# M-B fitchburg chipper blade adjustment



## hd_rmblz (Jul 1, 2005)

Great site guys. I'm trying to adjust the blades on my drum chipper. Its an m-b fitchberg 915 (15 inch blades). The manual gives me the specs on the feed plate and the bed knife. That dosen't seem to be a problem. How the cutter knives are adjusted in the drum are. There were a couple of gauges that were used but i don't have a clue on how to find one and the manufacturer couldn't help. Does anyone know how much the blades need to be adjusted out from the drum in order to set the feed plate and bed knife. Any makeshift ideas or were i could find an adjusting tool? Thanks, mike


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## Proj Eng (Jul 7, 2005)

This may or may not help... but here goes:
Adjust the "guage blocks" so that they are 1/2" from the cutter head and square/same distance for both of them. Then, use a "step guage" or a wedge shaped piece of steel to set the distance equal all the way around the drum for the knives. You would use the wedge between the knife edge and the guage block. I don't know the exact ditance though, and I guess it would vary from machine to machine as tolerances thru the mfr are not always exact. I would think you could set up one knife, check it and then go back and re-set it until you find the proper distance for the knife setting away from the cutter head to achieve the spec out of the manual. Then adjust all the rest of the knives to that same distance (that you would have marked on the wedge shaped tool).
I hope this helps.


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## rbtree (Jul 7, 2005)

Wow a Fitchburg user!! I worked with one of those up until 1984. 

With that hinged feed plate, it is a quite different design than most hand fed drums, and very sensitive. Anything out of whack and it won't take the brush easily at all.

Critical is the spring pressure (lots) on the feed plate, the position of the cutter bar in relation to the feed plate, (not much showing) the squareness of the cutter bar, the clearance between it and the knives (paper thin is best) and knife sharpness. 

nice chipper if all is set right and in good working condition, otherwise, a nightmare...


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## C-4 (May 17, 2006)

hd_rmblz said:


> ... and the manufacturer couldn't help. ...



Is Fitchburg Engineering Corp. (the name on my drum chipper) still in business? I can't seem to find them on the web or through 411. I've been trying to find a manual for a Fitchburg chipper and would greatly appreciate any help in locating a manual or the manufacture if they are still around...

Many thanks,
Michael


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## rbtree (May 17, 2006)

Nope. I'd guess it's been 20-30 years since they were made. Maybe more. The ones I used in the the mid 70's to 1984 were old then, so were likely made in the 60's.


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## cosmicmadman235 (Jan 21, 2018)

I use a Fitchburg 15" drum. I love it but like you say it has to be adjusted properly. but all chippers do. Love the old stuff.


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