Need help from the shaper guru's

[Jeff Duncan]

Ok so I recently started a large project and could use some input on it from the shaper experts. I'm re-milling a custom t&g on something like 25,000 lf of flooring. The flooring is an "engineered core" made up of several layers of softwood about 1/2" thick. The face is end grain white oak about 3/16" thick. I have to rip the existing pieces in half lengthwise and the re-mill the cut edge into either a new tongue or groove. The job was set up by another shop who had done it previously and so I took their advice on how best to set it up. I'm running a normal corrugated 2 knife head with carbide knives. I'm using two different shapers running in the neighborhood of 6k rpm's, (one for tongue, one for groove), and feeding varies between 22 - 29 fpm as I'm trying to hone in on an ideal speed. My issue is too much chipping on the end grain. I thought this could be a problem, and it turns out it is. With the groove cut I'm only removing about 1/16" of the end grain face so have gotten about 3k lf of stock before the chipping started getting a bit iffy. However with the tongue cut I'm removing about 5/16" of face material and by about 1000 lf the chipping is problematic. At that rate I'd need to sharpen both sets of knives I have and have at least 2 more sets of knives made! I've tried slowing the speed way down to get more CPI but that doesn't seem to make a difference and will likely wear the carbide that much faster.

So I have the client coming over to look at the edges. When I picked up the order they mentioned some problems with the quality of the previous batch and that I should contact the other shop as they supposedly had a solution.... their solution was that I should sharpen the knives:( So in the meantime I want to see about possible solutions I can offer to get a cleaner edge. I'm sure the tooling they use in the factory is some obscenely expensive custom made stuff. I'm wondering about something off-the-shelf that may get me by. I know there's an awful lot of stuff out there that I don't know about.... but maybe you guys do? I'm thinking a larger diameter head with 4+ insert knives might make a difference. I'm going to call CG Schmidt tomorrow as they have a 7" diameter coping head.... maybe could have custom inserts made for it? They also have an insert flooring head, but I don't think the diameter is large enough to affect any real difference? Anything else I should look into or recommendations? Not sure yet how much the client may be willing to spend or how clean they need those edges, but I'd like to have several options to offer for when they do come by.

thanks,
JeffD

[joe milana]

Just throwing this out there, but have you considered doing it in two passes, climb cutting the final light pass? Run the entire batch, then sharpen and do the final pass.

[Mel Fulks]

The chipping on "end grain". If I understand right the whole top layer is end grain, I've never seen any thing like that.
IS the whole layer end grain? If it is,then the only thing I can think of ,to try, is a no clearance fence.

[Bill Dufour]

Not clear, is the wood chipping or is the cutter chipping.

[Rod Sheridan]

Hi, have you considered running the piece vertically against the fence and using a rebate head to mill the top of the tongue?

I’m thinking that the scoring cutters may prevent chipping and they’re rotatable for sharpness.....Regards, Rod

[Jeff Duncan]

Hey guys, so yes, the top layer is a roughly 3/16" slice of end grain oak, it's pretty unique stuff and so not a ton of info on how to deal with it.

Two passes would possibly help Joe, but since it's 8 pallets of flooring in the neighborhood of 25k lf, that would not be practical.

I don't think I could do the no clearance fence idea Mel. Currently I'm running the parts on an outboard fence to make sure all the parts are the exact same size. I'm removing the material needed to form the t&g plus almost 1/16". Normal for long grain cutting, though not sure it's helping with end grain. But to change any part of the operation now outside of the cutter type/size would require a LOT of extra time.

Cant run vertically either Rod, as it would require multiple passes.

My thought was a larger diameter cutterhead with multiple insert knives may be the way to go, but I'm having second thoughts on that as well. Another issue with this flooring is that its a press fit, so when it goes together you have to tap it a bit for it to fully seat into the next piece. With the corrugated knives it's not a problem as I had them grind the tongue knives a couple thousands oversize, allowing me to offset the knives just a bit until I get the fit just right. With an insert style knife I won't be able to do that. And since they'd be templating off of a wood sample.... just not sure the inserts would be perfect. This is one of those jobs that the more you think about it the more difficult it becomes.

Jeff

[Larry Edgerton]

When you say you are having problems with the end grain are you recutting the end match?

I used that same flooring in my house and made some custom pieces so I could start in the middle and work both ways, and I made them with a 8" adjustable groover and had no tearout, but I did not redo the end match. That I know does not help you because two passes, but the large diameter cutter did fine, did not try a smaller one.

Does this have an aluminum oxide coating on it already? That would be hard on cutters.

Some of the things we get ourselves into because we like to eat!

[Joe Calhoon]

No experience with what you are doing Jeff but if it’s a square T&G you could adjust the fit to your liking with reversed adj groover cutters or stacking rebate cutters. I know my insert cutters with the thin carbide leave a better finish than any of my other heads. This also might be a case where Z4 leaves a better finish than Z 2.

[peter gagliardi]

Short of highly specific cutters being made, I think your best solution will be climb cutting it all, but that seems to wear the knives quicker in my experience.
The other 2 thoughts are, experiment with hook angle- I think less hook will help... , and a deeper cut on the pass.
Chipping and tearout on sensitive woods like Birdseye or curly Maple for example benefit from deep passes vs light.
Thats all I got.

[joe milana]

On second thought, climb cutting may give you a groove full of chips you'd need to clean out. What a nightmare that would be!

[peter gagliardi]

I have solved the groove full of chips with a strategically placed blowgun right after the outfeed fence. Kept it nice and clean, but you need a decent compressor......

[Jeff Duncan]

Thanks again for the suggestions!
Larry, your post surprised me just b/c this stuff is so uncommon!
I’m not doing end matching, those are left alone, it’s only the edge I rip that needs to be milled. And no coating on it at all, it’s just cutting into the end grain oak that’s dulling the knives. I could probably go for a mile with the softwood as the glue lines are minimal.
Joe, unfortunately not square edged. The tongue has a taper on one side so that it seats tightly when tapped to the next piece.
Peter, I’ll ask the guys about hook angle when I take this set back to sharpen. I believe the 2 knife Schmidt heads I have are the preferred angle for hardwoods, but maybe the knives can be tweaked?
I thought about climb cutting but that poses it’s own problems. As you mentioned the knives will wear even faster and the chips will be worse. I’m already having a tough time minimizing the dust blow back and that affects the grip of the rollers. So climb cutting would be hairy at best.
I’m not sure the deeper cut will make a difference either. Reason being is I’m only removing 1/16” or so on the groove cut vs 5/16” on the groove cut and the chipping is very similar. Only real difference being the longevity of the knives.

I do appreciate all the suggestions though! It’s just a tricky beast to tackle.
Jeff

[peter gagliardi]

Flooring in general is much fussier than people know. I have a Weinig molder, and I write down all the measurements for axial and radial positioning for all molding profiles run. The machine has little to no wear, and runs manual digital counters measuring in increments of .001”, but still, the settings for flooring are really only rough guidelines.
Flooring is one profile that I set by the “feel” of the way the groove just tucks under the tongue and hits the “interference fit” at about 1/16” before closing. That ensures the floor is held down tight on the groove side with no squeaking, but not needing to be BEAT into place.

I have been asked on more than one occasion to evaluate flooring made by some shops nearby, AFTER the installer or contractor has install issues.

[Jeff Duncan]

Peter, you aren't kidding! I'm spending probably close to an hour on the setups trying to get the right amount of offset in the knives to get a "perfect" fit. The groove knives are pretty close and only require about .002 of offset from one another. The tongue knives I had ground slightly oversize as the first grind was too loose even when I had the knives dead on to each other. Now I have them about .004 offset and am getting a good fit.

I do think the shallower cut is working much better. I think I'm in the neighborhood of about 5k+ lf though the groove cut with the first set of knives. With the much deeper tongue cut I'm at the same lf but used two sets of knives.

A couple pics I took this evening of the flooring in question....

[jim carter]

i use a router table with a 1/4 round bit to round over 1" x 2" pine. if i go the way you are supposed to go, it chips and worse depending on grain, if i run them on the other side of the bit[the side that pulls the piece in] i get clean cuts.

[peter gagliardi]

Is that honeycomb checking I see Jeff? If so, that really isn’t helping your situation.
Looks like your “eating that bull one bite at a time”
One BIG bite!

[Jeff Duncan]

Yeah so what your looking at are the pieces after they've been ripped in half. So the flooring as it comes is basically a 7' long core with 3/16" thick 7" square end grain blocks glued on to it. The end user doesn't want the "square" look, so they requested a rectangular, (think subway tile), look.... and that's where I come in:rolleyes:

[Brian Holcombe]

I dont have any time on a shaper, but I do cutting in this context. Is it only chipping out at the end of the run or throughout?

If you can somehow score it or saw cut it first you'll significantly reduce the amount of chipping. Leave just a touch needing removal, like .010".

I tend to avoid making knife marks except as a last resort but they do greatly reduce chipping out, if you knife the backside of those cuts with a gauge it will cut down on the chipping out. If I have something that is a real bear, I'll knife in the entire cut to the point where the cutter is just removing the knife line as it passes. I dont know if that will be the ticket on this end grain cutout but that would be my go-to if scoring were too much trouble.

[joe milana]

Brian, did you read the part where he has 25,000lf of flooring to do? That's a lot of hand scoring!
What fascinates me is how that flooring was made in the first place, and what a bad idea! Perhaps the wood had higher moisture content when fabricated & has now dried out & is under tension.
As you can see, even the ripping process caused chipping on that one piece in the picture, which indicates even climb cutting wouldn't help. those wood fibers are just too fragile. At this point, I dont think a 3' diameter cutter would help. I hope you prove me wrong!
Would increasing moisture content help? How about pre-finishing the flooring, or applying a seal coat? Just throwing ideas out there...

[Larry Edgerton]

The difference between the top and bottom cut is about 1/32", the cut being heavier on the bottom of course. If you were to use adjustable groover reversed you could easily have the set of cutters for the top ground down that much and still clear the head. I'm on the prowl for a set of 200mm groovers that I can reverse for this purpose. Have been doing a lot of shaker cabinets and the smaller diameter cutters are creating too much waste.

Another thought, may be crap, but what about using an adjustable groover to cut the tung in two passes in the vertical before it is ripped in half? That way the nickers would maybe stop the tearout. Probably a dumb idea, I have lots of failure on my way to brilliance.Gotta get back to work.........

[Brian Holcombe]

Brian, did you read the part where he has 25,000lf of flooring to do? That's a lot of hand scoring!
What fascinates me is how that flooring was made in the first place, and what a bad idea! Perhaps the wood had higher moisture content when fabricated & has now dried out & is under tension.
As you can see, even the ripping process caused chipping on that one piece in the picture, which indicates even climb cutting wouldn't help. those wood fibers are just too fragile. At this point, I dont think a 3' diameter cutter would help. I hope you prove me wrong!
Would increasing moisture content help? How about pre-finishing the flooring, or applying a seal coat? Just throwing ideas out there...

Point isn’t to hand score every board, it’s to learn if it solves the problem. If it does then you can use a machine oriented version of that addition to the process like the nicker cutters Larry mentions.

[Patrick Walsh]

I know little but I know when I’m having a hard time running a groove on the sharper “tear out” amazing gauge normally solves everything.

Well the marking gauge and dialing in the spindle speed.

25,000 life is a pile to mark but you know if t worked I’d rather spend a day scribing lines than days fighting with tear out and or destroying expensive material.

Infinitely variable speed can be very helpful in this case.

At the moment I’m working with flat dawn white oak and my sticks have been suffering quite a bit of chipping. So far no big deal as it’s only happening on the back of the panel side on panels that will get laminated/glued/screwed prefinished plywood. But man of man nothing can be more aggravating than tear out when doing stain grade work and your thing to cut stiles and rails so forth and so on out of the same board and your machine keeps eating pieces.

I didn’t look at how deep your cuts are. Well I did but I forget. I’d score your cut lines. Get adjustable groovers with nickers and give that a try.

I have a two rangate adjustable groovers you are welcome to borrow if you give them back with new knives. Pretty sure they would be perfect for this project.

[Jeff Duncan]

Thanks guys, I do appreciate all the suggestions. I will say that adding another operation is not an option, 25,000 lf sounds like a lot of material when you think about it for a second or two, but when you realize even adding a minute per piece will result in additional days of work.... you realize it's really a LOT of material, I just can't go down that path. Any additional handling adds enormous time at these numbers, heck I'm having to measure width to the thousand of an inch as the difference between 1/16" of width over the size of the project would be roughly 150 sf. on material that runs $10 sf.... it adds up quick! So any practical solution, (if there is one), has to be in a different type of cutter or head or?

Larry and Patrick, the adjustable groovers won't work either. One side of the tongue is tapered and so you'd still need a custom knife to keep the side of the cut square while the face of the tongue is tapered.

I though about upping spindle speed but the only higher speed I have is 10,000 rpms, and at that speed I'm not sure i could keep up with the feed rate? I think the pieces would be shooting out just to fast.

Joe, no one outside the factory knows how the flooring is made. The company I'm working for does end grain flooring and thats all they do. I don't know if they're the only game in town, but I do know they put floors in all over the country and I believe a lot of it is commercial... hotels, restaurants, corporate offices etc. I was told when the owner went to Germany to visit their offices they wouldn't even let him look in the factory. They consider their process to be their "secret sauce" and are not going to let anyone in on the methods.

With end grain there's always going to be some chipping and even on the solid block floors they put down there are gaps and imperfections that need to be filled. My goal is to minimize the chips to the extent I can. I'm bringing the first 2 sets of tongue cutters back for sharpening on Monday and will talk with the guys about possible different hook angles or other options. Having gotten input from you guys and from my own experience I think the only practical solution at this point is to just sharpen the knives more frequently, and likely have another set of tongue cutters ground as they dull much quicker than the groove.

thanks again!
Jeff

[J.R. Rutter]

Not sure what the timeline on this project looks like, but my insert cope heads are 2+2 alternating shear to give clean cuts on normally-oriented end grain. Not sure if this would translate to what you've got going on. But lead time and cost might be a no-go. As for regular insert heads, I've been impressed with Great Lakes universal heads. The backers install semi-permanently and the inserts I've used have very good tolerances. Their turn around time is 5-10 days.

[Jeff Duncan]

Thanks JR, I have until the end of the month, but hoping to get them out sooner than that. I think if I were to do it again I'd maybe try the Schmidt 3 knife T&G insert heads. I'd have to be comfortable that they could do the fit the way I need it done, but at least that way I could order a pile of inserts and just swap them out when they started getting bad. After having thought about the whole process and the way I need the parts fit, I think it's too late in the game to change things up.

Jeff

[Jeff Duncan]

Well it's done, came in under what I estimated at just about 24,070 lf all said and done when I hit the square foot target. Ended up using 3 sets of carbide knives for each profile, and probably really should have used a fourth on the tongue as the last thousand feet or so started to show the wear. Client was happy though, the chipping wasn't terrible and I got them a much better yield then the previous shop. I don't know that I'd ever do this type of job again but if so I think a custom ground insert head would be the way to go. The setups for each knife change getting the proper fit were a major pain, especially after sharpening when the knives had to be offset anywhere between .004 and .009 to get the fit right. Having the ability to just swap inserts would have saved a few hours of time.

One weird thing I haven't experienced before.... but then I don't usually run anything that needs to fit so accurately. In this case the fit needed to be dead on. I did occasional spot checks through running the flooring and noticed that after a bit of time the fit would creep, maybe a couple thousands at most. I'd tweak it and it would stay fine for the rest of the batch. I'm fairly confident the spindle wasn't moving at all, most of this was run through the T-160 which is a stout machine. I'm wondering though if the heat generated in the spindle, (got pretty warm running for hours), would have been enough to cause the cut to be off a couple thousands? Anyone else ever notice something like this?

JeffD

[Larry Edgerton]

I have noticed this on long runs of thin T&G, but never thought about spindle getting hot. Shaper is massive as well. I guess keeping the cutter low on the spindle would negate some of the change, I was stacking male/female on the same spindle. Hmmm......

[Jeff Duncan]

Yeah I'm not sure what would cause it.... I'm just not smart enough to figure it out I guess?! I did think at first, (well really second after I made sure the spindle height was locked), maybe it was when the micro edge of the knife wore off, but the fit of the pieces doesn't change.... so probably not that. I know metals expand and contract with temperature changes, just not sure how much expansion over the length of the spindle?

I had my cutter head mounted about 1" off the bottom of the spindle, I prefer them up a bit as it's easier to raise the cutter up high enough that I can use the dial caliper to do final adjustments of the knives. When the head is completely bottomed I can't get it high enough to tighten the set screws.

Jeff

[Jeff Duncan]

Update! Figure this info may help anyone who finds themselves in a similar situation.

So I got the call for another 3k square feet of this product and this time I took a different approach. I ordered custom T&G heads from Schmidt with carbide knives. I'm in the middle of the run and I can't believe I hesitated doing this before! Like night and day difference. Everything is ground darned near perfect and the way the knives are set I can still adjust them for fit, but far more accurately than corrugated. I can swap out a new set without any adjustments. Plus being designed this way I can swap the heads from tongue to groove cut without any height adjustment! I'm running a much faster feed rate, getting less chipping, and will actually spend less $ on the tooling than I did for the knives plus sharpening last time! I milled about 500 sq. ft. in less than an hour this afternoon. I'm a very happy camper:D

JeffD