Thicknesser/planer Wood sticking

Hey all! So I’ve started training at a carpentry college a few weeks back and today encountered a problem using the thicknesser machine. Firstly I cut my length of European redwood down to a good size. The fresh cut surface was fairly sticky. I then attempted to run through thicknesser to get last few mm’s removed. The length of wood was not passing through properly, stuttering through the machine, and even not moving at all. The wood that came out the other side was very black. I was also told off by one of the tutors for incorrect operation when the wood jammed. I was told that I should never stop the machine when the wood is still in the machine. I was told I must lower the bed before shutting down the machine. What is the reason behind this?

I have now also been accused of breaking the machine because of this. I’ve done loads of research tonight and everyone talks of simply cleaning the rollers etc.

Any thoughts would be greatly appreciated!

Sticking stock in a thickness planer is usually a sign of jamming into either the structure , the feed rollers, or that the blades are so dull they are hammering the stock instead of cutting.

You did not specify what type of planer you are using. Does the machine have a solid serrated feed roll? A solid rubber roll? Or a segmented serrated feed roll. I am not familiar with any machines with segmented rubber rolls.

The setting of the feed rolls to allow sufficient space for driving the stock without the stock fouling the supporting structure is critical. So is the feed roll spring stiffness. I want serrated rolls to leave "tooth marks" in the stock that are cut away by the thickness cutter knives.

Another critical issue is the feed table. Is it smooth cast iron? Or does it have rollers? If there are rollers, Are they set correctly? Correct is that the rollers are a bit proud of the support feed table. When running thin stock, rollers are lowered to flush with the table. My own Chi-com planer has "flip blocks" to quickly set the roller position.

If there are no rollers, Talc (baby powder) is a great lubricant for any "wood butcher" feed table.

If everything is as it should be, take very light depth cuts with each pass. No more than 1 mm to see how it goes.
But talc the table!

Is the "black" you see on the stock from rubbing against rubber feed rolls? Or is it burned wood. If burned wood, Get the knives sharpened.

Bushy said:

I have now also been accused of breaking the machine because of this.

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What thickness planer is this? My message to the accusers...

I had feed problems on my thicknesser and I noticed that the bed was slightly hazed with rust. To reduce the friction I sprayed it with Beeswax furniture polish which worked a dream, but the next day the rust was far worse - turns out there is water in the commercial aerosol.

So I made my own by dissolving Beeswax in genuine Turpentine - friction dramatically reduced and it stops the rusting totally.

A side benefit is that the workshop smells splendid with the Turpentine.

andrewmawson said:

So I made my own by dissolving Beeswax in genuine Turpentine -

Click to expand...

That is what I use. Great stuff.

In the USA Johnsons paste floor wax is the wood shop standard for cast iron. Make sure what ever you use has no silicone as it will cause finishing problems. A 2mm cut is too deep for a little sheet metal lunch box planer. Is there good dust removal on the planner, lack of chip removal can cause issues.
Does the planer weigh more or less then 25KG, or is it more like 100KG?
Bill D

I use Johnsons past wax also.

Did you check the board thickness at multiple places first.

You may have hit a thick or warped section that would not go through. Put the thick end through first or send though with the blade higher than needed till you find the high spots. If you run it over a jointer first you can usually pick out the high spots first.
Mine has a short block in the middle to prevent too much depth of cut at full width. That may be stopping the board
Narrower boards can be cut deeper.

The planer manual should also have a set up procedure to get the cutter head related to the feed rollers. If the chip breaker is set too tight it may cause problems also. Whoever maintains the shop should be checking that though.


Dave

Redwood tends to stick in thickness planers that rely solely upon small rubber feed rollers (most small portable planers). It's worse in this respect than most woods. One reason is that it tends to coat the rollers with dust. This is for California redwood -- I'm assuming your European version is much the same?

Some things that can help:
- sharp knives
- good dust collection
- figuring out a sensible amount to take off at a time
- smooth and maybe waxed bed, as noted above
- rollers to support the boards in and out
- possibly a human prepared to help a bit, if needed, on the outfeed end
- a planer better suited to handling rough cut boards

As for not ever shutting down the machine until you've lowered the bed -- well, there's a reason every machine has an emergency stop and there are plenty of reasons to use it. Including a jam. You would want to drop the bed (or, machine dependent, raise the cutter head) before attempting to wrestle a stuck board at one end or the other.

The burnt wood is on you, you didn't get one of the above things right. However, that's very easy to do with redwood, especially on a small machine. The wood is soft enough it encourages fairly deep cuts. But that wood also generates enough dust the rollers can't pull it through. Try to keep adding pressure to the rollers, and pretty soon you get that stuttering, burning, etc. Especially on rougher boards with some initial variation in thickness.

Cleaning dust out the machine and throughly cleaning the rollers should get the machine back in the running. Your instructors might have warned you about planing redwood -- especially if this is one of the smaller portable planers.

Just a note - what they (Europeans) call "Redwood" is a pine species more like old east coast red pine (pinus sylvestrii IIRC), so probably resiny/sticky not dry like our seqouia sempervirens et al or at all .

It sounds like you may have put a board in that was too thick at some spot, hanging it up on the infeed casting. If the feed rolls are rubber it is probably good you stopped it promptly so they didn't get chewed up. If however, you then started it back up without lowering the bed, more mayhem may have happened. But it probably would have blown the heaters at that point to protect the motor.

We need more info.

smt

The teachers should have taught you all those things before you ran the planer, it’s their fault for any misuse of the machine - it is a school isn’t it?

A friend of mine once gave me a tour of the Cornell architecture studio where he was in charge of the extensive shops. At one point in the tour were several then-new saw-stop saws, and on the wall he pointed out a row of blown cartridges. At that point IIRC they were blowing about 1 a month or more.

But the story that stuck in my mind was the student who stopped a young lady about to run a large sheet of glass through the saw. If people didn't grow up with machinery or around trades, they just don't know. And who would know to teach not to do that?

What Lanso said, though, was the first thing that crossed my mind in the current scenario - there should have been a well thought out lecture or 2 on the planer and a set of thorough hand outs diagramming the machine and the functions & settings of the component parts. There could (should)even be a simple quick reference wall chart for basic operations and jams.

smt

Glass on a table saw!?!? Good grief! That would make a neat Farmers Insurance commercial.
Joe

Joe Rogers said:

Glass on a table saw!?!? Good grief! That would make a neat Farmers Insurance commercial.
Joe

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I will give the student the benefit of a doubt and say they saw someone, somewhere using a table saw to cut plexiglass. But they should have asked before cutting anything other then wood on a machine designed to cut wood.
I was very surprised, in my fifties, to find out that chainsaw protection is not hard at all. it is soft padded quilted. The opposite of what I had always assumed not having grown up around chain saws.
Bil lD

Bill D said:

I will give the student the benefit of a doubt and say they saw someone, somewhere using a table saw to cut plexiglass. But they should have asked before cutting anything other then wood on a machine designed to cut wood.

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Every Tap Plastics store I have been to has a Delta Unisaw with a Beisemeyer fence. All they do is cut plastics.

Anybody who is using a table saw should be be taught what different blades are used for. Then some plexglass is no concern.

Bushy said:

Hey all! So I’ve started training at a carpentry college a few weeks back and today encountered a problem using the thicknesser machine. Firstly I cut my length of European redwood down to a good size. The fresh cut surface was fairly sticky. I then attempted to run through thicknesser to get last few mm’s removed. The length of wood was not passing through properly, stuttering through the machine, and even not moving at all. The wood that came out the other side was very black. I was also told off by one of the tutors for incorrect operation when the wood jammed. I was told that I should never stop the machine when the wood is still in the machine. I was told I must lower the bed before shutting down the machine. What is the reason behind this?

I have now also been accused of breaking the machine because of this. I’ve done loads of research tonight and everyone talks of simply cleaning the rollers etc.

Any thoughts would be greatly appreciated!

Click to expand...

European redwood/Scots pine/Baltic pine/Pinus sylvestris/Red deal/ whatever your pleasure can be LOADED with resin both within the wood and in resin pockets. This is possibly why you noted it was sticky. The resin coats feed rollers and if the bed of the machine doesn't have bed rollers it will tend to grip the cast iron bed. Bed rollers should be set high for roughing and low for finishing if the machine allows this.
I'm not a fan of having wood within any machine or setup without adequate feed, as burning is generally the result. It is a matter of keeping the timber moving by taking a couple of light cuts on roughsawn or bent/warped/cupped timber to even things out before setting a decent cut.
Dropping the table can be risky under power as the kickback fingers loose their grip as the pressure comes off and small pieces can be kicked back. I don't see any issue with stopping the feed if it jams or stopping the motor, mainly because the timber always jams on the infeed pressure bar and not on the spindle. Good thicknessers have a feed clutch or control independent of the spindle so are clearly designed to be used this way.

Yes, things jam in thicknessers but if you are under tuition you should be being tutored and not berated for learning the hard way. Dope slap if you do it a third time

I have noticed over the years in a particular line of planers:

- The two bed rollers where removed.
- the large dado cut in the bed was removed and steel spring guides installed on both side.
- the serrated steel infeed roller was replaced with a rubber roller.
- the oil bath gear chain drive replaced with a few rubber belts.

Another case of bean-counter economics.

stephen thomas said:

A friend of mine once gave me a tour of the Cornell architecture studio where he was in charge of the extensive shops. ... If people didn't grow up with machinery or around trades, they just don't know.
smt

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Stephen -

I think college shops can be one of the most dangerous places, at least based on my admittedly long ago experience.

In grad school a buddy of mine and I were using the shop in the student union over Thanksgiving weekend. We had both grown up around tools, worked summers on construction, etc - jackleg upstate NY carpenters. My buddy scored us a job to build a receptionist desk for a private school. The place was not supposed to be used for money making projects, but what they did not know would not hurt them and we were both broke newly married guys with working wives anyhow. This was 1970. A young female student came in. She was evidently making a bed and her solution for the side rails was to take two 2 X 8 SYP and chew out enough wood (I hesitate to call it a dado)to leave a ledge for the slats to rest on. She was a small woman, having a very hard time getting the wood to the table saw and using just a standard blade. With no experience she was not keeping it to the fence and was just about laying on top of it to jam it through the saw. We offered help and got ripped a new one for being sexist pigs. So we left to get a cup of coffee and avoid the carnage. To this day I don't know how she survived that time on that table saw - total disaster in the making but she was lucky. Goes without saying there were no safety or check out requirements to use the shop - which amazed me even then.

Like Clint Eastwood said in that one movie - 'A man has to know his limitations'. As I get older I realize more and more of mine!

Dale

Bushy, I join some others here to say they had no right to bash you about that planing operation. I guess we're never going to find out what make and model machine that was, but really, it comes down to thorough coaching before anyone powers up any machine. Clearly their protocol is lacking.

They even gave scary bad advice about lowering the bed before turning off the machine. Please tell them for me: NEVER release the feed's grip on a board while the cutterhead is under power or even coasting down. In the unusual case of the stock being exactly half way through the machine, probably/maybe it will balance and just ride down sweetly. More likely, a board could tip up into all that kinetic energy rotating above it, and eject at high speed, or break a casting, or some such. I am guessing that they did not even bother to tell you all to never look into the machine from the board's point of view. Put both of those scenarios together, and you have something that doesn't bear imagining vividly.

Good luck and success in your vocation! Lee Haelters