Building a independent design of extrusion machine here.
I noticed that my small oil press extrusion machine used a round fitting, so I will try it with the bigger screw.
Seems that this allows the plastic to enter the screw better than the v3 design.
overall view
Going back to the belt and pulley speed reduction instead of a gearbox.
Sheet metal frame, laser cut and CNC bent.
What appears to be bearings on the barrell, will be modded bearing holders.
Since these cheap bearings only cost a couple dollars, they are simpler to punch out the bearing and turn a holder on the lathe.
Easier alignment, lower cost. More professional looking than the present system
the pipe I have is 33mm OD so in order to fit the heater bands I bored out some female-female couplers as sleeves.
However it occurs to me that a easier method is to use short sections of plumbing nipples, couplers and a tee to make a no machining extrusion barrel.
Even though I have access to a lathe, sometimes the simplicity of putting the thing together from ready made stainless parts is easier.
Have run maybe 10 kilos thru the machine since it has been done.
The extrusion screw and shafting backed out of the barrel under pressure once and jammed the pulley. i may have to put some spacers on the thing to make it work right.
great, ack on the heatbands. The best results I’ve seen was with
4 heatbands – 35 (ID) – 60mm, and one brass nozzle heater but with and ID of 40 and a sleeve. I will try soon 1 or 2 more another PIDs.
Btw, about the support : we use a 15 cm long solid block, 35 x 35 mm and a smaller block on it for adjusting the final height. good thing is that the user doesn’t need to align much and it’s unbreakable 
So results are in with using the pipe tee for the extrusion input.
unequivocally YES IT IS WAY BETTER.
I was able to feed even the slightly larger pieces without problem.
the belt and pulley drive reduction still needs some tweaks. I did not use strong enough angle bar and part of the machine literally twisted itself.
Replaced parts with 1/4 inch x2 inch angle bar. Will see later this afternoon.
Also had a problem with the axles moving in the bearing blocks. Set screws were not enough to hold. So I will weld in some stoppers like I use on the shredder.
Otherwise, so far so good.
Also prob should add in more heaters, 4 is not even close to being enough.
Hey Butte, nice work again. That’s a challenging and extreme interesting topic btw. and there seems overwhelming home & research work to do, at least if somebody wants max. control over quality …
The hopper and feed is somewhat not fully investigated yet but from what I understand, there are quite some factors in the equation :
– screw parameters, eg: length, volume, pitch, flight width
– motor power / speed
– pellet, granulate or pellet size
– plastic type, moisture level
Having a circular hopper entry – with flange or not – , we may have a good start for experiments but also being able to use industrial hoppers. I agree this entry type is actually easier to machine as well. I can’t wait to see what happens if the hopper would have an auger to feed the plastic into the barrel. There is amazing head room for dry and pre-heat and possibly mixing addons.
Since we’re focusing on smaller bench top machines, this variant would also present also an ideal base to have pre-configured settings since all parts are known. That would lower the barrier for newbies as well.
thanks for sharing
