Jointer Cutter Head Replacement

[ssuel]

About three weeks ago, ShopSmith’s weekly email special was offering a complete jointer cutter head assembly (516196) for $135.92. My mid-1980’s jointer bearings were bad so I decided to take advantage of the offer.

So when working on it this morning, I noticed the 3-wedges in the new cutter head are different. They are longer and ShopSmith has drilled out holes to allow access through the wedges to adjust the knife leveling screws. In the picture, the new cutter is installed and the old one is at the top of the picture for comparison purposes.

NICE TO SEE SHOPSMITH IS STILL INNOVATING

[chapmanruss]

ssuel,

Shopsmith changed to the larger diameter Cutter Head in November 1990. The newer Cutter Head Assembly is a direct replacement for the old/original Cutter Head Assembly. As you noted the wedges are different and they are not interchangeable. The larger diameter Cutter Head leaves less of the blade exposed. The Blades themselves are the same and still cut at the same diameter. The shaft diameter of the Cutter Heads are the same. The Bearing Housings are the same for mounting the Cutter Head Assembly in the Jointer. The current Bearings can be used on older Cutter Head Assemblies. I replaced the Bearings on a 1960 Goldie Jointer I restored almost 6 years ago with the current Bearings.

As I have mentioned in other posts, almost all of the changes made to the Jointer through the years can be added to older Jointers. Some parts can be replaced individually while other like the Cutter Head must be replaced as an assembly.

[ssuel]

Thanks for the information!!!

[DLB]

...The larger diameter Cutter Head leaves less of the blade exposed. The Blades themselves are the same and still cut at the same diameter. The shaft diameter of the Cutter Heads are the same...

I was thinking about this earlier and it really has me wondering. IIRC in the Jim McCann interview that Scott Markwood did, Jim said that the new cutter head was superior, and specifically that it was demonstrated to take less power from the Mark to do the same work. I don't disagree, but I sure wonder why. I can see, I think, more rotating mass near the cut producing a better quality cut. Subjectively, I agree that the 'new' cutter heads are superior. But it's not obvious to me why it might use less power.(? )

- David

[jsburger]

More mass equals more inertia equals less power to keep the cutter head turning???

[JPG]

FLYWHEEL EFFECT.

[chapmanruss]

I remember the Jim McCann interview with Scott Markwood and the mention of the change to the Jointer Cutterhead. I would have to watch it again to remember what made it better.