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Roger Barlow
04-12-2008, 1:38 AM
Didn't want to hijack the earlier woodmaster thread...

I just purchased a 725 that I want to set for mainly moulding. I'm not a newb, 30 years of experience and own and maintain many pieces of of industrial ww equip. But I've got a couple of questions.

Anybody running multiple 2 knife corregated heads on the accessory shaft? Is there any shaft whip?

Is the 2 knife head a better cut finish than the single (is the speed tradeoff worth it)

Anybody ever have any knife slip in the non-corregated cutterhead?

James Suzda
04-12-2008, 6:22 AM
Hi Roger,
I've got a 712 Woodmaster but have no experience in using Woodmaster's molding head. However, I contacted "Tim" from http://www.customouldingknives.com/ and he suggested getting the molding head so I could use his custom corrugated knives. So, they must work.
Right now I just use the Woodmaster single knife head or a single knife in the planer head.
I shy away from a two knife setup because I always wonder how hard it is to get the two or three knives in proper alignment. Are corrugated knives easier to set up than the plain knives and gibs that Woodmaster sell?

Per Swenson
04-12-2008, 7:43 AM
I had a non corrugated knife slip. Once.

This strongly suggests operator error.

It happened on the 700c head.

Wasn't pretty. The mess in my pants.

Per

Chris Rosenberger
04-12-2008, 10:59 AM
I have a Woodmaster 718. Until 2 years ago I always ran a single molding knife in the planer head because most jobs were short runs. I have run 1000s of ft of molding over 16 years & only had one knift come out. It was because of operater error. I forgot to retighten the knife after making an adjustment. 2 years ago I got a 2 knife cutter head for a large job. The main advantage to the 2 knife head is that you can feed the wood faster through the molder. You also get less tearout on curly wood. For the most part, I did not see any difference in the finish quality. To cut down on whip on the shaft, I run the head to one side of the planer.

Roger Barlow
04-12-2008, 11:45 AM
IYou also get less tearout on curly wood. For the most part, I did not see any difference in the finish quality. To cut down on whip on the shaft, I run the head to one side of the planer.


Thanks, but as always - answers lead to more questions.

Is the speed increase worth the 2nd knife since cut seems to be about the same, and it seems that you do have whip (?), this should show up as some chatter on the finish, and some vibration in the machine. I figured that I would have to run the corregated heads slid to each side of the shaft end (far left, far right). Woodmaster shows a spacing of 4 or 5 single knife heads spaced accross a shaft. I thought that looked iffy.

James, setting up corregated knives in cutterheads is really hassle free. Orders of magnitude easier than setting smooth back knives (like a jointer).

James Suzda
04-12-2008, 1:01 PM
Thanks, but as always - answers lead to more questions.

Is the speed increase worth the 2nd knife since cut seems to be about the same, and it seems that you do have whip (?), this should show up as some chatter on the finish, and some vibration in the machine. I figured that I would have to run the corregated heads slid to each side of the shaft end (far left, far right). Woodmaster shows a spacing of 4 or 5 single knife heads spaced accross a shaft. I thought that looked iffy.

James, setting up corregated knives in cutterheads is really hassle free. Orders of magnitude easier than setting smooth back knives (like a jointer).
Like you said, "answers lead to more questions."
I've run my molding head in all positions on the shaft and I've not noticed any vibration.
If the knives are balanced and he cutter head is balanced why should there be any "whip"? Isn't this the point of having a balanced set of knives, gibs, and molding head?
But, I suppose the knife hitting the wood could cause some vibration.

Roger Barlow
04-12-2008, 1:57 PM
Like you said, "answers lead to more questions."
If the knives are balanced and he cutter head is balanced why should there be any "whip"? .......But, I suppose the knife hitting the wood could cause some vibration.


Yes, whip happens when the equipment is operating near harmonic resonance of the shaft. None of the equipment is zero balanced, there will be some residual imbalance forces and cutting forces. The longer the shaft and smaller the diameter the lower the shaft resonance(the smaller heads dosn't count for shaft stiffness , unless it's the planerhead - full length shaft dia increase).

So I just wanted to know about any 725 owners and if they had seen this so I could avoid making any dumb mistakes. If I had a 712, I wouldn't have even given it a second thought - i.e. due to the short shaft length. Cause I look at the length and dia of the 725 shaft and it made me think twice about loading it up. And hearing about a couple knife slips - not for me, I want a corregated head for sure now.

Side note, never having had a planer like this before now. How the heck do I pull the planer head. Yes I've RFTM, and the tapers are not comming out. I've loosened both locking collars, and the both taper bolts turn easy 1 full turn, and then they don't turn and I didn't want to wrench on them more. I don't think this head has ever been out of the machine.

Roger Barlow
04-12-2008, 4:34 PM
got the head out. manual never said the taper bolt had jamnuts on other side (inside cutterhead) and that you use the the threads to push out the taper. The lube had varnished and was like glue, so the taper was glued into the cutterhead.

James Suzda
04-12-2008, 5:14 PM
<snip>
So I just wanted to know about any 725 owners and if they had seen this so I could avoid making any dumb mistakes. If I had a 712, I wouldn't <SNIP> .

I guess I had a 712 mind set when I was thinking of any shaft movement. I can see how a 25 inch shaft might start to vibrate if the three inch molding head was in the center of the shaft.
I guess if I had a 725 and was concerned about the small shaft, I'd use a planer head to hold the molding knife, or run the molding head close to one edge.
But, on the same token wouldn't you have the same problem if you used the corrugated head?

Roger Barlow
04-12-2008, 7:08 PM
But, on the same token wouldn't you have the same problem if you used the corrugated head?

Absolutely, and the corregated is bigger that the single knife head.

Chris Rosenberger
04-13-2008, 4:02 PM
Thanks, but as always - answers lead to more questions.

Is the speed increase worth the 2nd knife since cut seems to be about the same, and it seems that you do have whip (?), this should show up as some chatter on the finish, and some vibration in the machine. I figured that I would have to run the corregated heads slid to each side of the shaft end (far left, far right). Woodmaster shows a spacing of 4 or 5 single knife heads spaced accross a shaft. I thought that looked iffy.

James, setting up corregated knives in cutterheads is really hassle free. Orders of magnitude easier than setting smooth back knives (like a jointer).

I work by myself so I go for the lowest cost unless I have a large job & need to get it out fast. I have 90+ single knives & 2 - 2 knife sets. The biggest thing I like about using the planer cutter head for molding knives is that I can setup several different knives at on time.