Leveling the Feed Beam on a Moulder

Detailed discussion of some maintenance and adjustment issues with a nine-inch moulder. April 4, 2011

We have a Weinig H23-C 9" moulder and the feed beam keeps getting out of level. Recently it dropped a little on the outfeed side when a piece of 13/16" followed a 15/16" piece though I would think it would have to jump a thread to do this so I don't understand how it could have done this. I have rebuilt both gearboxes front and back along with a new brass bushing in the top block and it continues to get out of level. I am suspect that there is a problem with the dove tails but can't seem to see anything obvious.

Forum Responses
(Architectural Woodworking Forum)
From contributor F:
The slide is not the issue. When you put everything back together and leveled the beam, all final adjustments must be in the up direction to eliminate backlash (the wear nut would have been pushed up tight to the bottom of the slide). In addition, when setting up a profile the last adjustment of the beam must be up as well. Given these two conditions there is no way one of the slides could drop.

From the original questioner:
What has me puzzled is that sometimes in the past it has become out of level pretty far and I just replaced the outfeed wear nut about a year ago and had to replace it again last week as I found shavings around the cover boot after noticing it was out of level again (I changed both wear nuts this time and like I said rebuilt both gear boxes completely). How far out of level could it get from slack alone? Should I even consider the slides or should I be looking elsewhere.

From contributor C:
Have you checked the coupling joints that join the main shaft for raising and lowering the feed beam? There is an allen head bolt that tightens each one in place to the shaft. It sounds like maybe the last one has worked loose and slid along the shaft a little or is worn, so isn't engaging the drive at the rear lifting screw.

From the original questioner:
In fact that was the first thing I checked and they were tight. I even took a white crayon and marked the collar and both sides of the shaft to see if maybe I had a broken tooth or slipping brass gear in the gear box. Today acting on Contributor Fs advice I checked the level then insured that I went down then back up just as you would with the head so I will see what happens. I was aware of the slack issue it's a standard operating practice on most any machine planers, moulders, etc. I made sure the operator who was not trained by me understood. I just didn't think it could get that far out by slack alone. Thank you for the suggestion because that is probably the most common cause of the out of level problem.

From contributor F:
Regarding the premature wear of the nut: Check for a bent jackscrew, insure the three bolts in the nut are tight (this should be done regularly), check the slide for galling and the gibb to make sure it is not too tight, also insure the slide is getting grease and regular maintenance is being done. Did you align the wear nut to the gearbox when you completed your work?

From the original questioner:
I do have some galling on the in-feed slide the out-feed side looks ok. I need to know what can be done about the galling aside from polishing it the best I can. Also what would be the optimum play if you will on the Gibb and do you set it with a feeler gauge? Also should I remove the Gibb and check it? So far so good on maintaining level. And you were absolutely right on the bent screw. The in-feed side was bent and I replaced it when I rebuilt the first gearbox (good call). The supervisor I replaced did no maintenance and I am paying for his sins so to speak. We have spent a lot of money trying to repair the damage done.