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/buildin...322082&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.

planer sled.JPG . Planer Sled-S-N.JPG . CoD-crnr-wide (2).jpg

[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