Jointer vibration/chatter

[bigmoguls]

While jointing some teak, I noticed a lot of chatter at the beginning and end of the pass. I took the blades out, made sure they were sharp.

While re-installing the blades, it became clear the accessory hub had come loose. By this time, the hub was turning freely on the jointer shaft. Not sure how it was actually jointing anything.

I secured the accessory hub, set the blades. But it is still vibrating/chattering during the pass. I tried pine stock as well...same vibration/chatter.

Does anyone have any advice on the likely source of the vibration?

[jsburger]

While jointing some teak, I noticed a lot of chatter at the beginning and end of the pass. I took the blades out, made sure they were sharp.

While re-installing the blades, it became clear the accessory hub had come loose. By this time, the hub was turning freely on the jointer shaft. Not sure how it was actually jointing anything.

I secured the accessory hub, set the blades. But it is still vibrating/chattering during the pass. I tried pine stock as well...same vibration/chatter.

Does anyone have any advice on the likely source of the vibration?

What does the jointed surface of the wood look like?

[JPG]

Vibration is typically an indication of dull blades.

Are you 'firmly' pressing the workpiece against the infeed/out feed table?

I know getting too close to the spinning blades can be scary, but the workpiece must maintain contact with the table surface. Use push blocks.

P.S. are you getting snipe at the ends?

[bigmoguls]

While jointing some teak, I noticed a lot of chatter at the beginning and end of the pass. I took the blades out, made sure they were sharp.

While re-installing the blades, it became clear the accessory hub had come loose. By this time, the hub was turning freely on the jointer shaft. Not sure how it was actually jointing anything.

I secured the accessory hub, set the blades. But it is still vibrating/chattering during the pass. I tried pine stock as well...same vibration/chatter.

Does anyone have any advice on the likely source of the vibration?

What does the jointed surface of the wood look like?

Generally not bad. Some scallop at the beginning and end of the pass.

[bigmoguls]

Vibration is typically an indication of dull blades.

Are you 'firmly' pressing the workpiece against the infeed/out feed table?

I know getting too close to the spinning blades can be scary, but the workpiece must maintain contact with the table surface. Use push blocks.

P.S. are you getting snipe at the ends?

Yes, firmly pressing the workpiece against the tables, moreso on the outfeed table.

Yes to the snipe question.

[jsburger]

While jointing some teak, I noticed a lot of chatter at the beginning and end of the pass. I took the blades out, made sure they were sharp.

While re-installing the blades, it became clear the accessory hub had come loose. By this time, the hub was turning freely on the jointer shaft. Not sure how it was actually jointing anything.

I secured the accessory hub, set the blades. But it is still vibrating/chattering during the pass. I tried pine stock as well...same vibration/chatter.

Does anyone have any advice on the likely source of the vibration?

What does the jointed surface of the wood look like?

Generally not bad. Some scallop at the beginning and end of the pass.

Scalloping would indicate one of the blades is set higher than the others. Not sure why you are only seeing it only on the ends. Is that what you are calling snipe?

How deep of a cut are you using? I never take off more than about a 1/32" at a time.

[jdhubenak]

Did you ever fix the issue? I just got done setting up my 8 inch jet jointer with the 3 knives and am having chatter while passing boards. I will say that I have room for improvement on my technique, but that is not the cause of this chatter. I can easily feel the vibrations in my arms, but if no wood is on it then its smooth and quite. Pine has some vibration, but it was really bad with hard maple and purple heart. I am a bit hesitant to try the 7 inch board across it right now.
I have the machine calibrated and the kinves are all set to the same height. Could the belt not be tight enough?

[JPG]

In addition to cut depth, blade sharpness comes to my mind. I assume we are not talking about knots nor wild grain nor end grain.

[charlese]

The blades may indeed be the chatter issue. But since the chatter vibrations caused the coupler to loosen - I recommend checking the cutter head bearings.

[JPG]

I just now noticed the 'scallop' at the ends comment. Is it scalloping, or a single scallop. If single it is a snipe. That can be caused by technique, but also by the outfeed table not equal to the blade height.

Let's assume the blades are sharp(not correct imho, but removes that issue from the following).

When starting the workpiece feed, maintain downward pressure on the leading end as it passes the blades(NOT DIRECTLY OVER THE BLADES). When the workpiece reaches the front end of the outfeed table, it should slide easily onto the outfeed table, but with NO discernible clearance. If it butts into the table end, the blades are set too low. If it clears the table with a gap, the blades are set too high.

A concave downward workpiece(bottom edge being joined) can also cause the workpiece to butt into the table.

We can go on&on, but this is a start and should establish the blade height is correct/not so.