Planer question

[Gramp's shop]

I have a Delta 12 inch planer. What is the shortest length I can safely run through the machine?

Larry

[Swingman]

[Dave Balderstone]

With a sled?

[dpb]

Besides the sled, butt the shorts end to end so the in-/out-feed rollers don't have an edge to roll off of until overall end and the end friction of the preceding/trailing piece also works to keep from tilting it up....

[russellseaton1]

By butting pieces end to end when running through the planer, it also keeps the planer from sniping the ends of boards. A common problem with planers. For the original post, for just one short piece, sandwich it end to end between two sacrificial pieces.

[Morgans]

I have a Delta 12 inch planer. What is the shortest length I can safely run through the machine?

*********************************************** Measure the distance (center to center) of the outfeed and infeed rollers. Take that measurement and add about 3" and that is the minimum length you should run.

As far as the sled goes, I would not want to use it unless there was at least one piece of stock as long as the above figure. Also, all pieces should be exactly the same starting thickness, or there will not be anything holding down the thinner pieces when multiple pieces are being run at the same time.

Myself, I do not run multiple pieces at one time for any reason. I also will not run pieces shorter than the figure I used in the above first line. If you have ever had a piece lift up under the cutter head, you would never ever want that to happen again. It is a good way to tear up the planer.

-- Jim in NC

[Gramp's shop]

Thanks, friends. A planer sled seems to be the right answer for what I need to do.

Larry

[dpb]

On 1/28/2012 8:06 PM, Morgans wrote: ...

Suit yourself, but you're certainly limiting the usefulness of the tool.

In 40+ years, I've never experienced such a lift using the butted-feed technique. (And, iirc, the old original Delta/Rockwell planer manual for the Model 7 is where I first saw it.)

--

[dpb]

OK, after my last posting sorta' chastising, I guess I oughta' 'splain the reasons...

Caveat is, I've never used or even seen up close to inspect internals one of the current generation lunchbox or four-column planers--my experience is all w/ traditional heavy planer design from the small Rockwell/Delta Model 13 thru the Model 240 Powermatic, etc., etc., ...

In those there is a cast pressure bar/chipbreaker directly behind the cutterhead w/ only 1/8" or less clearance behind the knives and that runs just barely above the planed surface; ideally it touches but adds essentially no friction when adjusted properly.

Therefore, as long as a piece is long enough that it still is being held down by the infeed roller by the time the front edge gets to the pressure bar an inch or less behind the cutterhead, the "rise up" simply cannot happen. Butting the piece behind (and optionally in front) does have the benefit of not having a roller run on/off the short piece end and thereby eliminates the upward force that can occur as well as the rear piece providing the force to push the front piece on through by being in contact w/ the infeed rollers while the shorter is reaching the outfeed.

As far as the multiple pieces, if one has a 12/13 or a 20+ inch planer, unless one is only working on a single board, it's simply a waste to not fill the throat w/ as much material as one can--besides cutting down the time required to do a bunch of material, it evens out the wear on the knives more uniformly across them...

So, there is a shortness limit below which one really shouldn't try it, but it's based on the length from the infeed to the pressure bar for the planers I'm accustomed to, not the longer distance between the in- and outfeed rollers.

[Dave Balderstone]

I also use a sled to plane wood to 1/8" or even thinner. I think we may have the same planer, too... Delta TP300, 12"?

[Morgans]

On 1/28/2012 8:06 PM, Morgans wrote: ...

Suit yourself, but you're certainly limiting the usefulness of the tool.

In 40+ years, I've never experienced such a lift using the butted-feed technique. (And, iirc, the old original Delta/Rockwell planer manual for the Model 7 is where I first saw it.)

********************************** Sorry if I implied it, but I have no problem at all with running pieces through but to but.

-- Jim in NC

[dpb]

On 1/29/2012 8:37 PM, Morgans wrote: ...

...

OK, the use of "never" w/ multiple pieces made me think you were also implying it wasn't a good technique.

As noted in my other followup, however, imo not filling the throat to capacity or as near as can is simply wasting time and capacity if limit oneself to only a single small board at a time when have multiple to do...the machine has a particular bed size for a reason :)

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