linear actuator mechanism
linear actuator mechanism
(OP)
Hi,
In my spare time I am working on a toy invention. For the purpose of this invention, I need to create a mechanism as follows:
1. The mechanism must lift 8oz (item 1) over a distance of 8" in one second or less. item 1 must then rotate 30 degrees clockwise, then 30 degrees counter clockwise, then retract.
2. The mechanism must fit within a 4 x 4" footprint.
For these requirements I figured I would use a leadscrew with a guide to limit rotation during extension and retraction which would also allow the 30 degrees rotation only at the extension limit. The single motor would then be controlling the extension, rotation, and retraction, movements.
The leadscrew I will use would be a 3/8" Stub Acme thread with a 1" lead per rotation (5 starts). To get the extension speed I need, I need to turn it at 480 RPM which I figure I could achieve by gearing down a small high rpm DC motor with sufficient torque.
This is the first time I have needed to design a small toy type mechanism and was looking for some feedback on my approach.
Any help or suggestions would be greatly appreciated.
Thanks!
In my spare time I am working on a toy invention. For the purpose of this invention, I need to create a mechanism as follows:
1. The mechanism must lift 8oz (item 1) over a distance of 8" in one second or less. item 1 must then rotate 30 degrees clockwise, then 30 degrees counter clockwise, then retract.
2. The mechanism must fit within a 4 x 4" footprint.
For these requirements I figured I would use a leadscrew with a guide to limit rotation during extension and retraction which would also allow the 30 degrees rotation only at the extension limit. The single motor would then be controlling the extension, rotation, and retraction, movements.
The leadscrew I will use would be a 3/8" Stub Acme thread with a 1" lead per rotation (5 starts). To get the extension speed I need, I need to turn it at 480 RPM which I figure I could achieve by gearing down a small high rpm DC motor with sufficient torque.
This is the first time I have needed to design a small toy type mechanism and was looking for some feedback on my approach.
Any help or suggestions would be greatly appreciated.
Thanks!





RE: linear actuator mechanism
Time to hire a consultant well versed in kinematics?
RE: linear actuator mechanism
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: linear actuator mechanism
This reminds me of typical design problems set when I was at university.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: linear actuator mechanism
It means, lower the load back to its starting position. It can be retracted, or it can be dropped. It just has to end up where it started
"and what are your other constraints? minimum cost? life? toxicity? ease of use? "
Cost - as little as possible. it's a toy that I need to be able to produce cheaply.
Life - 25,000 cycles
Toxicity - none since it's a kids toy. If if were a toy for politicians, I would say high toxicity.
Ease of use - automatic since the cycles is triggered by an event.
Also, I need to be able to power it with common household batteries.
Thanks you
RE: linear actuator mechanism
Are you limited to mechanical means, or is air an option? And what sort of "event" are you using to trigger the actuator/gripper? Are you tripping a switch to cause the circuit to fire, or are you looking for a sensor to dictate position, etc.? How 'bout geometry of the toy? If you've got to lift it, are you using mechanical grippers, magnetic means, air suction...take your pick???
RE: linear actuator mechanism
arm goes up, hits the open bit arm swings across hits reversing switch, motor reverses, arm swings other way, then the nut winds back down the lead-screw.
You need to have a hold-high relay or something on the motor circuit.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: linear actuator mechanism
Thanks!