Question Chopper Problem

[rhop]

I have a Morso Chopper. It is old but in good condition.
I am having a problem with the cuts. The chopper breaks
off a piece of the moulding at the bottom of the
45 degree angle at the sharpest point of the cut.

It does it more on cheap moulding but still does it on good moulding.
Don't think it is the sharpness of the blades.

Any recommendations as to what is happening and any solutions.

 

[Rick Granick]

If you use the Search button above you will find many discussions of this issue, and some potential solutions. That said, there are some mouldings which just do not do well on a chopper, such as those with curved backs, those with soft/crumbly wood, and those with a thick layer of brittle gesso.
Rick

 

[Greg Fremstad]

My guess is that the points of the blades have a sleight gap between them. My second guess is that the blades are not sticking out through the gap in the fence far enough. Mind your fingers!

 

[Baer Charlton]

the blades are not sticking out through the gap in the fence far enough.

Mind your visuals Greg.... that should NOT be "sticking out through" but "sticking into the gap".

rhop, get down on your knees, (OK stretch before you do this) twist your head around until you are looking at a large gland nut (just a very large nut that is bigger than your thumb).

Loosen the gland nut, and adjust the rod that pushes and pulls the blade assembly in and out (not up and down). CAREFULL it doesn't take much. You are trying to set the tip of the blade "V" just inside of the slot between the two backing rails. This can be as slight as 1/32" to almost 3/32".... it really doesn't take much.

The way I was taught is run the assembly out until you can drop your business card down between the backing rails and the leading edge of the blades. now adjust in until the business card is bisecting the angle between the blades and the rail. Tighten nut and retry chopping the same problem moulding. If you need more, reinsert the card and watch it move to half the distance to the blade. Retry.

All this being said, there are two very nasty things that are going on today (actually three) that also may be your problem or a part of the whole.

1. To better run the moulding through certain machines, the semi-sharp or "eased" edge on that back foot has bee shaved to a true round over, or even a chamfer. Neither are supportive in that last nano-second of a chop.
2. Compo shell used to be actual slurry compo that is extruded onto the wood very thin but resilient .... now it's thicker because then the underlying wood can be rough shaped and even contain hidden knots.
3. I'm not sure why, but as I have compared (crudely*) older compo shell from the 60s and 70s to the modern stuff, its now harder and more brittle and shatters easily when unsupported (see #1).

* We drove to long sheet-rock screws through a board that was set in a slide rail that allowed the board to go up and down evenly. We then set up two mouldings under the sharp tips of the screws. Slowly adding 4oz weights to the center of the board we were able to measure (crudely) the amount of pressure to cause a shell to crack or shatter. Almost all of the old shells took double the weight of the modern shells to break.

My gut thought is that somewhere along the way, things like Molasses were replaced with cheaper (and I do mean cheap) polymers and plasticizers.

If you think you don't like it; try being old enough in this business to know that there was a better way to do things and "quality" was the goal instead of maximizing stockholder equity. There are very good reasons why I rep for who I rep for.

 

[rhop]

Morso Chopper

Thanks for the info. Very helpful.


Got to go stretch.

Ray (rhop)