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screw
Posted: December 18th, 2015, 8:10 pm
by sridevi
how do i use a screw in my mission possible when motors/electronics are not allowed-screw has to have a full rotation
Re: screw
Posted: December 19th, 2015, 11:36 am
by Uncle Fester
Let me ask you this-- How did Archimedes, DaVinci and Isaac Newton power screws? It's simpler than you think.
Re: screw
Posted: December 25th, 2015, 11:48 am
by as_ap
Watch some videos on YouTube of what other people did. Do some research online for ideas. Get inspired from other people's ideas and create your own. Maybe your idea can inspire others too.
Re: screw
Posted: December 25th, 2015, 3:50 pm
by fuddermuffin777
An inclined plane wrapped around a pole also counts as a screw, as long as it makes a full circle.
Re: screw
Posted: December 27th, 2015, 6:53 pm
by Uncle Fester
Only if it acts like a screw. In other words, it turns, lifting (or allowing to drop) in a line parallel to the turning.
If it acts like a rotary inclined plane, it's an inclined plane. Example: having an electric toy truck push a ball up a spiral ramp. I saw this once back when electricity was allowed, and although it was pretty impressive (getting it to work had to have been a bear* to do), it wasn't a screw.
Just use a steel bolt. Either have the scrrew turn and move the nut along the bolt's axis, or turn a stationary nut and have the whole bolt move linearly -- both work just as well. Apply torque by a large wheel pre-wrapped with coils of string and a weight. Have the other end push a lever. WOW! Two transfers right there!
large diameter bolts work better. Also, slather some automobile grinding compound on tgeh bolt and run a nut back and forth for a SO team session to give it a looser, less-likely-to-stick it (scrupulously clean all the grinding compound off afterwards).
Need to use up time? Power the screw with an old Westclox (cheap example) wind-up alarm clock with the escape wheel removed. Or, using the falling weight on a sheel trick, having the bolt's turning paddles in cold syrup or water to slow it down.
Note: "Screw" vs "Bolt" : Interchangeable in terms of simple machines, but at Lowe's, a screw has a tapered shape and thread and can't hold a nut, while a bolt has a constant diameter and thread, and can hold a nut.
* Not referring to Bearasaurus.
Re: screw
Posted: January 9th, 2016, 5:20 pm
by HeatherFeather
"Only if it acts like a screw. In other words, it turns, lifting (or allowing to drop) in a line parallel to the turning. "
Is that all a wheel/axle does too? Is the only difference between the wheel/axle and screw the lack of threads on the wheel/axle?
Re: screw
Posted: January 18th, 2016, 8:33 pm
by Nair
can someone help us with the screw action?
We got some vague ideas of screws, but we are stuck on what action transfer will give the force required to start the screw.
For example - one idea in another chat room was to use a empty glue container and turning it will pop a marble out. But what force will really turn the glue container?
Are we really over thinking this? We are not able to figure out a screw task easily at all. If someone can give us some direction, it would be helpful.
Thanks,
Re: screw
Posted: January 22nd, 2016, 11:02 am
by Nick G CWCA
A pulley works great when you wrap the string around a screw. It can turn the screw slowly as a time killer or turn it fast, depending on what comes before the pulley.
Re: screw
Posted: January 27th, 2016, 7:09 am
by TimeLord
So, I know that this is unrelated to the topic of screws, but are pvc pipes that lean considered an inclined plane. I only ask this question here instead of the inclined planes section cause this one has had more recent replies. Thanks.
Re: screw
Posted: April 10th, 2016, 2:47 pm
by DankMcIntosh
From personal experience: a screw IS NOT a ball that just makes a full rotation. (Learned that the hard way lol)