Wallenstein BX42 Chipper Twig Breaker Replacement

[Runner]

Needed to do some chipping yesterday, but before I could do that, had to replace the "twig breaker" on the Wallenstein BX42 chipper. Well, didn't have to, it will work OK without it, but it helps break up stringy stuff. Not sure if other chippers have this but thought I would show the fix, up close and personal.

The twig breaker consists of a piece of bent plate with a rectangular hole punched through it, and a piece of 1/4" x 1 1/4" x 2" steel bar puddle-welded into the hole. There is a rectangular hole punched in the side of the rotor housing through which the bar is inserted and the bent plate is then bolted to the lip of the housing where the "clamshell" separates for maintenance. There is a corresponding slot cut in the rotor fan blades that rotates past the twig breaker, thereby cutting up long pieces into smaller pieces on their way out the discharge chute.

Obviously, this piece is subjected to some tremendous stresses when larger pieces get caught in it and this is the reason for the puddle-weld attachment method: it is made to break free when overstressed (or if it gets bent) to prevent damage to the rotor fan. I wind up replacing this piece at least once per season, so I keep a stock of the pieces of replacement bar stock.

Side view, twig breaker below separation line of the cutting chamber, directly below the discharge chute.

Note the hole in the weld where the breaker bar used to be

Inside fan chamber looking at punched hole where twig breaker enters. Note corresponding slot in rotor fan.

Twig breaker removed.

Twig breaker and new piece.

Twig breaker with old weld ground off.

Ready to weld.

Back in place.

Back in place, inside view.

Ready to chip.

 

[old and tired]

I'm surprised that the breaker bar is not chiseled to a sharp point to help it cut... even if just a little bit.

 

[Runner]

I'm surprised that the breaker bar is not chiseled to a sharp point to help it cut... even if just a little bit.

I just replicated what was there originally, but I might just try putting an edge on it to see what happens. Only thing is, if it was sharpened, it might have more of a tendency to just draw pieces through whole, rather than break them up. This is pretty much a brute force deal, meant to just snap stuff in half, rather than cut it (at least up until the force snaps off the bar).

 

[oosik]

I had a Wally BX42S for many years - now a BX62S. What happened to the OEM twig breaker on your 42??

BTW - you did a superb job on the replacement.

 

[Runner]

I had a Wally BX42S for many years - now a BX62S. What happened to the OEM twig breaker on your 42??

BTW - you did a superb job on the replacement.

It just broke off and, as mentioned, it happens on a regular basis. I don't think I saw it in the manual or anything, but just based on the design, it became obvious to me that it was made the way it was so that it could break off, rather than causing lots of damage if it got caught on something too hard for it to break. Kind of like a shear bolt.

If it were made to stay intact, no matter what, they would have extended the breaker past the outside edge of the bent plate on the outside, then welded it. Then, there would be no way it could come loose. I actually thought about doing the repair that way, but then I realized how much damage it might do if it couldn't break away.

Wallenstein offers them as a replacement part (the whole assembly, not just the part that goes inside the rotor housing).

I'm really glad that I was not in the path of the chute when that piece came out of there. I do have a bad habit of ducking under the chute in order to get to the PTO switch when I shut it down....

 

[oosik]

Every couple of years I thin my pine stands. I'm chipping green pines - one inch to six inches on the butt. Chipping these pines is like chipping fresh Twinkies. I don't think there are a lot of tree types that would be easier to chip.

I wish I could say that these chipping projects were all fun. I go into a pine stand with my chainsaw. When I'm done it looks like a giants game of Pick-Up-Sticks. The - not fun part - dragging all these pines to a central pile. If I don't stumble/fall - now and then - I'm not working hard enough.

These chipping projects will usually take two months. I end up - felling, dragging and chipping - 800 to 1000 small pines.

All of this because I can only burn in the winter. Summer equals too great a chance of wildfires.

 

[Runner]

Every couple of years I thin my pine stands. I'm chipping green pines - one inch to six inches on the butt. Chipping these pines is like chipping fresh Twinkies. I don't think there are a lot of tree types that would be easier to chip.

I wish I could say that these chipping projects were all fun. I go into a pine stand with my chainsaw. When I'm done it looks like a giants game of Pick-Up-Sticks. The - not fun part - dragging all these pines to a central pile. If I don't stumble/fall - now and then - I'm not working hard enough.

These chipping projects will usually take two months. I end up - felling, dragging and chipping - 800 to 1000 small pines.

All of this because I can only burn in the winter. Summer equals too great a chance of wildfires.

So have you ever had a twig breaker fail on your units?

Mine has been getting the acid test the last few years, chipping lots of hedge, locust and all sorts of dead, petrified wood so that probably explains why I'm replacing them so regularly these days.

 

[Captain Dirty]

Good looking repair. May I suggest that the next time the twig breaker fails, you continue to chip without it and notice if there is a change in performance. It appears designed to break dry, brittle twigs. I borrowed a friend's Wally 42 on which the twig breaker was present. I know because I spent a lot of time opening and closing the clamshell to free clogs. I was chipping a lot of green saplings with pliant twigs that, if ejected, were ejected as "birds' nests. Quite often they jammed in the throat or higher in the chute owing to the slight narrowing of the chute. My friend operated the chipper on his 1000rpm PTO and claimed to have no problem. Probably the near doubled speed greatly increased the airflow. My present chipper, a 6" Salsco, has no twig breaker; it still ejects "birds' nests", but as the chute doesn't narrow, I have had few jams.

 

[Runner]

Good looking repair. May I suggest that the next time the twig breaker fails, you continue to chip without it and notice if there is a change in performance. It appears designed to break dry, brittle twigs. I borrowed a friend's Wally 42 on which the twig breaker was present. I know because I spent a lot of time opening and closing the clamshell to free clogs. I was chipping a lot of green saplings with pliant twigs that, if ejected, were ejected as "birds' nests. Quite often they jammed in the throat or higher in the chute owing to the slight narrowing of the chute. My friend operated the chipper on his 1000rpm PTO and claimed to have no problem. Probably the near doubled speed greatly increased the airflow. My present chipper, a 6" Salsco, has no twig breaker; it still ejects "birds' nests", but as the chute doesn't narrow, I have had few jams.

I know what you mean. I have run it both ways and performance very much seems to depend on what I am chipping. For the dry, dead trees I've been chipping this fall, the twig breaker doesn't matter much.

However, what I'm normally running through it is fresh green branches, vines and bushes. For that stuff, I have determined that the breaker helps cut the stringy stuff smaller. As far as green leaves, pine needles and cedar foliage, the only way I know to prevent clogging is to try to give it a mixed diet, i.e., try to find woody material to run through at the same time as the fluffy green stuff.

Since it only takes a few minutes to fix it, I figure I might as well keep it in there. I do need to cut up a few more bars to keep in stock though.....

 

[oosik]

The short story - No, I've never had the twig thingey break.

However - discharge chute plug up was a REAL problem with my 42. Not a bit with the 62. When chipping green pine whole - there is a terrible amount of sticky sap. From the main trunk, limbs and all the needles. Plus - the 42 would get really quite warm with the continuous chipping. I'm sure this did not help the sticky sap situation.

The 42 compared to the 62. The 42 has a smaller chute diameter - smaller chipping chamber and significantly less discharge wind volume. I had a solution for this. Fell and drag all the pines to piles this year. Let the piles dry out and chip next year. Almost no plugging when done this way.

I went to the 62 because I got the bigger M6040. The 42 was run with a Ford 1700. The 62 allows me to chip up to six inch pines. The 42 only went up to four inch.

I've used the 62 for eleven years now. Blades are still sharp as razors. That's what you can expect when chipping green pines that have not been dragged thru the mud or dirt. I still haven't had to sharpen the blades nor switch to the second sides.