Heizohack HM8-400

[aodhagan]

Hello all,

 

i’m looking for any help or advice that anybody can offer regarding my Heizohack chipper. I have a Heizohack hm8-400 and in general I’m very happy with it.

 

it was supplied with a 35 x 40mm screen and I later bought a 50 x 50mm screen for it in order to supply a larger chip for a customer.

 

The 50mm screen had the Stop Bars fitted, I was advised to buy the screen with the stop bars in order to reduce the occurrence of long pieces in the chip and the stop bars do seem to be doing their job in that regard. 

 

My my problem now is that the machine seems to be producing a very large amount of fines in the chip. On the day when the 50mm screen arrived at the yard I had just chipped a few ton with the 35mm screen, i swapped over the screens and continued chipping and to be honest I couldn’t see any really noticeable difference in the chip size. Maybe I was expecting too much but the average chip size didn’t increase as much as I was hoping.

 

The fines are now causing my biggest customer to complain. I fitted new knives, I have the intake belt running as quick as it can and I’m running the drum at 540rpm but that doesn’t seem to make any difference.

 

now I’m wondering whether the stop bars on the screen might be causing the problem.. might it be the case that the stop bars are slowing down the speed at which the chips are getting through the screen thereby causing them to get another few whacks of a knife ? The timber I’m chipping is spruce with an average diameter of about 6 or 7 inches and it’s between 20 and 25 % moisture content. I’m also wondering if the small diameter, very dry timber is the problem, maybe it’s shattering when the knife hits it rather than being chipped..

 

Another thing which I need to mention is that I made a blunder a few months ago while I was swapping over the knives, I got distracted by the phone and as a result I forgot to tighten 3 of the knives, when I started chipping the knives came out of their mounts and completely destroyed all the other knives.. maybe the broken knives damaged the anvil while they were being thrown out of the chipper and this is causing the fines.. ?

 

I'm hoping that somebody can offer me some advice on this ..

 

 

thanks very very much for taking the time to read this..

 

 

regards

 

Aodhagan O’Hara

 

 

 

[Khriss]

In my experience with a hiezohack , the feed rate made the diference , not the screen size , was a nightmare just getting it set up to run ( brand new ! ) plus 6-7" spruce is tiny - we were putting thru 12" sweet chestnut / oak an you still got plenty of fines . K

[Khriss]

( Wicked chippers tho '.......those tiny blades ! )

[Khriss]

[aodhagan]

Thanks Khriss,

 

your machine looks nice and clean in the photo... hope you’re keeping it that way.. 

 

 

cheers

[Khriss]

Oh god no ! That was years ago - it had a hard life , but they build them well K

[Busy Daddy]

What horse power are you running it on , is it crane fed ? the blades need to be sharp and have the correct angle

 

[Khriss]

It was on a 160HP Valtra with upgraded clutch to run at 1040rpm and happily crane fed - took the safety rope off the infeed hopper as you would be in and out of the cab every five minutes ! K

[woodworm]

From experience, dry roundwood will always produce far more fines than slightly more damp or wet wood. Also if the stop bars are preventing long sliithers they will be creating extra cuts from the knives so will therefore be creating more fines. Multi blade chippers such as the Jenz and Heizohack will also create more fines than dual blade chippers.

[Busy Daddy]

Sometimes too much hp is a bad thing , if the blades are sharp and set to the anvil you should be fine

Try putting other timber through to see the difference

Was it a new machine , it could be the infeed rollers / conveyour teeth are a bit blunt not pulling in hard enough , just got that problem on mine at the moment