chopper problems

[art forster]

I have a 40 year old morso frame chopper. i'm having problems with it chipping out the last 1/16 to 1/8 of the back face, bottom of the moulding??? the blades were just sharpened and iv'e made all the adjustments i can think of. has anyone had this problem and how did you stop it???????

 

[Susan May]

How old are the blades? How often have they been sharpened? If they are really old, and been sharpened a lot... you may need new blades.

Also, I had a Morso, had some problems chopping the last bit. Look underneith where the wood falls, and make sure there isn't any blocking the blade from moving all the way to the front of the machine. Sometimes a good cleaning will fix a multitude of problems.

 

[Jim Miller]

The problem you describe may be in the moulding, and not in your chopper. Increasing numbers of our mouldings are being made with a solid coating of material resembling gesso. Some of the coatings are brittle and chip very easily. In my limited experience, a carbide-tipped saw blade cuts these coated mouldings better than a guillotine chopper, but some of them are almost impossible to cut cleanly by any means. As we come across these problematic mouldings, I'm taking their samples off our display walls.

 

[Baer Charlton]

Even a set of blades that have been sharpened a few times past
where they should have become paint scrapers or a blade best
used for beheading small farm animals. (Yes, I do know personally
from where I speak.)

They should clear the shearing floor. . . If the pull arm is adjusted
correctly.

for a fast check - - cut a strip of 8-ply or 2-3 regular mats about
1" wide and 6" long +/-. Place then laying down on the bottom,
then place the errant moulding on top.... and chop.

IF the moulding chops cleanly.... loosen the bolt and push down
on the chopping head, to start and finish lower. Tighten bolt
and try again without the matboard risers.

DO NOT shorten the pull arm. Even though there is an adjustment....
It was a manufacturing detail - - not an adjustment detail.

 

[Bill Henry-]

After blades a sharpened a number of times, the honing makes them a bit smaller and sometime the edges don’t quite reach the shearing floor.

Baer is referring to the lock nuts here … I think (with Baer it's sometimes hard to tell)

Another thing that seems to help me is to run a bead of silicone calking (not glue!) in the slot between the right and left fences, let it set up for a day or so, then trim the bead flush with a razor blade. It seems to reduce the break out and chipping.

 

[Baer Charlton]

That's right Bill..... those Lock Nuts..... the operative word here is "LOCK" DO NOT TOUCH

that bold just below the box saying Lock Nuts..... THAT is the bolt to adjust up or down....

 

[David Waldmann]

Baer - I have to disagree. The bolt you are referring to only adjusts the maximum HEIGHT that the pedal will come UP to. It's to reduce leg strain when chopping smaller mouldings.

The lock nuts Bill shows are indeed the adjustment for how far down the blades are when the foot pedal is all the way down. While it's possible to adjust the travel such that you will cut all the way through with fully worn out blades, you will be moving the blades unnecessarily far when you have new ones (they will be going probably close to an inch down past the bottom of the moulding). That means you will also have to lift your leg an inch further than necessary. Maybe not a big deal if you're only cutting a few frames a day, but it's a big difference when you're doing dozens or hundreds. I prefer to have the blades go 1/16 to 1/8" past the moulding. That lasts for a few sharpenings and then you will need to adjust it again.

Note that for the above approach to work well, you need to keep your sets of knives rotating so that they are all about the same width. Otherwise you'll have to adjust the travel height each time you change the blades. Not a huge deal, but if you pay attention to your rotation it will save some time.