Assignment 1

fb_b9032986_AlajmiJMahdy__24_.docx

Home >Nursing homework help >Assignment 1

fb_b9032986_Alajmi, Mahdy

Feedback for Assignment:- Product Design: – An introduction to the use of Bearings and Seals and mechanical fixings (Re-sit)

Research:-

A good few areas of research have been covered, but more can always be done so that you do not miss important technologies:

Not all required engineering elements have been covered.

Anthropometric data is required to help determine total gross weight.

The appropriate British Standards.

Your document ignores a few relevant machine element details. It may be considered a little superficial:

You give me positive and negative aspects of some machine element but many items you simply describe.

I want to see a detailed augment for 2 or 3 materials discussing criteria like. Yield strength, density, cost, machinability, availability.

No machining selection is given.

Reasoning for anthropometric data choice is not made.

Reliability and service life depends on the design and maintenance. All bearings have the same life if designed correctly

Are locking systems positive?

You include a lot of irrelevant material.

(Low 3rd.)

PDS:-

Your PDS is not as asked for. It should be in tabular form to concentrate your mind on the use of figures in your statements. We should use terms like:

The product will weigh less than…….

The product will sell for less than…….

The product will measure less than (L,D,B).

We will sell a minimum of '15' per year.

The stub axle will support a load of…….

The stub axle will be detachable.

The product will be capable of assembly using tools usually found in a typical garage.

A suitable manufacturing processes will be manual turning.

Please review the PDS notes on Blackboard before you complete your next design assessment.

Details the British Standards you would work to, i.e. Bolts, Nuts, Castellated nuts, Threads, Surface finish, limits and fits………...

(High fail)

Machine element application sketch:-

Little detail has been added to the machine element sketch's:

I need to see engineering elements sketched in situ, next to the bearings, in the housings and on the shaft so I can see that you understand how they work and how they are applied.

No real attempt has been seen to mount the stub axle to the car suspension.

The locking nut and washer must tighten directly onto the bearing.

Your axle mounting needs more attention. You need to show both location and fixing

Advantages and disadvantages of the elements was not discussed.

(medium to high fail)

Final Design Calc's:-

Basic calculation have been produced but there are some major issues that we need to re-examine:

You had some errors in the main calculations. Please re-examine the BB lesson on axle calculations.

You did not optimise the calculations. Remember we are not just interested in making the axle strong enough, but we should also remove surplus material to make it as light as possible.

You did not specify/justify a Factor of Safety for your design. This is required to optimise the design correctly.

No bearing selection was made.

You did not check the calculated loads against the selected bearings to see if they could withstand the loads.

Bearing RPM should have been calculated to check the correct bearing selection. This calculation was missing.

What about anthropometric data, where did you get the data from. This must be included in future reports.

(medium to high fail)

Axle detail drawing:-

No detail part engineering drawing was included.

(Zero)

Report/Referencing:-

There are many areas of this report where you have ignored the brief requirements and guidance that was discussed in class. In future work, try to work to the brief, otherwise you may be throwing marks away.

Your report lacked page numbers.

Your report lacked figure numbers.

Some of your report sections were in the wrong order. This is laid out for you in the assignment brief.

Page limits have not been observed.

Your text needs to be more to the point, for a technical report.

Please cut out any superfluous text.

You add references at the end of your report, but you do not cite them in the text.

Some poor sources have been used. Please get into the habit of using some books as sources.

Please use the add in to word to form your reference list in future work.

(High fail)

This marking still requires moderation and so marks may change slightly. Your overall mark is 25%

Criterion:

1st (100 to 70%)

2.1 (69 to 60%)

2.2 (59 to 50%)

3rd (49 to 40%)

Fail (39 to 0%)

Mark

Research 20%

Comprehensive range of sources, standards, machine elements, fixings, bearing retention, fixing methods, B.S’s, anthropometrics. Comprehensive FOS justification. Why are components applicable (strengths / weaknesses) discussed fully. Elements strengths and weaknesses detailed critical.

Broad range of sources, standards etc. FOS discussion is present but not fully justified. Why are components applicable (strengths / weaknesses) discussed quite well but not critically of comprehensively.

Not broad range of sources, standards etc. No FOS discussion. Why are components applicable (strengths / weaknesses) not discussed critically.

General research rather than specific strengths and weaknesses. Not always specific to our design.

No real attempt at research. Work appears to be an internet 'trawl' Research is generic and seems to be based on what was available / easy to find, rather than what is required by the design. No discussion of information presented.

Low 3rd.

PDS 10%

Quantified Requirements. Comprehensive; would provide basis for concept evaluation. Tabular.

Quantified requirements present, but some statements are ambiguous. Some important criteria are missing and so would make concept evaluation a little difficult.

Quantified requirements lacking in coverage. Is in tabular form.

Lacking in detail not really possible to use as criteria. Must be tabular.

No real attempt to use figures. May not be in tabular form. Criteria mainly irrelevant to the design.

High fail

Machine element application sketches 25%

Clear sketches show different materials, how bearings & axle are retained, and sealed Comprehensive sketches covering all details. Appropriate annotations included. Sketches showing elements fully in situ and show a comprehensive understanding of the application of machine elements.

Required elements included in a clear manner, only the odd element is missing. Appropriate annotations included. Sketches show most elements fully in situ indicate a good understanding of the application of machine elements.

Required elements included in a clear manner, the odd element may be missing. Some annotations included, but they are not a substitute for good sketches. Sketches do not show elements in situ. You show some understanding of the application of machine elements application, but this is far from comprehensive.

Required elements not sketched, clearly. Sketches elements in situ. There is no real evidence that you understand the application of the machine elements.

Sketches cannot be deciphered either because they are too feint, 'untidy' or very poorly formed. The most basic layout of the assembly is not shown, most basic elements not really included. Sketches elements only shown, not in the assembly position. Sketches not as required in the brief specification. No real understanding of elements shown.

medium to high fail

Final Design Realisation Calculations 25%

Excellent calculations identify fundamental component proportions e.g. axle diameters, bearing sizes. Design optimised. Bearings selection analysis: - load and speed ratings checked and proved. Full justification of FOS, Material seen.

Good attempt at calculations, FOS justified but with some errors. You show some attempt at optimisation, but there are issues. Bearing selection may have been checked, for loading or speed but is not evidenced well.

Some attempt at calculations, FOS justified but with some errors. May show some attempt at optimisation. Bearing selection may not be checked, i.e. No loading or speed checks, or may not be evidenced.

Little attempt at calculations. No consideration for practical application of design task at hand. No justification of FOS, anthropometric data etc.

Calculations have not been presented as a spread sheet. Calculations have many errors and do not really represent the design task. Many errors and practical assumptions either not made or are a stab in the dark' rather than well considered.

medium to high fail

Engineering stub axle part drawing - (HAND DRAWN) 15%

Part drawing with correct dims, correct surface finish and tolerances. Neat and tidy drawn in a professional manner showing only required view(s and info to manufacture the part.

Drawing frame has been personalised. Part drawing should have surface finishes and tolerance's added although they may not be correct. No redundant views. Some missing dims, but mostly complete. All required features are included.

Little personalisation of drawing frame. Part drawing may not have surface finishes and tolerance's added. May be excess views, missing dims. Most of the required features are included.

Poor or no part drawing. Little care or attention to look of drawing. May have redundant views (includes isometric views). Could not manufacture part from drawing. Sketches too feint to read.

A photographed image is not acceptable and will receive a max mark of 20%. .The drawing is feint / illegible. Ruled lines are not used; lines are not orthogonal to the paper edges. The title block is lacking detail/appears to be an after-thought. Details not printed (lower case).

Zero

Report 5%

Well-structured report Correct referencing & citation etc.

Good report structure. On the whole correct referencing & citation etc. used.

Fair report structure, but some areas require attention before your next work is submitted.

Your report is lacking many of the niceties that a professional technical report should have. This requires a good deal of attention.

No real effort, lose sheets, drawings images poorly presented. No real effort to use referencing system/incorrectly done.

High fail