potential fix for poor cut capacity with shelix head

[Andy Pratt]

I have struggled with poor cut capacity on my planer since replacing the standard cutterhead with a shelix byrd head about six years ago. Recently, I replaced the motor and added a vfd and gained significant improvement, but it still wasn't where I wanted it.

After exhausting all other options, I tested out what would happen if I removed every other row of cutters on the shelix head. I am fortunate in this regard, because my head has 6 full rows of cutters (6 spirals with blades nearly touching). If it had 5 I couldn't have done this, as the head wouldn't have remained balanced. Don't do this without really thinking it through and looking over your particular cutterhead, it worked for me but could be dangerous if your setup is different than mine and you create an unbalanced system. I know some cutterheads have much fewer spirals and/or cutters per spiral, so you could also get into mischief if you remove a row that is necessary to complete a full width pass.

After doing this, I now had a cutterhead with 3 spiral rows of cutters, making a total of three full cuts per revolution instead of the previous six. The result was vastly improved cut capacity, with no noticeable degradation in surface quality. I compared before/after on side-by-side passes on a birds-eye maple board and a curly maple board and you had to get it in raking light to even tell which was which. Even in the raking light, the only difference was in the visual appearance of the cut markings, there was no tearout on either, everything felt the same and the marks still needed just one pass on the sander to go away. There was no unevenness to the 3-cut surface like I had worried there might be.

I planed off 1/6" (not 1/16th) off a 6" western maple board, and did the same almost non-stop on a series of pine 2x6's. On wider/harder boards, where I could only have done 1/16" before, I now do 3/32" or 1/8".

If the data helps anyone decide how many cutters they want on their cutterhead (I believe some machines have multiple options for replacement heads), here are my specs: 12" robland/laguna xsd-31 jointer planer, 3hp cont. duty marathon motor, 3ph, 230v, vfd. Feed rate is modified to 16fpm (instead of 20 from the factory) and cutterhead speed is still 4500 rpm I believe.

I was worried the empty mounting holes might fill with crud but so far they have not shown any tendency to. As a side bonus, I now own a free replacement set of carbide bits, since I removed exactly half of what it came with.

This is in relation to a previous issue I had with my planer and wrote about in another thread, which contains more detail if you want it, see here: http://www.sawmillcreek.org/showthread.php?106794-robland-j-p-bogging-down/page7

Hope this is helpful,
Andy

[Jim Andrew]

Hard to imagine you had so much overlap that you could remove 1/2 the cutters. I had a Woodmaster, and it had a large diameter cutterhead, and was very slow, my Grizzly GO453px has a much smaller diameter cutterhead, only 3hp, and cuts twice as fast. I can use the fast feed speed to surface boards the same size as I could at about 1/4 the speed of the Woodmaster with a 5hp motor. I could not run the Woodmaster at full feed speed except for very narrow boards. I did buy the helical head for the Woodmaster.

[David Kumm]

What planer and what size motor? Was it a motor issue or a feed problem? Dave

[glenn bradley]

Hard to imagine you had so much overlap that you could remove 1/2 the cutters.

If you look at the Steel City heads you will see that they do not use the insert density like many of us are used to seeing. A spiral head does have near constant contact with the material and requires an appropriate power plant. You read many mixed reviews of folks who have simply swapped the head and gotten unexpected results. Andy has found a good solution for his machine and this info could certainly help someone else in the same situation. If you need to hog 1/8" off your material in a pass, your machine requirements will differ from those that don't. Good tip and Andy has a built in extra set of inserts ;-)

[Rich Riddle]

Guess I have always been satisfied taking off 1/16" at a time. If I wanted to hog off huge amounts I would resaw it on a band saw and then plane it when it was closer to the needed size.

[Phil Thien]

Mark me impressed that anyone ever has thick enough stock to remove 1/8" in a single pass. It isn't uncommon for me to remove 1/64" per pass, as I sneak up on final thickness but need to figure out which side to cut to get the best result.

Glad you found a solution!

[Andy Pratt]

Each of my spirals cut probably 75%-80% of a full width pass, so I definitely did have enough overlap to do this fine.

I often find myself taking 4/4 lumber down to 3/4 (don't we all?) which typically means 1/16th (or less) off once face on the jointer, 1/8" off the opposing face on the planer, and ~1/16th planed off the initial jointed face to fully clean it up and get it to 3/4. If I could not take 1/8" off on the second pass it would often cost me 33% more planing time, and would frequently cost me 40-50% more time.

I know that, before I did this, the planer always limited me to a capacity that was less than I desired. After the modification, I can take off the amount I want in most applications, and I am now typically limited by the amount that is sensible to remove, rather than my machine. Especially given that it did not result in a degradation of quality, I am really happy with the results.