Assignment 1 MEC2304 Solid modelling Due date: 26 August 2016 Value: 250 of the 1000 marks for this course Question 1: (50 Marks) Undertake the Roller bracket exercise as detailed in section 3 of the Tutorial exercises which is available on StudyDesk. You will need to create part models of all the components that make up the Roller Bracket device as well as the Roller Bracket assembly model. Also create a fully dimensioned working detail drawing for the Bracket part. For this drawing you are required to show the necessary orthographic views and a 3D view on a suitable drawing sheet template as provided on StudyDesk. Do not specify surface finish requirements and general or specific tolerances. Question 2: (200 Marks) Background Figure 1 shows a clutch hydraulic Master cylinder which is commonly used in automotive vehicles. The diagrams that follow show the various components which make up the Master cylinder. There are two critical design requirements to be built into the Master cylinder models. a) The master cylinder will be fitted to different vehicles which in turn may have different mounting hole centre-to-centre measurements. This measurement could be any value from 50 mm to 65 mm. In order to cater for this, the design of the Cylinder body model must be such that the flange profile is updated accordingly whenever a change is made to the centre-to-centre dimension. The *R10 measurement in figure 3 is to be maintained for all designs. b) It is likely that the Piston could be supplied in two different sizes - ϕ16 mm or ϕ15.5 mm. The actual Piston size will govern the Cylinder body bore which in turn will set the working outside diameter of the Piston seal. So that the model design reflects this you need to set up parametric relationships between the features and parts affected. The Cylinder body bore size should be 0.05 mm larger than whichever size Piston is used and the assembled outside diameter of the Piston seal should be equal to the Cylinder bore size. The Task Your task is to complete the overall design of the master cylinder from the diagrams provided. More specifically you are required to: 1. Create parametric feature-based solid models for all the components either shown or listed in the following pages. 2. Produce an assembled model of the Master cylinder with all parts in their working position as if the hydraulic fluid is not pressurised i.e. with the piston assembly modelled as in figure 2. 3. Develop and incorporate model designs that allow automatic updates to the features / parts in order to satisfy the requirements in (a) and (b) of the Background information above. (Submit the Master cylinder with the ϕ 16 mm Piston and the Cylinder body with the 56 mm spaced holes.) Guidance on the Project You are be expected to combine some research with sound practical judgement to obtain missing details in the information given and the drawings provided. Before commencing this assignment you should think about the function of each feature and each part and how the individual components might be made. Also consider the physical assembly process i.e. how the parts actually fit together, the order in which the components might be put together and the use of sub-assemblies. Your model creation process should reflect this wherever possible. Some guidance is given in the instructions for the Roller Bracket exercise. What and how you need to submit Your assignment solution is to be submitted online through MEC2304 StudyDesk. Your solution to each question should be submitted in a single compressed 'zipped' folder – i.e you will need to submit two compressed folders in total – one for question 1 and one for question 2. Do not include sub folders. For question 1, submit one compressed folder with: x Electronic copies of all the Creo3.0 models - i.e. part '.prt' files and assembly '.asm' files* x An electronic copy of a '.pdf ' file for the Bracket drawing. x An electronic copy of an A4 sheet (in .pdf format created from a word document) with a listing of the file names you used for each part and each assembly. For question 2, submit one compressed folder with: x Electronic copies of all the Creo3.0 models - i.e. part '.prt' files and assembly '.asm' files* x An electronic copy of an A4 sheet (in .pdf format created from a word document) with: A listing of the file names you used for each part and each assembly and Instructions on how to 'test' the parametric relationship developed for the Piston, Cylinder body and Piston seal. Check that all files, in particular the assembly files, open correctly from your compressed folders before submitting them. It is very important that you do this as a marks penalty will apply if the files cannot be readily accessed by the markers. *If you have been given approval to use a program other than PTC Creo3.0 parametric you will need to convert your files to Creo '.prt' and '.asm' files. If your software does not support this conversion then save or export them as IGES or STEP files. Either way you should also submit all original / native model files - e.g. if you use Solid Edge then you would need to submit the Solid Edge files as well as the IGES or STEP files. You must also include screenshots (in '.pdf ' format) of the model / feature tree directories so that your model creation process can be assessed. Submit all these files in a single compressed folder for each question. You will also need to include a detailed account of how you set up the parametric relationship and how to test it. Marking this assignment The following sample marking sheet has been included to indicate the criterion to be assessed and the relative marking for each criteria. MEC2304 Assignment 1 – marking sheet Student name: _______________________________ Marker : ______________________________ Total mark / 250 Question 1 Criterion Your mark Out of 1. completeness – all parts modelled 10 2. completeness – all features included 5 3. presentation and accuracy of the Bracket detail drawing 10 4. modelling process and accuracy of models 25 total 50 Question 2 Criterion Your mark Out of 1. completeness – all parts modelled 25 2. completeness – all features included 25 3. modelling process and accuracy of models 100 4. parametric relationship 25 5. presentation of computer models 25 total 200 Marker's feedback and comments: Figure 1: Clutch master cylinder Figure 2: Piston assembly Figure 3: Cylinder body details Figure 4: Cap details Figure 5: Piston parts Figure 6: Master cylinder details