Operating switch stands

[Anonymous]

I have operating switch stands by NJ International. I managed to connect them to my throw arm so they rotate when my tortoise switch machines throw the turnout, but they don't rotate enough to align the targets. Anyone know how I can increase the rotation on the switchstands when the turnout is thrown? I've been so frustrated, I actually called in sick from work to figure it out! Don't tell my boss!

[Big_Boy_4005]

Perhaps changing the crank length would work. By shortening the offset, the rotation will increase, but watch out, because too short will cause it to bind. Tricky business.

[ndbprr]

Obviously as you know they have to rotate 90 degrees to allign completely. Something is allowing them to short stroke and that is what needs to be fixed. As stated above - tircky business.

[Big_Boy_4005]

After I typed that, I had a thought. How about some kind of friction wheel on the shaft that would rub against the side of the throwbar. You aren't planning on throwing them manually, you just want then to turn properly when you use the machine, right? Sizing is still the key, because you want it to rotate 90 degrees using only the travel distance that the points allow, which isn't much.

Here is a quick diagram. Y is the throw distance, which should be equal to the length of a chord across perpendicular lines intersecting the center of a circle whose radius is X. X will be the crank length. A slot should be cut in the throw bar to keep the crank from binding.