Surface planer is one of several tools that you'll need in a shop if you're going to mill and square up rough lumber, but it also has a separate function which is just to reduce the thickness of boards so you can use it as a thickness planer and also as a surfacer.
If you use it as a thickness planer it is pretty simple to operate. The basic way this is setup is there is a set of blades in the middle of this housing and there is a couple rollers and so you pass the board in and it gets grabbed by the roller, goes under the blades, comes out on the other roller and the blades are skimming off material as its passing through. It can skim off up to an 16th or even an 8th of an inch, that's pretty aggressive at one pass. Normally what you're doing is passing a board through multiple times to skim off the little bits of material until you get down to the thickness that you want. The way it works is there is a crank on the side which raises and lowers this entire housing, that's essentially changing where the blade height is. You need to setup that up first when you're working with a board. You have to know how thick a board you have. You can measure it and set the height on this gauge here or you can measure it by feel which is what I do. I actually put it in the machine and start lowering it and I'll feel when it starts to hit the rollers and other mechanisms underneath the housing.
When I hit the roller I will back off a little bit and then I know that I'm probably at the surface of the wood at this point. From there I will go a half turn and I know I will be taking off probably about a 16th of an inch. Now, there's a couple of options for setting controls on here. You can go between two types of finishes. One is called finishing cut and one is called dimensioning. Essentially, switching between these two positions usually speeds up or slows down the rollers so either you're getting more cuts per inch or fewer cuts per inch depending on the setting. More cuts per inch make a finer finish so you can use that for a finish cut.
Another control that is pretty useful on this machine is a depth stop. You can use this to set a depth you don't want to go beyond. Lets say I have this board, its one and a quarter inches, I only want to go down to an inch. It is very easy to go past an inch sometimes if you're not being careful with this wheel, what this does is it prevents this wheel from turning once it gets down to one inch, you can't even turn the wheel anymore. That's useful, if you're not using that just put it down to some low dimension that you'll never get to and you'll never be stopped.
Now one thing that is really important on surface planers is dust collection. These machines make a huge amount of dust and this machine particularly ejects that dust at a high velocity. So that machine next to us, the dust collector, has to be on when this is on otherwise you get a big mess of dust in the shop. That's it for the setup of this machine. I'm going to run this board through to see how it works. One thing you'll want to do when you're running a board through the planer is draw some lines on it just so you can your progress. Sometimes the top surface of the board may have some hills or valleys maybe cupped. One of the things you need to be aware of with this machine is that it only works if you have one flat face already. What happens is it references off the bottom face which is on this bed down here and it takes whatever it reads down there and does it to the top face. So if you have a bow or twist in your board as this is passing through the planer it is going to get pushed down by the roller and it's just going to accentuate the shape of whatever board you have. It's not a magic box. It just doesn't make a flat piece of wood out of a twisted one. You need to actually have one flat faced before bringing your wood over here. Once you do then you're ready to go.
This machine is extremely loud and you will want to wear ear protection when using it. Okay, that's our finished product and I wanted to run this through to show you one other thing about the planer which is something that happens a lot. It's called snipe. I don't know if you can see this but there is a slight difference in height where the planer blades have chunked out a little bit extra on these last couple of inches of the wood. What happens is when passing the wood through there, the roller grabs it and actually pulls it up into the blade. So at the beginning and at the end of the cuts, the roller does that, it pulls it up into the blade. You can counteract that by lifting up on the piece of wood as its going in and as long as it gets past the first roller and onto the blade then you can let go. Same on the out feed side. You want to lift up as it's coming out to make sure while it's exiting, it doesn't get pulled up onto the blade. That's it for the surface planer, the other tool we have for milling is the jointer.