I hate to say it, @Bill , but I think you may be expecting too much of a modern domestic machine to go through all that lot. 
Has a longer stitch length helped? 
Can you do the construction in any different order to avoid so many layers?
If any of the layers are lining, can you use a thinner fabric for those?

Funnily enough, I was thinking of how to do that today. The instructions say to clip the seams to reduce bulk and I wasn't sure how to do that but I have an idea. I haven't tried a longer stitch yet but I will.

What fabric are you trying to sew, @Bill ?  And what type of needle?  If it's a heavy outdoors-y type fabric, it may just be that the machine won't cope with it.  Another thought is, if it's quite thick, have you tried a longer stitch length?  Sorry, I can't remember if that's already been mentioned.

The first 2 wallets were done using a medium (I think) weight cotton. Going from 1 then 2, then, then 3 and then 4 layers. Then it was all doubled over.
Here's a pic with a manly, butch Yorkie bar for comparison.

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Used a schmetz 80 needle to start with. That didn't work too well. Then I found my last remaining janome blue tip needle...which after some sewing...got royally destroyed into 3 or 4 pieces. No idea what happened there. Anyhoo, skipped stitches seemed to disappear using that. Then I tried an 80 organ needle to do the remaining bits and last 2 wallets. Which I cocked up.
I get the impression my atelier doesn't like schmetz needles. I think I posted something along those lines not long after I got it.
 My shiny new Janome needles arrived today along with the new needle threader which caused a great deal of swearing and huffing and puffing to fit.
I'll see what happens when I attempt wallet no.4.


@Iminei the magic black button! Discovered that when I got the machine. I'd had a foot like it when I had the brother machines only the button was on the left of the foot. Why janome put it on the right is a mystery to me. Anyhoo, the fabric was slipping out from under it when I tried.

Thankyou very much everyone for your suggestions. You really are the best 

Howdy doody @Ploshkin
It isn't a pivot as such on the feet but a bit of play. Every machine I've had has had that. It allows the feet to run flat on slightly uneven surfaces.  Never had a Pfaff though. I know they're built to high standards but no play at all? 

Moving the needle to the right is what started all this skipping malarky off. It has to move 4.5mm due to its 9mm stitch width for a 1/4" seam. Maybe 4.5mm is pushing the limits a bit too far.
I'll give the folded card thing a go though in a couple hours or so.

This thing came with the atelier I think. Too thick though.
One thing I've noticed is that the skipping stitches problem is worse when the foot isn't level when edge stitching whilst going through increasingly thick layers like a staircase.. The right side sits lower than the left if you get me.

Forgot the pic.....

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Hello and welcome @Annedonnelly
I'm vantage from cyclechat 

I've done binding on my last couple mugrugs. They're...tricky. It's when joining the ends that causes the problems for me coz I have to undo almost two sides to get enough fabric free to sew it then try to reattach it to the rug.
Struggling with a lack of imagination this season...again. 

Again! 
I've a new phone and as usual, my Google password rememberer thingybob has my old password which doesn't work.
Can the powers that be send me a magic key to log in pwitty pweeze wiv sugar on top?