Technical documentation and costing
A drawing that only the person who made it can understand is no use for manufacturing. This section documents work at a professional level: standardised drawings, complete bills of materials and costings justified item by item.
Standardisation of drawings: formats and title block
Standardising a drawing means producing it according to rules shared across the whole industry, so that anyone in the workshop can interpret it, not just the person who made it.
Standard paper sizes are DIN A4, A3, A2... Explain the size relationship between them (how many A4s fit into an A3) and why large drawings are folded down to A4 size for…
Standard paper sizes are DIN A4, A3, A2... Explain the size relationship between them (how many A4s fit into an A3) and why large drawings are folded down to A4 size for filing.
What is the title block of a drawing and where is it placed? Name at least four pieces of information it must contain (title, scale, author, date...).
What is the title block of a drawing and where is it placed? Name at least four pieces of information it must contain (title, scale, author, date...).
To document a piece of workshop furniture, your team is torn between drawing on A4 or A3. Reason which format you would choose for (a) a quick sketch of an idea and (b)…
To document a piece of workshop furniture, your team is torn between drawing on A4 or A3. Reason which format you would choose for (a) a quick sketch of an idea and (b) the final detail drawing, and justify your choice.
Assembly drawing, exploded drawing and standard views
An object made of several parts needs more than one type of drawing, with its views correctly projected, so that it can be manufactured and assembled.
Distinguish between an assembly drawing and a detail drawing: what each one shows and what each is used for during manufacturing.
Distinguish between an assembly drawing and a detail drawing: what each one shows and what each is used for during manufacturing.
The figure shows a standardised drawing with its title block, in which a piece of information marked with ? is missing. State which piece of information it is, why it is…
The figure shows a standardised drawing with its title block, in which a piece of information marked with ? is missing. State which piece of information it is, why it is essential in that drawing and what problem the workshop would face if it were missing.
In a detail drawing, each part has a number and dimensions. Explain what dimensions are used for and how the part numbers on the drawing link to the parts list.
In a detail drawing, each part has a number and dimensions. Explain what dimensions are used for and how the part numbers on the drawing link to the parts list.
Bill of materials and costing by items
The bill of materials specifies what is needed; the costing turns that list into a cost justified item by item.
Draft the parts list for this project: a wooden table with a pine tabletop measuring $80 \cdot 50\ \text{cm}$, four 70 cm legs, twelve $4 \cdot 40\ \text{mm}$ screws and…
Draft the parts list for this project: a wooden table with a pine tabletop measuring $80 \cdot 50\ \text{cm}$, four 70 cm legs, twelve $4 \cdot 40\ \text{mm}$ screws and PVA glue. Use the columns: quantity, part or material, dimensions and notes.
Calculate the budget for a small carpentry project: $2{,}5\ \text{m}^2$ of pine board at $12\ \text{€}$ per $\text{m}^2$, 20 screws at $0{,}10\ \text{€}$ each and…
Calculate the budget for a small carpentry project: $2{,}5\ \text{m}^2$ of pine board at $12\ \text{€}$ per $\text{m}^2$, 20 screws at $0{,}10\ \text{€}$ each and $0{,}5\ \text{l}$ of varnish at $16\ \text{€}$ per litre. Give the cost of each item and the total.
Your team has a fixed, non-extendable municipal grant of $325,00\ \text{€}$ ($21\ \%$ VAT included) to develop a weather station prototype. The initial budget estimates…
Your team has a fixed, non-extendable municipal grant of $325,00\ \text{€}$ ($21\ \%$ VAT included) to develop a weather station prototype. The initial budget estimates a material expenditure of $240,00\ \text{€}$ (tax base). The regulations of the call require adding a $10\ \%$ contingency line item on materials and, subsequently, calculating VAT on the sum of both items.
-
During assembly, a microcontroller breaks down and you must urgently replace it, generating an unforeseen expense of $35,00\ \text{€}$ before taxes. Numerically evaluate whether the reserved contingency fund covers this breakdown and calculate whether the final total cost exceeds or does not exceed the awarded grant.
-
If the cost of the remaining sensors also increases by $8\ \%$ over their initial estimate of $90,00\ \text{€}$, justify what technical or material selection decision you should make in the project so as not to exceed the financial limit without eliminating essential meteorological variables.
Specification of conditions and scale calculations
When the work is carried out by another person or company, the requirements must be set out in writing, and drawings still need their scale calculated correctly in both directions.
Explain what a specification document is and who writes it: what type of requirements does it set for whoever is executing the work (materials, deadlines, quality)?
Explain what a specification document is and who writes it: what type of requirements does it set for whoever is executing the work (materials, deadlines, quality)?
A part measures 6 cm on a drawing drawn to a scale of 1:5. Calculate its real measurement and, conversely, state what length a real part of 2 m would have on the drawing…
A part measures 6 cm on a drawing drawn to a scale of 1:5. Calculate its real measurement and, conversely, state what length a real part of 2 m would have on the drawing at that same scale.
A city council is tendering the construction of a children's playground with a maximum budget of $25.000,00\ \text{€}$ (VAT included). The Technical Specifications…
A city council is tendering the construction of a children's playground with a maximum budget of $25.000,00\ \text{€}$ (VAT included). The Technical Specifications establish two mandatory and disqualifying clauses:
-
Play structure: autoclave-treated wood class 4 or AISI 304 stainless steel.
-
Impact-absorbing surfacing: in-situ continuous rubber flooring with a minimum thickness of $45\ \text{mm}$ certified under EN 1177.
Three bids are received:
-
Company A: $19.200,00\ \text{€}$ (VAT included). Structure made of pine treated with outdoor weather-resistant varnish; $30\ \text{mm}$ precast rubber tiles.
-
Company B: $24.100,00\ \text{€}$ (VAT included). Structure made of AISI 304 steel; certified $50\ \text{mm}$ in-situ continuous rubber.
-
Company C: $20.000,00\ \text{€}$ tax base (the applicable VAT is $21\ \%$). Autoclave-treated wood class 4; certified $45\ \text{mm}$ in-situ continuous rubber.
-
As an evaluating technician, analyse the compliance of each proposal with the specifications and determine which companies must be disqualified, justifying the exact technical or economic reason.
-
A council member insists on awarding the contract to Company A because it represents a saving of almost $5.000,00\ \text{€}$. Refute their position by explaining the safety, maintenance, and civil liability risks that bypassing the tender specifications would entail.