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Rockwell 4800 Jointer

TJScharp

Aluminum
Joined
Aug 6, 2011
Location
Alberta, Canada

I recently picked up a Rockwell 6" 4800 Jointer. I have lost significant time adjusting planer knives and was hoping I might be able to replace the cutter head to a more modern style which has self aligning knives?
Any suggestions would be appreciated.
 
I have an 8 inch Powermatic jointer. Setting the knives to project the same can be frustrating
What happens is when you tighten the screws against the blade, they act like little cams moving the blade up or down.The only solution I have found is to sharpen them in the head. The same as on my planer.
 
On my jointer the adjustment screws had heads that were not completely flat. Thus a can action. I replaced the screws/nuts with some 316 inventory.
I flattened the heads on the screws. I can get knives to almost .001 dead on. Still takes a lot of time.
But not as much time when I sharpen the blades with a wet grinder with fixture.
 
Thank you for the replies.. I have dug into the Shelix head option but the initial cost was a little daunting.

I am curious about how one would sharpen the blade while mounted in the cutter head?
I’ve only changed the blades once and would like to simplify the process if possible.
I have access to lathes and milllibg machines and could make basically whatever I’d need fixture wise.
 
You can set up a router with a cup grinding wheel. Lock your cutter head into position. Not great but it does make all the knives the same height. You may find something on utube to help you. On my 20 inch Oliver Jointer, I bolted my planer grinder on it, that worked well.
 
Tersa has single knife solutions. Had to get them wrong. Byrd or any of that type are a totally different thing. Nick a knife leaving a raised stripe? Replace or rotate just that knife. Tersa you can offset the knife a bit but be aware rebating on the jointer needs to be kept in mind. It is only a spendy option up front. Once you do it the first project you make will be a very nice walnut asskicker. Stand in front and pull hard on the chain. Your favorite boot shoots up and kicks you in the butt.
 
Byrd or any of that type are a totally different thing. Nick a knife leaving a raised stripe? Replace or rotate just that knife.

Sounds good in theory, however unless the existing set of knives in the cutter head is all near-new when the nick happens, then rotating a single insert knife into position to provide a fresh cutting edge, when the rest are all dulled to some extent, will make for a situation where the new edge is cutting deeper than the rest and will leave a scallop in the surface, for some period of time. In that situation, the insert will also be taking a heavier cut than the rest and will dull more quickly than normal. And, then one also has the issue of keeping track of which insert was rotated, and which inserts have not been rotated, a problem the next time you go to rotate inserts.

Changing insert knives on a cutter wider than 6~8" is not a task to be done quickly given the quantity involved, and if you are not fastidious about keeping the insert seats clean, and seating the inserts properly, then one can end up with problems. I would put it roughly on a par, time-wise, with replacing conventional knives.

I am a fan of Tersa, but for anything other than softwoods the carbide knives are the only ones worth having, IMO. The carbide knives do have a steep up-front cost (which I feel more than reasonable considering how incredibly long the carbide knives last, even in wood known to decimate knives, like teak. Tersa offers quite good performance on figured woods due to the minimal knife projection from the cutter head. Would never opt for anything else, and I do have a Byrd shelix cutter for use on my shaper, so it is familiar to me. Byrd is not inexpensive and I gather the wait times for production have become quite long for certain cutter heads.
 








 
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