I got a lot of the mechanical parts from Farnell and was most impressed with their free next day delivery.
Some of the part numbers had gone obsolete, mainly due to ROHS, so I made the following substitutions :-
|Steel M5 Studding||517343||517409|
|Steel M3 Nuts||758796||8861250|
|Steel M3 Washers||149687||8861447|
|Steel 25mm M3 cap screws||100165||8838887|
10mm PTFE rod was out of stock but I found a cheap source of 12mm rod on eBay at Fantastic Plastic.
I also ordered a 5Kg reel of HDPE filament to get started with. It cost £85 including shipping. I plan to recycle milk bottles eventually but that will require a grinder. A four pint milk bottle weighs about 25g which makes them worth about 42p each. They must cost a lot less than that to make so the implication is that this stuff, sold as plastic welding rod, is overpriced.
The reel is a bit big and heavy to mount on the machine so I will probably have to re-spool it somehow.
It is a good job that I bought the filament before I made the extruder. The instructions specify to drill out the barrel to 3mm but my filament measures 3.2mm! I have ordered a 3.3mm drill from www.toolfastdirect.co.uk.
I also bought some nichrome wire to make the heater and some J-B Weld to attach it to the barrel and provide the electrical insulation and thermal coupling.
This stuff is rated up to 600°F. It is a departure from the original design which uses PTFE tape so it will be a bit experimental. I am hoping the thermal coupling will be good enough to allow me to use the resistance of the nichrome wire to measure the temperature rather than having a separate thermistor.
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