Grizzly shapers putting a dip in the end of our stock

[Kevin Cackler]

Pretty much like the title says. We have 3 grizzly shapers. All 3 exhibit the same issue and it's about to drive me nuts. Basically, as the tail end of a piece of stock passes the cutter head, it dips (For lack of a better word) into the cutter, giving us an uneven profile. We have this problem with multiple Freeborn cutters. We have spent hours trying to square up the fence and are able to get it very very close, but still have this problem. We are using a power feeder to feed the stock, but it's still dipping into the cutter.

Any thoughts? I'm about ready to throw these things in the dump.

[James Biddle]

When you say dipping into the cutter, is the stock moving in towards cutter in the direction of the fence or the direction of the floor? First thing I would check it to make sure the angle of the power feeder isn't causing the problem. Then I would check to see it the fence halves are coplanar and the top is flat across it's length, depending on which way the stock is moving. No flex in the fence, right?

[Mel Fulks]

I've seen a number of those heavy fences that are just not straight. Some attribute that to castings that are not aged before machining. For most things I 've preferred my own shop -made fences. Many shops only use that type . I worked for years before ever seeing a factory made fence.

[Kevin Cackler]

James, yeah it's dipping into the cutter. Table is very consistently flat. My first thought was power feeder as well but I've literally spent 8 hours tweaking the power feeder angle and positioning and I always always get the stock being pulled into the cutter at the tail end.

Mel - Making our own fence was my next idea, but I wanted to make sure I couldn't make this work before going to that effort. Is there a generally accepted "best" design for shop made fences on a shaper?

[Mel Fulks]

No. And the wooden ones will,of course ,move too and often need a little shimming. But for repeated use I find the "dedicated " shop made fences easier to use. And not so danged heavy! Some use both types.

[Kevin Cackler]

Alright. Thanks for the advice. I'll go hack together a fence tomorrow and see if it helps.

[Mel Fulks]

I guess there is one common type,but just for small tooling; a piece of plywood (often with a glued on wood strip for quick re- straightening on the jointer) C- clamped to table top.

[Darcy Warner]

What are you making? Large cut?

Face cut? It happens on some shaper work.

[Kevin Cackler]

What are you making? Large cut?

Face cut? It happens on some shaper work.

We mostly experience the issue on our edge profiles (cabinet doors) and on our stile cutter. Our panel raising cutters have a one piece fence mounted to the cast iron and the fence goes below the cutter so that keeps the panel from being pulled in. I think we tried to come up with a similar set up for the edge profile cutters but for some reason couldn't make it work.

[Darcy Warner]

We mostly experience the issue on our edge profiles (cabinet doors) and on our stile cutter. Our panel raising cutters have a one piece fence mounted to the cast iron and the fence goes below the cutter so that keeps the panel from being pulled in. I think we tried to come up with a similar set up for the edge profile cutters but for some reason couldn't make it work.

It's just the nature of shapers, you butt your pieces you feed? The cutter will want to suck material into it a little.

Best I can offer is a long board screwed to both fences and push it into the cutter to create a 0 clearance fence set up.

[Bill Dufour]

Set the fences flat and run it over the jointer to make them parallel. Then adjust for depth of cut.
make sure the power feeder is pushing stock into outfeed fence not the infeed.
Bill D

[Kevin Cackler]

Now that's not something I've tried yet. That seems like a really easy way to get them in line with each other and compensate for that goofy cast iron

[Justin Ludwig]

Outboard fence, outboard fence, outboard fence.

[Bill Dufour]

Now that's not something I've tried yet. That seems like a really easy way to get them in line with each other and compensate for that goofy cast iron

Make sure the attachment bolt heads are tight and well below flush before jointing

[J.R. Rutter]

Outboard fence, outboard fence, outboard fence.

Amen, amen, amen.

[Leo Graywacz]

Not sure what the profile looks like so I'm not sure if this will work for you. Make a single fence instead of two individual fences. Mount the fence so the cutter is inside of it and slightly loosen one of the fence hold downs and using a mallet tap the fence into the cutter. Keep doing this going back and forth loosening and tightening the opposite sides of the fence until you are a little bit farther in than the cutter requires. Then pull it back out to the proper fence position and you can run your pcs without fear of them getting that rear snipe.

It won't work if you are using a destructive setup, only if there is a flat edge remaining.

I do this with my raised panels. So no chance of the panel getting sucked in if it's very narrow.

[Rod Sheridan]

Outboard fence, outboard fence, outboard fence.

Yup, profile and dimension in one pass..............Rod.

[Bill Orbine]

Yep! Yep! Yep! This has been discused quite a bit on this forum. An example: https://sawmillcreek.org/showthread.php?239500-Adjustable-outboard-shaper-fence&highlight=outboard

[Tony Joyce]

Amen, amen, amen.

Amen, first thing I would work on.
Also, Both fences should be as close as possible to cutter.

[Steve Jenkins]

For stiles definitely an outboard fence, dimension and profile in one pass. Door edges the fences must be parallel and the outfeed fence set forward by the amount you are removing from edge.

[Mel Fulks]

Kevin, I'm sorry I did not ask you what type of work you were doing. Certainly agree with back fence for small cuts.

[Leo Graywacz]

If you are edging doors you can't do an outboard fence unless you are adjusting constantly. Unless I misunderstood what he was doing I thought he was edging doors, not making door frame parts.

[Kevin Cackler]

We experience the problem on the stiles as well, Leo. We started using an outboard fence last week and that indeed resolved the problem there. Our biggest issue is the edge profiles now. Last time we tried a one piece fence on our edge cutter, the fence was hitting the spindle nut when we moved it back far enough to get the proper cut. Now that I know that that will indeed help our situation, I'll have another look at it later this week.

[J.R. Rutter]

Do you have a dedicated shaper for the door edging? If so, one of my old SCM manuals suggested installing wooden fence plates, and then running the whole fence/hood assembly over the jointer. Obviously, any metal fasteners have to be blow the plane that gets jointed off...

[Martin Wasner]

Outboard fence, outboard fence, outboard fence.

For edging doors?

Otherwise, yeah. Outboard fence

[Martin Wasner]

You either need to have a bearing, a through fence under the cutter, or perfect fences. Even if they are perfect, you'll still roach some doors, it won't be dummy proof like the first two options.

If you've got a cutter for dimensioning, get something that just cuts the profile.

[Kevin Cackler]

Do you have a dedicated shaper for the door edging? If so, one of my old SCM manuals suggested installing wooden fence plates, and then running the whole fence/hood assembly over the jointer. Obviously, any metal fasteners have to be blow the plane that gets jointed off...

Yeah that was recommended earlier in this thread and definitely something that I want to try out this week.

[Leo Graywacz]

We experience the problem on the stiles as well, Leo. We started using an outboard fence last week and that indeed resolved the problem there. Our biggest issue is the edge profiles now. Last time we tried a one piece fence on our edge cutter, the fence was hitting the spindle nut when we moved it back far enough to get the proper cut. Now that I know that that will indeed help our situation, I'll have another look at it later this week.

Just grind out the back of the fence in the area of the nut until it's not a problem anymore. I had to do the same thing on my cope setup.

[Martin Wasner]

Just grind out the back of the fence in the area of the nut until it's not a problem anymore. I had to do the same thing on my cope setup.


I laminated Richlite over Baltic Birch plywood with epoxy and buried T nuts in the Baltic Birch with epoxy prior to lamination on both of my copers. That way the face is completely smooth but still adjustable. Richlite is awesome for things like that. You can sand and polish it until it is stupid smooth and slippery. It's fairly stable with temp changes too.

[Justin Ludwig]

Edging doors... I'll take a picture of my board/fence and my dedicated miter gauge with sacrificial board screwed to it. It's too confusing to explain.

[rudy de haas]

Something is causing your wood to pivot as soon as the end clears the infeed fence. To beat that I'd suggest first ensuring that the feeder pushes against the outfeed fence, not the infeed; and, if that doesn't suffice, clamp a guide to the edge of the shaper table on the outfeed side to prevent that end of the wood swinging away from the outfeed fence. It's dirty, but it works because it stops the pivot and doesn't get anywhere near the fence, the feeder, or the cutter.

[peter gagliardi]

It hasn't been determined what the root cause is yet. Have you checked planarity of both halves of the fence with a known precise straightedge?
If no, you need to.
If yes, and they are indeed straight, and you are butted into the cutterhead on each side as close as possible- hopefully with wood plates, and it still happens, it can only be one of two things.
1. Your outfeed fence is set back at a smaller diameter than your smallest cutting circle diameter.
2. Your feeder wheels are not in a good location linearly in relation to the fence opening.

Are you using a 3 or 4 wheel feeder, and how long are your parts?

I have metal fence plates, I run almost exclusively with the factory fence setup vs an outboard fence, and have done so for about 20 years.
Accurate setup is the key.

You can accurately dimension parts without a back fence, but you have to be diligent in setup and stock prep.
I mill my door parts about .015- .030 over width, and dimension to width with the split in and outfeed fences.

It is fundamental to good shaper results to have an accurate fence.
Without addressing the root cause, and skipping to a backfence, you are just kicking the can down the road so to speak.

[Joe Calhoon]

Accurate fence on shaper is a must if you want precise snipe free parts. Fence plates square to the table and coplaner with each other before offsetting. It’s like a jointer with the fence plates being the jointer bed.

We use the outboard fence a lot for window parts. Easy to get snipe free cuts on the Martin using the offset fence but you can get a slight wedge effect even with no snipe. To keep precision in slot and tenon work the outboard is best. For house doors with various width parts we sometimes use the split fence.

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For outside frame profiling that that might be similar to cabinet door edges we use a add on fence that is milled with a 1mm offset. (Our normal removal) This is a 8” diameter cutter and also serves to close the opening when taking the whole edge.

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If not removing the whole edge we bridge the cut with the Aigner fence. We have a add on for that when using our small diameter Freeborn cutters. This is also a good solution if you do not have a finger fence.
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The add on fences are are easy to attach with no screws and less than a 5 minute setup with all. We do not use dedicated shapers.

I second making wood plates coplaner by running across the jointer. We used to do that with a Italian shaper, works well.