My First Dave Hakkens Shreds
Here it is:
– Motor 1.5kw, 2800rpm, 3ph (1ph – 3ph inverter)
– 40:1 worm gear
– HRC type coupling, 35mm gear shaft dia. to 20mm shredder dia.(went for keyways)
– Shredder – mostly mild steel. 6mm bits re-cut in stainless.
– Stand – angle iron drilled and bolted together.
– Hopper – still under construction…
Its not perfect, but it works!
I’d say it works pretty damn well!
How much did you spend in total?
It looks great!
Are you in the US by any chance and did you get your stainless steel cut?
@andyn Cheers! I want to tally up all my receipts in an excel sheet and also calculate the costs for producing a bunch of them. Until then i’m guessing at least R15000, which is about 650 Pound. Probably more in the direction of R20000. I was impatient and just bought new stuff to get it working. Hows yours coming on?
@santybarrios Thanks! Nope, I’m in South Africa. Yes, I had a local laser cutting company do the actual shredder parts from Dave’s drawing files. I envy you guys in the US though, you have ebay and the likes and also affordable, locally made, stuff. Just about everything here is imported. Agggr!
Here’s mine so far (except I now have a hopper on it):
You can see it’s quite different to the Dave Hakkens design. That’s a 1/4HP 1400rpm motor from an old drill press (yes, just 1/4HP – 180W) and a 62:1 gearbox. The two were not made to fit together so I had to make some modifications. This gives max. 75Nm at the shredder which is not quite enough. It will jam if I put too much material in so I’m now looking for a bigger motor, 250W should do, but I’ll probably go for 1/2HP-370w for a bit more in reserve. Another problem with the current motor is that it’s not reversible. I’d like to have it automatically detect any jam and reverse for a single turn to clear it, though with a bigger motor it probably won’t jam anyway.
Total weight is about 15Kg, I’d like to keep it to not much more so it’s fairly portable.
Oh, and I put a screen it it, but it seems to get clogged no matter how big the holes are, so I think I’ll do away with it and just reshred until the pieces are small enough. This twin-shaft design seems to like to shred into long strips unless the plastic is above a certain thickness, then it just ‘nibbles’ it instead of dragging the whole lot through.
For those who are interested these are my material costs so far. The lasered parts I left as they are because the price for stainless works out to about the same. The last thee items are guessed – still need to be done. All in all I’d say its pretty much what you could do it for as a completely new machine.
Most suppliers I went to would have given about 10% less for bulk orders (I always asked for price of 10 units).
Like I said, just costs, without markup and without the time I put in…
@timslab Howzit Tim!
Sourcing the equipment was actually very easy. I’m sure it’ll be easier for you in JHB, also as far as price goes. Difficult was to try and get stuff second hand. On my shredder the only used part was the Motor (which was actually new, but sat in some blokes workshop for years because the rpms were high and its steel). If you’ve got time, and patience, I’m sure you’ll be able to get some good second hand equipment in JHB. On Gumtree, OLX and the likes, but shipping here to Durban is always an extra cost.
If you need tips or advice, just let me know and I’ll gladly help.
Be sure to let us know how you are getting on.
Our Woolworths milk bottles (HDPE)…
Getting ready for the final touches.
Fitted the control box, just need to wire it again and then on to the hopper…
Now with control box…
My shredder is slowly coming together up in Joburg ^^.. I was wondering if you’ve started finding parts for the extrusion machine? I’ve been searching everywhere for a large 600mm Auger bit for the extrusion screw, but not very many sources in SA. Would you be interested in sharing costs for ordering from overseas?
Shot a lot
Howzit Tim! Nice to have more Saffas on here!
Yes, but I’m not quite ready yet. I need someone to finance the next one(extruder).
I think that screw is going to be next to impossible to find in South Africa.
It looks like you can only get it on German or Dutch CONRAD in Europe.
I think my machining guy here in Durban could prob turn something similar, but I’m not sure about the hardening etc.
Hows your shredder coming on?
Did you go DOL or did you use a VSD?
Could you get 5mm stainless cut?
Yea I’m finding these machines involve quite a bit of capital to get started.. but if you do decide to order a screw from the EU let me know and we can share shipping costs.
The shredder’s coming along well.. I’ve got most of the parts and just need to collect the motor and wire it all up!
Thanks for the input,
Nice to see some South Africans on here 🙂 I recently also started building a shredder. The shredder box has been assembled and I now need to source a motor and couplings before starting on the framework and hopper.
I’m also in JHB. Where did you source your motor from? Are they available in 220V?
Hey @fuzzchucker, Shredder’s lookin sweet. I’m interested to see how the mild steel compares to stainless steel. I’m having to make quite a few alterations to accommodate for the 4.5mm SS sheets and may end up re-cutting the parts from mild steel…
I’ve been making trips to Chazen’s Electromotors to rummage for motors. There are thousands upon thousands and I’m sure he’ll be able to hook you up. Tell him I recommended you ^^
Hope it helps.
Hi all, also from SA, Alberton just south of Johannesburg. Quick idea in case you have not resolved it yet.
Torkcraft sell a 25mm auger drill bit:
Price was around R 270.00
Length is listed as 460mm but it may work with a bit of adjustment to the original design.
Unconfirmed if the 460mm is actual auger part only with the hex drill fitting adding to that lenght in which case even better as the auger part which works at feeding only needs to go from under the hopper to the nozzle which according to drawing is 485mm. Compensation can be made in pipe length or even lengthen the drill by wedling on a good steel bar and truing up on a steel lathe.
We have some lying around our factory will try confirm if length includes shaft or if it’s an overall length.
I’ve seen extruder hacks with shorter out feeds on, and I am pretty sure its much easier to make adjustments to the inside diameter of a pipe to suit 25mm diameter than importing an auger bit of 26mm.
Will get back re: sample ones.
I’m very interested to see how the Torcraft Auger bit works out.. I’ve been searching through local market tool stalls..
It also seems there are quite a few South African’s popping up in the forums and joining the project.. perhaps a meet should be organised next year to share what we’ve made/learned in building these machines within SA.. Just a thought..
Hi Tim, thanks for response, nice to meet you. A meeting could be cool especially locally to share suppliers, as always a.) hard and b.) expensive when sourcing materials locally. My suggestion for auger bit is for a workaround in response to earlier post as I myself will be building first the shredder and then injection machine. So will definitely be picking local brains for assistance regarding motors and the bandheaters and pid controllers so far researching and contacting suppliers they seem quite pricy.
You must be logged in to reply to this topic.