Wood Jamming in Powermatic Planer

[TomInNC]

A few months back I bought a PM15HH to replace a dewalt lunch box planer. The cuts I get are great, but I have had a strange issue with wood jamming on the infeed side. Sometimes, even if I am taking a light pass, the wood jams completely during the infeed. I then have to turn the power off, raise the head, remove the wood, and run it through again. Anyone have any idea what might be going on here? I have been on hold with PM for hours, so hoping the internet can help me out here. 

[Askland09]

Is it possible the pressure roller is getting seized up or has too much downward pressure? I’ve never worked with a PM before but those are two things that pop into my head as potential issues. 

[TomInNC]

I just got off the phone with them, and the suggestion was to raise the height of the chipbreaker. I will give that a shot and report back.

[Tom King]

That should do it.  How uneven is the board to start with?

[TomInNC]

On 2/4/2022 at 11:19 AM, Tom King said:

That should do it.  How uneven is the board to start with?

I have always face jointed the boards first, so the part of the board facing the table is flat. The top part of the boards that have gotten stuck have also been pretty flat. 

[Chestnut]

The bottom rollers may also have an impact on that. I've had odd boards or boards with knots get hung up on the lower roller slots. I honestly wish the bottom feed surface didn't have rollers and was just a flat casting. I'd check the chip breaker first though if that was their advice. My other question is the lower rollers.

[TomInNC]

On 2/4/2022 at 2:12 PM, Chestnut said:

The bottom rollers may also have an impact on that. I've had odd boards or boards with knots get hung up on the lower roller slots. I honestly wish the bottom feed surface didn't have rollers and was just a flat casting. I'd check the chip breaker first though if that was their advice. My other question is the lower rollers.

I have that magswitch dial gauge, and adjusting the chip breaker with that was very easy. I raised it a hair and will test it later. If the issues persist, I will tinker with the rollers.

One thing I couldn't make sense of is that in the manual it indicates that the breaker is set "in the path of the blade" or something like that. When I looked at the factory alignment, the lowest point on the breaker was quite a bit higher than the lowest point on the helical head.

I have a tendency to take very light passes at the planer. My intuition is that this should make jamming less, not more, likely. Is that correct?

[TomInNC]

I was thinking about your roller comment some more. If the bottom of the board is dead flat, then the elevated roller would basically angle the board into the chip breaker, right? 

I do frequently get a "smacking" sound when the planer grabs the board. I am now wondering if the roller height is what is causing the smack.

[BonPacific]

I think those elevated rollers are specifically intended to be used with rougher stock, so if they're set high all the time that could be causing your alignment issues.

[TomInNC]

After work I ran a board and manage to replicate the issue. This time I was smart enough to take a picture. So I think what was happening is that the rollers on the infeed side were actually too low. I may have dropped them when I mounted the tables; I can't remember. Anyway, when the roller was bottomed out, this creates a very small depression for the board to go into. Because of the depression, the roller was spinning but would not contact the board. I recalibrated the roller to protrude a bit above the plane of the tables, and I haven't had the issue on about 20 boards I just ran through.

[Sven]

On 2/4/2022 at 8:13 PM, TomInNC said:

After work I ran a board and manage to replicate the issue. This time I was smart enough to take a picture. So I think what was happening is that the rollers on the infeed side were actually too low. I may have dropped them when I mounted the tables; I can't remember. Anyway, when the roller was bottomed out, this creates a very small depression for the board to go into. Because of the depression, the roller was spinning but would not contact the board. I recalibrated the roller to protrude a bit above the plane of the tables, and I haven't had the issue on about 20 boards I just ran through.

Do you recall what you set your knives to?  I have a HH15 and I am experiencing the same problem.  Last I checked I think my rollers were at 0.002" above the table.  

Another "fix" someone suggested was to file a slight bevel along the lip where the rollers reside.  That way the leading edge of the board is not running perpendicular to the depression.  Probably something Powermatic should be doing during fabrication.

Thanks!

Sven

[Ronn W]

So I have a question.  Why have the rollers in the first place?  Dewalt does not have them and I know the the Marc Adams school has installed a melamine board on the bed of its Powermatic planers so the rollers are not used.

[wtnhighlander]

On the surface, rollers opposite the feed rolls seem like a good idea. Friction on the bed is the biggest problem I have from my Dewalt, it needs waxing frequently.

But, keeping such rollers aligned is a chore, too.

[Chestnut]

17 hours ago, Ronn W said:

So I have a question.  Why have the rollers in the first place?  Dewalt does not have them and I know the the Marc Adams school has installed a melamine board on the bed of its Powermatic planers so the rollers are not used.

The rollers are supposedly better for running rough wood and skip planing. It allows the rough boards to reference off a smaller surface. Also it's geared more towards commercial shops that probably only take heavy cuts and never wax the bed.

The melamine board is a good idea. I get lumber stuck in the slots the rollers stick out of all the time it's annoying. Honestly the little DW735 got a lot right. Rubber feed rollers are much better than the metal ones.