Budgets and Ordering for Group Robotics Project
- jonathan.procter
- Alejandro Pascual San Roman (Deactivated)
As part of the summer Group Robotics Project you will be required to keep your parts and manufacturing costs within a budget.
- The budgets will be separate for parts and manufacturing.
- Funds cannot be transferred between the two.
- All requests will be reviewed by one of the technicians and may be rejected if we think it is unreasonable or unfeasible.
- All ordering and manufacturing requests must be made as specified in this document, otherwise they may also be rejected.
The budgets and ordering formats are as follows:
Component Ordering
Each team will be given a selection of components as used in the previous practical assessments for free. This includes:
| Qty | Component | Cost for additional |
|---|---|---|
| 1x | Raspberry Pi 4 incl. 32 GB SD card | £60 |
| 1x | Raspberry Pi Camera with cable | £20 |
| 1x | Raspberry Pi ProHat | Included with Pi |
| 2x | ARB with Arduino Nano 33 BLE and motor driver | £55 |
| 4x | HC-SR04+ Ultrasonic distance sensors | £2.85 |
| 4x | GP2Y0E02B IR distance sensors | £8 |
| 4x | Micro Metal Gear Motor 298:1 with moonbuggy wheels | £5 |
| 4x | FEETECH servos | £15 |
| 1x | Arduino Servo Harness Board with Arduino Nano | £50 |
| 2x | 5v USB power bank | £16 |
| 1x | 45w USB-C PD power bank with USB-C breakout adapter for powering the servos | £60 |
- Consumables such as fasteners, wires and passive components like resistors and capacitors may be taken from the stock in the lab with no charge.
- All additional parts will need to be requested, and their cost will come out of your budget.
- For fairness this includes parts that we may already have in stock from previous year's projects, and any additional quantities of components you have already been given.
- Other than the pricing above, you are responsible for finding pricing for requested items, even if we already have them in stock.
- Please look after the components you are given, as replacements for components that are lost or damaged through misuse may be charged to your budget.
Any alternate power sources must be approved by a technician. Lithium batteries are not allowed, unless they are in a sealed unit like a power bank.
All components should be sourced through the technicians, so they can be properly assigned to your budget, so we can verify that they are safe to use, and prepare to support their use if required. We may not be able to support any components not sourced through us.
Other than consumables, components should not be taken from the lab storage. We need to keep track of our inventory so we can prepare for next years course. Any parts taken without authorisation may be confiscated. If you are unsure what counts as a consumable, please ask before taking anything.
"Preferred" suppliers are places we already have accounts with, they are the easiest for us to order from. We can order from elsewhere, but they require purchasing with a credit card, which takes additional time:
| Preferred (Next day delivery) | Preferred (Slower delivery) | Common credit card suppliers |
|---|---|---|
If possible, please try to order your components from these suppliers for the quickest turnaround.
Manufacturing
- Your team will be charged for any manufacturing requests, including iterations of the same design.
- Multiple iterations of large 3D printed parts will be costly, you need to take this into account
- This means you should try to validate your designs before making a request
- You should create full assemblies with your parts to visualise how they will fit together
- Include all fasteners in your assemblies, and take into tolerances for hole sizes
- Have test pieces manufactured before having the full part manufactured
- Designs can be printed onto paper or laser cut from card to test hole spacing etc.
- It is also highly recommended to modify existing parts using the hand tools provided, rather than manufacturing a whole new part every time, wherever possible, especially with 3D printed parts.
- This budget is larger and separate to account for the high cost of running our industrial 3D printers.
- This should be enough budget for around 900cc of printing, including the other associated costs, and two 1000x600mm 5mm acrylic sheets of laser cutting.
- There will be no size limits on parts, other than the sizes of our machines (254mm x 254mm x 254mm volume for the 3D printer) or sheets of material (800mm x 600mm for clear acrylic, 600mm x 400mm for coloured acrylic, 250mm x 250mm for acetal), but we reserve the right to reject any requests that we feel are unreasonable.
- Laser cutting is done in clear acrylic by default. Coloured acrylic costs the same as clear acrylic, so if you would like a different colour, check what we have in the material store and let us know. Please note, not all colours are available in all thicknesses.
- We are also able to engrave a design into your laser cut parts, e.g text. This should be specified as a different colour in the DXF file, and stated in your email. This can be done by importing your DXF into Corel DRAW.
- 3D printing is done in whatever colour we have loaded in the printers, unless there is a specific technical reason it needs to be a specific colour. This may also mean for large parts you may get multi-colour prints if we need to switch the roll mid way. This allows us to reduce plastic waste.
As before all manufacturing requests should be emailed to roboticsjob-group@york.ac.uk, and please remember to include your group number, and any specifications for the manufacturing, such as quantity, material thickness and material type.
Parts for laser cutting should be sent in DXF format, and parts for 3D printing should be sent in IPT format, for parts designed in Autodesk Inventor, or STEP format, for parts designed in other software.
For requests that cost a significant amount we may email back with the price for confirmation, so please keep checking your emails.
Estimating Cost
For 3D printing an estimated cost can be calculated as follows:
Cost in GBP (£) = Volume of part in cc (cm^3) * 0.27
You can find the volume of a part in Autodesk Inventor by following these instructions.
For laser cutting our pricing is as follows:
| Material | Cost per unit | Minimum units to charge |
| Perspex 2mm | £1.60 | 1 |
| Perspex 3mm | £2.50 | 1 |
| Perspex 5mm | £3.10 | 1 |
| Acetal 5mm | £12.24 | 0.2 |
| Laser Rubber | £23.00 | 0.2 |
Where 1 unit is 500cm^2. This is measured as the rectangular box that surrounds your design, e.g. a circle with a 10cm diameter would have the same cost as a square with 10cm sides.
These are all estimated pricing, please email roboticsjob-group@york.ac.uk if you would like an actual quote. Any other queries about either budgets should also be sent to roboticsjob-group@york.ac.uk.