Video Making an extrusion screw

Polymer Craft Machine Development
1

here a little video about making an extrusion screw. it only outlines what’s needed, the process and the dangers.

here again in numbers/details:

metal lathe : min. 2Tons, min. 1meter cutting length capacity, min. 3Kw, 1000 Euro second hand
inverter for lathe: Omron MX2, 200 Euro, needed to add some more electronics
material: chromium, min. length 70 cm, start diameter 25/25 mm
labor – cutting time: 10 – 15 hours in total
optional : angel grinder to take off most material (safes 2 hours lathe time)
cutters: HSS blanks, min. 2x2x10cm
output quality : near perfect but compared to industrial screws rather middle 😉
required skill-set : medium – advanced
danger : high, but can be limited with ‘limit switches’

others: grinding papers ( 80/120 grid), some files to make better edges

2

about 2-3 hours later with the grinding paper (stripes, and a lot of water), a near mirror like finish. i could grind another 3 hours but i guess that’s more than enough 🙂
g

3

screw material is chromium, works quite well.

4

looks attractive, nice stabilizer.
did you use aluminium for screw material @anne_barbier ?

5

there is btw. another , and more safe method : https://www.youtube.com/watch?v=cf4dQ2xw4OM, (@andyn)

6

i’ve made a lathe attachment to overcome the biggest problem when turning the screw (screw bends easily, even with 30mm diameter). takes 2 days to make it, it has to be pretty precise.

the attachment can also stabilize the stock when cutting an OD.