Planer Danger: Feeding Multiple Boards at a Time

[Phil Simard]

I was reading instruction manual for a Grizzly planer. It says that you should not feed multiple board at the same time in the planer. It can result in kickback. This planer has no sectional feed roller nor sectional chip breaker. I read that sectional feed roller allows for feeding multiple boards safely.

I have been doing this technique to save time on my lunchbox DW735 for years and never had a kickback. I always use jointed stock. I feed 1 to 3 boards at the same time in the machine.

Now I'm shopping for a bigger planer. I was hesitating between 15 and 20 inch planer, and decided to get the 20 inch so I could put multiple boards across the width of the machine to save a lot of time when planing. But if I cannot plane multiple boards at the same time, the 20 inch become only useful for large glueups and is less interesting.

Is it a real danger issue to plane multiple boards at the same time (jointed stock) or it is unlikely to happen?

I would like to hear from you to see if you feed multiple boards at the same time and if you had issues.

Thanks!

[peter gagliardi]

If you have been doing this with a solid roll planer, and nothing has happened, count yourself VERY lucky!!! They make segmented feeds for very good reason! I have a segmented feed L.Power 24" planer that even still when things are just right- too much stock thickness variance - will back feed ! It is rare, and I try to keep an eye out. Thankfully, nothing serious yet has happened. Most of the bigger machines offer this, but you have to be willing to pay more than the base rate. More complex machine= more parts= more production= more cost . Some machines come with solid rubber infeed rolls which will tolerate a very slight difference between pieces allowing multi feed if needed.

[Joe Hillmann]

It may be unlikely to happen but when it does it is far worse than a table saw kick back. My stepdad has a large 20" or 24". He was planing some 3x8's. One of them kicked back and knocked him down, The weight of the two 3x8's caused the planer to tip over until the ends of the the boards hit the ground. Since the planer was still running and pulling the boards through the planer kept falling lower and lower until it was completely on its side and boards fed out the top and fell down. The switched was pinned down so he had to shut off the planer at the breaker box.

Before that happened I would always feed two boards through at a time with their ends staggered to prevent snipe, now I just accept that snipe will happen and plan for it.

[Erik Loza]

Phil, I can't tell you how your machine will/might behave but I will say this: I can order our big SCMi planers from the factory with either a solid or with a segmented infeed roller and pretty much across the board, shops dismiss it right away if it's the solid one. As a matter of fact, that's the only way we stock them. I think it's pretty much mandatory if you plan to run multiple pieces through at the same time. Good luck.

Erik Loza
Minimax USA

[jack forsberg]

you can mill two boards one on each side of the bed with out any fear with a solid infeed roller. the problem/danger is a lack of ante-kickback fingers on the older planers. At any rate narrow strip planing should be done carefully even with a segmented roller as the segments are about 2" wide and one board can hold two of the rollers higher. the kickback fingers are a safety not the seg roller on it own IMO. The seg roller IMO keeps the work down for ripple free finish but does help with kick back but is not full proof.

[Clarence Martin]

Does this kickback danger apply to the Jet 13 inch planer moulder ?

[pat warner]

" would like to hear from you to see if you feed multiple boards at the same time and if you had issues"
*************************************
Indeed I agree, all stock should be single faced before entering the planer.
And it's not a bad idea to feed stock singularly until it's uniform in thickness either.
Taking more wood from equal thicknessed stock is essentially a benign practice.
But why tempt the hands of faith? For the sake of production?
And if in production, a machine should be chosen that can handle all-day milling.
The Stratoplanes I've seen, e.g., take wood all day long over the full width of the blades.
They're built for the job.
One final note: I'd stay with a narrow well built machine, an older 14" General is a good example.
Remachining a glueup, because you have 20" of blade or not, indicates a crummy glueup.
Stuff should be ready for the sander or scraper after gluing, not wasteful remilling, no?.

[Roy Harding]

...
Remachining a glueup, because you have 20" of blade or not, indicates a crummy glueup.
Stuff should be ready for the sander or scraper after gluing, not wasteful remilling, no?.

Depends upon whether you want to waste material or time. I usually cut my panel stock around 1/16" thicker than needed - then run the panel through my drum sander after glue up to flatten it and bring it to final thickness. I may be wasting some material - but the process is MUCH faster.

That said - running multiple boards of uneven thickness through a planer without a segmented infeed roller is asking for trouble - and you will find it eventually. If you have a solid infeed roller, first run all your pieces through once singly (or until they are all the same thickness) - THEN you will be okay to feed them together on subsequent passes.

[mreza Salav]

I think you got away with DW735 because it has a rubber roller (not solid metal) and so it can tolerate variance of thickness of the pieces and still have a grab on them (but that is not a guarantee either). I have seen a planar kick back and it's a nasty stuff (juse like a table saw); it is scary!

[Peter Quinn]

I run multiples through a 15" solid roller planer all the time...after the first pass creates an even thickness. Until then, no way. I've seen a kick back on a 24" industrial planer at work. It has segmented infeed roller, segmented chip breaker, anti kickback fingers. But a guy passed narrow stock too close together...whamo batman, it was like one of those cannons they use to shoot 2X4's at a block wall for tornado testing. Not cute. Once the stock is of consistent thickness I've had little issue in the home shop, I do space them several inches, generally two rows, one left, one right. And I NEVER stand behind the planer when feeding. If something gets loose I'm not playing target. I've seen bits of wood break off an edge and come back too. Its rare but special when it happens.:eek: Big cutter head + big motor + lost stock control= wood cannon.

[Stephen Cherry]

And I NEVER stand behind the planer when feeding. If something gets loose I'm not playing target. I've seen bits of wood break off an edge and come back too. Its rare but special when it happens.:eek: Big cutter head + big motor + lost stock control= wood cannon.

This is a fundamental of woodworking. I learned this lesson when starting with my shaper, climb cutting some parts with the power feed incorrectly set. A door part shot out of the machine like a canon, bounced off my old landcruiser, and was shot into orbit.

Always stand to the side!

[Rick Fisher]

I have a General 20" HH and run multiples through all the time .. It has kickback fingers.. Never an issue.. I have run 8 pieces of 1x2 through at a time for hours.. never a problem..

If the planer had no anti kickback fingers.. yikes..

You do run into some boards not feeding.. its annoying and you want a segmented infeed after a while.

Now.. A Wide Belt sander is a different animal.. When that really catches and kicks.. its impressive.

( having said that .. never stand behind the boards .. on anything.. for any reason.. )

[Phil Simard]

Thanks you guys for sharing your experience with me, it is very valuable information.

- The DW735 (DeWalt) small planer that I currently use has indeed rubber feed roller. This may explain why I never had issues feeding multiple boards at the same time. It think it also have an anti kickback device, but smaller than the finger that we find on new import planers
- Some say that the anti kickback fingers are the real safety device, and not the segmented infeed roller. The segmented roller would allow to feed uneven thickness boards without having feed problem. The anti kickback would keep the boards from shooting back at the operator. Therefore, even feeding one board in a machine without anti-kickback fingers is dangerous.
- Some say that once all the boards have reached uniform thickness, they could be fed two at the time if spaced across the bed of the planer, with a machine that has anti-kickback fingers. I guess that would allow the infeed roller to tolerate small difference in thickness since it is supported by springs at the ends.

- Climb cutting at the shaper: same story. Some say that it should never be attempted even with a power feeder, other do that all the time. I do it personally and make sure that there is no valuable objects or persons in the line of fire but I never had issues.