Climb Cutting Door Parts on a Shaper

Here's a long, detailed discussion of climb cutting, with some strongly worded cautions and many practical tips. April 21, 2011

I want to climb cut door rails on a shaper with a four wheel power feeder. Is this ok to do if you pay attention and make sure it is set correctly? We have western roller wheels on all our feeders.

Forum Responses
(Solid Wood Machining Forum)
From contributor A:
Just make sure you have two wheels on the outfeed side of the stock, and adequate pressure down; should be no problems.

From contributor D:
I wouldn't do it. Too easy to feed a rail in at a wrong angle and have it shoot across the shop. Even if your setup is perfect, a slick spot on a part, or a grain orientation change which increases load all of a sudden, or cutters getting dull, or dust collection not getting every single chip and some getting under the feed rollers. It can be a pretty violent event if you've never witnessed it. The danger decreases with less dense stock, and the smaller the diameter and subsequent rim speed of your cutter, so depending how big of a sweep it's making and if the body of your cutter limits the bite with an anti-kickback design all affect how hard it will grab your part. Sure it can be done. Very little gain for a lot of risk though.

From contributor O:
Sounds too dangerous to me - the piece will shoot out faster than anyone can react. Why would you need to do such a risky operation?

From contributor U:
We do this all the time. Nearly everything that is long grain fed on the shapers or even router tables is climb cut. This yields an exceptional quality of cut. Curved work is even climb cut. Tenons are not, as with any endwork. The dust collection is lousy, and the cutting action requires more power, but the cut is worth it. Four wheel or larger feeders on everything, and everybody is sober and aware. I only recommend it for those that know what they are getting into and understand the forces involved and the parameters of safe work.

From contributor F:
When you say door rails are you talking about coping? I don't think I'd try that. If youíre talking about your sticking cuts, I did this for a little while when I was using a Delta HD shaper with 3/4" spindle. I upgraded to a slightly larger shaper with bigger 1-1/4" spindle and cutters and haven't had a need to do it anymore. I now run material the normal way and get excellent cuts. BTW the dust is brutal when climb cutting. I was told on this forum some time ago that climb cutting wears the knives faster, don't know as I didn't do enough to find out, but something to be aware of anyway.

From contributor A:
I climb cut about 30% of the time. Quite safe if you pay attention to set ups and details. There is more stress on the spindle, so a 1.25 is preferred. The only thing you really never want to do is climb cut with the spindle at or near its tilt limits (for tilting arbor shaper). The stock gets trapped and will bend the spindle when it flies out - really scary. Cutters with higher rake angles and shear angles tend to grab more, thus more dangerous. Most rail set cutter geometries are fine to climb cut with.

From contributor F:
I thought the purpose of double spindle shapers was just the opposite, so that you could have two sets of cutters and always make cuts with the grain? You certainly don't need two spindles to climb cut. Usually it's done with the same spindle, as youíre just changing the direction of the feed. Weren't double spindle shapers around long before powerfeeds? I can't imagine trying to climb cut panels without a feeder?

From contributor V:
The main reason I climb cut with feed on my shaper is that certain woods tend to chip heavily on the edges of the panel groove. I have never had a stile get away from the power feed (yet). I have noticed that the latest generations of stile and rail sets eliminate groove chipout by putting a small radius on the panel groove edges. I do a lot more climb cutting with routers actually. For the quality of router cuts I want, climb cutting is a must. As long as someone understands what is going on while climbcutting it can be done safely.

From contributor N:
Climb cutting is a widely used practice that deserves caution. There is a balance between the amount of material to be removed and the control of the workpiece. Climb cutting will reduce tearout at the expense of increased heat and wear on the cutter and reduced dust collection. In our shop some operators use it for small profiles and edge grooving, with a four roll power feed, always with a vertical plywood backstop behind the shaper and attention to shop traffic in that direction. For heavy cuts, we just don't do it.

Personally, for grooving frame edges I pre-score with a marking gauge before milling in the normal direction. One suggestion I have seen that should work for cutter sets that cut the entire profile of the door edge is to take a 1/16" deep cut off the entire edge of the frame parts, thus removing the groove tearout as you go. This would probably work best with an outboard fence.

Climb cutting with handheld routers is best confined to very light cuts. I witnessed a nasty kickback when my shopmate was climbcutting a trim cut on the end of a 2" thick door with a pattern cutting bit. All went well until the bit hit the endgrain of the second door stile, took off and spun into the base of his thumb. He was very lucky not to lose any function of that hand.

From contributor O:
Climb cutting on a shaper is generally bad practice. Modern insert tooling and a good heavy duty shaper with a 30mm plus spindle will eliminate the need for this. Door stiles can be profiled chip free with either an outboard fence or split fence removing at least 1mm of the entire edge.

We used to do a little climb cutting with braised tooling when putting a groove or rebate into the stock without removing the entire edge. Insert grooving and rebate tooling usually has scribing spurs built into the cutter design that eliminate any tearout. The only material I have seen tearout in with these tools is wide grain VG Fir. For a groove or rebate in this case we make a light cut climb cutting then finish the full depth with conventional cutting.

If you look at CE safety standards shapers with power feeds are still considered manual feed. Moulders, tenoners, profilers and CNC machining centers that have heavy duty well guarded feed and hold down mechanisms are considered mechanical feed and allow some counter rotating cutting.

From contributor R:
Climb cutting with a feeder is the only way to fly as far as I am concerned. It is not dangerous or tricky to setup. Just apply some common sense. The improvement in the finished product is truly amazing. Tear-out and chipping is almost non-existent. Since I started climb cutting, my reject rate dropped by at least 90%. Just for the heck of it, I made a screen door from some red oak I had left over from another job today. Everything that could be climb cut was. I have a three wheeled feeder. Not one bit of tearout on the entire door. Once you try climb cutting, you will never go back.

I have Western Roller wheels on my feeder as well. I picked the blue urethane for my feeder. They are slightly softer than the stock wheels. I have also mounted my feeder horizontally and climb cut that way too. I was making custom trim for a guest house. Not a single board had any tearout. If you want to see the difference between climb cutting and non-climb cutting, I can run a couple of pieces of left over red oak and take some pictures. I think you will be impressed.

From contributor J:
Power machine woodworking involves controlled risk in every operation. A drill press can kill a man. Learning the safe operation of equipment is a process. From the novice to the grand master, it's just a matter of experience and acquired skill. Climb cutting is just another one of those skills. It's not voodoo any more than straightening boards on the jointer. As with any operation, one never feeds the board unless all doubt is addressed in the setup. Then, keep the downrange area clear of valuable people anyway.

The one specific I will share is to not take too big of a bight. I have found that if one tries to remove much more than 10% of the stock profile, the force of the cutter may overtake the holding power of the feeder. Profiles that offer more face contact such as slats run flat are safest, whereas a tall narrow profile can take off.

One of my favorite climb cuts is in dressing S4S with an outboard fence. Clamp a wide board to the shaper table with the desired net finished width to the cutter arc, turn the feeder to hold tight into the board/fence, crank up the speed and watch the perfect square edges zoom by.

From contributor C:
To contributor F: you are correct about the two spindle shaper. The reverse rotation is for cutting into and across the grain and has nothing to do with the direction the material is feed. Yet the material was feed against the rotation of the cutters in a mill cutting fashion in order to control the feeding of the stock. One spindle was feed one direction the other feed the other manually.

From contributor I:
I have been climb cutting all my stiles and rails for years, with absolutely no problems. I use a 1 1/2 hp shaper with freeborn tantung cutters and 3/4 spindle, a delta 3 wheel power feeder and good dust collection. I replaced the top straight 1/2" cutter with a rub bearing of the same diameter. It cuts very smooth with no excessive cutter wear. It also allows me to run short lengths of stock without the chance of the stock being sucked into the cutter. I also use a feather board to hold the stock tight to the fence. I've shaped rails as short as 3" with this method, with no trouble and no slippage of the material under the power feeder. As fast as I can feed the material under the feeder it cuts with no problems, just make sure the power feeder wheels are parallel with the table so all make contact with the material.

From contributor H:
One can climb cut with a router as well and by hand. The reason is in the design of the new router bits. They are made so that the amount of cut is controlled by a shoulder. It works much like the raker teeth on a chain saw that limit the amount the chain will cut. Many of the new router bits are made that way today.

From contributor A:
My friend lost his hand climb cutting. He made a really poor choice when making a large redwood crown moulding. I have had to climb cut smaller parts like door stile/rails due to grain tearout problems over the years. It is a good technique in those situations. However, the extra setup time can be a waste of time unless doing large batches of parts. 95% of parts should go through a shaper with good results. The 5% is when climb cutting would be a good choice. Climb cutting is dangerous. As others have stated many operations are dangerous. Using a decent size bandsaw requires constant focus and practice.

From contributor R:
You friend that was injured was likely not using a stock feeder. Climb cutting without a stock feeder is just plain wrong on more levels than I care to count. Properly setup with a stock feeder, climb cutting is no more dangerous than regular feeding. Setup correctly, a stock feeder makes shaper operations safer because it is makes it nearly impossible to get your fingers near the cutters.

From contributor H:
One tip, my feeder rolls were slipping, I thought I would have to replace the rolls, but then I took and fastened some 80 grit paper to a board, then turned the feeder on and sanded the rolls. It is working just fine now.

From contributor R:
I am afraid sanding the tires is postponing the inevitable. Western roller products are good and I recommend them highly. Their tires and wheels (hubs) give you more choices. I went with a slightly softer tire with my feeders. I am very happy with the added traction.

To summarize, if you do not have a stock feeder, do not even try climb cutting. It is a recipe for disaster. It is akin to using a radial arm saw with a common positive rake blade. I won't even try climb cutting using a hand router let alone actually do it.

If you have a four wheeled feeder set up with two wheels before and after the cutter, all you need to do is to cant the feeder the opposite way and reverse the direction of feed and poof - instantly better profiles. Never climb cut when feeding stock by hand. Don't even try.

From contributor H:
One comment on climb cutting: The newer shaper cutters are not as dangerous as the older ones. They have shoulders on them that limit the amount the knife will cut. Still don't try them by hand. Now the newer router bits are made the same way with the shoulder and you can make a climb cut with them. I have large Freud chamfer cutter and climb cut with that all the time.

From contributor R:
They way the original posted described it, I thought he was referring to the groove and profile cut made with the grain. I am not sure how you would make the cross grain cut at the ends of the rails and have it fed by a stock feeder. Maybe if you have eight or more clamped together in a fixture.

From contributor E:
No need to try to climb cut the cope on door rails. Use a sled with a backer board and you will not get any tearout on the cut. I made a sled using the bar from a miter guage in the table slot. Next fasten a piece of 1/2" baltic ply or a piece of plastic(1/2" thick I used) and fasten to miter bar and butting against the shaper fence. Cut a dado in the plastic at 90 degrees to the fence and install a piece of wood as a place to set the piece you want to cope against.

Run this through the cope cutter to get a profile on the end of the newly made fence on the plastic. Then put the rails you want to cope against the sled fence and up to the shaper fence and slide the sled past the cutter. The sled fence keeps the cut from blowing out when exiting the shaper. As the fence wears, replace it with new wood. I also installed a toggle clamp behind the sled fence that holds the rails down to the sled. The only drawback I see from this method is if you only have one shaper, you will have to re-adjust the height of the cutters when you set up for the sticking (long grain cut) because of the thickness of the sled. I have two shapers for door cope and sticking cutters, and this makes door making fast.

From contributor R:
I am having problems visualizing your jig. Is it any different than a regular coping sled with a backer board to prevent blowout?

From contributor E:
Itís pretty much like commercial coping sleds. 6"wide by 10" long 1/2" thick piece of plastic with a wood fence to set the rail against. Toggle the clamp behind the fence to hold down the rail.