Delta cutterhead lock bar screw

[Dave Morris]

The screws that tighten the lock bar and hold the knives in the cutterhead on my DJ-15 need to be replaced. The screw threads don't want to turn easily, and it's making adjusting the knives a real PITA. Every time I tighten a screw, the knife moves. I'm using a plate of glass with magnets to hold the knife up flush with the outfeed table, but the lock bar still moves the knife as I tighten it since the screws are so hard to turn.

In case you are wondering, I've cleaned the threads in both the lock bar and the screws. I thought it might help, but it didn't.

Anyway, do I have to order these screws from Delta, or is there any reason I can't use screws from the local hardware store if they are the same size/length/thread count? Just want to know if the original screws are anything special that "has" to come from Delta. I'd rather not have to wait for shipping on 9 lousy screws before installing a new set of sharp knives on my jointer.

[Rick Lizek]

Seriously doubt you can find these screws at your local hardware store. I've replace similar screws on our 20" RGA jointer with screws from mcmaster but still had to round the heads on a lathe. Have you tried chasing the threads in the lock-bar (gib) with a tap and using a die on the screws themselves? I typically keep the end screws with slight tension on the lock-bars and use a dial indicator with a flat tip and special flat base a(non-magnetic) and clamp the cutter head in place. Takes me about 8 minutes to do an 8" jointer within .0005". I start with the knives high and tap them down to flush with the outfeed table. I take out the springs.

[Dave Morris]

The DJ-15 doesn't use any springs in the cutterhead assembly. It uses a pair of notched nuts with allen screws to set the knife height. Even taking them out of the equation (nuts loose below the knife) and using the magnets to hold the knife up to the glass plate (making the knife even with the outfeed table), the problem occurs at the end of the tightening sequence. The problem stems from the "final" tightening of the screws.

It goes like this: Knife loose in slot, it's okay, flush with outfeed table and touching the glass. Knife "snugged" up with lockbar screws, it's okay, flush with outfeed table and touching the glass. Knife tightened up with lockbar screws (final couple 1/16 turns with the wrench), and the knife is now higher than the outfeed table by a good .008", even raising the glass off the outfeed table.

I considered using my TS-Aligner instead of the glass plate, but this final raising of the knife has me stumped and the problem would still exist using the Aligner's dial indicator. I'm probably doing something wrong, but don't know what that could be.

Do you use a piece of wood when tapping the knives down to prevent dulling the edge? I'll give that a try, using the dial indicator on the Aligner to check how things turn out, then tighten the notched nuts in the cutterhead so they are not loose under the knives during use.

[Rick Lizek]

I just did a DJ30 and it had the springs. They make changes on models. There's another DJ30 I work on that has the adjusters. I adjust machines for a living so I don't worry about what the adjusters are. After doing heads with no springs of adjusters like the Cresvcent I just take all adjusters and springs out.
I tap it with a piece of wood typically. I also have a steel tapping tool with a v notch and a hole where the knife tip is so you only push on the bevel. A pair of vice grips with a pice of leather to grab the head on the shaft in the front to keep it at top dead center. Make sure the tops of the screws are domed and not flat. I lightly snug the first and last bolts on the gib or lock-bar on little jointers like 8" and start with the knife 1/32" high and tap it down. My knives never move when I finish tighten them.

Literally a minute a knife when you get it down. Use a flat 1/2" tip on your indicator. One can do it it all with a $15 import indicator and some cobbled up bases for all your set up needs. I personally don't advocate the TS Aligner to anyone.

[Dave Morris]

Thanks Rick, that did the trick. I have the Aligner Jr, not the mucho expensive TS Aligner (senior?), but it's helped me set up my TS real tight.

Wasn't quite a minute a knife, but then again, the last time I had to install different knives was probably 5 years ago. :o Still had the problem with the knives rising up at the end, but the dial indicator let me set them high, tighten and measure the rise, loosen the bolts and then tap the knife with a piece of wood, and measure where it ended up after re-tightening again. I snuck up on 'em, and the end result is knives within half a thou of the outfeed table.:D

<<< ...on little jointers like 8" ...>>>

Too cool. :cool: Not often you read a line like that on these forums. Now I'll go set up a new set on a 1948 Delta 6" short-bed jointer I have. Would that make it a "baby" jointer? ;)

Thanks again.

[Rick Lizek]

You just need to keep enough tensionon the knives so they can be tapped into place. When you tighten it should be where it won't move anymore.