Servo trouble

Hi Royston,

Sometimes it is hard to know where to begin, because the question could be interpreted in many ways. It may take up days of your time to reach the correct answer.

This was an interesting site just for occasionally referring to (I check it from time to time). If I'm asking a question on forums I'll often pause and then maybe delete and re-type the whole thing:

https://www.biostars.org/p/75548/

However probably nowadays it should also state that where possible a picture/diagram can also say a thousand words.

Here is the full explanation.

   1)Why are you using servo?

Ans:It is because in my project I would like to build a transportation jet. The load I want to carry is 15-20kg. A very powerful motor drain all the amps of the battery within no time. So I thought a servo to lift weight. Then I realized it would also drain amps. I was not going to move the servo. It would be stationery. So why should I power it if it can lift the weight without power and signal. SO that is why I  asked the question. Hope this clearifies the problem.

Royston,  thank you for your explanation.  As Peter said, a diagram would help greatly. Based on what you have given us so far:

I agree a winch servo or a servo modified for continuous movement passed 360 degrees, is the best choice for your project.  However,  it will not hold a load reliability without power.

You may need something in the box the passivity hood the load during transport. Or a transmission with a worm drive or brake to hold the load.

A diagram will confirm this.

Regards,

-Steve

http://www.ez-robot.com/Shop/Images/Products/1355/Adapter%20with%20servo.jpg

http://www.ez-robot.com/Shop/Images/Products/1355-hd.jpg

Had problems sving a image to the discussion so had to find a similar one/s. Hope you copperate. The fomer one is like the servo clipped to the latter one. The fomer's part clips to the humanoid.(sorry for the lame explanation).The latter will be the rectangular one with the box. Only a different. Once I figure a way to upload picture I will try to.

Goes to a whole new page and in the url shows the file location and displays the picture. What next?

Select the picture and press "Insert Picture" lower right side of the pop up.

http://img.deusm.com/eetimes/2013/10/1319757/max-0087-03.jpg

In this, the top part is what I want to hold heavy object. I want to use servo under the lower frame to hold the top one. If I don't power the servo, will the frame hold or servo fail? I don't want to load or anything. Just hold the weight on the servo without power.

Can someone make a tutorial for loading custom pictures. My dosen't load.

Hi Royston,

Will the servo be used to tip load bed like a dump truck?

If I understand it...

When the load bed is flat and inactive, it could simply rest on fixed "stop" posts, taking the load off the servo.

When the servo needs to move the load bed, the load bed would simply lift off the stop post(s) and hinge up.

The servo is stationery, no tipping, no loading. The thing is that I'm using it to hold load since the motors are brushed. Yo the servo will be kept underneath and I want the servo to carry the weight without transferring to the load to the motors/frame(since all the weight is absorbed by the gears). You all are a long way from my point I've noticed.I prefer you ask everything to clear your mind to the point.

Greetings, 

do you have a drawing the the load plate removed showing how the servo is connected to the vehicle.  That would help. The way servos are designed , I don't see it holding the load plate stationary without help such as a transmission or a support that can be moved out of the way when the load is to be moved.

-Steve

You are correct, I am a long way from understanding why this servo is needed - it sounds like there is no motion.

Any load on the servo horn will be transferred through the motor mounts to the frame, whether it is moving or not.

If the servo never needs to move, why use a servo at all? Why not just a fixed bracket?

If the servo is being used as a shock absorber, it will require movement - the restoring/holding force could be provided by power to the motor or a simple spring.

You are correct, I am a long way from understanding why this servo is needed - it sounds like there is no motion.

Any load on the servo horn will be transferred through the motor mounts to the frame, whether it is moving or not.

If the servo never needs to move, why use a servo at all? Why not just a fixed bracket?

If the servo is being used as a shock absorber, it will require movement - the restoring/holding force could be provided by power to the motor or a simple spring.

I agree Douglas,

It sounds like he's using the servo as an expense hinge or shock absorber.

-Steve

Or like you say, a mounting device.

-Steve

Not like a cheap mounting bracket/shock absorber. My plan is to mount a servo horn on the servo and the servo horn to the top load. I learnt that all the weight that is put on the servo is absorbed by the gears. So my plan is to use a medium between the top and bottom frame without transferring the weight of the top frame to the bottom. I thought of using a servo as the medium.

You all are talking about it as an expense hinge or shock absorber. I wanted to use the servo to absorb all the weight by the gears and not put any force on the motors. Also, can a shock absorber be used as a medium between the top and bottom frame without transferring the weight of the top frame to the bottom.Also if a shock absorber can be used, how much weight can it carry?

Is the servo going to be powered at any time to move anything?

-Steve

I am not sure if I am understanding you correctly but you cant have a frame carrying another frame, carrying a load and not have the weight be transferred all the way down though the frames to the ground the wheels are touching (Unless you have invented Anti Gravity, in which case I will be suitably impressed)

You can use shock absorbers (Active or passive) to absorb inertial shock either from  a rough terrain while moving or from a change in the load say dues to extra load being added, but this is absorbing the shock and vidration, not eliminating the weight from being transferred to the ground through all the parts between the load and the ground

So if your going to program a controller to manage a servo in an attempt to function as a shock absorber, well then please say so, if not then im not sure what your trying to achieve as your description appears to defy gravity and other laws of physics

This is why we are repeatedly asking you to provide a sketch of the complete frames how there all connected and how the servo plays a part in all of it (Or how you plan for it to play a part)

Sorry but im just not getting what your trying to achieve, my colleagues on the forum have been trying to wean this additional information from you but so far it is still rather vague, sorry ?

I'll try to explain my objective in a different manner.

Let's say I have a quadrotor. I want to mount an airsoft gun to it. I want the gun to be mounted in such a way that it dosen't put weight on the quadrotor. So which is the best way to do it? First thoughts are servo's. But I don't want the servos to consume power. So will the servo hold the airsoft on my quadrotor without putting the weight ok the servo?

As per the picture, I don't have a frame.

by definition of what your describing, it cant be done

if you have a quad-copter and add anything to the device such that it will "Fly with it" then the weight of that attached object MUST be carried by the Quad-copter,

it does not matter how you attach the object (Suspend underneath, sit on top, other options), it will always add weight to the flight frame if the frame is to carry the object with it in flight

the only way you could do this without adding weight to the quad copter is to make the airsoft have its own flight mechanism and have it fly in perfect synchronization with the quad-copter , but then you just put the load onto another air frame instead.

Sorry to sound like a downer but maybe im not getting what you need from your description

Peter

Greetings  Royston, 

Peter is right,  your description sounds like you want to build a device any that can carry weight  without the device  feeling  the weight. 

It's like being able to carry an African elephant  on a small car.  The only way to make  the car not feel the weight of the elephant  is to suspend  the elephant  with another  device.

Or maybe  design an anti gravity  device.  Regardless, a servo will not do this.

-Steve

The quad copter's an example, not a real idea. I want to carry the weight on this-http://img.deusm.com/eetimes/2013/10/1319757/max-0087-03.jpg

Secondly, the quadcpoter's an examle, all I want to know is will the quad hold the airsoft with the servo as the medium and putting the weight of only the servo and not the weight of the servo and the gun.