engr seg 5 assemblydrawingpowerpoint

8/10/2019 ENGR SEG 5 AssemblyDrawingPowerPoint

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ASSEMBLY DRAWINGS

Dr. Catherine Turner


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ASSEMBLY DRAWING -

When a product has more than one part, an assembly drawing isnecessary to show how the product is assembled when it isfinished. It shows someone a general idea about how the finishedproduct is supposed to look.It is called a working drawing that tells what is made, what

material to use, what tolerance is applicable, and other criticalinformation.The assembly drawing can have as many views as needed toshow all the parts.

A sectional view is often included to show the material used forone or more parts and also to show how the final product isassembled.If any of the parts have an inclined plane, an auxiliary drawing isincluded somewhere in the plans.Each part has a circled number that is used in an accompanyingtable to show critical information needed to manufacture the parts

and to assemble the product.


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WHAT VIEWS DO WE USE?

Engineering Design suggests that we use as many kinds of views asnecessary to fully document and to show each part of a product,including sectional views to show materials, and auxiliary views forinclined parts.

An assembly drawing is often necessary to provide all the information

needed to take an idea from the sketch pad to full production.The following slides contain all the information you need to answer thequestions on the Worksheet and to get started with your own assemblydrawings.


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DESIGN LAYOUT -

Usually a sketched idea, the design layout is a rough draft of the finisheddrawing.It is recommended that the engineering designer use standard parts asmuch as possible as well as including established methods ofmanufacturing.

If a manufacturer has to completely change their machinery to make apart just for you, the price may take your product out of the market.Usually parts are not dimensioned in the design layout. That is added inon the formal drawings.


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DETAIL DRAWING -

The detail drawing shows each individual part with a drawing numberand title, including all required information for manufacture. NOTE: Eachindividual part has its OWN page. The detail drawing will include dimensions, location on the assemblydrawing, all required views, and a title block that includes part

specifications. As mentioned in the assembly drawing, an auxiliary view is required toshow the true length and width of any part that has an inclined plane.The auxiliary view is often shown on the detail drawing when applicable.


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PURCHASED PARTS -

Nuts, bolts, washers and other on the shelf items are consideredstandard and do not require their own detail drawing.Purchased parts are simply identified on the assembly drawing by size,material type, and finish.It is recommended that engineering designers use purchased andstandard items as much as possible for ease of manufacturing and costeffectiveness.


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SUBASSEMBLY DRAWING -

Sometimes parts are permanently fastened and cannot betaken back apart once assembled.This need to be shown and identified in a separate,subassembly drawing.For example, two parts that are welded together requiretheir own subassembly drawing.


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CALLOUT, BALLOON, AND BILL OF MATERIALS -

If every piece of information necessary tomanufacture each part were placed on anassembly drawing, the drawing itself would becovered in information.To minimize confusion and to clarify pertinentinformation, a circled number is often identified witha leader line (arrow head with text) which correlatesto a number in a chart either on the drawing or onattached documentation.

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BOM

This information is then used to generate a BOM orBill of Materials that has all the importantinformation for the part that matches the circled

number.


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SUGGESTED IMPORTANT INFORMATION FOR BOM

Item NumberMatches the callout or balloon number on the drawing.

Description of the designShort and sweet information about the specific part.

Manufacturers Part NumberThis will be assigned by the manufacturer and does NOT match theitem number on the assembly drawing and BOM


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MORE BOM POSSIBLE INFORMATION

ManufacturerMost companies will specify a manufacturer for a part and is oftendependent on the purchasing agent who negotiates the best pricesand delivery

Material UsedBecause the strength, quality, compression and tension resistanceand other properties differ with the materials, it is critical that theengineering designer research and choose the best material for theproduct.


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AND MORE BOM POSSIBLE INFORMATION

QuantityHow many of each part do you need?If you say 1, it is read as 1 part.If you really mean 1 gross and just put 1 on your BOM, dont besurprised when you are 143 short of whatever it is you need.

A gross is 12 dozens or 12 x 12 = 144.Often, standard small parts like washers, bolts, and fasteners aresold by the gross.Remember that people ordering your stuff will use your BOM andmost will not be able to read your mind so be sure and put AS MUCHinformation as possible that someone would require to get yourcorrect parts.


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YOUR BOM MAY LOOK LIKE THIS:

Item Number Description ManufacturerPart Number

Manufacturer Material Quantity

1 Sheet metalScrews

20-98993 Jones MetalSupply

Steel 24


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CALLOUTS & BALLOONS

Callouts and balloons are used every time, onevery part on an assembly drawing, to keep thedrawing as clean as possible.

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NOTE THE CALLOUTS & BALLOONS


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THIS IS HOW YOUR BILL OF MATERIALS MATCHTHE CALLOUTS & BALLOONS


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FOR OUR ASSIGNMENTS, WE WILL GENERATE OUR OWN BOM, EITHER IN THE TITLEBLOCK, OR ON A WORD PROCESSING OR DATABASE DOCUMENT.

Just a suggestion for important information:Item NumberDescriptionManufacturer Part NumberManufacturerMaterialQuantity


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TITLE BLOCK

Assembly drawings all have title blocks and that is where the similarityfrom one drawing to another ends.Companies all have their own ideas of what is needed in the title blockso it is a good idea to view existing drawings when starting a newposition that requires assembly drawings.When drawings are changed, a revision number is placed on the titleblock and the date so that someone looking at all the drawings later candetermine the most current version.


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COMMON INFORMATION IN A TITLE BLOCK

Company name and addressWhat the product is (drawing title)The part numberThe scale of the drawing

Who is the drafter and when was the drawing finished or submittedWho checked the drawing and the date checkedWho approved the drawing and the date approvedWhat material was used for the partWhat are the tolerances

Any heat treatments or finishing not specified on the drawing


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NUMBERING SYSTEMS

Just like the title blocks, the numbering systems vary fromone company to the next.It is common for drawings to be sequential and the numbersfollowed by a letter that states the size of the paper.For example, drawing 33800 on a size B sheet of papercould be numbered B-33800 in most situations.


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REMINDER ASSEMBLY DRAWINGS

Show what the finished product is supposed to look likeShow where all the parts are located for assemblyHave information on a separate table (parts list or Bill ofMaterials) that matches identifying circled numbers on theassembly drawingMay have several views in order to show all the importantdetails on the productHas all the information needed to produce a part

engr seg 5 assemblydrawingpowerpoint

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