Machine straight stitch with regular zigzag stitches.

[MorriganManor]

I have just started to use an old Janome machine I inherited. It’s about 40 years old, but hardly used, kept in pristine condition, all parts oiled and working smoothly etc.
It’s making a stitch pattern in the shape in the attached diagram. Using ordinary cotton, Guterman thread. Tension set as required for straight stitch and I have also tried altering the tension slightly.
Bobbin wound correctly. Machine threaded up properly. Needle changed for a new one (again, pristine condition, kept in case, never used).
I’m not dragging the material through, or going too fast.
What could be going wrong?

Buy some new needles, if they're 40 years old, they'll be blunt.

Image here

Thanks @PrincessofWells , is that the problem then? Blunt needle? I don’t mind buying new, I just thought they felt sharp enough and I know the spares weren’t used. I can see the mechanism moving to the side to make the pattern.

It looks like a regular pattern. Maybe it’s been left at that setting?

I know you say straight but I wonder if the machine is lying? I don’t think a blunt needle would caused this?

I know, it confused me! It’s not a pattern in the instruction book though and I’ve moved all the dials away from straight stitch and back again, so that bit is absolutely correct.

It’s probably going to be something really obvious in the end. Some quirk of the Janome At Home model

Good heavens does noone sew anymore? Nothing wrong with your machine. It is simply set on "hem stitch" instead of "straight stitch". I don't have a Janome machine but the stitch selector is probably on top somewhere and needs to be switched to straight stitches-- if it is an analogous machine. If it is a digital then you will need the manual.

You probably can Google a manual/ guide for this specific machine, no matter what age it is. I recommend you read it thoroughly because sewing machines require being handled with care and know how so not to mess them up.

HTH Good luck ! ;)

Also , you will dull your machine needle in no time if you sew on paper with it!

Good heavens does noone sew anymore?
Well, no, @Whataretalkingabout , but I’m trying my best to put that right!
I do a lot of knitting, hand dyeing, crocheting and used to do a lot of cross stitch and hand embroidery. Learned to hand sew at school, made my own clothes as a teenager but very out of practice (and that was on an old workhorse of a Singer that practically took your hand and walked you through it). So I know crafting takes patience and time investment to gain the skills.
I’m 99.9% sure the settings are straight stitch. It’s not a digital machine and I have the original manual.

The diagram is drawn on paper, I didn’t sew it.

Hope you get it sorted. I’m not great at sewing and most just sew guide badges and turn up trousers. But I followed a simplicity pattern and made an apron for DC2 this weekend. It was a lot of fun and she now has an apron with lots of pockets, in a fabric she loves and the correct size.

Do you have a picture of the dials?

If the zigzag is happening at regular intervals I’d guess it’s the machine and not the tension/blunt needle/dodgy thread/ any other reason for skipped stitches. (Though how old is the thread?).

Is there a switch to change your dial from regular to stretch stitches?

Oh, I am sorry OP . I hope I didn't offend you. Of course you must be a fantastic crafter to even try this !

Have you tried stitching each of the different settings on scrap fabric?
Be sure and set your width selector on straight and not a variation of wide.

And yes, as pp said take a photo of your machine and all of its settings so we can take a look. ;)

That's a blind hem stitch. You've just got the machine set to the wrong stitch.

Yep I have this hem stitch on my Janome!

That's definitely not a fault with tension/needles/thread/whatever.

I wonder if the dials are set incorrectly so that what you think is the straight setting isn't. Does it have knobs that pull off or anything like that which might have messed with how th esettings look?

Post a photo of the machine @MorriganManor and we can probably tell you what to change to get straight stitch.

I agree that it’s a regular stitch shape. But with the machine having sat for so long I would start with new thread and a new needle. Also, does it need oiling? If it’s sat for so long a service or oiling would Laos be wise. Good luck OP.

Does it have pattern settings or cams?

Thanks everyone, you’re being very helpful! It’s not appearing like a tension problem etc, it is a definite Stitch and blind hem looks like the one.
These are the settings, dials not loose and won’t come off if I tug. It’s genuinely not been used enough for that sort of wear and tear. But blind hem fits, as probably used for simple curtains.
Here are the dials as set.

And the corresponding instructions in the booklet, which covers several models including this 1508 one.

All new thread used too.

Maybe the A has actually stuck on B. Has it been serviced?

What does it do if you set it to the blind hem stitch?