Changing Heads on an Eighteen-Inch Planer

A woodworker who is swapping out straight knives for an S-helix head for his new Powermatic planer gets advice on the task.October 19, 2013

Question
(WOODWEB Member) :
I just purchased a Powermatic 180 18" planer in beautiful condition for $400. Because I got it for such a good price I've decided to invest in upgrading to a Byrd Shelix cutterhead. The head is on its way with bearings mounted, so I've started to get the machine ready for the change-out. I'm in as far as needing to remove the flanged bearing housing from the drive side of the machine. My problem is that the outside diameter of the housing and the inside diameter of the hole in the cast iron portion of the frame are virtually without tolerance and I can't get this thing to move at all.

Does anyone have experience with this? I'm just going step by step removing parts until, I hope, the logic of how to change heads presents itself. I can't find any info online about how to do this and there are no service techs left in the Philadelphia area that I can call on.

Has anyone done this change-out on this particular machine? Could you provide any info on making it happen without disassembling the entire machine (though what better way to get to know it, right?!)?

Forum Responses
(Solid Wood Machining Forum)
From contributor B:
My Model 100 has what sounds like a similar bearing installation arrangement. The bearing housing is held in by a bolt on the top side that pinches the housing in place. Perhaps there is a similar bolt on the 18" machines.

I actually had just the opposite problem years ago with the Model 100. Unknown to me, the bearing housing was vibrating due to the bolt being loose and became undersized. I went through a few sets of bearings before finally replacing both the bearings and the housings. This solved the problem, and now I check the bolts with each blade change.

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From the original questioner:
I'll take a look first thing tomorrow morning and see if there's anything like a set screw holding it in place. Hadn't thought of that. Stay tuned.

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From contributor J:
I too have a PM180 and swapped out the original 4 knife cutter head for a Byrd head. I am absolutely thrilled with the results. Plan to take as much time as necessary to make the swap. In my case, it was about 8 hours. Also, an arbor press is almost mandatory. Spend some time tweaking the bed rollers and pressure bar.

Another tip, double check the torque on the cutters using a good quality torque wrench. The driver Byrd ships with the spare cutters is mickey mouse at best. Let me know how it goes.

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From contributor M:
I've replaced the cutterhead bearings in mine, same work, but sadly no new head out of it. I'll take a peek at it tomorrow to see if I can remember, but you are probably stuck at either needing a gear puller or a spanner wrench. It seems like I remember that housing having a threaded collar to hold the bearing in. You can tap it around ever so carefully and evenly with a fat nail set in the spanner wrench notches if you don't want to drop a Grant on a use-once tool.

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From the original questioner:
So I've managed to get the head out - it took 2 gear pullers, one really small and one large - but it went off without a hitch. It's amazing how tight the fit is between the bearing housing and the machine body. Still waiting for Byrd to make the head, but it should be done in the next day or two, so for now I'm just cleaning the machine up as best I can. Thanks for the help.