Questions tagged [machine-design]
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54
questions
-1
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0answers
22 views
Gear Terminology [closed]
Can someone please explain to me what are each of the radii that are involved in creating an involute spur gear. There are so many, if you can please explain to me what the difference between each one ...
10
votes
2answers
4k views
How do vending machines prevent people from stealing goods?
I never understood mechanically how a vending machine prevents people from accessing goods through the dispensing panel. From what I understand it's not a locked door that unlocks only upon payment, ...
1
vote
0answers
39 views
Can a semi-conductor cooler be powerful enough for a room? [duplicate]
I see semiconductors used for small fridges. I cannot find one large enough to cool a room (in place of a conventional Freon based, window air-conditioner). What engineering problems might a up scaled ...
2
votes
1answer
31 views
How is the assumption that stress and strain are elastic everywhere is valid for STRESS-LIFE method for fatigue life calculation?
Stress life method is generally employed for high-cycle fatigue (HCF) applications. while HCF region is approximated by $\sigma=a(N)^b$ which gives a linear graph on log-log scale, for steels it ...
0
votes
1answer
64 views
What type of electrical machine component for counting time?
I am looking for the proper piece of hardware to do what I'm looking for on my current prototype machine build.
I want a timer to begin counting upwards in seconds when a switch is activated, and ...
1
vote
0answers
26 views
How to determine minimum aluminum t-slot profile type for frame?
For a frame with dimensions 1000x1000x400, I am determining which T-slot extrusion type will be strong enough.
I am considering both 30-6060 (30 series I-type, metric) and 20-4040 (20 series I-type, ...
0
votes
0answers
52 views
Is it possible to narrow down a portion of shaft to its 1/5 of its diameter?
I designed this shaft for my center gripper. However the slot requires to be very deep, as you can see. I want to know if it's possible to produce
this part.
The main diameter is 30 mm and the small ...
0
votes
2answers
57 views
How do I read this schematic drawing notation for a drill hole?
It's for an NX part. I can't figure out the depths and such. I just know the placement of the 4 holes and that the diameters are 10 mm each.
0
votes
0answers
36 views
Number of Kinematic Pairs
Kinematic pairs are the connection between 2 links that can have relative motion between them.
But In six bar chain as shown below:
There are five pairs for them to be a kinematic chain. But if I ...
0
votes
0answers
52 views
Machine Analysis Problem: Finding the vertical force at joint K
Help me in determining the right solution in this problem. I already have an initial solution here but when I compute, my answer does not match to the answer key. I would like to know where did I ...
0
votes
2answers
46 views
How to measure a dovetail slot and it's mating component?
I have had some trouble determining the best way to measure a dovetail slot and it's mating component. The parts have some difficulty mating occasionally, and our QC department is having trouble ...
1
vote
3answers
40 views
static friction of gear pair
Im working on a project that has gearing system integrated. From my simulation results im dealing with a relatively small amount of input force at the gearbox and would like to know if the force would ...
1
vote
1answer
53 views
Sleeve and cotter joint
What does 0.1D signify in this cotter joint. I meant is it denotes spacing between pin and hole. I am new to machine drawing , kindly let me know. Thanks in advance
2
votes
1answer
88 views
Relation between links and pairs in Kinematic chain
I came across a equation for kinematic chain (for lower pairs only) :
L = 2P-4
where L: Number of Links;
P is the number of pairs
how could this equation be derived ?
EDIT: I tried putting values in ...
0
votes
2answers
47 views
3D linkage design - terminology
I am designing an animatronic head, which has five degrees of freedom: pitch, roll and yaw for the head part, and pitch and yaw for the neck part. However, the yaw movements for the head and neck are ...
0
votes
1answer
22 views
How to find a reference line for “ Form Tolerances”?
In my project I have to choose a form tolerances ( parallelism ) between the handle ( purple part ) and the part that sits inside it ( the grey part ), where the two parts slide on each other.
But I ...
1
vote
3answers
69 views
Mechanical Engineering: How To Amplify Kinetic Energy In Axial Rotational Gear Machinery? [closed]
When I originally posted this question 2021-04-08, I was inspired by pulley physics, especially after viewing these videos at this link and this link and this link. It is not necessary to go to these ...
0
votes
2answers
44 views
Gear configuration for a legged hexapod
I have an assignment for my Mobile Robotics course to design the drive mechanism for a legged hexapod and demonstrate its gait in motion.
The idea is to design the hexapod as per the following ...
0
votes
1answer
30 views
Shape of the shaft of knurling device
I'm trying to design and simulate a simple knurling device.
The shaft ( blue part ) has a flat surface at the other end, where the small grey pin connect the green body to the shaft. I guess you can ...
1
vote
1answer
44 views
Applying ISO fits to radial bearings
Do you need to take the bearing size tolerance into account when creating the tolerances for the mating hole/shaft when using ISO 286 tolerances?
For example, a 125 mm OD bearing with a desired H7 ...
1
vote
0answers
48 views
Design a Jig and Fixture for 3-axis CNC Milling Machine
Newbie Here!!!
This is my assignment task. I am required to design a Jig and Fixture for 3-axis CNC Milling Machine. The workpiece will be a simple aluminium block and it will be cut and shaped into a ...
0
votes
2answers
44 views
What is the name for a low pressure, low volume air reservoir?
I'm working on a project that requires very precise, but low pressure controls. I'm using a pump to charge a chamber to <15kPa, then a manifold of proportional valves to control output pressures ...
0
votes
0answers
37 views
how do i keep static deflection in a spring at a minimum upon applying gravity in a mass spring system without altering the response?
i modelled a simple mass spring damper system (with a vertical orientation) with base excitation in solidworks. After applying all necessary parameters, i plotted responses with and without gravity ...
0
votes
2answers
63 views
Where water goes in split air conditioner system in “dry” mode?
In split air conditioners, there are two tubes connecting the indoor unit and the outdoor unit. According to the generic schematics I find online (like this one), they are part of the closed circuit ...
1
vote
1answer
169 views
How can I decrease strip tension with bridle rolls in tension leveller? How can I find total elongation after the strip exits initial bridle rolls?
I'm working on a tension leveller design which consists of 3 main sections. These are
Input Bridle Rolls Zone: Increase the strip tension coming out of the decoiler.
Leveller Zone: Strip goes through ...
0
votes
0answers
30 views
How to disassemble this eccentric bushing
This eccentric bushing:
belongs to the hand crank of this machine:
It cannot be seen clearly in the photo, but the small blocking bar inside the bushing is not hovering over but rather, is sunk into ...
0
votes
1answer
51 views
What is this strange nut and what to do with it
I bought a cheap version of this machine, because all decent ones had costs of hundreds of dollars of transport to my region. The machine seems to be made of solid parts, but is really badly assembled....
2
votes
4answers
269 views
Why one big cargo ship is more efficient than 10 or 100 smaller ships?
Given the fact that small container ships are easier to manufacture than big container ships.. then why is it considered better to build bigger ships instead of many smaller ships?
And to see why ...
0
votes
2answers
65 views
Looking for dropping servo mechanism idea
My friend and I have an idea to make prototype of vending machine.
We need suggestions for making strong dropping mechanism.
The idea is:
The user orders X item. Let's take a can of cola for example.
...
0
votes
1answer
39 views
Safety types and definition [closed]
I am searching for some Engineering terms but couldn't find any of the definition.
Direct safety
Indirect safety
Warnings
Thank you in advance
1
vote
1answer
50 views
What would be the best mechanism to rotate a plate from 0 to 15 degrees?
I'm designing a machine in a small university project that change position of a two-state gate. The two states shown in the Figure below are 0 and 17 degrees of elevation, correspondingly. The ...
1
vote
2answers
57 views
What does it mean for a machine design to be “kinematic”?
I've seen the term "kinematic" used qualitatively to describe machines several times in books and on YouTube. I think I understand what kinematics is as a study, but I'm not sure what people ...
0
votes
1answer
62 views
Is there any way to conserve energy for the following scenario of lifting weight?
A pulley can be used to provide mechanical advantage while lifting weight.
Suppose a combination pulley is made such that in order to lift something four times heavier, one can use the same force but ...
3
votes
3answers
310 views
What is “reversal” in mechanical engineering drawing?
I've come across these terms "reversals allowed" and "reversals not allowed" in a sample drawing while reading a GD&T course.
What exactly are these terms? What do they mean?
0
votes
1answer
70 views
Adding the effects of two rods to move a single rod
I have to deal with a situation where I have two parallel and completely independent rods whose motion is dependent only on external inputs, and I want to add up the lengths traveled by each rod.
My ...
1
vote
1answer
67 views
Bending moment when there are no constraints
I faced this problem in an old book (Hall Allen S., Theory and Problems of Machine Design; 1961)
The answer according to the book is 592 [in.lb], but I think the bending moment should be 0 because ...
1
vote
1answer
43 views
A device to provide real-time proportional resistance to variable force
I'm considering a potential product but I'm not sure about the core technology I'd need.
The fundamental idea is that there would be a cable (or something similar) that would be pulled. But as it ...
-1
votes
1answer
53 views
Mechanical design of a bioreactor
What books and online materials exist that explain the mechanical design of a bioreactor? Can someone recommend any?
2
votes
0answers
44 views
Differentiating between Two Orthographic Projections
I came across the infamous control handle assembly in two different books, referencing the views differently. One of the had it like the following photo
The other book labelled the side view in this ...
1
vote
1answer
38 views
Reading Motor Datasheet
I'm doing my first machine design for a project and I have a Honda GX160 combustion motor which has the following specs for power and speed:
I'd like to use 0.24 HP at 2000 rpm. Is this possible? Or ...
0
votes
0answers
1k views
Toggle position of a fourbar slider-crank
In the fourbar mechanism as in the following picture, I have to find the toggle position, the sliding distance and the time ratio.
Here is my understanding/plan to do this:
The toggle positions ("...
2
votes
1answer
107 views
What mechanism is available to rotate a metal piece on another metal piece?
I am trying to find some type of mechanism where I can have a smooth but not too stiff rotation between two metal pieces. I was thinking of putting a shoulder screw through the pieces (the pieces will ...
0
votes
0answers
152 views
Fitting a sprocket on a small motor shaft
I have a bit of a newbie question. I've inherited a mechanical system, wherein the motor has a D-type output shaft with a diameter of 8mm.
(https://www.ebay.co.uk/itm/DC-High-Torque-Worm-Reducer-...
0
votes
1answer
110 views
Any books about design of complex machines? [closed]
I'm familiar with several books that deal with the analysis and design of simple mechanisms (such as Norton's Design of Machinery), including four-bar linkages, gear trains and cams. There are also ...
-1
votes
1answer
108 views
visualization of intersection of two objects [closed]
This is from a design entrance that I am preparing for. I know it's a little different than a theoretical projection drawing that engineering books usually cover. It is more practical and ...
0
votes
2answers
119 views
Analysis of Machine Frames With Cut Outs
I have a structure that is used to support two shafts which are carrying relatively high loads. It is composed of two columns and a "shaft supporting block" in the centre (almost acting as a beam). ...
0
votes
2answers
244 views
What kind of mechanism can be used to rotate a part in 180 degrees (Ψ (yaw)) and 30degrees in 𝜃 (pitch) direction?
Let's say we have a flat object. We are asked to create some mechanism so that the part can rotate in the shown angles above. What mechanisms can be used?
0
votes
1answer
50 views
What are the different methods to join 2 parts so that one can rotate 180 degrees around the other?
Let's say we have one simple box and its bottom has been cut in a circular shape. We want to attach another box to this box that can rotate 180deg around the first one. What mechanism can be used to ...
1
vote
0answers
64 views
Springs on a pulley… When to use?
I saw a machine that fed a sheet of laminate through some rollers. The motor had a pulley attached to its shaft, and a spring connected to the pulley. Why not use a belt? Wouldnt the spring make it ...
0
votes
0answers
287 views
Machine Frame Design
How do I select the cross section for a machine frame? Do I need to refer to the AISC steel construction manual to find the capacity of beams, columns, etc?
