WC-8 Chipper Mods

[bradblazer]

I bought a WC-8 chipper used from a local guy via Craigslist who bought it directly from an importer. It didn't appear to be used a whole lot. The original blades were pretty dull but hadn't been flipped and it came with an extra set of blades. It has the u-joint type of roller drive shaft and the safety bar works by levers/linkages, not cables.

I made a few mods before I ever used it based on problems reported here and elsewhere related to the roller drive. The window the pulley shaft comes through is over-sized so I made a little plate that covers most of the opening and also has a tab bent in that extends almost to the flywheel with the idea that it will cut any vines that try to wrap around the shaft. To address chips entering from the feed area and fouling the belt I made a simple guard that covers the belt at that end and otherwise let the chips fall where they may. Lastly I added some M6 set screws to the u-joint shaft ends where they slide onto the square male ends.

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[bradblazer]

I am attaching the pics directly and it only lets me attach 3 per post. Anyhow, it runs good and I haven't had any feed roller trouble yet. I was disappointed in the blade life. That fresh edge dulled after a few days of chipping to the point where the wood didn't feed well. I was chipping mostly fairly dry pine. I cut small trees and brush and feed to my goats. They eat all of the needles and bark off the pine and it drys out pretty quickly. Reading around dry wood is apparently known to be hard on the blades. Do you guys have any similar experiences or do you think I just got poor blades with mine?

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[Rich Waugh]

Dry wood is harder on chipper blades than green wood, for sure. That said, your blades may ot have been heat treated as well as they might, or they could be just too low in carbon content to harden sufficiently to really take and hold an edge. If you have a good steel supplier near you, I'd invest in some blades made from D-2 steel and heat treated professionally to about 59-62 Rockwell C. Those would be about as tough as you could get and should outlast anything OEM. Don't expect to get them ceap,though. D2 is an alloy intended for making dies for high production and is expensive, but worth every penny.

[bradblazer]

Thanks Rich. I'll take my blades in to work and have them hardness tested. It looks like I would have about $120 in raw material for D2. The blades at this site seem a lot cheaper than I could have them made: www.tskgrinding.com/Jinma-chipper-blades-s/1860.htm

[Rich Waugh]

Those look like a decent deal and A8 is good steel.

[bradblazer]

I tested the dull blades. They were both rc54.
Here's another source of USA blades I found with very similar pricing.
www.baileysonline.com/shop.axd/Search?keywords=jinma