[damunk]

Hi Damunk- Firstly you have to study motion. Here's something on Kinematics. I haven't looked at it closely, first glance seems good. Peter

https://study.com/academy/topic/over...inematics.html

i cant wait to delve into it while having my shake.

a final question. is a 1300N belt strong enough providing it is aligned and tensioned correct; based on the figures above.

also when i tension it , i am able to tension it to the point where the pulleys get hard to turn by hand.
When I loosen the tension i am able to turn the pulleys by hand.
At which point is there proper tension so there is no stress on the bearings and will not damage the belt it self.

[peteeng]

Hi Damunk - I expect so but have a look at these design manuals to see what they say. In terms of tension the guideline is that a tight belt is a good belt and it needs to be tight enough to do the job.... If its working its fine. The usual failure mode is fatigue and that can be accelerated if the tensioning pulley is too small. Its best if there is no reverse bending in a belt for maximum life. Have a good read most answers are in these manuals. Peter

[peteeng]

Hi all- There is an error on page 3 of the calcs. I'll leave it there to see if anyone finds it. I also did the full calc to account for the pulley ratio and the tension reduced. But 100N is a good round figure for the tension...

Re belt tension and motor bearings. The motor shaft has a loading spec. Look at that and then you will know what the motor manufacturer specs for the bearing. If the tension exceeds that spec then the bearing may die early or the shaft may fatigue. That's why some drives you use the motor to drive a bearing block (or spindle) of suitable size then the drive comes off that so the motor shaft is not loaded... Peter

[damunk]

Morning - Here's the new numbers - around 55N tension plus belt preload. So in reality maybe 100N. Check the numbers. I have not balanced the inertia via the belt ratio. But it would change the numbers only slightly. Check the math I have been wrong in the past. Lime is a fav. Peter

When you finish with a calculation of 100N belt tension. Is this the force you have worked out that is acting on the belt.
So for example if the belt was rated at 80N; it would snap straight away.?

[peteeng]

Yes - Peter Plus you need to consider pre tension, read the manuals....

[damunk]

Yes - Peter Plus you need to consider pre tension, read the manuals....

What’s fascinating is how you can turn the pulleys by hand and with certain easy lift a weight via the lead screw.

What is the science / mechanism behind that.?

I am intrigued that what appear to be thin belts of a few minutes in thickness that are able to work so hard.

[peteeng]

A screw is a lever wrapped around a rod. If you dig around you'll find out about its physics. Enroll in an engineering course. The world needs more engineers. Peter

[peteeng]

more accurately its an inclined plane wrapped around a rod. Peter

[damunk]

more accurately its an inclined plane wrapped around a rod. Peter

true i can imagine that

[Mooser]

.... If I were making such a rig I'd use a crank not a belt and pulley.... much easier.

Could you elaborate on this crank idea a bit?
I've got a similar kind of thing going on, lifting a 15kg weight with a ball screw / linear guides. Distance is 700mm and the speed needed is comical. Right now as the motor is maxed out at 1000rpm, 4mm pitch ball screw so and I was going to see about using a timing belt and set of cogs to maybe do a 3:1 or 4:1 to the screw instead of just a straight drive and stumbled across this thread.

Just not really getting my head around the crank idea

Thanks

[peteeng]

Hi Mooser - Same as a crank pushes a piston in an IC engine. Use a round flywheel or a crank. Comes down to torque available at the motor at the required speed. Peter

[Mooser]

Ahhhh, ok now I know what you mean. I was trying to figure out how the crank was replacing the belt and cogs in his gear-reduction lol
Thanks

[peteeng]

a picture is worth etc etc etc