehyde”. You have some Formaldehyd in chipboard wood. So came the name. It was very amusing to look at visitors. The recognized the gates opening and you could count to three, their heads went under the module – or they didn’t look carefully.

This factory got a gate for loading the cars in the house. And the area got a fence from Alloy Forms. Yes, I used at this time Alloy Forms for my German module. The fence needed a gate, too. And these gates had to be moveable.

The operation of the manual thrown turnouts in “Naumburg” works reliably without motor or relay drive. This method is admitted for movements caused by muscle power accordingly. Like that it was only logical to remain further independent from strange energy sources with a purely mechanically design.

One of these tasks which can be drawn constructionally was the gate mechanics for the “MobelFormAldehyde GmbH”. A crank drive for the gate movement was the first idea. But it was rejected as too complex. A simpler solution, as it had been in principle already found for the manual thrown turnout (first time published in Hpl model railroad 2/88): a connecting rod in connection with levers.

As connecting rod thereby was a square wooden rod, lever and guidance made of wire. The connecting rod possesses two delimitations: the rear module frame (thus pushed in), if the gate is closed, and a piece of wire, which pushes when opening (pulled out) against the front of the module. The regulating distance amounts to four centimeters (1.5’’), which turned out as sufficient.

The gate hinge was maintained in the upper fulcrum, which is intended with the gate from Alloy Forms. The lower hinge at the fence post was removed and instead a 0.5 mm ( 0.0197’’) wire glued with ACC into the eye of the gate. It led into a socket, made of 1mm (0.039’’) brass tube.
A droplet oil makes this construction very easy going.

And now to the underground mechanics, whereby the sketch serves as guidance.

As margin I fastened a piece of wire to this connecting rod (with connecting rod pushed in) 4 cm (1.5’’) from the front module edge. (drawing #6 and #8) Since both gates should turn over 90°, I drew two 90° angles on the module.
Parallel to the connecting rod you draw a 4 cm distance in such a way
now (the thrust length) are drawn in that they connect the two thighs of the 90 degrees of angles. Since the gate wings turn opposite, both angles point also to opposite directions.

As guidance in each case I attached two wires (drawing #9) right-angled to the connecting rod (drawing #5) . In addition two holes were drilled into this rod, the wires put through and the ends soldered together for better dependability. The distance between the two wires of the guidance is to be selected in such a way that the short thigh of the L-shaped gate lever is led well between them. This time I’ve choosen steel wire and you see in the pic a little bit different solution.

Important it is only that on the one hand the friction between guidance and lever arm remains as small as possible, and on the other hand the guidance is not sufficiently stable, in order after each opening and closing to have to make a readjustment of the gate.

If you use this mechanics at a shed gate, then there are different possibilities for the attachment of the 0, 5 mm diameter gate axle. Glueing is not recommended, since the mechanical force could be too big and the splice breaks. If the gate has a sufficient wall thickness (about 1 mm), then fasten the gate axle into an appropriate drilling, with thinner gates probably only glueing will be possible. Then however it is appropriate to bend the gate axle and to stick this increased adhesive surface as hinge camouflaged on the gate.