Suspend those pesky physics laws!

Buerste · 2010-03-04T19:31:33+00:00

Damn inertia!I have an air cylinder, 1.5" x 4" stroke, that pushes a crank on a shaft to rotate the shaft about 90 deg. On the shaft is a gear with a one-way clutch. The 4" x 1/2" gear turns about 3" at the perimeter per stroke of the cylinder. By moving the link to the air cylinder up or down on the crank the gear will rotate more or less per stroke. A second gear is meshed into the first gear with pressure from another air cylinder. Wire is fed between the gears in a grove cut in the face of each gear. The idea is to feed wire 3" per stroke.Is works perfectly and fast! By varying the pressure in the cylinder that presses the gears together, the wire is gripped very well at 60 lbs air pressure and will slip through the gears easily at no pressure.The only problem I have is that the gears over-run and feed too much wire. I've considered lightening the gears by drilling a bunch of holes. Also, a drag brake on one or both gears with screws pressing brass pucks against it. Another idea is an air limit switch that is struck at the end of the stroke by the crank. This switch would unload the pressure on the clamping cylinder and let the wire slip between the gears when they over-run.Would the air limit switch work fast enough to unclamp the wire in time? Would I be better off with an electric switch and valve? I might have to lighten the gears, brake them and switch off the air clamp The feed has to take place in

Mar 04, 2010 64 Replies

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Paul Hovnanian P.E. 16 years ago

Control the clamping with a spring and a cam so its based on the position of the feed. It sounds like you are having problems controlling the air driven clamping scheme timing.

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Paul Hovnanian P.E. 16 years ago

[snip]

Transformers are all made in China now. The coil winding machines you refer to are 10 year olds.

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Don Foreman 16 years ago

I saw one in operation in an engineering prototype lab in Minnapolis quite recently, though it very probably was more than 10 years old. Yes, most production has gone offshore. Not all in China BTW.

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Don Foreman 16 years ago

I'm starting to regret having mentioned tape.

I'm looking at a servomotor with stall (all day) torque of 0.734 N-m, peak torque of 5.5 N-m. The whole damned motor weighs about 2.4 kg, the rotor mass is surely less than half of that. Motor OD is about

80mm or 3.125". Do you think this motor could accomplish Tom's task? I think it could do it easily and for a very long time.

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Martin H. Eastburn 16 years ago

Depends on the transformer. There is a company 30 miles from here and they have a sister site in Mexico. These are power line xformers.

Mart> D> [snip]

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