I am trying to dispense some food from the container using a rack and a pinion, but was not successful in that, as the stepper motor I use doesnt give enough torque. So I need to know the torque I am supposed to generate to dispense the food. But I am not sure how to measure the force required to dispense the food. Please help me out in designing this. Thanks a ton in advance.🙂

I have attached the rough explanation drawing and an image of what I have done already. ]]>

I am Eko from Indonesia, kindly need your help to assist me to provide good reference ( with completed case study ) for Shaft Design & analysis,

Special case : Vertical Arrangement Fan COoler Shaft as per attached filed,

Many Thanks if you mind to help me ASAP

regards

Eko M

]]>

And here is the link: https://www.youtube.com/watch?v=xX14NK8GrDY&ab_channel=PeterAxe

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IMPORTANT NOTE 1. It is highly recommendable that the above mentioned experiments are evaluated and realized by a highly qualified expert (Ph.D.) in theoretical and applied mechanics. Otherwise nothing will come of it (most probably).

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IMPORTANT NOTE 2. The key question in the above mentioned experiments is how to reduce standard friction (where necessary) to a certain minimum limit, beyond which the experimental error (due to friction) is small enough and can be neglected. The answer is simple. You can use for example permanent magnet slides as shown in the link https://www.youtube.com/watch?v=NoW0A8hYs5A . (Permanent magnet slides reduce friction practically to zero and the measuring devices do not register any force of friction.) Alternatively you can use hundreds of other methods for reducing of friction (as much as necessary) as modern technologies allow this feat. We live in 21st century after all.

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Looking forward to your comments after repeating the above mentioned simple experiments.

]]>Thanks

PD: The cylinder is similar like the one in the image, just that the cylinder of my problem is composed of 4 stages and the one from the image has 3 stages.

]]>

I want to deep draw steel into a cylindrical drinking cup. Diameter is 50 mm and length is 80 mm. thickness is about 0.25 mm

Now the base of the cup had photo etched patterns... Which might get stretched upon deep drawing...

Is there any way to deep draw steel without any stretching of the base..?

Regards

]]>

I have a question about the tuning of a PID (PI) controller in hydraulic drive trains with high inertia. I have a system with a 100kW hydraulic motor with an installed on its shaft encoder. That is how I am getting feedback from it. Not surprisingly I have a controller for acquisition and control of the hydraulic system (there are a few valves in the circuit). The last time when I was trying to tune the PID in the system (in the controller’s software), but I failed miserably. I did everything according to the standard tuning procedure (https://robotics.stackexchange.com/questions/167/what-are-good-strategies-for-tuning-pid-loops like here for instance) increase the proportional gain to reach steady oscillations and so on. At the end of the day the controller works, but too slow. And since it is a big hydraulic system that spins quite fast, I’ve decided not to go too crazy with the parameters and stopped there.

I read that it is quite challenging to tune PID controllers in hydraulic systems. The funniest thing is that I have a mathematical model of the system in Matlab/Simulink. So, in theory, I can easily derive the PID parameters. I did it once, and it did not work out either. So could you please advise any best practice for PID (PI) tuning when it comes to fairly big hydraulic drive trains? Thank you in advance.

]]>Calculate:

-The vertical reaction acting on the most critical weld line?

-the horizontal reaction acting on the most critical weld line?

Here is my solution I just need it to be confirmed

Many thanks in advance!

Chandra N Bhattacharya.

]]>I have a question that I am struggling and need your help. So I am working on a project which is essentially two syringes, A & B, with different cross-sectional areas, A1 & A2, connected via a tube filled with water. If we assume loss-less system, Pascal's law, the input force ,F1 ,will be transmitted to the second syringe and the output force, F2, will be a multiplication of the two cross-sectional areas [F2=F1*(A2/A1)].

So my question is if that is the case because in real life?

Hydraulic systems are affected by viscous forces (minor and major losses) which cause a pressure gradient in the system. In simple words the efficiency is not 100% but something else. Is there a way to calculate that efficiency and what would be the actual output force (F2) in such a system. Is Bernoulli's equation including losses a suitable equation?

Thank you very much. ]]>

I wanted to know how I can calculate the interference (shrink fit) needed for a shaft and propeller if I know the dimensions, material, speed and torque.

Thanks for any help you can provide.

]]>
**I have a car with a broken right and left front chassis.**

**does this have an effect on stability of the car on the straight road,U-turns,sharp turns or when driving with a high speed then suddenly breaking?**

**I know that I must mention more about the type of the break but really I don't know a lot.**

**please if there is more than one condition to deal with,mention that.**

**please I need your scientific answer with a reference book.(very important)**

**looking forward to your reply.**

Yours,

**M.Z**

]]>

Does anyone in the group know how to calculate the design working period of cranes or know any books to refer to.

Thanks in advance

]]>I'm working on a project for my machine design class and I am needing to find out a mechanical advantage on the device shown below. As you can see, it is a scissor lift like device that lifts a load upward with a linear actuator. The actuator, for the moment, is horizontal and is pushing in the direction of the red arrow shown, it's just not modeled yet. I've done some research but the most I can find is that the mechanical advantage is the (distance output/distance input) but I just wanted to double check if anybody had a different equation. Thank you so much!

PS I wasn't sure how to upload an image on here so I put the imgur link below. Thanks!

Image link:

https://imgur.com/ulLlUAP

]]>My name is Alex. I'm from Poland. I need some help with my proeblem. I'am writing my BEng thesis about dumper with tracked chassis. I've problem with finding force which load caterpillars during driving up to hill and turning in the same time. I have one old books but There are a lot of fault. Do you have any ideas, Where I can looking any help?

Greetings

Alex

]]>I am trying to design a telescopic elevating platform based on a rack and pinion configuration. The design is based on this video from youtube (click the link here). The video shoes this in a horizontal configuration. I want to use this mechanism to build a vertical lift. For that I need to perform some calculations. The telescoping effect achieved by this mechanism is of practical use in compact applications. Can anyone please help me out with the calculations needed to size the motors and the size if the rack and pinon for this? Please see the diagrams attached to get a better idea of the problem. I am particularly stuck with the effects of friction in this system.

]]>

It is certainly true that FEA allows for a good detailed stress analysis of complex geometries, something that was not possible in general by the older methods. But the results obtained are highly dependent on the skill of the user in applying the correct boundary conditions, something that is a bit of an art in itself.

I have observed a tendency to even want to use FEA to do kinematics, rather than using simple, rigid body kinematic relations. This seems like pure foolishness in almost all cases. Are we not developing a tendency to lean too heavily on the computer, rather than to learn to think as engineers?

I would be happy to hear some comments and discussion from others on these matters.

]]>
I would like some validation on my calculations of the **required torque and power **for a motor to drive a heavy but slow conveyor belt assembly. I feel that I may have underestimated these values significantly.

Method of driving: Motor pinion drives a large roller via a internal ring rack-and-pinion transmission, with the pinion acting as the only (driving) internal gear and the large roller acting as the (driven) ring gear.

System: This is a conveyor belt setup where the large Cement Roller (the driving pulley) drives the steel belt over a few idle steel rollers (driven pulleys). It depends on surface friction between the belt and the roller, so no chain & sprockets are involved. All idle rollers are hollow cylinders with cover plates, bolts, bearings and axial shafts attached to their sides.

__Specifications__

For convenience/privacy I'll leave out the roller configurations, and get to the behavior of the rollers immediately. I also approximate the pitch diameter of the cement roller as equal to its outer diameter (in contact with the belt). Instead of providing the mass of each roller, the moment of inertia about their rotating axis is given, which accounts for the mass distribution of the entire roller (including the bolts and plates etc.).

**Motor pinion**, the internal gear: M3, 10 teeth, 30 mm diameter [drives cement drum]

1 x **Cement Roller**, also the Ring Gear: M3, 300 teeth, 900 mm diameter; Inerta 100 kg m^2

10 x **Idle Roller**: 200mm diameter; Inertia 0.500 kg m^2

**Belt**: 500 kg, operating speed at **0.2 m/s **(slow!)

**Time to reach operating speed from rest**: 5 seconds

__My Approach__

I only calculated the **accelerating torque** as I assumed that it was significantly larger than the continuous torque required to overcome bearing friction.

My end goal was to determine the **tangential force** on the pinion required to accelerate the belt to an operating speed of 0.2 m/s in 5 seconds. The tangential force on the pitch diameter of the Cement Roller is equal and opposite to that on the pinion. Three things contribute to the tangential force:

- the torque to turn the Cement Roller from rest (Inertia of Cement Roller x Angular Acceleration of Cement Roller), divided by the diameter of the Cement Roller;
- the torque required to the accelerate the belt from rest (Inertia of Belt x Angular Acceleration of Cement Roller), divided by the diameter of the Cement Roller;
- and the torque required to turn each Idle Rollers from rest (Inertia of Idle Roller x Angular Acceleration of Idle Roller), divided by the diameter of the Idle Roller and multiplied by the number of Idle Rollers.

For 1 & 3, angular acceleration was found by dividing the angular velocity by 5 seconds; angular velocity was found by dividing the linear belt speed by the circumference of the Cement Roller or Idle Roller respectively.

For 2, I treated the belt as a point mass on the diameter of the Cement Roller, hence obtaining its moment of inertia using I = MR^2.

__Final Calculations__

- Accelerating torque to move Cement Roller = 0.148 Nm; Tangential force contributed = 0.329 N
- Belt Inertia = 101.25 kg m^2; Accelerating torque to move Belt = 0.150 Nm; Tangential force contributed = 0.333 N
- Accelerating torque to move one Idle Roller = 0.00333 Nm; Tangential force contributed (for 10 rollers) = 0.333 N

Total tangential force experienced by Cement Roller = 0.996 N

... which is also the tangential force experienced by the Pinion.

Hence, motor torque provided to Pinion = 0.996N x Pinion pitch diameter (30mm) / 2 = 0.0149 Nm

Finally, **motor power = torque x angular velocity = 0.0149 Nm x 0.222 rad/s = 0.00664 W**

We can find the angular velocity of the motor pinion using the gear ratio between the Cement Roller (Ring Gear) and the Pinion.

**Help!** As you can see, the final power calculated is very small. Motors start at 100 W and above. I would appreciate any validation of my calculations, or feedback on more dynamic components to include. Thank you so much!

this question might seem too easy or stupid to some of you but well, i'm kinda stuck with it. Can anyone help identify the forces on each parts and nodes please?

it's a mechanism to lift a weight on the top surface. the link in the bottom moves to the right and causes the upper link to go up. Node 'E' rolls on the wall.

]]>I faced this problem in an old book (Hall Allen S., Theory and Problems of Machine Design; 1961)

the answer is according to the book 592 [in.lb]

but I think the bending moment should be 0 because there is no constraints.

Could anybody help me to understand this?

(the photo is attached)

]]>Being a mechanical Engineer, I have to design many application where stepper motor is required, Please any one suggest me the perfect selection method of stepper motor

Thanks in Advance. ]]>

If I have my torque that the worm wheel (driven gear) is supposed to generate and have decided on my reduction ratio. How do i go about deciding on the pitch, gear diameters ,teeth and rotational speeds. I've looked at many resources but all those calculations work form the motor properties(ie power and speed) while I'm kinda working backwards. The purpose of the analysis is to design the gear box, calculate forces on gears and calculate the operating conditions of the motor (current and voltage needed to obtain that speed or torque).

Thank you

]]>
__Scenario 1:__ Single long belt from servo motor to driven shaft

__Scenario 2: __Using compound belt drive (two belts) between servo motor to driven shaft of same centers as of scenario 1 (function requirement calls for compound belt drive)

Thanks in advance.

]]>
I am currently an undergrad engineering student in need of some advice. I am designing a motorized scissor jack and don't know how to approach the gearbox. The torque calculated for the power screw of the jack is 146.77 Nm and the maximum torque the motor can provide is 8.6 Nm with a maximum allowable radical force of 25N. I've tried to use 3 pairs of helical gears to reduce the torque but the radical force is too large. I need the gears to be small enough to fit inside a relatively compact housing.

I'm looking for any tips on how to approach this problem will a relatively simple solution that I could approach at my engineering level.

]]>The first term in the equation is derived from the passive earth pressure equations and only this term is used for tracked vehicles, the additional terms only apply to wheels. These additional terms are what I am unsure of and do not know how they have been derived. It seems as if they have something to do with the geometry of the wheel but beyond that I am unsure.

where bw(m) is the width of the contact area, α(◦) is the angle of approach of the wheel, z_max(m) is the depth of the rut left by the wheel, γ(gcm−3) is the soil density, D(m) is the diameter of the wheel, and lr(m) is the distance of rupture.

Kγ is the modulus of density of soil deformation, c(Pa) is the soil cohesion, Kc is the modulus of cohesion of soil deformation, φ(◦) is the angle of internal friction; all of these are experimental soil parameters.

The diagram below might give some additional context.

Xc = 45◦ - φ /2,

z_max = h

Any help would be much appreciated.

]]>

https://m.youtube.com/watch?v=pEXKuyVCkNg

]]>I wanted some clarification for how would the reaction loads at end supports and joint will be calculated in the case shown in the schematic diagram. The load of right block structure would be supported by roller A however that load would also be transmitted to roller B. So, how are we going to calculate the load at right and left end support and roller A and roller B. This is a simplified version of structure in actual the structure would resemble a passenger boarding bridge where one column is mobile and can move horizontally and roller basically facilitates the movement. The outer block can move over the inner block.

Thank you in advance.

]]>I need your help.

Problem is this: Suppose I have a round drum, rotating about its main vertical axis. Top and bottom are closed off. The drum is partially filled with a liquid. How do I calculate the force that the liquid exerts on the top end bottom lid of the drum. Let's ignore gravity.

I have attached 2 calculations I did. The picture I found somewhere on the web.

Which one of the two is wrong and why? Or are they both wrong???

Looking forward to hear from you!

]]>

I got a problem. If i got a truss frame with 2 bars and an initial nodal displacement for the common node , then how can i calculate the velocity of the oscilation as function of time ? (the 2 bars have different length , same elasticity modulus , same density and different angle with the horizontal line and they are connected to a common node as i said )

I would be glad if you help me !

]]>

- A series (few in number)of electrically driven rotary gears (pinions) in a rack and pinion system are in contact with a rack. Would it be fair to assume that the displacement of the rack would be a superposition of the motions of the rotors (and hence the driving electrical waveforms ) ??

- If only some of the rotors are electrically driven, would the above still be the case ? For example, when only one of the rotors is driven, would the displacement of the rack still track the driving waveform(s) or would the passive rotors significantly affect the transfer of energy / momentum ? (Assume that the rotors are lightweight , small and have low inertia and there is enough lubrication to avoid wear and tear etc ).

Thanks,

Sundar

]]>

Dear DrD

A person trained as a mechanical engineer in the early 1970s rose through the ranks to be Engineering Manager from the mid-1980s and worked for various companies as Engineering Manager. The person had a period where he was not working. He then decided to start working but this time not as an Engineering Manager but as an ordinary mechanical maintenance engineer in manufacturing industry. What problems would such a person have or experience in this new position as an ordinary mechanical maintenance engineer or would he have no problems at all?

In my bachelor thesis, I am investigating the effects of vibration on the lifespan of induction motors. For this purpose, electric motors from various areas of application are to be ordered first. One of them is used in a vertical circular pump with 15kW, 400V line feed. I compared the catalogs of the big manufacturers like Grundfos, WILO and KSB. I asked myself whether these companies also manufacture the motors for their pumps themselves or are they produced by other manufacturers.

Furthermore I tried to define the current parameters for this application, if someone has an idea about that topic, it would be nice to take a look over there.

· 15 kW, 50 Hz, 400 V three-phase current, line feed (IEC 60038)

· 2 poles, 3000 rpm approx.

· Housing size 160M (IEC 60072-1)

· Efficiency IE3 (IEC 60034-30-1)

· Mounting: Flange mounted IM3011, IMV1 (IEC 60034-7)

· Insulation class 155 (F) (IEC 60085)

· Ingress protection class: IP55 (IEC 60529)

· Cooling: self-ventilating (IC 411), TECF (IEC 60034-6)

· Housing material: cast iron

· Starting method: Direct on line

Thanks in advance,

Rodin

]]>especially what should i suppose it and what for example is fixed and if some one will give me how the safety factor values should be i need this help as soon as possible if someone can help and thanks for all

the question :

A mechanical engineer has proposed the design of the power lift shown in the figure below, you are kindly asked to help in designing this lift by answering the questions (A) to (G). The lift is required to raise a maximum load of 3000 lb a distance of 7 ft in 2 min at constant speed. Other specifications of the lift are given in the figure. The speed ratios are indicated in the figure. Assume uniform operation and self-locking power screw. (A)The system has estimated efficiency of 75%, find the power of the required motor in units of hp. (B) Find the magnitude and direction of the rotational speed of shaft a when viewed from right while the lift is raising the load. (C) Due to space limitations, select a suitable V-belt drive to transmit motion between shafts a and b. Identify belt section, a reasonable central distance between the two shafts, the diameter of each pulley. Make any necessary assumption (D) Calculate the torque in shaft b. You may benefit from knowing belt tensions. (E) Find the tangential and radial components of the force between gears 2 and 3. Make any necessary assumption. (Specify central distance between shafts b and c, specify number of teeth on each gear, and identify the diametral pitch.) (F) Find an appropriate face width of gear 2; identify suitable material specifications and working conditions (use AGMA method). Make any necessary assumption. (G) Calculate the radial reactions with which bearings B and C push against the shaft b. Assume belt tensile forces vertical. You need to specify reasonable shaft length and bearing locations. (H) Consider static stress analysis of shaft b, use maximum shear stress theory to determine a suitable shaft diameter with a reasonable factor of safety; select suitable steel for the shaft material. (I ) Use the diameter found in part (H) to calculate first estimate for the fatigue factor of safety of shaft b using the Goodman method. Make any necessary assumption. (J) Select a suitable deep groove ball bearing to be located at C and D, assume uniform load, 90% reliability and desired life of 13000 hours. (K) Find an appropriate face width of the bevel gears; identify suitable material specifications and working conditions (use AGMA method). Assume 15 teeth and 20o pressure angel. Make any necessary assumptions. (L) Due to distance constraints, select a suitable sprocket-chain drive to transmit motion between shafts c and d. Make any necessary assumption. Identify chain number, length of the chain in number of pitches, number of teeth on the small and large sprockets. (M) Consider static force analysis of shaft d, calculate the bearing reactions at bearings G and H. Assume the tension in the chain is perpendicular to shaft

d and parallel to shaft c. You need to specify suitable shaft length and bearing locations.

]]>