jointer knives

[onedash]

I swapped out the knives on my jointer last week and it was ****. They seem pretty **** close to being equal height but I seem to be getting some chips every time I run cherry boards over it. Before I just had to avoid the nicks so it wouldn't put a line in it but I wasn't having the problem. So I am wondering is it the knives being less than perfect or the boards? I guess I could try a few other boards but my first thought was it must be crooked knives. I tried moving the fence to hit different sections and it didn't seem to matter. I quick pass through the planer fixed them right up though. I guess I should buy one of those magnet jigs and adjust them again.

[cwsmith]

Not sure if you really need to go and spend money for a Jig. I have yet to need any adjustments on my Ridgid jointer, but the manual and other articles that I've read make it look like a fairly simply task... just having them perfectly sit at the height of the out-feed table. While that appears to be done with a straight edge or similar straight object resting on the edge of the out-feed table and making sure the knives are in contact with that as you tighten them.

Seeing one of the magnetic jigs a year or so ago, made me wonder if it simply couldn't be done with a couple of magnets (if you feel the jig would be the perfect thing). For example, I have a few rectangular Harbor Freight magnets (Ceramic Block Magnets item 97504) that measure 7/8 x 1-7/8 x 3/8" thick. I'm thinking that I could just stick four of those on the lip, having the blades coming into contact as I tighten them. They're pretty strong. My thoughts are the magnets are pretty strong and placed as described would provide a perfect contact area to match the out-feed table.

Just a thought,

CWS

[onedash]

I think some have a spring which seems like it would be easier. I tried the method where you lower the outfeed table, then put a board over it and mark where it starts and stops when the blade catches and releases it. Then i raised the outfeed table until the blade no longer grabbed the wood. I was thinking magnetic levels but another one of those would cost more than the jig.

[capncarl]

Right off I'd say you are taking a deep pass on the jointer. Jointers have really liberal depth adjustments. The planer that you used to clean up the jointers mess has really conservative depth control. I think that my planer depth control is 1/64 per revolution per crank, and I usually crank it 1/4 revolution per pass. I don't think that I could ever get that fine of adjustment with my jointer. If jointers had decent depth control they would be much easier to use. Your knife installation was probably correct.

[poolhound]

Can you be more specific about the issue i.e what do you mean by "chips?" can you explain and possible post some pics. I have tried using magnets and in my case the way that the gibs tighten down doesn't really let me do it this way. I use a home made wooden jig and a dial indicator. It is rather a pain but I can get the knives within a few thou. of each other. I will post a pic later when I am home.

[Doctor Jeff]

Just buy the magnet jig. It's about $30--I think I have seen them at Harbor Freight for much less, I might be wrong. Anyway, a piece of cake more or less with the jig even with a rudimentary machine like the HF jointer.

[jabe]

When jointing hardwoods, chip outs are common. 1. Turn the board around, feed the other end of the board in first, the grain direction on the edge will cause chip outs. 2. Knives are not the same height, need to joint the knives, follow your machine manufacture's direction on this. I agree with Dr. Jeff the jig makes it easier.

[cwsmith]

I have a Ridgid Joiner and really haven't had occasion to use it much. However, I have been wondering about the task of eventually changing out the knives. Reading a couple of articles or postings about the challenges, and looking at a couple of suggested jigs, I was wondering if one couldn't use just a two or three of those block magnets like HF sells for next to nothing?

The task appears to be fairly simple, mechanics wise. My thinking is to just stick two or three of these magnets on the out-feed table, where they would extend over the roller and hold the blade edge in place as they are tightened.

Since I have yet to do this task, I am wondering if my thinking is too simplistic.

CWS

[capncarl]

If your Ridgid joiner is like the one I looked at at HD last week ( a neighbor saw me in the store and asked if I would give him an opinion on it for his shop ) I didn't see anything that indicated the blades are adjustable. It looked to be the same Chinese mfg as my Craftsman planer, and its blades are located on pins. It takes about 10 minutes to change/rotate the blades.

[Relative]

Built a magnetic alignment pair of gauges for the jointer from an article long ago. What you need is 6 magnets, two short (8 - 10 inch) straight boards and some epoxy.

Set 3 of the magnets on the jointer outfeed table in a straight line. Two of them fairly close together and the 3rd near the opposite end, all with the length of your boards. Put a little epoxy on the top of each magnet and set the edge of one of the boards on top with some weight. Do the same thing with the second board and 3 magnets. Wait the appropriate time for your epoxy to cure. Look at the attached pictures to get a better idea of what mine look like. Because you used the flat top of the jointer, all the magnet bottoms should be exactly on the same plane.

To use: set the two gauges so that the single magnet is centered over the blades while the other two magnets keep everything secure. Put one gauge on each end of the blades. With a blade loose and directly under the magnet, it should be attracted up into the bottom and you can tighten it in place. Make sure it doesn't lift or drop as you tighten it down and make sure the edge is at its highest point. Do each blade and you should have the top of all the blades in perfect alignment with the outfeed table. Slowly rotate the blades and they should just "kiss" the bottom of the magnet at both ends.

This jig does the same as the commercial version.

This all presupposes that you have an older jointer with adjustable blades. The newer ones seem to have throw-away blades that are fixed position or helical blades.

Hope this helps.

Mike