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the washing machine experiment is a success. I filled the machine with aprox 7 kilos of bottle caps, added in a bit of bleach and ran the machine.
It came out nice. With the spin cycle there was not much water left and it dried fast. I then shredded it.
The washed plastic comes out much better than the unwashed from the extruder. no pops, steam, or smoke unlike the dirty plastic that has a lot of contamination.
It also smells better.
Locally I found new washing machines for 80usd without an agitator or spin basket. there are separate laundry spin baskets for sale locally that are fairly low cost.
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.
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
Looks interesting but I can not justify the price. There is the Spanish guy who has a extruder that does the same thing for a couple hundred euro, and printer costs have fallen so far now days.
With the shipping cost it is more than buying a new lathe and 6090 cnc router combined.
v3 is apparently larger,
However v2 step file is in the download pack, and the axle layout drawing is for a smaller v2 shredder as well
DWG is the format that my laser provider takes. Not a scaling issue, the step file was never updated in the download pack to v3
v3 CAD models are not in the current download pack. Just downloaded it again a few min ago.
the step files? Or the overview? so you are saying you reduced the size?
Because I downloaded the new pack recently and it still had the same files.
Can someone post the bigger step file model?
I have based all my designs around the larger machine as shown in the overview.
It is at least $150usd that will not go towards the R&D of my new combo compression mold/injection mold machine or a week salary for my
Whomever did the download pack, exported updated files for laser layout, but failed to export and update the solid CAD files.
Now i am sitting on a big pile of expensive scrap
Got a new sheet press running here in the shop.
Based on a bearing press.
I did see bearing presses for sale locally, but they were not that wide unless I went up to 10 tons and then the costs skyrocketed to 1000USD vs 300usd for 3 tons.
I used a car jack on mine.
Video here. https://web.facebook.com/preciousplasticphils/videos/2434277790125073/
1 ton per square foot or roughly every 300mm square pressure for HDPE.
I used 3/4 inch Phenolic plywood for the molds.
the plywood worked well except that it will needing more support on the top and bottom during the initial pressing. It warps at 1 ton as it was only supported from 2 sides. I have some 12mm MS plate that I will cut up to fit in the frame maybe this week.
I used a 50usd turbo cooker to melt the plastic in a teflon baking pan. the molten plastic will stick to teflon. It also stuck to a silicone baking pan, however It does not stick to a silicone spatula. Probably the grade of silicone. I prepared a pan with high temp RTV silicone gasket material yesterday. It has not cured fully yet. Possibly the tube I got was old. I will try it this afternoon and see.
If one is to do production, they would need at least 5 turbo cookers to make it worth while. Also insulating the turbo cooker so save on electric usage.
This method would have a much lower initial investment than using a extrusion machine, but over the long time, possibly a higher operating cost. Much would depend on if you insulated the turbo cooker (rated 1200 watts)
the turbo cooker has a fan which makes the plastic heat much faster than ordinary convection ovens.
Overall I would call the experiment a success.
Just reporting back on my development here.
After sharpening the v3 blade teeth to a sharp chisel point, and the 1.25 inch hex shafting with 25mm bearing. Upping the power to 5hp.
I am getting 50 kilos of bottle caps shredded on the existing design. However this is without a screen. I have to feed the material thru a second time to cross cut the material. It still does not like pet bottles much without crushing first. The blades wont grab it easily.
My double size shredder on the other hand grabs pet bottles nicely. Same 5hp motor. That machine has been running 4-8 hours per day for 2 months now at a plastic foam factory.
My other clients who shred mostly sachet do not get 50kg per hour. Mostly due to the bulky nature of the plastic. They feed the hopper as fast as they can with big handfulls of material. It digests plastic bags nice too.
So far jams result in the belt spinning not the motor stopping. On 2 latest machines, the belt is very tight and no jams despite over feeding it.
The use of a 63 amp transfer switch to reverse the motor has made life easier.
Initial supplier ripped me off with a german switch that cost 90usd. I since found indentical China switch for 15usd that i imported.
there is no GPL license! This whole thread is masturbatory at this point discussing something that does not exist! See the terms under which it was released. (screams in frustration)
@sharma-sagar need I refer you back to the terms and conditions also?
Originally we planned to write one of those long terms and conditions things here. Yep, super boring to read and write. So we made the short version: Everything is free for whatever use (commercial or personal). We would appreciate it if you mentioned our name somewhere though. Oh, and you can’t sue us if something goes wrong. Be careful!
As far as I am concerned, further discussion on this is a waste of time.
@xxxolivierxxx I would like to nuance the last part of your statement. from the beginning there was a profit motive, but not by Dave personally. The guy has done some amazing stuff given what he has to work with. 300k is nothing in the grand scheme of things when it comes to organizing something as big as this.
However He said in the intro and I am paraphrasing here, It has to be profitable for those to build the machines and use them for the project to be self sustaining.
Hippie art projects will not pay the bills. We need to produce real things with real value if we are to get others on board to recycle plastic in a meaningful way.
Considering that the Philippines is the third largest ocean plastic polluter I have a very big road ahead. The amount of plastic in the water around Cebu city for example is absolutely mind blowing. Like a literal soup of plastic. In order to get more people to recycle this plastic, the machinery to do this must be as affordable and profitable as buying and running a pushcart food franchise.
Ah yes Sharma, because profit is evil. Since you seem to be in charge around here lately. To affirm your stance I suggest you send me some paperwork by registered mail kicking the Philippines out of the project. You can DM me for the mailing address.
I am talking specifically about the files for this frame. Does this look like anything in the videos? NO
Sure the PP shredder unit attached to it is open source, and I share those blueprints freely. I even sell just that part seperately.
However I got some yahoo going to me directly DEMANDING I give him my blueprints for that frame as well.
I cant even get y’all to acknowledge our work over here in the Philippines and now I got some random dude wanting my blueprints and apparently according to one guy money?
I freely give away the PP blueprints, but my personal new frame design I will not release. It cost me a LOT of money to design my shredder motor frame and it is still a ongoing process. Mainly because I had to build something that looked professional and able to be assembled in my shop with basic hand tools.
Some guy the other day contacts me and flat out demanded I give him my particular frame blueprints layout drawings etc.
Are the existing blueprints not good enough for them? That is how I built the machines based on Daves designs until I developed a new frame.
So, no… I gotta earn and eat too.
So in the interests of efficiency and costs, at the expense of some precision. A panto-graph with a grinder would be ideal.
Maybe this sounds dumb…
can I 3D print and cast from aluminum bronze?
I can print and cast, so no worries, but will the alu bronze be durable?
Oil extraction machines with compression screws are cast, that is why they are so low cost.
so now my mind is thinking…
the manual grinding idea posted above with the angle grinder and bit as a pattern.
This device could be 3D printed…
Alternately, I think we could 3D print a geared grinder using thread rod. the big issue is that lathes do not have the right gearing to turn the pitch. Yet using a angle grinder we do not need the stiffness of a machine unlike a lathe, so we could use ordinary pipe for the lathe ways. Print reduction gears sync it all together.
Maybe a thousand dollars in materials and work?
Production run of shredders.
Still getting the process down. First time building 3 at once.
Ran into some issues with the CNC bending.
Last batch the chains and belts were perfect tightness without any mods.
This batch the CNC bender operator quit and the new guy is sending different bends. just slightly different enough that it took hours of re-work to get everything to fit.
Also having issues with the pulley set screws. Machinist did everything in imperial thread. Had a hard time getting the right units. Also it seems I have bought out nearly every B type 47 inch belt in the area auto parts stores.
I have also bought out every affordable 64 amp double pole double throw transfer switch around town. I have ordered a box of them from overseas now. Just can not justify buying the only remaining transfer switches here that cost $90usd vs the $14USD I paid before.
Also for now I have abandoned the use of caster wheels on the bottom of the shredders. I will revisit that in the next batch. It was not the cost, rather all the drilling of bolt holes as they were not drawn in yet.
Also a new extrusion design on the drawing board. Abandoning the PP design in favor of a sheet metal frame, and some other parts inspired by a meat grinder.
Actually I am wondering if a 2hp meat grinder is capable of being modded to use with a extrusion machine? I keep the hopper, and attach a barrel, and PP compression screw to it? Something to think about.
Added in a better discharge chute.
Reverse switch added in to clear jams
small mods to the files to correct some errors in the holes that needed re-work
added in motor mount
PET is 230-240c
You will get a hard brittle plastic output.
Try a Tee shirt transfer press instead.
regarding pressing pressure. At the moment I do not have a proper press in the shop. However I was pressing sheets of HDPE between 2 sheets of 3/4 inch phenolic plywood and standing on it.
2 ton car jack and a big hand wheel in a press?
I really need to experiment more with this.
My local motor supplier sells 12v motorized scissor jacks. It may be something to check.
after a lot of experimenting last week, We came up with some usable results.
Compared to the oven press which is just soo slow in my experience.
1, Melting HDPE in a turbo cooker, then pressing worked surprisingly faster than using a oven. The air movement really made the difference.
2. Melted HDPE sticks to teflon, and the cheap silicone baking trays. yet did not stick to silicone spatulas. It did stick to baking sheets but released when cool and released from teflon baking trays when cool but not when hot.
3 Extrusion and then pressing was the fastest and most energy efficient of all the methods we tried, although moisture will make bubbles much more this method than with the turbo cooker allowing the vapor to escape.
4 heat gun does work as well, but it is wasteful on power. best to use it for heating up the end of the extrusion machine and bending beams/sheets. We made several sheets from shredded HDPE. It was kinda slow and using unshredded bottle caps resulted in a better weld.
5 mixing LDPE and HDPE resulted in a better product if we was going to make boats. the added LDPE gave it a bit of flex and made it much harder to break.
6 Using unsorted HDPE color material, the end result is a greyish material with a slight red tinge. Not exactly a pleasant color. However with the addition of graphite powder. I got a matte black color that also had a nice smooth feel, It also adds in UV resistance. It did not take much to change the color. one hopper with 1table spoon. mixed directly in the hopper so as to avoid making extra messes.
the PP machine shreds that type of foam easily. I built a 2x size specifically for it. It did heat up after a hour or use from the friction. Remove any metal buttons first.
Unfortunately attempting to extrude it after shredding results in a useless material.
Maybe you could re-fuse it to make carpet underlay?
If you have any uses for it, let me know. I got thousands of cubic meters of the stuff available.
I upgraded my current specs to 1.25 inch aka 32mm hex bar and 1 inch bearings.
M14 grade 8 bolts that have the heads cut off and TIG welded on with lock nuts.
BTW you MUST I can not stress it enough use lock nuts or lock washers and the best grade of bolt you can source/afford
Earlier machines had issues with nuts constantly vibrating loose and one time a loose nut somehow got into the cutting blades from the hopper.
some video of it in operation https://web.facebook.com/preciousplasticphils/videos/2264036923925777/
Ok lets see if we can get it to work now
I tried a different method for the blades yesterday. I ground the side of the blades to a point from one side so it was more of a pointy chisel like a lathe tool.
We shredded a very large sack of material in a hour. It handled material almost as fast as we could feed the machine. The only difficulties were LDPE plastic bags.
HDPE shreds fine, LDPE is more greasy and can build up in the machine.
A few times I had to reverse the machine to clear it out, and a few times it jammed, but it was really a huge improvement.
I think next up changing from case hardened blades to armor plate. Although will have to re-draw the cad files as the material is only available in imperial thickness