Shredder build IDEA

experimenting to find alternate ways to build.
The motor and its electronics specifically,

I noticed that garden mulchers/shredders have quite a powerful output, what I’m interested in is attaching the stainless steel shredding unit, to replace the barrel component usually found in these garden units.

garden mulchers appear to have a relatively small motor compared to the ones specified for this project, but most seem to be 2800watts, and (geared) much like a cordless drill .you can pick them up for £120 new.

whats good about them also is all the electronics are ready, forward/reverse/ with safety measures,
most come with a circuit break on the box, a clip which has to be engaged to make the shredder work. which could be rigged as a pull chord for extra safety, treadmills have this feature I’m describing.

There will have to be some cutting up of the existing body work to make things fit. but thats why you buy second hand. 🙂

Interesting plan, would definitely good to have different options for the motor. Never worked with those mulchers but it would be a good option!

@leflora its been a while since you posted, did you make your wood chipper work as a plastic shredder?

Hey Ewan, ewanenj


Such a quick and informative answer 🙂

Turns out I am getting a free woodchipper on Saturday, so we will see what I can do with that. I am under the impression it is a fairly small one. Might end up modifying it, if nothing else. Maybe my American chipper will do the trick lol!

I definitely want to make sure my shredded plastic is usable in the future (right now I am focused on cleaning, shredding, and banking my local {precious} plastic– product production is my phase 2– although I am interested in your flower pot design!)

I will post if I come across anything interesting in my woodchipper work.


Thanks Precious Plastic People!

icmore409   Tag!

Hi Leflora
Using a non-modified shredder is certainly easy but unfortunately it is not very effective.
There are 2 basic types of garden shredder:
The type being modified in the thread above grinds the wood using a slowly rotating wheel with sharp teeth. If you put plastic through this it will basically just squash it and occasionally cut through it. It will produce large pieces of squashed plastic. If the plastic is something brittle (e.g. a CD case) then it will shatter and the pieces will be a bit smaller.
The other type of shredder uses a fast spinning disc with two or more slits in it; there is a sharp blade attached to the edge of each slit. If you put plastic in this then the high speed of the wheel means that the plastic bounces around for ages. The pieces that emerge tend to be of a very wide range of sizes from a fine dust up to large flat pieces measuing up to 5cm across. The slits let through the large flat pieces, so I tried putting a mesh across the slits (drilling into the disc), but the same size pieses can also slip around the wheel. If you put in a big lump of plastic (e.g. waste from the injection machine) then it bounces around making a very loud noise for a long time. The output from this type of shredder is slow but might be suitable for the compression machine. The injection machine and extruder will need a smaller more regularly sized plastic.
So sadly using a non-modified garden shredder is not a great option unless you’re only going to use the compression machine. I have a seen a few people on PP who have found second-hand industrial plastic shredders – presumably these are more expensive? Or there are people in the Bazar who will make machines for you (generally for 1000 euros or more).

Any updates?


Anyone just used the woodchipper? I am interested in getting one and modifying it as little as possible so I can focus on shredding and storing my communities plastic ASAP


Thanks PPP!

hi ,
my shredder is the Titan
I got mine for 20£ as it was second hand,
works fine,
thickest I’ve put in is about 2mm ,
the design of the teeth is what causes issues
as it clogs due to the cutting action,  however I never got around to sanding and polishing the blades , which will help ,

the RPM is around 80. I think  which is alittle faster than daves

youl need to consider couplings sizes, anything above L110 but different borehole size, as on the gearbox the shank is 35mm where as the shredder is 20mn

I’ve been researching different ways to go about building the shredder (different motor options etc.) and this definitely looks like the best. Someone suggested the motor was a bit slow – looks fast enough in the video,  do you happen to know the RPM? This looks like this model from Titan (am I correct?) Even new it’s pretty cheap considering I was looking at an industrial motor and gear box for £350 without any of the switches or controls included.
What’s the thickest thing you’ve managed to get it to munch?

@waddy37 hi, yes my shredder is still very good, i only shredder milk bottles though,

I’ve not even welded the box together and its doing fine hahaha,
would have to try and get a few quotes from different laser cutters, businesses in the midwest England tends to be cheaper in my experience,

Adam, this motor idea is genius. I’m looking to build the shredder for a college project but didn’t think I’d be able to afford it with the prices I was being quoted for the motor and gear reduction, but this could work for me! Was just wondering if your shredder is still going strong and if you could give me a source for your laser cut parts. I’m in the UK and on a tight budget so any help would be appreciated


Ahhhh, mine was seized on. Ended up having to angle grind a slit down the gear so that I could prise it free. Not a problem since I don’t need the gear anyway 🙂


hi , if you mean the barrel tooth , then mine just slid off after opening the front plate, which basically centres the axle, some might have a C or E clip holding it on, in which case you’l need to fight it, or buy the special pliers for C/E clips

@kettlekekkers I was wondering how you separated the shredding gear from the axle (part 32 and 33 in the above exploded diagram) which way did the gear come off. It looks like all these garden shredders are pretty much built in the same way.

@trent-robertson this may help

@trent-robertson that is correct, i used the motor/gearbox/and electronics
i coupled it with a pair of jaws to compensate any misalignment.

@xxxolivierxxx thankyou! yes it does look a monster.

That’s a gorgeous frankenshredder, congratulations 😉

@kettlekekkers I really love your build, but had some questions before I pick up one on my local classifieds.

If I understand correctly, you have taken a shredder/chipper/mulcher apart just for the motor and electronics?
Instead of using the chipper’s blades, you’ve coupled it to Dave’s shredder design?

< those ore ok for specific plastics and products for a certain amount of time, but the blades wont stay sharp for long, as plastic is more dense and consistent than wood twigs, you might as well put it through a lawn mower,

(DON”T though… haha ) !!!

but i suppose if you want to go even cheaper, and do no mechanical engineering it will suffice

Found this seems to work, but it make big pieces.