Does anyone on here sew piped cushions with concealed zippers?

[Rheeso]

I'm losing the will to live. I've watched youtube videos & still I can't get it right. I've made my covered piping cord, so far so good. And I pin it in place & sew using a piping foot on the machine. No matter how hard I try with needle positons, the cord gets pulled a bit leaving an ugly gap on the right side of the fabric. I'm about to unpick my 3rd attempt & the fabric is getting damaged now. Short of laboriously hand-tacking the piping in place to force it to stay put I don't know what to do. If I move the needle any closer it catches the cord itself. I wish I could whizz around the piping like the people on youtube do.

Next issue is the zip. Even with my needle hard to the left, the zip teeth sitting exactly against the piping, a gap shows on the right side of the fabric. I'm beginning to think the only way to make a decent cushion is to hand sew the whole fucking thing. An hour's job is taking me days.

Can you bit the bullet and put the zip halfway down the 'back' side of the cushion then there's less bulk to worry about all in one go? I know that's not quite the look you were going for but you can still do a great smooth finish. Maybe try 25/75 split so it's less noticeable?

I did think about that but I want the cushions to be reversible, so when the dc gunk up one side I can turn it round

I don't really understand where the gap you're talking about is. If it's a tiny bit of zip that's visible next to the piping, I think that's supposed to be there. The idea is that the piping is big enough to cover this up. Have you tried putting the cushion in and seeing how it looks? The only other way would be to put the zip as though adding it halfway down (but could be close to the top).

If it's some other gap, some things You could try:
You could try sewing the cord into the piping(by machine) before sewing the cushion and piping together.
You could try a regular foot which would sit on top of the piping keeping it in place.
You could try not pinning.
You could try sewing with smaller cord/string and then pulling through the actual cord after sewing.
Does it actually show if the cord gets caught?

I've attached a pic as that's easier. My piping cord is made in advance & then I'm trying to attach it to the cushion face. If you look at the picture, you can see the original piping stitching shows on the face of the cushion because I can't get the needle close enough. It seems close enough when I'm on the machine but it comes out crap. I'm using a Bernina, with piping foot & needle hard over to the left. I might try the suggestion of a regular foot next but I'm going to have to tack the whole thing tightly on this attempt to hold it exactly perfect. I don't understand how other people do this so easily.

You sewed the piping too tight. You can't get as close to the cord through 4+ layers as you can through 2, no matter how good you are. If you leave an extra couple of mm (really not much though) when doing the piping (so the cord is a little loose in the piping) you can get much closer when sewing it in because there's more slack to work with. Which means your cushion seam is closer to The cord than the piping seam. The bottom of the machine is flat so where you think you're dealing with a lollipop shape, you're actually dealing with a p shape, and what you want is a teardrop shape that you force into a p shape. And gently pull the fabric towards the needle(sideways) with the piping foot to take advantage of any stretch, then the needle needn't be so far over that it catches the cord. If you sew it by hand you can work with the lollipop shape.

I don't know if that made sense, would be easier with a diagram but I can't upload one at the moment. Maybe someone else will be along. But basically I think you'd be fine with looser piping.

If you're going to redo as is, only unpick where you've caught the piping, less damage to the fabric and you have a guide that you need to be closer than. Or unpick the piping seam not the cushion seam, it might look flabby but it might look okay.

Ahhh brilliant, @XrayFish I never thought of it like that with the piping tube a little loose. Makes a lot of sense. Many thanks!

Here is what I can recommend doing.
Begin by cutting fabric squares for your cushions. I'm using lovely cotton from Thailand, but the weave is a little loose, so I serged the edges. Finishing the edges isn't essential if your fabric doesn't ravel a much because they'll be buried within the pillow. Cutting the cloth 1-2 inches smaller than the size of your pillow form is a good idea. This will make your cushion appear stuffed rather than deflated.
Sew piping all the way around one square's edges. An excellent solution is to use a serger, then your stitches from the inside will be more even. You can find a good one here. Because this is simply a pillow, the seam allowance doesn't have to be precise, so I just line the piping up with the fabric's edge. To get your needle as near to the piping as possible, use your zipper foot. I used ready-made piping on this example, but I stitched my own piping on the majority of the pillows. Because this piping isn't easing around any bends, it doesn't need to be cut on the bias, so cutting strips of fabric 1′′ to 1 1/2′′ wide and folding them in half with a piece of cording along the center is all it takes to construct your own.
Bring each corner in slightly. As you can see, the flat doesn't make a perfect square to pull the corners in a bit, but when you place the pillow form into the final pillow cover, it will make your pillow seem square rather than having corners that protrude out like ears.
Allow the piping to slightly curve from the seam line to the edge of the cloth when you start and stop it so that you have an overlap for a barely noticeable connection. Allow the cloth to loosen on the piping at the corners by snipping it.
Use an invisible zipper the length of one of your pillow's sides. Sew the zipper to one side of the cushion with the right sides facing each other.
I normally do a first pass that only anchors the zipper in place and then a second pass that is near to the invisible zipper when I sew down the zipper. (I realize this isn't the most beautiful technique to install an invisible zip, but it's quick and straightforward, and it works just fine on a project like the bottom of a cushion, where it's concealed by piping.)
Sew the other square of cloth right sides together with the opposite side of the invisible zipper.
Place the squares on top of each other, right sides together, and stitch them together. To stitch right up to the piping, you'll need to use your zipper foot. Sew around the curve and down the side a half inch or so when you arrive to the start and stop of the zipper (seen on the right side of this photo).
Insert a pillow form into the right side of the pillow case.