Realistic Costs – Shredder
I started out building the shredder enthusiastically. At the time I did realize the cost of 180 euros wasn’t realistic, which didn’t bother then, thinking it would come to a bit more or maybe double. I’ve got the actual shredder done, the frame costed, worm gear costed, motor bought, and now the total is probably going in the direction of 750 euros. I think mostly because some of it just has to be bought new. Is anyone experiencing the same issue?
Realistically, would someone (from near here of course) still be interested in buying these things when those are the material costs alone? I’m not so convinced anymore that this is still all viable.
Please help restore my faith someone!
@lopesviii the bar can be 27mm or 1 inch thick (25.4mm), that’s the one I got and only has 1mm of space left, which doesn’t affect the machine functioning.
A 22mm shaft won’t work, unless you modify the laser cutting files to have 22mm holes instead of 27mm, as @paulfreed suggested
You would then have to adjust the size of the lasered parts and the bearings accordingly. The final shaft diameter would come out considerably less – not sure if that would be okay. It seems like plenty of changes that would need to be made with the uncertainty of the shaft diameter being adequate. It may end up being more work than its worth. Then again, maybe not. Have you worked out what the shaft diameter would end up being?
Does the hex bar have to be 27? the biggest I get is 22 =S
Maybe for the people who are interested in the ‘raw’ steel prices.
I’m working for a steel constructor, at the moment the prices we use (in Belgium) for calculation are:
S235JR (steel) – €0.62 / kg
RVS 304 (stainless) – €2.45 / kg
Of course this is without the work like laser/plasma etc.
Quick note on how to simply calculate the weight;
width (in m) x length (in m) x thickness (in mm) x 8
e.g. 2m x 1m steel of 5mm thick would be:
2m x 1m x 5mm x 8 = 80 kg -> 80kg x 0.62 = €49.6
@enviro aka Hansie?
I was interested in shipping prices.. So All shredder lasered parts (without shaft/bearings/angled iron/sieve). Weigh about 12Kg.. Shipping them by post would cost 110€, to get them From the Netherlands to Australia (No idea about importing costs, on your side).
250€ for the parts and 110 for shipping, makes 360€ if ordered in the Netherlands..
369€ would be 560 AUD$ ??
To whom it might concern….
I looked up the laser costs we paid (in the Netherlands) for the Laserfiles in the downloadpackage. It was 250Euro incl. VAT and material and a delivery time of 2 weeks (makes a big difference for online laserservices).
To cut the costs a little and to adapt the gauge system a little easier I posted some dxf knife files with Hex. 1″ holes and a frame made from square tube and flat iron.
Should reduce the laser costs 🙂 .
My machine is cut with HA250 Plate steel. It all arrived today, but I am at work and can’t check the accuracy of the thickness – I will provide an update later re: that.
The way I see it, this project is a new concept. Dave Hakkens has done a good design to start with, but with any open-source project, once more minds get involved, with different perspectives and ways of thinking, the designs evolve. It is still in the Proof-of-concept stage. I suspect that the designs will morph – I have already identified an improvement to the internals of the machine to make obtaining the hex bar easier and cheaper. Other people will have other ideas.
Once I get the machine running, I will then start on the Injection Machine. Once I have got that up and running, I will be getting templates made and using them to make items to sell at markets. I will not know how they will be accepted, or if there is a market for them until then.
At this stage, I don’t want to spend a fortune to get a gold-plated system, only to find that the market isn’t there, or that a better design had evolved that is cheaper/easier/more efficient etc.
If I find that there is a strong market, I could then get the internals replaced with stainless steel (if required) or even replace the entire machine. Until I have established the market, I don’t want to get a premium system (eg – stainless over mild steel) because the risk is still too high.
That’s my opinion anyway…
I just got a paper shredder from my local value village, I tried shreading a xbox dvd case (PP) with it but it was having alot of expected struggle being that it can only shread 5 pieces of paper at a time, but luckily I thick I can pull thr cutters out of it and save alot on materials and machinery costs. I’ll keep you many posted once I get home and take it apart.
These will be the two gears that link the shafts of my shredder. My design is actually more like the FilaMaker shredder than the Dave Hakkens one. I hope to find a worm gearbox for the main drive from the motor, I’m considering using a wheelchair drive unit if it can handle the torque, but swapping the DC motor for an induction motor.
Pictured are my cutters, CNC’d from 6mm gauge plate, this is not stainless so not rust-proof, but it is very accurately ground to 6mm thick and it can also be hardened.
For the frame I’m using 12mm thick mild steel, drilled and tapped and also bored for the bearings to be pressed in directly.
@simonm this is the best laser cut price I could get in stainless $954, would still need to get someone to weld it all up + $90 for the axle, then the stand, motor + gear box. easy cost $1600.
If I use mild steel, the laser cutting is $356. however worried I’ll have the same probs as @paulfreed or if they get wet at all have black stains contaminate the plastic.
I am in Australia too and was quoting AUD prices 🙂
What are you guys doing for the frame? Welding yourselves, or getting it done? I looked into slotted strut, but it is way too expensive!
@andyn half the size you say? Sounds good! Please post pics when you’re done!
@bulegila I went for the mild steel option and had issues with the 6mm thicknesses. It threw my blade spacing off and i ended up getting it done again in stainless.
$1600 seems a bit on the expensive side to me. I am looking at paying less than half of that for the shredder (and I don’t have anything for milling etc).
What is costing you so much?
Some good points made guys, I personally have put in a lot of time looking at all the resources available to me, I’m looking at around the $1,600.00 AUD at the moment, I’m trying very hard to get thats price down. What doesn’t help, unfortunately I don’t have hack shops or machine shops where I can do the milling myself, so there is a lot I will have to pay someone else to do. Example, the axle alone will cost $90 just to machine, that’s with me providing the Hex bar which I have sourced from one of my crow bars.
Also I’m looking at a other things, so if I have to, because of the high cost &/or what’s available/accessible to me, I mite make a different type of Shredder
Well, conversely, my shredder is half finished and so far I’ve spent less than 100 euros on it, most of that being raw materials (steel). However I’ve done all the machining of the parts myself and it takes a long time! Probably 50+ hours and counting, and my design is different (about half the size). I’ve yet to source a motor, which will probably be the most expensive part. I do think some of the pricing in the bill of materials is ‘optimistic’!
I think it can be built cheaply if you are prepared to spend time on it, or are lucky enough to be able to source parts cheaply/ for free. But by the time mine is finished I’m sure I wouldn’t part with it for 750 euros.
here are my latest numbers, from Catalonia (near spain) : here
, totalling 830 Euro (150 for labor) with a powerful 5hp motor and laser cutted parts.
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