Guys, thank you so much for the info, it will all help in my journey into the sewing world! Going through the points raised above, I found my issue...

My bobbin wasn't threaded correctly. In the manual, all the pictures are hand drawn and it wasn't clear. I didn't have the thread exiting in the centre of the tension plate, it was to the side under the little hook on the side of the plate. Which is how it looked in the picture.This worked fine for normal fabrics so I assumed it was OK. The tension still needs setting up but at least I've found it to be consistent. I will compare the tensions like you said dream4est, having a cat that wants to climb the Christmas tree means I can't devote ALL my attention to the machine!

I checked the routing was smooth, as far as I could see it is. I will strip down the tension plates and give them a proper clean out.
My needle is brand new, but I will change it for a new one just to be sure, who knows, I may have bent it slightly!

I've ordered two colours of a different brand thread too.

One question, speed shouldn't be an issue should it? I need to put a wedge under the pedal as its too easy to go max chat all the time, I need to be able to go slow!

Thanks again, I will follow up when I have done some more playing.

Thanks, I like the zig zag tip, will try that tonight. I have ordered some more colours so that will help too!

Hi all, this is my first post here.
Been reading all the threads for the past few months and that's prompted me to dig out the sewing machine and have a go!

I have a Frister + Rossmann Cub 5 Super Stitch which is a sturdy beast. With a 100 needle, it'll pierce through anything! I'm using Coats Epic 80 thread and P5 PU Coated Nylons with P18 Heavyweight P.U. coated texturised nylon from Pennine Outdoor. Just some cheap fabrics to practice on. Hopefully they are close enough to VX21 and proper Cordura 500.

I'm stitching the thin P5 to the heavier P18, the thin P5 is on the top. Stitch length is about 2mm. I presume the lower thread tension is correct. If I jerk the thread, the bobbin falls about an inch to inch and a half...

My issue is, the upper tension seems to be too loose. The lower thread doesn't pull up into the layers which leaves the lower thread looking loose. I can increase the upper tension and all looks good for a while. Then balance between the upper and lower stitches becomes inconsistent.

I will post some pics tonight but I'm using the same colour thread for both so it isnt easy to see!

Any tips from you gurus will be much appreciated!

Thanks