How to Eliminate Snipe on Lunchbox Planers

Snipe's a dirty word.  In a class of its own: it has 5 letters!

Way long ago, I wrote about reducing snipe on lunchbox planers, but the planer in this video was all installed in a machine stand so the pictures required some imagination.  Tonight, I was replying to someone about how to reduce snipe with a lunchbox planer and realized the planer was in a for-sale pile and available for a last shot at (very very limited) fame!

The popular forum solution to lunchbox snipe is to elevate the two flip-down tables to compensate for the flex that happens in use.  That relies on a little black magic if you ask me... you can't guess the weight of the boards you are planning on running through and with an elevated table, the load is variable as the stock progresses through the planer.  Either that or I can't figure it out.

My solution consists of two feed tables, but their torsion-box construction and how they are used with the planer on an assembly table is the key.  The boxes can also be used in different ways for thin or short stock like box parts or drawer sides.

When I used this system before getting a big industrial planer, I never was concerned with snipe because it just didn't happen even on a set of 12 foot by 1 foot planks I ran through it for a large cabinet on my patio.

If snipe is making you use slightly shorter words to scare neighborhood children, give this a shot; I'm sure you'll like the results.

Change Your Oil!

I bought a used PM20 industrial planer awhile back.  I asked the guy a question about changing the oil and the answer was that he never did.  That got logged in my lil brain as a to-do.  Thing is, I could never locate the manual for the planer online.  A very similar looking Jet was all I could find and it stood to reason that the Jet replaced the now discontinued PM20 when WHM brought the two together.  They are actually quite different under the shrouds.
Anyway, some personal distractions kept me from that part of my brain with the to-dos for a year (and the shop, too, so no additional hours on the planer).  I got to it last weekend.

If you've never seen treacle, or treacle with metal filings, this 'oil' was a dead-ringer!

It was definitely time to make up for lost maintenance time so I took the gear housing off, brushed the chains and pulleys with a brass brush to knock the gunk off then hit them heavily with grease.

The power-roller tension screws have, what I discovered, were holes in the top for adding lubricating oil.  They had enough dust in the holes to be useless, however.

...but nothing an Allen wrench could poke out for next time.

I will say, however, that the fill plug for the oil was in the most obnoxious place. In this shot, I have a plastic tube into the hole so...

...I could squeeze the oil through the tube to the box.  I assumed some treacle remained so I filled it until it overflowed then opened the drain a big for a big blob of blackness to escape.

This is the difference between the old and new.  Moral?  If you have a planer that takes oil, go change it!!  Wish these had hour-meters on them... wonder if that could be retrofitted? hmm...

(okay, how many of you went: "oil? my planer has oil?!")

Simple Ways to Reduce Snipe with Lunchbox Planers

I wrote this a long time ago and, as the article states, my lunchbox planer was installed in a machine stand at the time (the trick relies on the planer being portable).  Although I describe everything here, photos are lacking.  I've since rolled a video explaining it all here: How to Eliminate Snipe on Lunchbox Planers.

Snipe sucks.  Even starts with an "S", too.

A lot of people have tips to gently lift the piece as it enters the planer and press down as it exits or the usual "you just need to make sure the tables are coplanar" (duh).  Thing is, the lift can introduce a hump in place of the snipe and even if the tables are coplanar, most are rather flimsy and flex under the variable load of the board (variable due to the change in loading as it enters the lunchbox).

Before getting a battleship (er, sorry, PM20 planer), I had a Ridgid 12" lunchbox and honestly I highly recommend it.  To avoid the problem with snipe, I wanted more stable tables on both sides especially for the long boards I was running through (my first projects had dimensions from 4'-8' routinely... don't ask).

My solution was to build two torsion boxes and top them with strips of melamine-coated particle (MCP) board.

I made them as torsion boxes on an assembly table to ensure they were flat.  Using strips of MCP allows the stock to move smoothly (with half the friction since half the box isn't covered) and allows a place for ejected chips to go rather than lodge under the stock.

Now, I have since put my planer inside a stand so removing it for a picture is an hour affair, but the way I used these tables was to put the planer on the assembly table shown with a table on the infeed side and the other on the outfeed side.  The stack of grey wood are shims to get the tables to the correct height.  Since the assembly table is built to be flat, I can place the planer anywhere on it with the in/out-feed tables and have everything work well.  This was extraordinarily useful with longer stock.

Today, I use this planer for drawer stock or small box stock (think small thin stuff).  Since I cannot put the planer on the assembly table, I put one of the auxiliary tables inside the planer.  Written on the side is 82mm, the thickness of these tables.  I always plane in metric since fractional millimeters are easier to deal with than imperial measures.

In my case, I'm reusing the tables I already made that were about 4' long, sized conveniently to fit on my assembly table in the original orientation.  If you like this idea and want to use it, I'd suggest making a 5' box so you have at least 2' on each side (maybe even longer).  Other than applying the offset, everything is the same as before, except no lifting or feeling shame that apparently your tables aren't as coplanar as the other guy (-psst!- he likely read it on a forum :)

Floor-standing Planers vs Lunchbox Planers

No, no, no, a lunchbox planer does not flatten your lunchbox or your big heaping pastrami sandwich.  It's a cute term of endearment for a benchtop planer.

They are very different beasts and it is well worth knowing the differences.  Here are my observations after going from a Ridgid lunchbox to a Powermatic 20" floor-standing planer:

Lunchbox planers have pressure rollers.  Basically picture a long roller pressed down with a spring.  Floor-standing models have power rollers.  These press down with much more force.

Let's break down this observation to see what it means:

Since the pressure rollers are just rollers, it will press down until it hits the tallest thingumajig you are running through it.  If a board has a rough surface, the roller will follow the highest point.  This isn't a big problem.  The problem comes when you start a narrow board through and decide to push a second board through beside it.  If those boards aren't exactly the same thickness, the roller will press on the thickest one and leave the other one free to kickback (fly backwards) due to the cutter's direction of cut.  This means you can't run two boards through simultaneously without risk.  If you insist on doing so, you could put one on each extreme side of the planer's width and likely get away with it since the springs on each side of the pressure roller would get some contact; side-by-side, however, is bad news.

On a floor-standing planer, the power rollers look like helical cutters with a long spiraling tooth. It is also set with springs, but decidedly stronger ones.  Further, there are anti-kickback fingers hanging down in front of the roller.  Each finger operates independently to prevent a board from kicking back.  If you run two boards of significantly different thicknesses through simultaneously, the anti-kickback fingers will stop the thinner one from kicking back, though it won't make any progress through the planer unless you push it.  I say 'significantly different sizes' because I've found that some difference is easily tolerated by the stronger power rollers.  I still keep them to the outside edges, though, and resist the temptation to put a third board between them.


Another difference these rollers make is in the woodworker's saying "never run a cupped board through a planer as it flattens it, thins it, and it comes back out cupped".  The saying is true, if you are using a planer with strong rollers and you are trying to take a lot off at once.

Assume a board is going through cup-down in a lunchbox planer set to take 3/32" off.  The roller will press down relatively lightly and do nothing to deflect the cup before taking off 3/32" off the top.  In a floor-standing planer, the rollers are set to press hard right up to the level of the cutters.  On this planer, it will press hard through the 3/32" difference between the rollers and cutters and may be able to flatten the cup with the stronger springs.  In this case, the board is flattened, some removed, then it springs back with a curved surface.  Hardly useful.  For floor-standing models, flatten the top of the cup by taking very light passes so the rollers can't deflect the board

FWW's Planer Sled Notes

Awhile ago, I built the planer sled shown in this video on Fine Woodworking's online site: Keith Rust's Planer Sled.  I don't have access to the article so some of the observations below may have appeared in the article.

Voilà, my sled:

The first difference you'll notice is that I didn't use bungee cords to hold the levelers in place (my term for them).  Rather, they are in a box.  You'll see why later.

The base is a torsion box that I took care to make flat.  Turns out there is a slight variance over the whole length, but not too bad.

My levelers actually look a lot like Keith's including the bungee slot I decided against.  In my case, I put a fence near the back for the victim board to register against and prevent movement.  It is only 5/16" taller than the levelers.

The tape on the top of the levelers and the bottom of the wedges is 3M's safety tape.  Very sticky and very consistent grit; available at a borg near you.  Cheaper stuff at Harbor Freight was very inconsistent, which concerned me.

I drew a red mark on one side of the levelers.  Note the direction of the wedges.  When placing a board on the sled, I want all the red lines facing away from the back fence.  In this way, if the board moves a very little backwards during the planing operation (or after shuttling it back and forth for repeated passes), the planer will be pushing the leveler into the wedge tightening it rather than loosening it.  I didn't think of this ahead of time.  On my first trial board, it became an issue and thus the red pen pulled out.

The first board I had to run through had an evil twist/cup combination.  Normally you'd run a board through cup-down, but with the twist, I had places where I needed support for cup-up meaning support on the outside edges, but since it dipped down in the middle, there was no room for the full length of a leveler.  Follow that?!  So, I made a batch of "half-levelers" that I can put on any spot.  The portion that faces down (leftmost tape in this picture) is gently planed so as the far side is raised with the wedge, there is always flat contact somewhere along the tape.  The portion that faces up (rightmost tape in picture) is gently rounded so it, too, always has contact depending on the wedge angle.  This proved to be very useful for this odd board and likely will be useful in the future for a bloodwood board with serious attitude on my rack.

Here is a piece of sapele with a bit of twist.  The only wedge used is the one in the foreground.  Notice again how the wedge is on the fence-side of the leveler so the action of the cutters pushing the board towards the fence will only tighten the wedge, not loosen it.

Another important point has to do with the type of planer you have.  I have a floor-standing (floor-crushing?!) Powermatic 20"planer.  Unlike my Ridgid lunchbox planer, it has power rollers, not pressure feeders (after this post, I'll post about those differences).  "Power" in this case really means it, unlike "power" meaning anything in "power chord" of 80's metal.  Note the following picture:

this is the correct way to place the leveler... there MUST be a leveler at the board extremes.  If you do the following:

the power rollers will press down so hard on the first unsupported inch of the board that the other end will pop up in the air.  Likely your leveler settings will be in disarray or, worse, everything might go amuck while being fed into the planer.  While I'm sure you can see how this would happen on this tiny sapele board, the board from which it came from was 7' long, 11" wide 4/4 sapele.  I had about an inch before the first leveler like in this picture.  The back of the board popped up 3-4 inches as the roller pressed down then when the roller was over the leveler, it slammed it down.  I nearly had very embarrassing laundry.