Weima shredder

5:21 PM

Here a thread to discuss it.

what about sharpening the blades?

Were they able to calculate potential throughput?

Super interesting!

The reduced cost and footprint along with the realization of the single axis drum options is awesome.

sponsoons

what about sharpening the blades?

The drum and pipe seem to have a replaceable set, for the laser you would swap out the single piece blades eventually.

@b.asuazo @chelbig

Yes does look awesome, and agree on cutting the cost of these machines to make it more inclusive for all to be able to afford and implement our common goal of recycling plastics. My question here is of the 3 rotors design which will be the most efficient/destructive at getting the jobs done. I suspect the "Laser cut" rotor... but would obviously be the most expensive option. Anyways good job in getting it done

Hope to see it in April if all goes well for you, tag me in your releases as am in the market to buy a shredder pro.

@Butte (PP Philippines) any thoughts here?

I have a few questions about the reasoning behind some features and why maybe they were added? My main question is on the Screen halves. Why are they human operated and does shredding still efficiently occur without human interaction? These also look like quite serious lasercuts (thickness of stock) to allow for the strength required. Bending the 2mm/3mm mesh is currently kind of easy for a low to mid level machine shop, but if that's as thick as I think it is, the equipment to bend that thickness isn't very accessible or cheap. I would also ask what the advantage of having a drum in the Pipe or Classic configurations vs the lasercut? Ps. The business man needs some PPE!

(edited)

Yann can add more info here but I know keeping the price low was a big consideration in the human operation part. Plus they said they pretty much always recommend a person being there to operate a shredder - that you don't want to leave it alone in case something gets in there that shouldn't be.

To answer first about the rotor confirguration :

The "classic" is what Weima usually use : most efficienty, possibility to replace the tip, so low maintenance cost, very precise cutting position.

But : it require a combined lathe / mill machine to manufacture, so expensive and not so easy to provide. This could still be an option if Weima for example manufacture this axis in serie, and sell them on the bazar.

The "laser cut" is what we are used too, this is relativly easy to find and assemble, this is still reparable by replacing a blade

But : this is still not available everywhere in the world, and it is less efficient than the "classic" due to laser cut tolerances This is the classic PP compromise.

The "pipe" would be the cheaper, available everywhere option. Also having a lighter rotor, would mean needing a smaller motor.

But : this would require a long time to build, and in its current confirguration, not easily reparable (grinding and welding new blades). And lighter rotor means less inertia, so less powerfull as well. This would be for DIY, or far away place configuration more than for machine builders.

11:15 AM

So we will probably go for the 3 options, so it can be chossen from depending on each needs, and make the shredder more universal that way. This is also still open for other options, or ideas to compensate each idea weakness.

11:21 AM

And yes, for the manual operating, there is 2 reason for that :

First you need someone behind the machine at all time, so the operator might as well do something.
For cost efficiency reason the brief was : manual operated machine, with the possibility to upgrade/hack easily : Generally Weima shredder have a motor or an hydraulic system, automatised with a program that analyse motor electricity consumption. This would also easy to implement by replacing these arms by a servomotor doing this job.

The idea for a machine builder is :

Low capital, low hourly rate target machine builder will go for the manual option.
High capital, high hourly rate target machine builder can hack the machine to automatize it.

I like the idea of having options for the rotor, but i think it's very important which one we choose as the default. As 90% of people won't choose one of the upgrades or downgrades, they will simply stick with the default. (edited)

Cool, thanks for explaining. Makes a lot of sense. I understand that your are trying to create a alternative version to this https://youtu.be/WacsqEo03yE making it manual is a good step and makes a lot of sense. Clever design really shows here on your teams thinking.

Obviously you already know I am a lasercut fan boy

but I would argue that all of the designs require lasercutting anyway. The teeth on the classic and the pipe and classic will likely be lasercut. Not forgetting the mesh which doesn't look like stock. So although lasercutting maybe not all that accessible, everyone can gain access to the parts required even if it means going a little further from home. I would be concerned about creating a method that requires the user to need to buy a part from one supplier. That could create a monopoly. What if they stopped making it for some reason, or wouldn't ship to Togo for an example? I think we kinda have that issue now with the extruder Pro screw, and PP Type Buttons. The final option is good, but again. The beauty of lasercuts is the ease of steps to follow to understand and build. Lower the skill level/craftsmanship, easier and more accessible the design. The beauty of lasercuts on the orginal PP shredder is that its like a jigsaw puzzle. Also if a few teeth break, it doesn't require the whole "pipe" to be replaced. Which I think could be quite problematic. Any thoughts on how the mesh is constructed?

Rawmec Ltd

DGM 1500 Single Shaft Shredder

Yeah the thing about the lazercutting is that even if someone can't access it, they can access someone selling it on the Bazar

Just a message to keep the thread alive (it archive automatically after 24h inactivity). Tomorrow at that time, I will compile all comment and summarize them to Weima, last 24h to give feedback !

How fast will the rotor run? / How loud it will be? Will it also be OpenSource?

Good question, I will add them to the feedback, we will know more after the first prototype I guess. And of course it will be open-source ! Probably being the new version of the shredder PRO developed during V4, but we will see once we are there

(edited)

I've been looking into shredding as it's the biggest hurdle to me. I've stated to look at what are called plastic granulators. These seem more effective and accurate as opposed to an actual shredder. They consist of a weighted blade chopping/smashing the plastic continually until it becomes small enough to fit through a sieve. Perhaps this is a better way to go.

Granulator definitely works the best for small plastic object like bottle caps or industrial sprues and runners. But they get quickly jammed by bigger pieces like oil jerricans or plastic chairs, unless these have been pre-shredded. It is the main challenge, ideally, you would like two machines, a shredder and a granulator. We are still trying to combine both with this shredder development, we'll see if this goes somewhere or not.

Is there any update to this project? Last I heard (November 2022), the intention was to release design specs/drawings by the end of last year- I can't find any such information.