What are these screws for on this old craftsman jointer and another question.

[stryped]

As you know I have a vintage 50's craftsman jointer. There are 3 knives in the cutterhead. Each knife is held in with 4 allen screws. But also on the cutterhead in one spot are two allen screws on on each end og the cutter. (Fence side and person side). Any idea what these are for? The old manual I downloaded dont mention them. SOmeone on another newsgroup said maybe they are for angeling the blade? But my manual does not mention this. I loosened one of them and could not tell anything. I was afraid to take them out as I had just adjusted the cutter head height and did not want to mess it up.

I also had been thinking about my knive adjustment plight. My cutterhead has adjustment screws on each side of it to raise and lower it. Why could I not just install each knife secuely and adjust the knife height by raising lowering that side of the cutterhead? The manual makes no reference to that and just says to adjust each individual knife with a straightedge. The only thing I could think of is maybe it would be impossible to get each knife the right height using that method.

[Leon]

Blade height/level adjustment.

[dadiOH]

Maybe because the head is round?

[stryped]

[stryped]

[todd1814]

They control the height of the cutterhead to which your blades are mounted. Your blades need to be mounted the same distance from the cutterhead. That is, they should extend the same distance from the cutterhead to the end of the blade. This gives them consistent height and hopefully makes them parallel to the table. If the blades are mounted consistently then you could use those screws to move the cutterhead up/down and make it parallel to the table. If you're blades are not consistently positioned then one blade will contact the wood and another one won't.

[stryped]

Ok. My mind is not working right as always.

The two screws I was refering to are on the cutterhead themself. There are two bolts on the cutter head bracket that controls the up/down placement of the cutterhead, so I dont think those two allen screws I was saying I dont know what they go to control that.

My manual shouls how to adjust the cutterhead by adjusting the bolts on the bracket which i understand, but it also shows that you must adjust the individual blades level to the outfeed table bu having them touch a straight edge all equally.

So, why could you not skip that last step and adust the cutterhead height to place the knife at the height of the outfeed table?

Still not sure what those allen screws are for.

I know sometimes I have a mental block about th> They control the height of the cutterhead to which your blades are

[Leon]

Sorry, I expanded what you were saying and "thought" 2 Allen screws on each end of each blade. My old Craftsman has 2 screws under each knife on each end for the purpose that I stated.

[dadiOH]

As I said, because the head is round. Consider...

1. One knife is set at the right height
2. One knife is too low
3. One knife is too high

Now, what happens to #1 & 2 if you raise the entire head so #2 is OK? Or, what happens to #1 and #3 if you lower the head to fix #3?

[dpb]

...

If you adjust the whole head and each knife is not at the same _relative_ height, you can move any particular knife to the correct height, but the others are _STILL_ off relative to each other.

This is the jointer I had in the days before the 'net...no manual then! :)

I looked at the manual, it seems quite clear and straightforward to me if you'll simply follow along in order and not try to make up new things. I will say (again) that this particular jointer is "touchy" to get aligned properly, but once it is, it will do excellent work.

I'll go through this one more time...

The flat-headed Allen screw shown in Fig 3 at each end under the knife is for setting the knife height individually. The easiest way to get these even w/ each other is to set each one slightly low and then use the set screw to bring them up to the correct height. I do not recall if this jointer has them offset sufficiently to allow that, but I think it does. In doing this, you have to have the locking gibs in place, of course, but not yet tight so the knife can be moved. However, they have to be snug enough to keep the alignment close.

The head-leveling screws on the cutterhead itself are to adjust the overall height of the cutterhead itself and to level it so it will be parallel to the tables, left to right. If, once the knives are all set at the same height with respect to each other, the cut is too much or too little to achieve a straight edge as described in the manual, _THEN_ and _ONLY_ then, you can correct that by tweaking the cutterhead height. This, too, is described in the manual (p 3).

Simply think about what moves relative to what by the various adjustments and it should be clear what the purpose of each is. The screws on each knife set individual knife height relative to the cutter head. The screws on the cutter mount adjust the height of the cutter head relative to the table.

[RayV]

Maybe they hold the cutterhead in place on the shaft.

The shaft does have two flat spots on it. Is that where these screws are?

[stryped]

Everything in that online manual looks like my jointer but the pictorial of the cutterhead does not. Mine only has a blade, wedge, and

4 allen headed bolts for each blade to tighten the blade. It does not have any of those "fine adjustment" screws.

The manual I have at home does not show them either. These > stryped wrote:

[dpb]

...

Are the holes there but just missing the screws or does the cutterhead not have provision for them? There were cutterheads w/o them for sure, I presume that would indicate earlier models or perhaps there were some other minor niceties as well that made different models, I don't know. Either way, if the head doesn't have the depth-setting screws, that makes it more of a pita to align but the same steps are to be followed--first you have to get the knives all in a concentric circle, then if necessary, adjust the cutterhead relative to the tables. (Of course, to get the knives on a concentric circle means the head needs to be parallel to the tables to start with since the reference point is the table, so you need to check that first.)

[Locutus]

Why don't you take some pictures so everyone can see what you are talking about?

(if this jointer actually exists...)

[Nova]

Are you sure they're not oil ports?

[dpb]

stryped wrote: ...

screws to hold the cutterhead on the shaft. That would be Item 38 on the parts list (p 6), the drawing (p 5) shows them w/ the shaft, not the cutterhead detail. A better drawing/parts list would have dashed lines showing the placement on the drawing and the parts list would spell out quantities for each item, but by elimination of other pieces/parts, that's pretty much what they have to be. As someone else noted, the two flats shown on the shaft are also telling--the cutterhead has to be locked on there somehow, and that's obviously how.

[stryped]

[dpb]

... That's no different--the only difference is the convenience of having the screw below the knife isn't there and that does make the adjustment more tricky to get done precisely. If I had a jointer w/ that type of head, it would quite possibly be the incentive to get one of the magnetic knife-holding jigs or rig up something similar to ease the alignment.

The problem/difficulty is that if the gib is too lose so the knife moves easily, the accuracy isn't very good. If the gib is snug, and the knife needs to come up (out) some, when it does move, often the whole gib moves at the same time and if it needs to go down (in), that doesn't work well because it just tightens the gib by forcing it into the taper. That's how the adjusting screw really helps, it gives you that force from behind the knife to start a little low and "sneak up" on perfection.

That said, it _is_ doable, just takes patience and a little touch. As noted before, check that the cutter head is parallel to the table first, then get the knives all even. It's very important that they are even so that each takes the same cut depth. Otherwise you'll get an uneven edge as one will take a deeper cut than the others.

After you've got them all the same, take some test cuts and check that the cut is straight--the manual describes the symptoms with too high/too low and how to correct it w/ the fine adjustment of the cutter head quite well. The thing there is to make very small corrections and do precisely the same on both ends to maintain the knvies parallel to the bed tables. As I recall, those adjusting screws are a standard thread which is pretty coarse for this kind of adjustment, so a fraction of a turn is quite a lot of height travel.

HTH...again, having had one of these beasties, while they are touchy, it can be set up correctly and will do excellent work once this is done.

[charlie b]

If the knives in the cutter head are not all set to the same height above the cutter head it doesn't matter if you set the cutter head to the outfeed table.

If you remove a knife you'll probably find some springs under it. Have a look at this page and the next one

charlie b

[Bill]

Any chance that they are sitting ON TOP of other screws, keeping them from backing out of the hole? When I worked as a machinist / die-maker, this was a common way to use one allen screw to set an adjustment and another, on top of it, to lock the adjusting screw in place. Tou could set the adjusting screw 'just so' and then lean into the second crew to tighten things in place without disturbing the first screw.

Might also be plugs, not screws. Any chance they are plugging up a lubrication channel?

Bill