A well intention and experienced guy taught me what he knows. Problem is, his information contradicts what I read online. For example he runs the cutters as high on the spindle as possible, doesn't understand why I would want to use a back fence to size my door sticks and we have a different idea of quality.

I'm currently having a few main problems/questions,
1. How should the power feeder be set up? It's a 4 wheel, Should two wheels be in front of the cutter and 2 behind slightly angled toward the fence? This is the way its currently set up.
2. Chatter when using certain cutters. I'm getting a lot of chatter when using a freeborn 6 piece cutter set or a shaker door set. But if I'm running a simple rabbet or round over on drawer parts no chatter.
3. When making doors the left and right stiles always want to bow up at an angle. It's not a clamp pressure issue that is just the natural angle it wants to sit at. Could this be caused by an out of align spindle or possibly the coping sled isn't perpendicular to the spindle?

It's frustrating because the chatter is significant no matter what speed i feed it at. Any advise would be appreciated.

Cutter should be as low on the spindle as possible. The higher up it is the more run out is possible. Just simple geometry.

I always try to have 1 wheel on the feeder about the center of the cutterhead, but mine is a smaller 3 wheel.

Not sure what a back fence is. I have mine setup like a jointer with the feeder slightly angled towards it to keep it in contact. I still press the stock against the fence to assure it doesn't wander.

To make cabinet doors that meet my level of satisfaction requires a lot of work. The trade off is I never have failures. Most would scoff but, here goes.

I purchase material 15/16" hit and miss planed. Cross cut 1" over length for stiles. Rip thru a straight line saw 2 1/2" wide. Depending on board width and style length it might get ripped twice to insure it's as straight as it can be. I joint one face and plane to .82 thickness. This insures the part is not twisted. Using an out board fence on the shaper I run stick (Freeborn Tooling) Rails are coped before sticking. If there is any tear out or grain fuzzing I can re-run the part changing the width. The outboard fence allows for part width and making it as straight as can be. It also allows for shorter rails to be run thru with the power feeder. It's as perfect as I can make. I re-cut the parts to 60mm wide. This cuts off any tear out the cope cutter left. You could set the out board fence on the shaper to cut final dimension. I chose not to.

After door assembly there is still 3mm to trim off all the way around the door to get to final size. I build an european cabinet and expect my doors to be exact. I never have out of square doors, wrong size nor ones that are twisted.

As for your four wheeled feeder, mine has a gap in the center so I set two wheels in board and two wheels out board. If your cutters are new or have been sharpened (I send mine to Freeborn) by a reputable shop I don't know how you would get stiles bowed at an angle. As for chatter, lube the table. I run blue wheels from Western Roller on the feeder. These grip the best. The ones that came with your feeder are junk. My guess is your chatter is caused by the feeder and/or the table.

Leo, I meant outboard fence, i call it a back fence

Bruce H, I think you are on to something with the feeder it is a maggi power feed and i'm sure its about 15 years old with the same wheels. How much did those blue wheels cost? I use glide coat on the table before every batch of doors. I'm concerned that my bowing is caused by an out of alignment spindle because the groove and tennon are not a snug fit, I have to shim the cope cutter set. Thank you for taking me through your process there is defiantly things i will incorporate there. Over-sizing the doors is a great idea because we too build frameless cabinets and like our revel a perfect 1/8"

I prefer to use an outboard fence(1/2" x 3" hardwood with a jointed waxed edge) when running door parts. It works much better with the shorter rails. The parts are fully supported the entire time they are in contact with the cutter. I typically straddle the spindle with 4 wheel. I put 2 wheels in front 1 wheel behind the spindle with a 3 wheel.
Definitely, keep the cutters as low as possible on the spindle. Based upon that one piece of misinformation from your "teacher", I would not put my trust in that person's opinions.

The first time out you have to buy the aluminum hub and the tire. After that you can replace just the tire. Mine came from Barbo Machinery, Portland, Oregon. Don't remember the cost.

I have my shaper set up so that I can change between cope and stick profiles without changing the spindle height or the fence. I can cope on the same machine without making set up changes. Using Freeborn bits, when making glass rebate doors by swapping the cutters, I put a washer under the cutters to raise them up making the profile slightly thicker. This is because you don't use the center groove cutter. My outboard fence is indexed from the out feed side of the split fence using a wood spacer. Makes changing style/rail widths easy and repeatable without having to guess or do a test piece.

Chattering is a definite problem that you will have to solve before everything else. Start with sharp cutters. I have a three wheel feeder. I the the wheels set for 1/8" below stock thickness. With a back fence I climb cut. The cutters drive the stock against the fence. Using the split fence I mostly conventional cut which also drives the stock towards the fence. I toe in the feeder very little. Too much can turn the stock away from the fence at the end of the cut.
Are you getting chatter with the coping sled or feeder? Check for bearing runout. If you have a dial indicator you can zero on the spindle and push the spindle firmly to check for deflection. Also check the spindle nut is tight. The former owner of my shaper claimed the bearings were shot but it was only a loose spindle nut. Does your sled sit flat on the table? Press on opposite corners to see if it is twisted.
Check for spindle runout. Manually spin the spindle with a dial indicator against it.
You can check the squareness of the spindle to the table with a coat hanger wire bent into an a 6" x 2" L pinched under the spindle nut point one leg of the wire down and sweep 360°. The spindle is square if the wire just touches the table all around.

You have a spindle out of tram causing rail to stile joint to be out of whack. Or, if using stacked tooling, something has been sharpened out of whack.

It takes a pretty robust shaper to handle tooling far from the bearings. He's just wrong. Now that we know that, we can just dismiss anything else he said until properly verified.

Chatter is likely a feed issue

Having the cutter at the top of the spindle could be causing what looks like chatter.

Do not attempt climb cutting on shapers, unless you have a vast amount of experience. It is not a router. Climb cutting is not necessary. I’ve had to do twice in 30 years on bad materials.

Chatter is frequently caused by not tightening all of the adjustments on the power feed. It will have a very slight bounce if they aren’t tight. Very easy to forget to tighten all of them. Rollers should rise 1/8-1/4 depending on your feeder design.

Be safe. Shapers should be taught. It’s not a forgiving machine.

With a proper setup, climb cutting isn't an issue. With less than desirable tooling, far too infrequent sharpenings, and shaper, I used to run almost everything in a climb cut.

Better machines, better tooling, and a better setup, a power cut will give better results most of the time

Chatter could be easily from the lash in the cheap drivetrain in the power feeder. Going to a power cut would help that as well.

Having to shim the cutters does not necessarily indicate a spindle problem. The stiles clamping out of plane could be from that though, so check by tramming as Thomas said, and check if your coping sled surface is parallel to the table. If those check out the problem is in the cutter set which may need replacement. You can measure the offset between the top and bottom shoulders on the cope and stick cutters with a dial indicator or have your sharpening service check it for you.

The chatter could be spindle runout or bad bearings but more likely a feed issue. If the feeder wheels are stiff and slippery replace them with yellow polyurethane from Western Roller or the like. If you are using a back fence and removing material from the full edge climb cutting should be unnecessary. It is harder on the tooling as the chips don't exit as easily.

If you are not removing the entire edge that could be causing the clamping issue.

"If you are not removing the entire edge that could be causing the clamping issue."

I hadn't thought of that. Totally possible. I was assuming a full pass

I'm not sure about Freeborn, but DIT insert tooling: the engineer there specifically said don't climb cut with their tooling. I get almost perfect results sticking on a power cut as Karl suggests and taking 1/16-1/8" from the rail width when profiling - every now and then I get chip out on a hard maple squirrely-grained piece and I just cull that to the woodstove.

I know its been a while but a quick update.
-I was able to solve the clamping problem by running the sticking face down and the copes face up. I don't know why this works but it does.

Chatter is still a problem and hand sanding is always needed. I bought brand new t alloy shaker cutters from freeborn this week and got chatter right out the gate. So I'm ordering wheels from western roller.

I wouldn't be surprised if the spindle is out of whack. the .25 center groover cuts a .264 groove. The guys at the shop tighten the spindle nut by using the fence as leverage... as you can imagine this causes a great amount of lateral force on the spindle.

I'll report back once i replace the wheels and let you know how it goes. thanks for all the help.