The aim is to complete the build for under £200.00, ideally under £150.00, which I believe is very achievable compared to a purchase price of about $1125.00 (£721.15) for an off-the-shelf version.
Cost of PLA printed parts
|Frame Top (20x20)||13704.1||33.0||0.469||3||1.408|
|Frame Motor (20x20)||34007.6||81.8||1.165||3||3.495|
Cost of Vitamins and Electronics
|20x20 profile 600mm||Motedis||2.46||1.58||3||4.73|
|20x20 profile 240mm||Motedis||0.89||0.57||9||5.16|
|Slider for 20x20 profile||Motedis||2.71||1.74||3||5.22|
|Carbon fibre Tube 5mm OD, 3mm ID, 180mm (6)||Robotdigg||5.00||3.20||1||3.20|
|Tie Rods & Ball Joints (12)||Robotdigg||7.00||4.49||1||4.49|
|GT2 Belt Loop 1350mm (675 tooth)||Robotdigg||2.40||1.54||3||4.62|
|Geared Nema17 Stepper Motor||Robotdigg||28.00||17.95||1||17.95|
|Filament Gear Drive||Robotdigg||4.00||2.56||1||2.56|
|Nema17 Stepper Motors||Ebay||12.55||8.04||3||24.13|
|J Head Hot End||Ebay||24.94||15.99||1||15.99|
|Step Stick Stepper Drivers||Ebay||2.30||1.48||4||5.92|
I don't bother with FDTI chips on the Sanguinololu boards, or the associated components, I either program them via the ICSP header if I need to burn a bootloader, or an external FTDI serial programmer if just updating firmware, I also use bluetooth modules for wireless communications.
M4 or M5 T nuts I buy from Robotdigg at $7.50 (£4.80) for 100, other nuts, bolts and washers I buy from Orbital Fastners in quantities of 100 or more. Something like M4x25mm Allen Socket Button Screws are £3.72 ($5.80) for 100, I just order multiples of 100 as I use them up pretty fast anyway.
As such I will allow a fairly generous figure of £10.00 for nuts, bolts and washers, bringing our total thus far to around £120.00.
I do not want to use a heated bed, so this will save huge amounts of power and I will be able to use one of my many surplus laptop power supplies as a power source.
The print bed will be an 8mm disc of acrylic that has been sanded on one side to give a frosted appearance, this should allow PLA prints to stick yet still be removable once the print completes - a 175mm disc of 8mm acrylic can be had on Ebay for £10.70 ($16.70).
I am intending to try the Acetal Slider from Motedis instead of linear rails, I am not aware of anyone trying this idea before, and I have no idea how well it will work - it may have way too much slop to be of any real use, but at only £1.74 ($2.71) per axis, they have to be worth a try.
If this does not work, then I can use their Acetal rollers instead, these are designed to run in the 6mm slot on the side of the 20x20mm profile, these are £2.67 ($4.17) each, and I would need 9 or more, so I think it is worth the shot on the sliders first, many people have made alternate carriages to run on similar wheels/rollers, so I should be able to adapt one of these fairly simply.
Then there is always the fallback option of Chinese Linear rails at $58.00 (£37.18) from Robotdigg for a set of 3 x 400mm rails and carriages.
Even if end up I trying all 3 options, the total cost should still be well below the target of £200.00.