Shredder DIY

[m_c]

Whose aiming for sawdust?

You mentioned course sawdust in your first post..

 

[prepman]

You mentioned course sawdust in your first post..

Sorry yes.....but coarse sawdust is what I meant large pieces 4mm or so

 

[gaz1]

then a 4 blade spinning disk would be better

for more info look here

 

[prepman]

As with most things in life ....one job produces others. This no exception. Needed the shaper to make a part, Wanted the vertical feed to work, to do it. Vertical feed ran to end and broke the gear taper pin. Decided to make a new ratchet friction assembly but needed to make radial slots. So over to the long unused mill. Dividing head had seized...so free that off first. Rummage around for an end mill of correct size...didn't have. But have slitting saws. So off with vertical head and on with the horizontal arbor. Put blade on ....it wouldn't cut butter. Ordered a new blade ~£10. Then thought about sharpening the blunt one........SO. today have got a rig 80% completed to sharpen using angle grinder.

But found a use for an old caliper piston, cleand up and welded a tag to hanging for a pen caddy....

 

[prepman]

No set on the teeth as far as I can deduce. So 1mm cutting disc should do it. Nothing to lose, as saw blade is (k)nackered. Not this blade for sharpenening an other more (k)nackered one. Used a piece of my muchly available 50mm angle and a scrapped DIY QCTP holder. Need a clip spring for a set pawl and limit stop.

 

[prepman]

Another first...finally used my MT2 reamers successfully to produce a tail-stock for the miller to produce a ratchet wheel on a mandrel.
12years I've had the set. Today hopefully the 2 other set of thrust races will arrive to fit on the modified shaper feed to make the part to enable me to continue with the shredder project. 'There's a hole in my bucket....'
Extremely inexpensive.....

4 Kit 7/8", 3/4" 2TRA Thrust Needle Roller Bearings Plane Agricultural Machinery | eBay

Complete Package: Includes 4 sets of NTA1423+2TRA/ NTA1220+2TRA thrust needle roller bearings. Dimensions: Inner Diameter = 7/8 inches/ 3/4 inches, Outer Diameter = 1-7/16 inches/ 1-1/4 inches, Thickness = 5/64 inches. Durable Material: Crafted from high-temperature bearing steel, ensuring wear...

www.ebay.co.uk

 

[prepman]

Having had a futile session trying to shred green stuff with the Hyundai shredder, which uses a paddle wheel blade array against an adjustable pressure plate, Which is not a good system. It resurrected my interest in the DIY jobbie. I think that if the blade teeth were all aligned in a row they it would act like a series of closely spaced chipper blades?

 

[8ob]

Having had a futile session trying to shred green stuff with the Hyundai shredder, which uses a paddle wheel blade array against an adjustable pressure plate, Which is not a good system. It resurrected my interest in the DIY jobbie. I think that if the blade teeth were all aligned in a row they it would act like a series of closely spaced chipper blades?

It’s all a bit of a compromise with these small shredder/chippers, a good shredder won’t double up as a good chipper in the same way a good chipper makes a lousy shredder. The best all round chipper/shredder drum would have the same type of boot flails used on side arm hedge flails. A lot of them also don’t make enough windage and block up unless they are fed small amounts and allowed enough time to clear.

Bob

 

[Jelly_Sheffield]

Having had a futile session trying to shred green stuff with the Hyundai shredder, which uses a paddle wheel blade array against an adjustable pressure plate, Which is not a good system. It resurrected my interest in the DIY jobbie. I think that if the blade teeth were all aligned in a row they it would act like a series of closely spaced chipper blades?

I think you would have much more success with that approach than your initial idea of trying to mimick the interlocking knives on twin-shaft industrial shredders (which, fwiw I don't think is a design that's well suited to what you're trying to achieve here anyway).

However at that point, rather than buying oodles of saw blades, wouldn't it be cheaper to buy an old planer or spindle moulder head (non-chip limited ones are cheap on ebay) that takes serrated knives (again cheap as chips and easy to resharpen)?

 

[prepman]

I think you would have much more success with that approach than your initial idea of trying to mimick the interlocking knives on twin-shaft industrial shredders (which, fwiw I don't think is a design that's well suited to what you're trying to achieve here anyway).

However at that point, rather than buying oodles of saw blades, wouldn't it be cheaper to buy an old planer or spindle moulder head (non-chip limited ones are cheap on ebay) that takes serrated knives (again cheap as chips and easy to resharpen)?

I already have the oodles of blades....

 

[prepman]

I have a spare 3ph motor (3hp) and VFD lying around. but would prefer to run off the tractor PTO. Want to avoid small petrol engines.

 

[Jelly_Sheffield]

I have a spare 3ph motor (3hp) and VFD lying around. but would prefer to run off the tractor PTO. Want to avoid small petrol engines.

3hp probably won't cut it for shredding wood up to 4" diameters at any appreciable speed, a small commercial unit for that kind of application would usually be around 22kW...

So either direct PTO driven with some sort of safety clutch, or a hydraulic motor that runs off the tractor would be my choice.

If you look at the design of Andritz "ADuro U" single-shaft granulators, they have many small teeth arranged in a spiral configuration so only a few are engaged at any one time (reducing peak torque).

That's almost certainly something you could replicate with your oodles of saw blades...

Cutting off somewhere between 2 in every 3, to 5 in every 6 teeth, then pinning them together on the shaft once assembled and clamping with a whack-off great arbour nut, would effectively replicate that spiral effect, trimming off teeth also means that you can align the many small blades easily without the set of the teeth clashing.

For single shaft shredders the clearance between the top of the teeth and the wear plate on top of the shredder "bar" that they run against is critical:

- it should be pretty close fitting, and both too tight or too loose will massively increase the loads on the teeth,

- if there's not at least some taper of the edge towards the underside to give clearance the bar will frequently clog and jam.

As you're only building one of these, it's probably best to make that part adjustable in-out so you can slowly dial it in.

Regards the clearance angle if you had the wear-plate laser or water-jet cut out of 826M40/EN26W or hardox plate, then the natural taper of the kerf might be sufficient to achieve what you need, otherwise it would be a case of just carefully grinding in more taper by hand with a flap wheel until it runs smooth.

 

[prepman]

Well....finally finished it... I know..I know

CRYTEC CRC200X 212CC 60mm Wood Chipper Garden Shredder Petrol Chipping Garden | eBay

Transform your garden maintenance with the CRC200X Wood Chipper, a powerhouse designed for efficiency and convenience. Perfect for both amateur gardeners and professional landscapers, the CRC200X effortlessly handles all your garden waste needs.

www.ebay.co.uk

 

[Jelly_Sheffield]

Well....finally finished it... I know..I know

CRYTEC CRC200X 212CC 60mm Wood Chipper Garden Shredder Petrol Chipping Garden | eBay

Transform your garden maintenance with the CRC200X Wood Chipper, a powerhouse designed for efficiency and convenience. Perfect for both amateur gardeners and professional landscapers, the CRC200X effortlessly handles all your garden waste needs.

www.ebay.co.uk

Congratulations, you solved your problem!

 

[MattF]

Well....finally finished it... I know..I know

CRYTEC CRC200X 212CC 60mm Wood Chipper Garden Shredder Petrol Chipping Garden | eBay

Transform your garden maintenance with the CRC200X Wood Chipper, a powerhouse designed for efficiency and convenience. Perfect for both amateur gardeners and professional landscapers, the CRC200X effortlessly handles all your garden waste needs.

www.ebay.co.uk

Will that shred/mulch soft green waste, as in flower type stems & such?

Tried the chipper a month or two ago on that front, & it's not happy doing that until it gets a mix of hard & soft material, as in mixing in a few small branches or such.

 

[prepman]

Will that shred/mulch soft green waste, as in flower type stems & such?

Tried the chipper a month or two ago on that front, & it's not happy doing that until it gets a mix of hard & soft material, as in mixing in a few small branches or such.

Yes it does pretty much anything that'll slide down the shute. Want I don't like is, that the discharge will only point downwards. Made a vertical one from sheet steel, but the blower hasn't enough puff and the chute blocks. I think they probably blundered in the design as the discharge is upwards pointing and they've cranked it downwards. Afterthought?
A bottle of oil for the engine would have been nice if it had ben included. Other than that, it's a pretty mean machine. 7hp motor. Not a machine for the suburbs with neighbours though.......OK here.