Hammer blades for chipper.

[Mr J Morton]

Theye should be high strength steel and heat treated....half the problem when I used similar machines in the past is the grill at the output end of the machine being too small to let material pass through.....so the material gets stuck inside the machine and then the hammers destroy themselves trying to beat it to a pulp. My workaround was to play around with different sizes of grill openings....still reduced the size of the material you feed in, but a quicker passage out....all depends what kind of result you want really...

Yes it can happen, you could buy different size grills awhile ago, it's very rarly happened to me and I give it some abuse, but it also behaves differently depending on species being chipped. I must say the most annoying thing about it is the low out feed. You constantly have to clear the front of it or it blocks up the chamber, chipping on a slope and chocking the front up works well as does running it on a pallet.

 

[Mr J Morton]

All of these machines are. Bramble has a fair strength to it, enought that it was past used for making ropes.
You've seen the ropes in a chipper video? If not..

Jesus that a one way ride!
I'm a farmers son, out of the stuff I'm regularly running, this chipper ranks pretty low. Nowhere near as power as that one in the video, It would stall out and belt slip before dragging me in, but still mega dangerous so I try not too get nonchalant.

 

[Mr J Morton]

Whatever you do, you should get them red hot before straightening. Give them a good look over for cracks because it's difficult to bend a hardened steel without it cracking. You might have to draw back the temper a fair bit too which is a bit tricky without knowing the grade of steel but certainly a blue (spring temper)
or beyond.

I don't think they are tempered, I will strip it down and take a file to them, but from memory I think they are relatively soft. But by my way of thinking they would wear on the holes, if not they would ware the pins, I can remember rotating them all last time it stripped down, possibly that was why, I just can't remember.

I wondered if there was a bendable steel like mild steel that was abrasion resistant, but not quite as hard as the pins?

 

[Kram]

15hp driving a decent rotating mass would remove/shed/mangle limbs without hesitation and you'd die from blood loss before any one noticed, unless very lucky!
Yes it would be very low risk compared to other kit on a farm but a soft squishy human would not win.

 

[Screwdriver]

I don't think they are tempered, I will strip it down and take a file to them, but from memory I think they are relatively soft. But by my way of thinking they would wear on the holes, if not they would ware the pins, I can remember rotating them all last time it stripped down, possibly that was why, I just can't remember.

I wondered if there was a bendable steel like mild steel that was abrasion resistant, but not quite as hard as the pins?

There are a zillion grades of steel alloy and if these are hammers then I expect they would be a grade for toughness rather than hardness or the ability to hold an edge. You can spark test it to see. Should be fairly obvious.

I would expect them still to go through a heat treatment though which would involve hardening and then tempering. Just a very hot temper, beyond blue, probably in the sort of 400ºC range but that's pure guesswork and just something I would try myself.

I am guessing from your replies above, you are, like me, happy to suck it and see...

 

[Agroshield]

I wondered if there was a bendable steel like mild steel that was abrasion resistant, but not quite as hard as the pins?

Dunno if Hardox would work. Thinnest I can see it is available is 4mm.

Draw up one of the blades (for something that simple, a pencil and paper sketch would be fine), send it to these people and see what price a set of 16 would come to:

Catalog :: Metal Sheet, Plate & Parts :: HARDOX / RAEX (400, 450 & 500) :: Sheet & Plate :: 4mm RAEX 400 HARDOX wear sheet plate profiles blanks - Custom cut to size free of charge, enter exact dimension for pricing better than 400 450

4mm laser cut 400 Grade Wear plate Hardox / RAEX BS EN 10051 sheet blanks profiles Cut exactly to your specifications on our 6kw fiber laser Specification 400 Grade Wear plate Hardox / RAEX BS EN 10051 Min / Max 15mm 0 6 minimum | 1490mm 58 6 maximum Quick turnaround with express options on checkout

hawksheadmetal.co.uk

 

[Gareth J]

Be a similar steel to mower blades I suspect? They seem to bend quite well before breaking but be decent enough to withstand a lot of abuse before wearing out or bending.

Better they bend than break or be so large they distort the drive bar before failing.

 

[Mr J Morton]

Dunno if Hardox would work. Thinnest I can see it is available is 4mm.

Draw up one of the blades (for something that simple, a pencil and paper sketch would be fine), send it to these people and see what price a set of 16 would come to:

Catalog :: Metal Sheet, Plate & Parts :: HARDOX / RAEX (400, 450 & 500) :: Sheet & Plate :: 4mm RAEX 400 HARDOX wear sheet plate profiles blanks - Custom cut to size free of charge, enter exact dimension for pricing better than 400 450

4mm laser cut 400 Grade Wear plate Hardox / RAEX BS EN 10051 sheet blanks profiles Cut exactly to your specifications on our 6kw fiber laser Specification 400 Grade Wear plate Hardox / RAEX BS EN 10051 Min / Max 15mm 0 6 minimum | 1490mm 58 6 maximum Quick turnaround with express options on checkout

hawksheadmetal.co.uk

To be honest I will probably end up buying the ones which are cheap on the above link at half price if I have to replace them. But a good option as a back up

 

[Mr J Morton]

Be a similar steel to mower blades I suspect? They seem to bend quite well before breaking but be decent enough to withstand a lot of abuse before wearing out or bending.

Better they bend than break or be so large they distort the drive bar before failing.

This was my thought. I have tried to harden mower blade steel to make knife but it didn't work. Which is why I thought these hammers might be mild steel. I'm not sure at the original price point they would have spent much money on the metallurgy when they were first designed.

 

[Screwdriver]

Spark test!

 

[Mr J Morton]

Spark test!

Will do!

 

[jo1010]

Yes it can happen, you could buy different size grills awhile ago,...

I remember not using the grill (#16 in the attached) but using several lengths of thin wall water pipe or similar mounted on threaded rod that locates in the holes already in the chassis (in the same way that #15 pins mounts your current grill). Then you can add or remove the total number of rods to give a coarser or finer output. Btw the diagram is an Italian machine so likely the parts will be even more expensive than yours

 

[jo1010]

Size of that insertion was supposed to be a thumbnail, sorry..

 

[Mr J Morton]

File and spark test shows mild steel! Very soft to the file.

 

[Mr J Morton]

I remember not using the grill (#16 in the attached) but using several lengths of thin wall water pipe or similar mounted on threaded rod that locates in the holes already in the chassis (in the same way that #15 pins mounts your current grill). Then you can add or remove the total number of rods to give a coarser or finer output. Btw the diagram is an Italian machine so likely the parts will be even more expensive than yoursView attachment 464370

The design is identical. The titan used to be the expensive, original one with a decent engine, that said the drive shaft was made of cheese grade steel.

I won't be making the grill change as it's never blocked due to the grill, but if the exit shoot doesn't get cleared it compacts after the grill. Clearing the blockage is safer with the existing grill, I use a stick I've shaped, but if it got into the hammers I would loose my teeth

 

[Screwdriver]

I have not heard of this type of chipper/shredder using a hammer action. This is very interesting for me since I hope to be able to recycle plastic (HDPE bottles) by first shredding them down to say 2-3mm particles.

Would anyone here know how such a machine might handle plastics? I might end up building something along these lines. I'm guessing speed and power are the two main requisites!

Interesting that the so called hammers are not hardened steel though. I would have thought that would be an absolute necessity.

 

[Agroshield]

I might end up building something along these lines.

Pedal-powered:

The plastic bottle shredder with spinning EnergyBike - Energorower

Energy needed to power the shredder is generated by a person pedaling on a bicycle. Grinding 1 bottle of 1.5 liters takes about 20 seconds.

energorower.pl

Most of the bottle shredders seem to be of the same design principle as a paper letter shredder (two-contra-rotating blades).

A shredder and a granulator (what I understand to be required to achieve 2-3mm size) appear to be different machines.

Jordan Reduction Solutions

Industrial shredders, grinders & granulators with a legacy of quality, durability and performance

www.jordanreductionsolutions.com

Badly-named company as Jordan has never to my knowledge gone for a reduction solution.

 

[Turbo]

You could use flails from a flail mower, provided you can get ones with a suitable hole size. They are a hardened steel but you can sharpen them with a file.
Take an old blade into an agricultural eqpt suppliers to get a close match.

 

[Migmac]

Found this one, should have more somewhere. It measures 8.5cm long 3cm wide, hole is 2cm x 1cm

 

[Mr J Morton]

I'm not sure plastic would work in this, it's too tough. This works great on most things, but fresh pyracantha gives it a real work out as it's so tough. The side chute would work well but that's a large spinning knife, like an upgraded version of the domestic electric chippers.

There used to be another make by Eleit and I'm sure I read someone used it for plastic. However it's designed differently and known to get regularly jammed.