shaper questions - offset fence

[David Zaret]

we recently upgraded shapers, and i'm having a few issues that i'm hoping the hive mind can assist with.

this is a Martin T12 with the digital aigner offset fence - i've used this offset fence on other shapers for years, it's not a new piece of equipment. what i'm finding now is that when i'm running sticking cuts, with the feeder toed out towards the offset fence, I'm getting a strange divot in the part a few inches back from the start - it appears to be catching one of the feeder wheels and somehow kicking towards to the cutter, away from the offset fence, 1/4" or so, causing a concave divot in the edge. the piece appears to be shoved against the outfeed fence, there's nothing obvious going on (though obviously there is). the cutter is a Zuani cope/stick set.

my gut feel is that it's an issue with the feeder alignment, but it looks ... ok to me, and attempts to tweak it don't seem to help.

so, with this as the backdrop, i have two questions:

1) how much toe-out should i be using with this feeder - let's say, with the feeder ends relative to the parallel offset fence, is 1/4" too much? not enough?

2) how much downward pressure should i be using with this feeder? the feeder on the Martin has a height gauge in mm, and i have it pushing .... a few mm or so.

3) i would like to add pressure boards to the infeed and outfeed fences, but with the Martin it's not clear how to do so - we have the aigner fences on (and backed off the cut, obviously). should i look at attaching something to the infeed edge of the table? does anyone use pressure fingers, aiming out towards an offset fence, with the aigner fences?

thanks for any guidance.

--- dz

[brent stanley]

By offset fence, do you mean outboard fence?

Does the timing of the divot coincide with when the end of the piece meets a feeder wheel? Perhaps the last wheel is sagging down a bit or is misshapen and causes momentary resistance that results in the piece kicking out momentarily.

[Patrick Walsh]

Sounds to me like you have it set up as usual like a shaper to take a bit off the stick. So outfeed is set a whisper behind knife and infeed set a bit back from that.

I know at least for me when I’m struggling with sticking and cut quality and my fences are setup right it always the feeder not toed in correctly and or applying enough and or to much pressure.

I assume you checked to make sure everything on the new machine is flat. Also just not having a fresh perfectly jointed edge can cause issues or a slightest splinter on the leading edge.

Once you get it lied though it should be mindless..

[Joe Calhoon]

Dave,
Snipe at front of workpiece indicates entire fence needs to move back a bit. But you are saying the snipe is after it starts and the leading edge has no snipe?
Check all the basics first- With a straight edge check that the fence plates are coplaner when digital display is on 0. If not set fences correct and recalibrate the zero. Check that fence is calibrated to center of spindle. Cutter you are using is 130mm cutting circle so fence zero will be 65mm or 0 if you have programmed the cutter. T12 has a fence that is accurate to 100th mm and if getting snipe at either end you might have to move it just slightly to get no snipe. For example instead of 65mm might be 64.96 or something like that if fence needs to move back a hair.

But if you are getting snipe after it starts and hits the outfeed fence it could be the feeder.
First make sure feed wheels are flat across their width to the table. When you lower the feeder to the table the outfeed wheels should touch first by about 2mm or so. In other words the feeder is not exactly parallel to the cast table. For feeder height in relation to the workpiece usually 3 to 6mm - workpiece thickness is best. I set the readout on the Wegoma feeder so I just have to set it to workpiece thickness. Too much pressure can cause problems.

Toe in to the fence can be 5 to 8mm. This is pretty forgiving and some people go more. I normally center the feeder wheels on the shaft. 2 wheels feeding in and 2 outfeed.

I have set up a few Wegoma feeders with the smart stand and have found a few things. Sometimes they are not as tight as they should be when locked and will move. There are some adjustments for this. When you have it locked in place grab it and see if any movement. If so I will take some pictures when back in the shop to show the adjustments.
also if you are using the split wheels on the 2 center wheels they sometimes are slightly different diameter than the stock wheels on the ends. Don’t remember if Martin sends the split wheels on all four wheels.

let me know if any of this works.
Joe

[brent stanley]

It sounds to me like your outfeed roller is causing you some headache. Check too that the rollers are parallel to the table left to right and only a little toe down along the length of at all. The amount of toe-out (or in depending) is pretty forgiving but is usually somewhere around a few degrees. Your 1/4" should be just fine. I don't usually compress the wheels more than 5mm. I have a fence similar to the Aigner but use featherboards to help if needed. Some shop made narrow ones or magnetic if there's room. Aigner probably has a nifty Gizmo for this purpose that attaches to the main fence.

[Matt Tebo]

Dave,

If I understand you correctly, I think you’re using an outboard fence, not the factory fence with the aigner fence plates. It seems like you’re having an issue with the board pulling into the cutterhead and away from the out outboard fence.

If that’s the case, I am imagining you have the aigner centrex guard too. I can’t remember exactly if the plastic pressure fingers come with that guard or are aftermarket, but Joe would know for sure. This plastic device provides a light pressure against the outboard fence keeping what you describe from happening.

I don’t have the centrex guard but I have had great results with my homemade outboard fence and the mag switch feather boards. They work great and are 100% universal for all machines.

I hope I’ve understood your issue correctly.

Matt

[Joe Calhoon]

Matt, I think you are right. After re reading I think Dave is talking about the Aigner outboard fence. They call it a Thickness Stop.

I find when doing thicker workpieces 1 3/4” door parts and thicker you need spring pressure against the outboard fence. Otherwise the cutter wants to suck the piece in towards the start of the cut. Cabinet door parts you can get away without this pressure.
here is a video showing the Aigner pressure jaws putting pressure towards the outboard fence.

,https://youtu.be/usa_YmhWTpE

You can also use the infeed fence to keep pressure against the outboard fence. For this your fence and outboard fence need to be parallel and the S4S of parts accurate and consistent.

here is a Instagram link showing inside and outside profiling on the T12 with the outboard fence used for inside profiling.
https://www.instagram.com/p/B4pMVj7g...d=ookfa2y08ey8

swipe right to see all the pictures

[brent stanley]

Dave,

If I understand you correctly, I think you’re using an outboard fence, not the factory fence with the aigner fence plates. It seems like you’re having an issue with the board pulling into the cutterhead and away from the out outboard fence.

I
Matt

That's what I understood.

[David Zaret]

guys, sorry for the delay. first of all, yes, it's the aigner digital adjustable outboard fence - here's a link to a picture of my rather simple setup:

aigner outboard fence

the feeder has split wheels on all four, and joe, they are pretty much dead nuts flat to the table:

feeder wheels

the stock is definitely straight, S4S, and the fence edge is ... perfect. it has to be something with the feeder. i'm going to go back and study your responses, see if anything jumps out. thanks again.

-- dz

[Joe Calhoon]

Dave,
outboard setup is pretty simple and eliminates all the nuances of the split fence. Although with the accuracy of the T12 fence split fence setups are no problem.

I think pressure against the fence is good for the thicker parts. If you don’t have the setup for this you can turn the feeder more toward the outboard fence. Like 1/2” or more overall. Some shops do this instead of side pressure and seem to have luck with it. Will wear the wheels faster though.

[brent stanley]

guys, sorry for the delay. first of all, yes, it's the aigner digital adjustable outboard fence - here's a link to a picture of my rather simple setup:

aigner outboard fence

the feeder has split wheels on all four, and joe, they are pretty much dead nuts flat to the table:

feeder wheels

the stock is definitely straight, S4S, and the fence edge is ... perfect. it has to be something with the feeder. i'm going to go back and study your responses, see if anything jumps out. thanks again.

-- dz

That's exactly the settup I was picturing from your post, and it looks like there's plenty of material for the stock feeder to grab on to. Feather boards or similar pushing against the outboard fence wouldn't hurt of course but I've never needed it for wide stock the feeder can get a full purchase on with a lighter cut. I would check to see if the divot happens when the stock is just hitting the last wheel.

[Patrick Walsh]

Forgive me for interrupting or just tell me to go away “really” I get it.

But how do you setup a outboards fence for sticking. Like in the case of shaker style freeborn set that puts 3/8 groove in the material.

As I understand the outboard fence the material runs against this as apposed to the split fence. The split fence had a pressure bar that applies pressure back at the outboard fence.

So do you just move your split fence way back and inboard fence forward till the cutters at putting that 3/8 rebate in your workpiece.

This technique was explained to me by the seller of my t75 but he did it with a home made deal with a spring that put back pressure on everything and climb cut.

I’d like to get comfortable working with a back fence for sticking I suppose if for no other reason than another option. Normally I have zero issue doing stick cuts with a split fence setup to take a 32nd or so and the powerfeeder.

[brent stanley]

Forgive me for interrupting or just tell me to go away “really” I get it.

But how do you setup a outboards fence for sticking. Like in the case of shaker style freeborn set that puts 3/8 groove in the material.

As I understand the outboard fence the material runs against this as apposed to the split fence. The split fence had a pressure bar that applies pressure back at the outboard fence.

So do you just move your split fence way back and inboard fence forward till the cutters at putting that 3/8 rebate in your workpiece.

This technique was explained to me by the seller of my t75 but he did it with a home made deal with a spring that put back pressure on everything and climb cut.

I’d like to get comfortable working with a back fence for sticking I suppose if for no other reason than another option. Normally I have zero issue doing stick cuts with a split fence setup to take a 32nd or so and the powerfeeder.

You've got the gist of it! There are always multiple ways to skin a cat, and the additional pressure against the outboard fence can happen in a number of different ways, but pressure against it usually cant hurt. No need to move the split fence any further back than necessary especially if it's required for guarding and dust collection.

It's quite quick to set up especially with templates for the various cutter/sticking width combinations that you can use to make sure the outboard is set at the right offset.

[David Zaret]

i think i know what's happening. i think that the board is hitting the split in the last (or perhaps third) feeder wheel, and due to the "lift" from the first few, the edge of the split is kicking the board temporarily towards the cutter before the material gets under the wheel. so, a few things:

1) i like those aigner plastic fingers - where and how do they mount to the fence? the video doesn't really show that.
2) i'll try backing off the feeder so only the "front half" of the split wheels contacts the material
3) joe - how do you mount the aigner outboard unit to the machine? do you have an aigner mounting bar in-between the two posts for the big outfeed extension?

thanks again guys.

--- dz

[David Zaret]

patrick - for what it's worth, and despite my recent issues, i would never go back to doing sticking cuts against the fence. this method effectively ensures there's no snipe, and, you only have to S3S the stock - the cut edge is removed entirely, and can be... rough. sticking is a breeze with an outboard fence.

that is, of course, unless your split feeder wheels (and your lack of experience) kick the stock back towards the cutter, causing a nice dip in your perfect cut.

--- dz

Forgive me for interrupting or just tell me to go away “really” I get it.

But how do you setup a outboards fence for sticking. Like in the case of shaker style freeborn set that puts 3/8 groove in the material.

As I understand the outboard fence the material runs against this as apposed to the split fence. The split fence had a pressure bar that applies pressure back at the outboard fence.

So do you just move your split fence way back and inboard fence forward till the cutters at putting that 3/8 rebate in your workpiece.

This technique was explained to me by the seller of my t75 but he did it with a home made deal with a spring that put back pressure on everything and climb cut.

I’d like to get comfortable working with a back fence for sticking I suppose if for no other reason than another option. Normally I have zero issue doing stick cuts with a split fence setup to take a 32nd or so and the powerfeeder.