Delta 22-840 Planer Knife Grinding Jointing tool

[Jeffrey McAllister]

Hello!

I recently purchased a Delta RC-51 20" planer. A beast for sure... The owner also had the planer grinder/jointer accessory. It too is a beast! While it was easy to find the manual for the RC-51, the knife sharpening tool seems to be a ghost! I searched the forums here, and there was a post from over 10 years ago, but the links contained in the post no longer yielded the results that they did.

I tried Vintage Machinery, no luck. I also tried Mikes Manuals... same result.

Does anyone know of a website where I might download the operating manual? Or, does someone HAVE the manual and might possibly scan it (or take pictures of the pages)?

I also looked to see if there were any videos of the tool actually being used. Again... nothing.

Any help would be greatly appreciated.

Jeff

[Bill Dufour]

I believe there is a locking pin for the cutterhead to index it into three positions for the grinding. Use multiple light cuts or you will overheat the knives. I believe after grinding many do a light bevel sharpening. Look at hand plane sharpening for ideas.
Bill D

http://vintagemachinery.org/pubs/detail.aspx?id=4837

[Kevin Jenness]

Can't help with the manual, but I have used two onboard grinding systems. The Scmi 52 had a grinder only, parked to the side of the cutterhead, pivoted on its mount and adjusted with a support sliding on another bar. Quick and easy. My PM 160 has a jointer as well as a grinder which are stored separately from the permanently attached guide bar. The jointer stone is carefully fed down to kiss the spinning cutterhead and get the knives in an even cutting circle, then replaced with the grinder which is traversed across the stationary cutterhead in three indexed positions. Both the fixtures are fed across the head with a handwheel and down with fine adjusting screws and held vertically in adjustable gibs. The grind is not quite brought out to the jointed edge, leaving a small (<.010") land, presumably for a longer lasting edge. The grinder wheel has to be dressed periodically and traversed rapidly to avoid burning the knives.

I can't say that the jointed edge is really any better cutting than just grinding, but it does ensure that the knives are all in the same cutting circle. The first time jointing is a bit disconcerting -make sure the stone is above all the knives all the way across before starting and feed it down slowly, stopping when it has touched all the edges. I hope that is helpful.

One thing you might consider is having a face bevel put on your knives by a sharpening shop. I have a 10* bevel on mine which improves the performance on figured woods considerably at the cost of a bit more power and noise.

[Tom M King]

Take the lightest pass possible with the jointing stone. You want the smallest flat possible, and don't quite do all the way to the edge of the flat with the grinder. I've never seen the Delta setup, but have the one on an old Powermatic that I expect works the same way. It's a great thing to have.

[Jeffrey McAllister]

Take the lightest pass possible with the jointing stone. You want the smallest flat possible, and don't quite do all the way to the edge of the flat with the grinder. I've never seen the Delta setup, but have the one on an old Powermatic that I expect works the same way. It's a great thing to have.

Bill, Kevin and Tom.... Thank you for your input and ideas.

With any luck, someone will have a copy of the manual. It is the type that is placed on the machine for sharpening and then removed again. I suspect getting that setup correctly is very important.

[Warren Lake]

Kevin that is a good description and matches a Wadkin Manual I read. One thing they said was knife projection was .120 above the head which is over double what I normally set up at .050 projection. They do this so you can hone a number of times before the knives have to be lifted again. I think I read 5-6 times on average can be done on the machine that has both a grinder and hone on it. Yet to have used a grinder on a machine. I dont know how you maintain parrallel on all knives when you use an onboard grinder. From a sharpening shop the knives should all be the same and parallel.

We were taught to hand hone fresh knives with oil and hard arkansas after they come back from sharpening. Wicked sharp after that is done.

Ive never had the back bevel you talk about. Even with the machine hone you end up with a double bevel on the bevel side and this can cut better on figured woods at times. Moulding company owner told me this years ago.

[Bill Dufour]

I dont know how you maintain parrallel on all knives when you use an onboard grinder. From a sharpening shop the knives should all be the same and parallel.

Good point. They will be parallel as ground. Assuming the grinder guide bar is parallel and at right angles to the bed. I guess when you have to jack them up you need to turn each jack screw the same number of turns before grinding.
Bill D

[Tom M King]

The jointer stone gets them all parallel, as well as takes out any knicks.

[Tom M King]

This is the only youtube video I found on one being used. I just breezed through it, so don't offer any recommendation about how this guy does anything. It looks like he doesn't have the jointer stone, but gets by with just the grinder. The jointer stone is operated while the machine is running to bring all the knives down to where you want to start, much like jointing a handsaw before you file it.

https://www.youtube.com/watch?v=WqjRdsxaf5Q

[Tom M King]

Here's another one:

https://www.youtube.com/watch?v=9iMTPze2qYM

[Tom M King]

check ebay. copy and paste this in the search box there:

Delta Rockwell 22426 Knife Grindging Attachment / 13" x 6" Planer Instructions

[Kevin Jenness]

Kevin that is a good description and matches a Wadkin Manual I read. One thing they said was knife projection was .120 above the head which is over double what I normally set up at .050 projection. They do this so you can hone a number of times before the knives have to be lifted again. I think I read 5-6 times on average can be done on the machine that has both a grinder and hone on it. Yet to have used a grinder on a machine. I dont know how you maintain parrallel on all knives when you use an onboard grinder. From a sharpening shop the knives should all be the same and parallel.

We were taught to hand hone fresh knives with oil and hard arkansas after they come back from sharpening. Wicked sharp after that is done.

Ive never had the back bevel you talk about. Even with the machine hone you end up with a double bevel on the bevel side and this can cut better on figured woods at times. Moulding company owner told me this years ago.

The grinder bar is factory pinned to the top casting and the jointer does get the knives parallel to the cutterhead. For some reason the grinder is a little off so I have to taper the grinding a bit to match the jointed land. Powermatic specs .125" projection and I do get about 6 sharpenings before I have to raise the knives. I leave the chipbreaker and roller settings alone but I do have to adjust the pressure bar.

The process is a bit time consuming but faster than swapping out the knives, plus I save the sharpening cost and I get better results. If I were buying a new planer I would probably want a segmented head but an old one with a knife grinder is the next best thing to a Tersa head.

[Warren Lake]

thanks good info the wadkin does say you have to adjust as the cutting circle changes, each time after a grind. Memory said they said its .005 change in the roller height after a hone and there is a knob each side you turn one clic to a detent position after hone. have to read the manual when I have time.