Selection of a linear actuator 1

[NathanielM]

Howdy,

I am searching for a continous duty electric linear actuator. My application is for a test stand for a bicycle wheel. The actuator needs to be able to tilt the test stand from -5 degrees, to 0 degrees, to +5 degrees and back, repeatedly about a pivot point located 2 feet from the actuator. The actuator will be located under the assembly, pushing up on the load (about 600 pounds).

I am having difficulty locating an actuator that has a high enough duty cycle rating (preferably continuous duty) but is also inexpensive.

I've already looked at products by Powerjacks, Ultramotion's Bug, and Nook Industries.

Does anyone have any experience with these brands or suggestions of other brands?

Any tips or hints would be greatly appreciated!

-Nathaniel

 

[asimpson]

Speed is an important factor. What is the cycle time?

Have you considered pneumatic? Cheap , fast, simple good for contiuous operation. Look at Festo, SMC, Bimba, Fabco. Parker

 

[Compositepro]

This is usually done by turning rotary motion into linear with a crank mechanism. The reason is energy efficiency. A crank and flywheel (which can simply be the motor itself) can recover energy from one cycle to the next.

 

[TheTick]

I would go with Compositepro's advice.

I have worked extensively with linear actuators in the past few years, to the point where vendors were learning from me about their own products. Don't count on finding a continuous-duty electric linear actuator of that size anywhere. Maybe 15% duty if the load is light enough.

For continuous duty linear, I recommend pneumatic actuators.

 

[NathanielM]

I have considered pneumatic. The problem is that I need to have position control, and from what I've learned (correct me if this is wrong) an electric actuator is more accurate than trying to use pneumatic when you need fine position tuning.

 

[MintJulep]

Use a crank mechanism and regular motor with encoder.

Avoid linear actuators unless there is no other choice.

You don't need position control to accomplish the functional requirement listed in your first post.

 

[rmw]

If you are dead set on an electric linear, look here.

http://www.rotork.com/en/product/index/processcontrolactuators

These guys made linear actuators for boiler burner tilts which were continuously modulating service.

or here:

http://www.rotork.com/en/product/index/jordanlegacyproducts

These guys too:

http://www.haroldbeck.com/products/damper/group42.htm

I think among these you should find something - BUT - cheap isn't an option, so if you insist on cheap, save your time.


To tick - were you engaged with these either of these guys at all in your quest for linear actuators?

rmw

 

[TheTick]

I worked mostly with actuators used in medical industry, beds and lifts. I was responsible for testing product and prospective new components. Most familiar with Linak, Ilcon, and DeWert. The loads the OP describes are very similar to medical bed loads.

Rotork is more industrial. I do know who they are (even met a few of the folks here in Milwaukee). Different league, very different $$$.

The motion described in the OP is a bit more rigorous than what one would consider to be continuous modulation.

Pneumatic isn't accurate enough? How accurate do you need to be? Can the accuracy be controlled by other means? OP doesn't mention speed at all, so he doesn't know how much power he needs.

 

[EngAzat]

Hi NathanielM,
I think for your application power screw with reversible direction motor will be sufficient and reasonable price.