Planer sled troubles- snipe and not perfectly square

[Nick Mazzino]

Hi all,

I am trying to s4s some rough saw walnut.

I have a 6" jointer. Boards are 7-9" wide, 1" thick and I cut them 16" long. I have a very simple planer sled that I just made. I ran both 1" thick sides on the jointer then shimmed up on the planer sled so they did not rock at all. Hot glued in place. Double checked for no rocking. Ran through the planer. Once all my pencil marks on the board were gone from the planer I took off the sled to check squareness and there is still a decent amount of rock. There looks to be some planer snipe, so I am not sure if that is what is causing the rock or if my planed surface is not square to my 2 jointed edges.

I am just using scrap wood shims and sometimes a business card.

Any tips to reduce the snipe and overall squaring of the board with a planer sled? Should I be running a sacrifice piece before and after the sled?
I have a 15" grizzly spiral head planer and 6" delta jointer.

Thanks all!

[Nick Decker]

Don't know about your squareness problem, but in my experience a sled doesn't eliminate snipe. Whenever possible I just make the boards a couple inches longer on each end and cut off the snipe. If your sled's long enough, yes, attaching boards of the same thickness fore and aft of your keeper piece would probably work.

[Todd Mason-Darnell]

While not an expert, there could be a few of things going on (I am assuming no equipment issues).

1. The sled might not be flat or might be flexing as it is going through the planer. I have had this problem with a MDF sled.

2. While you think you are shimming sufficiently, the pressure of the rollers is compressing the stock or compressing the shims.

[Nick Mazzino]

I am using plywood for the sled.

I thought about the shims getting compressed.
Is there something specific you recommend to use? Make sure the shims are of hardwood scraps?

[Nick Decker]

How thick is the plywood? Also, I wouldn't trust plywood to be flat.

[Nick Decker]

I have a couple of planer sleds made with this stuff from Menards:

https://www.menards.com/main/building-materials/shelves-shelving-units/prefinished-shelving/dakota-trade-1-1-8-x-11-1-4-w-x-6-l-industrial-shelving/shelf118112572/p-1444428263538-c-5702.htm?tid=-5142258779903322082&ipos=31

It's thick, heavy and flat. Been working fine for a couple years.

The shims I use (hot glued in place) are just cheap pine construction shims.

[Steve Jenkins]

You need to run them thru the planer on your sled first then The opposite face without the sled then joint the edges . You need a flat reference face in order to get the edges square to it.

[Rod Sheridan]

Hi, I have no idea what you mean by squareness.

A planer only makes things parallel.

If you want square you need to joint an edge square to one face.

Snipe is caused by improper planer setup, a planer that's not strong enough to resist deflecting, or the sled is deflecting.

If you can't get your snipe eliminated you'll have to make the pieces longer and cut the snipe off.............Rod.

[Mark Hennebury]

what Steve and Rod said. And you should realize that what you are trying to accomplish with the thickness planer is flat, not square.

[Zachary Hoyt]

My preference is always to plane longer pieces and then cut them into short lengths, when possible. If you had a 7 foot board and ran it through the planer you would only have snipe on the two ends, and then you could cut it into five 16" long pieces and throw away 1-1/2" or so at each end of the long board. If your walnut is already cut to short lengths this wouldn't help.

[Robert Engel]

Hey Nick I think I've got a better way for boards wider than your jointer that doesn't involve a sled or any fiddling.

1. Joint one side flat. The extra width will appear as an unjointed strip proud of the surface.

2. Then place the jointed side down on a 1/4" thick piece of plywood (or thicker than the elevated strip) and run through the jointer. This maintains the jointed side down allowing you to surface the opposite face flat and parallel.

3. After this side is planed flat, flip over and plane off the strip.

This is a really easy technique I've used many times.

Give it a try it works for me every time!

[glenn bradley]

I am using plywood for the sled.

I thought about the shims getting compressed.
Is there something specific you recommend to use? Make sure the shims are of hardwood scraps?

As mentioned, a piece of plywood is flexible. You are trying to provide a base that will stay flat under the pressure of the feed rollers which is considerable. A piece of MDF or ply may act as a helper but, provides no real support surface for irregular material. My sled is a sandwich of 1/2" BB ply with a grid in between like a torsion box. Most shop made sleds you see in the magazines use this principle to provide a flat inflexible carrier.

385211 . 385209 . 385210

[Nick Mazzino]

Thank you everyone for the input. I meant trying to achieve flat on the jointer/planer said then square up with the planer.

I have seen some videos and plans for a more robust sled like that. I am going to make one soon.
I tried the jointer then have the overhang off the 1/4" plywood as described.

I ended up finding out my issue. I checked the calibration on my jointer with the squareness of the fence to the tables, the infeed levelness, outfeed levelness, and knife levelness. I found each knife was off around 20 thousands from front of the knife to back in 2/3 of them. I just calibrated it around a month ago. I will have to calibrate them again

I have a DJ 37-220. An older 6" Delta. It unfortunately does not have the screws to raise and lower the knives. What a pain this is to get calibrated!
Any tips?

I am very new to woodworking. I just got my shop set up around a month ago and am definitely still learning.

[Rod Sheridan]

Hey Nick I think I've got a better way for boards wider than your jointer that doesn't involve a sled or any fiddling.

1. Joint one side flat. The extra width will appear as an unjointed strip proud of the surface.

2. Then place the jointed side down on a 1/4" thick piece of plywood (or thicker than the elevated strip) and run through the jointer. This maintains the jointed side down allowing you to surface the opposite face flat and parallel.

3. After this side is planed flat, flip over and plane off the strip.

This is a really easy technique I've used many times.

Give it a try it works for me every time!

Robert, how do you do that without removing the jointer guard?

regards, Rod.

[Steve Jenkins]

Robert, how do you do that without removing the jointer guard?

regards, Rod.
I think he meant to say planer not jointer

[William Young]

I have found that using 3/4" MDF or plywood alone as a sled is not satisfactory. They are too flexible. There are two best ways to solve this, IMHO. One is to make a level auxiliary table that extends all the way through the planer with a sufficient infeed and outfeed surface. Then slide your MDF or plywood sled on this surface. The support of this surface will eliminate any flexing of the sled. The second way is to make your sled by building it as a torsion box. Mine is made of 1/4" plywood top and bottom with 1/2" ribs and is then covered with plastic laminate. It is rigid and slick so it slides smoothly without flex. A roller stand at each end also helps make it easier to handle.

I also hot glue my boards to the sled using a series of small wedges. The glue and wedges then pop off of the laminate easily with an old chisel. This is a simple and effective sled and I have planed many many BF of lumber with it. My jointer is a 6" short bed Delta and serves my edge jointing needs nicely.

I understand that snipe is more prevalent with some planers than others. My Dewalt does not snipe too badly and can be mostly eliminated if I gently lift the trailing end of the work piece (or sled) when starting the cut and the leading edge when finishing the cut. As you mentioned, you can also use sacrificial pieces at each end. My understanding is that using the auxiliary table eliminates sniping problems.

Rather than trying to flatten a whole plank, particularly if it's warped or twisted, try your best to plan ahead and cut it into smaller pieces before flattening and thicknessing. This way, the amount of twist, warp, bow, etc. in each piece will be less pronounced and you will remove less wood in the process. Always support a board on your sled with shims or wedges every 6"- 8" inches to prevent the downward pressure of the feed rollers from flexing it. Take light cuts.

[Dustin Bullard]

I was watching an interesting video on squaring stock recently from the Gwinnett Woodworking Association: The 4 Square Method (https://youtu.be/KMpbeRr44jw?t=1577) (this link takes you to the specific time about planer sleds but the whole video is great) the TLDW; Make a bunch of shims and use a pinner or brad nailer and nail the shims in place when you are done just use a mallet to knock the shims loose and throw them away...

Using a planer sled is not rocket surgery and it is frequently over complicated...

Something that is key to understanding with a planer sled is that it's a very simple device... If you think about how much pressure the infeed and outfeed rollers are putting down in a planer (enough to smash 8/4 stock flat) having a torsion box under your workpiece is just an added layer reducing the thickness you can surface... Think about it like this, the planer itself is compressing the workpiece and sled to the table between the pressure rollers, as long as your workpiece is not so long that uses its own weight as a lever to bow between the pressure rollers you don't need any additional support. If you are trying to joint something 8' long (eg something long enough that it bows under its own weight) just use some additional infeed/outfeed support (rollers, saw horses, etc...)

What really matters is that your sled is on a flat surface before you start shimming your workpiece and make sure you secure your shims and workpiece so it can't move. A simple sled made out of 3/4" MDF or Ply is more than sufficient...

[William Young]

I was watching an interesting video on squaring stock recently from the Gwinnett Woodworking Association: The 4 Square Method (https://youtu.be/KMpbeRr44jw?t=1577) (this link takes you to the specific time about planer sleds but the whole video is great) the TLDW; Make a bunch of shims and use a pinner or brad nailer and nail the shims in place when you are done just use a mallet to knock the shims loose and throw them away...

Using a planer sled is not rocket surgery and it is frequently over complicated...

Something that is key to understanding with a planer sled is that it's a very simple device... If you think about how much pressure the infeed and outfeed rollers are putting down in a planer (enough to smash 8/4 stock flat) having a torsion box under your workpiece is just an added layer reducing the thickness you can surface... Think about it like this, the planer itself is compressing the workpiece and sled to the table between the pressure rollers, as long as your workpiece is not so long that uses its own weight as a lever to bow between the pressure rollers you don't need any additional support. If you are trying to joint something 8' long (eg something long enough that it bows under its own weight) just use some additional infeed/outfeed support (rollers, saw horses, etc...)

What really matters is that your sled is on a flat surface before you start shimming your workpiece and make sure you secure your shims and workpiece so it can't move. A simple sled made out of 3/4" MDF or Ply is more than sufficient...

All I can tell you is that I did not get satisfactory results with only 3/4" MDF or Ply; even when using infeed and outfeed roller supports. It seems to defy logic, but planed surfaces did not come out consistently flat from one end to the other. When I started using the torsion box the planed surfaces came out perfectly flat consistently. My sled is 6' long and It is only about 1 1/4" thick leaving plenty of planer capacity above for any thickness I'll be working with.

[johnny means]

The first issue that jumps out at me is jointing the sides first.
The correct OoO is to flatten one face (planer sled), plane the other side, joint one edge, then rip the other parallel.

[Bill Space]

I don’t think anyone mentioned the bed rollers.

In in my case with my 15” Grizzly planer, snipe went to next to zero when I lowered the rollers to be level with the table.

My understanding is that the rollers are less important when planing relatively smooth wood. A sled would be smooth wood.

If the sled is much longer than the piece it is carrying (and very stiff), then this may be a non issue (if the piece were centered on it).

So I would suggest you lower the bed rollers to be even with the bed and see what happens.

Bill

[Brian Holcombe]

The first issue that jumps out at me is jointing the sides first.
The correct OoO is to flatten one face (planer sled), plane the other side, joint one edge, then rip the other parallel.

Interesting, I prefer to face joint, then edge joint. I then plane the opposite edge parallel and finally thickness plane.

I alternate sides once the opposing side cleans up so to minimize wood movement from taking excessive material from one side. It also produces a finished result on all sides.

I rough cut the stock prior to working any faces(typically) or after face and edge jointing if it’s really rough. I use my bandsaw to do this and sometimes set the stock overnight after this operation if the results are critically in need of perfect flatness.

[johnny means]

Interesting, I prefer to face joint, then edge joint. I then plane the opposite edge parallel and finally thickness plane.

I alternate sides once the opposing side cleans up so to minimize wood movement from taking excessive material from one side. It also produces a finished result on all sides.

I rough cut the stock prior to working any faces(typically) or after face and edge jointing if it’s really rough. I use my bandsaw to do this and sometimes set the stock overnight after this operation if the results are critically in need of perfect flatness.

Your OoO assumes that your final width fits into your planer. Anyway, I think we agree that the crucial idea is to flatten one face first, then all other sides are somehow referenced to that face.