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Shredder modifications – 1″ Hex Hole parts

keesdeligt keesdeligt

Shredder modifications – 1″ Hex Hole parts

12/05/2016 at 09:47

Finally found some time to update and add some shredder issues, I’ve read in some topics.

For “Oldfashioned” 😉 countries not (yet) working in Metric.
The rotating knifes and spacer, with a 1″ Hex. Hole. Easier to find in some countries I guess.

And to reduce the lasercosts a little, I took a older prototype frame from the shelf, made from Square tube and some flatiron. Worked well and strong enough, but we opted for the lasered version in the end, because it is easier to align and always square.
The ‘older’ version is also easier to change, being it smaller or wider to Fit when 5 and 6 mm sheet is not available. Do the Math Yourself, and adjust the tubelength a little.
On one side You need to close the gap between sieve and frame with piece of sheet, should be no problem.

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13/05/2016 at 19:43

How do I load this in FreeCAD?

13/05/2016 at 21:59

how do you mean loading into freecad?
The file contains 4 dxf’s to sent to the laser service and a pdf for the tube frame, that is all there is to it.
Not familiar with freecad but it should load basic dxf files I guess?

I could consider it make a step file of the shredder available, that should work for most 3D cad software

21/05/2016 at 07:45


I did some recounting on the Laserfiles quantity’s.
Knife 3 changed from 5x to 4x
Fixed Knife small from 15x to 14x
Changed the description of the 6 mm bearingspacer to 34x34x6mm

See the PDF

Regards Kees

29/05/2016 at 08:22

Modified Hopper 2.1.

Made a drawing of a hopper prototype we used in the workshop.
Witch, I think, is safer and easier to use.
Holds or even Pushes the material down.
No need to put your hands inside.
Can be made of any material you want.

30/05/2016 at 09:40

Looks good.
I think I’ll go for this.

07/06/2016 at 09:14

Hi All,

is there a possibility to have the design of a bigger shredder,

a shredder which can have a capacity of 50 to 100 kg per hour, with this you can make people in Africa think about a micro business for recycling.

thanks in advance

09/06/2016 at 13:38

@keesdeligt I didn’t understand if these sizes are for those that use the imperial system or for us who use the metric system.

also, I have a big doubt.. do you have special units in the nederlands? 🙂
do you by any chance have products that use the inches or the Whitworth standard?
this question is also for @davehakkens

I’m asking this because I see weird sizes in your files that don’t match up with products we have here in Spain:
nut and bolt sizes, threaded bars, and now, especially for the extrusion machine, I can’t find a tube that has 26mm in diameter inside. I Spain It doesn’t exist.
I found one that is 26,9 or one that is 25

I will have to lathe with a drill head a 25mm tube, but that is more costly as nobody wants to weld a 26mm drill onto a large rod to put into the lathe :S.

Let me know about the sizes please

09/06/2016 at 15:16

as far as i can see, the used bolts, shafts etc. are all regular metric stuff, just the tubing is plumbers tubing, which is in inches…

but then again, i’m from the netherlands too 🙂

09/06/2016 at 21:15

Hi @lyricalpolymath a.k.a. @beltran ..
If you can be more specific on witch sizes?.
Always thought spain was a european metric country, but you are half way there! At least you are driving on the right side off the road ;).
Spending 25 years of my life on Drawing and building machinery, maintaining repairing and servicing machines from Sweden to Spain and from Russia to California. I found the only common things are Drivechains, Plumbing and fittings.
In the Netherlands we work with SI (Système international d’unités) by Law since the 70’s.
So I do not know how to make a drawing to fit all, if you can, please feel free to try. I posted some laserfiles for 1″ hex shafts, posted a shredder frame easy to adapt for alien-like US gauge sheets. So if anyone can tell me what to adapt or make a alternate drawing no problem. IMHO the download package is just a guideline.

Back to your question :).
We could lay our hands on a 26mm seamless tube for the injection machine, so looked for a tube to fit around that. Came up with a seamless tube almost 1″ (easy to make the 1″thread on). So that was a easy choice for the extruder as well.

If a 25.4mm (1″) or 25mm drill is easy to find in spain, perhaps a 1″inch tube is easy to find?

Regards Kees

23/06/2016 at 21:21

Would it be possible to publish individual step files of the rotar blades and static cutouts in the the shredder. I am in the us where we don’t have ready or inexpensive access to metric plate. I’d like to create a cad version of the shredder box using standard English plate sizes. I realize it’s just a matter of stacking the plates up and placing a spacer at the end or shortening the box. However I’d like to check it in cad before I have a bunch of parts laser cut. I have opened the .step version of the assembled shredder in autodesk inventor and it opens correctly but loses all of the dimensions, parameters and sketches from the individual parts. I’ve also downloaded fusion and looked for the sketches defining each blade to no avail. I know I could pull the individual dxf drawings and import them to create new parts for each blade and then reassemble them but I’d rather use inventors capabilities to resize things like the hex hole that’s cut into each one in one shot. Also which cad system did you use to create all the plans with?

11/07/2016 at 15:49


Does anyone know where to get a cheap, suitable motor and somewhere to cut out the teeth parts in The Hague? I do have a headache since I don’t speak Dutch…


11/07/2016 at 21:50

I wish I had seen this update earlier. I ended up cutting the knifes with the 27mm hex hole, but I was only able to find a 1″ hex bar, and now the knifes fit loose into the shaft.
One company offered me to make a 27mm hex shaft from a steel round tube, but they were charging $200 for that work, so I ended up buying the 1″ bar.

21/07/2016 at 12:45

I live in South Africa and it seems 5mm Stainless steel sheets are not available. Instead I’ve only got access to 4.5mm sheets.
For those with a similar problem who still want to use the laser cut body, I’ve altered the 3mm cuts to accommodate for the thinner material.

All other measurements should remain the same, except the length of hex bar will now change from 148mm to 141mm.

Hope this helps

27/07/2016 at 23:07

@keesdeligt a.k.a @kees 🙂 thanks for your answers
we too work with the SI (luckily 🙂 )
The pipe measure is weird but this is not the post to talk about the extruder.

In the shredder we had the problem that the laser-cut parts where not exactly 6, 5, or 3 mm as in the files..they where microns thicker than that, and when adding all the 13, or 14 parts that added to almost 2mm extra, which made everything be too tight, or too loose on the extremities of the hexbar :/

that’s not the design’s fault though 🙂

All this said, we’ve managed to build the shredder and make it work…sort of…
I’ll post a specific post about those questions we have. the basics: it works, but it clogs often and we have to turn it the other direction.

also the inside of the laser-cut parts that go onto the hexbar where soo tight that we couldn’t fit them, so we had to file them to make them fit. unfortunately we ended up filing too much and now some of the parts wiggle a bit. that’s not a big problem once everything is tight, but you can still see the parts wiggle a bit, all over the shredder. do you think that is a problem?

we had to disassemble it a few time to make it work right too. I’m starting to wonder if there aren’t other, easier, low cost shredders
something like those that @xxxolivierxxx has fond on this post

25/08/2016 at 15:45

How about using the blades from an office paper shredder?
Most modern paper shredders are capable of shredding CDs and credit cards.
The blades, guides and possibly even the frame from the shredded with a larger motor would make a cheap plastic shredder…

25/08/2016 at 20:37

@landrovermanuk this has been attemped already, but paper shredder are not that good for this job. Depending on the type of plastic you use and the quantity of plastic, they will get clogged.

Look at this topic for more info: http://onearmy.world/community/forums/topic/plastic-bags-2/

27/08/2016 at 00:43

Thanks for your reply.
Think I could still be tempted to try it with a larger motor.
If for no other reason than apart from the motor, it would cost next to nothing to build and the motor could be transfered into a full size shredder at a later date…

31/08/2016 at 07:30

@landrovermanuk Go for it, and let us know the results of your shredding test 😉
The good thing about experimenting with a paper shredder is that they cost a bargain, so in case that the project doesn’t work as expected, you won’t lose much.

13/09/2016 at 18:40

anyone? @davehakkens ?

14/09/2016 at 14:05

Hey Everybody,
i am thinking to use a Bike instead for a Motor.
Could somebody help me, how i need to transform the Bike that i can make up enough Power on the Shredder or wont this be Posible?

04/10/2016 at 17:53

sorry for offtop, but please can you tell me, @davehakkens, @keesdeligt what size of holes in mesh do you prefer and have on practice? Does 5mm good or it will shredd plastic much longer then 6-7mm?

06/10/2016 at 20:49

Hi @maxshcholokov,
I guess the mesh we used was 4 or 5 mm.
If shredding takes to long or you can handle bigger pieces you could drill some holes a little bigger 🙂

01/11/2016 at 16:43

The main problem my metal cutter is having is scaling. They want a scaling PDF in U.S. measurements and says with that they can use the original metric cad files and scale it to the PDF. So if you could include that that would be very helpful thanks

06/11/2016 at 17:57

I am looking for CAD files on the shredder for 1/4in thick metal for all 3mm, 5mm, 6mm parts. Can anyone refer me to the link or post it here?

Thank you

08/11/2016 at 15:14

Hi @keesdeligt and PP community,

We’re working on building this in Aruba, but have run into a combination of metric and imperial materials through our European and American connections. So we’re using your 1″ hex bar design, but using 3mm, 6mm, and 3/16″ (instead of 5mm) stainless sheets for the laser cut parts. So we need to contract the box a bit, by about 3mm, but I don’t know how to edit the DXF files. Specifically, I need to change the following part dimensions while making sure the connections still line up:

L + R Back 161mm -> 157.9125mm
L + R Top, Bottom 149mm -> 145.9125mm

Any advice on how I can do this? I’m trying to figure out some open source CAD programs but haven’t used them before so it is a bit slow and frustrating. Any help is appreciated 🙂


08/11/2016 at 20:04

Hi @tonyman,

Aruba……. Need any help on site ;), this morning the first time to defrost the windscreen :(..
I think I could post some modified dxf’s tomorrow if you want?

regards Kees

09/11/2016 at 03:01

Hi @keesdeligt,

Thanks for the quick response! We would love some on-site help, might need to work together on the funding to get you here, but we’ve got a place for you to stay for sure 😉

The DXF’s would be awesome if you have time to make the changes. I’d also love to learn how to do it myself, do you know any good tutorials for starting out with CAD?

Thanks again, let me know if you need any more details / clarification on the changes.


10/11/2016 at 16:26


I see what you are looking for….
Have you seen the above modification with the boxtube?
That’s a lot easier to adapt different sheet sizes….

Regards Kees

10/11/2016 at 21:03

Look this project:

13/11/2016 at 19:51


I did see that one, but thought it would be nicer to adjust the laser files, to make sure it is perfectly square and aligned. If you do have some time to make some modified DXF’s it would be great, as I still haven’t figured out how to do it myself. I will keep trying though 🙂

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