Looking for shredder/mulcher suggestions for vines and non-woody material

Hello permies,

I was wondering if I could get some suggestions or advice on a good mulcher/shredder for our composting system for my workplace. The shredder will be used for the permaculture farm that I am managing at a nonprofit school in the Bahamas. We already have a heavy duty wood chipper which does an awesome job for woody material like trees and branches but doesn't handle non-woody material very well. I am having a tough time finding the shredder that meets our needs so I thought there must be other people on here who would know some good brands/models to look at.

I am looking for a shredder that can handle green waste and organic material, particularly vines, herbaceous material, landscaping waste, leaves, smaller branches. Maybe half a ton per week? Basically I want to shred all that stuff up and compost it all mixed in with pig manure to get some nice high quality compost. A flail shredder is not ideal since the vines tend to get tangled in those types of shredders. As many of you have probably experienced, it's no fun to have to turn off, open up, and untangle vines and stringy material from a shredder. It needs to be beefier than a tiny backyard model but not nearly as big as the big expensive municipal/commercial beasts out there.

Some other considerations:
- preferrably diesel (we make our own biodiesel here so would be great to use our own fuel)
- electric is 2nd choice as we generate our own renewable energy, but all the electric shredders I have seen are so wimpy
- distributed out of the US to keep down shipping costs and for the ease of ordering parts
- under 3000 USD

It seems a lot of people on the Aussie permaculture forum like the Greenfeild piecemaker (http://www.greenfield.com.au/products/shredders/piecemaker.html) which is the best thing I've found so far but I'd have to ship it all the way from Australia and it looks like they don't have a diesel version. It also seems just a tiny bit smaller than what we need.

Anyone have some suggestions or ideas? I'd really appreciate other people's wisdom on the topic. Whatever model we do end up going with I'd be happy to write a nice long review post on the forum after we have been using it for a while to share our experience.

It is hard to find a machine that doesn't wrap vines. This one: http://www.mackissic.com/HSC_12P.html is supposed to do good on vines if you have the knives set tight and feed them through the chipper first. You may need a different hammer mill screen to adjust the chip size. I have not tried to use it like that.

I have the tractor version of that shredder and have done a few grapevines with it. I have used a machete or lopper to cut them to two foot long pieces and fed them into the hammermill. That way they are too short to wrap. It isn't perfect but acceptable for my needs and budget (I only paid 150 for it in like new condition).

Any hammermill should work with similar pre-treatment of the vines and the right choice of screens--the bigger the mill the longer the pieces could be.