Jigsaw
Would you mind sharing your measurements. I see you have a keggle as do I and I am not sure my numbers are correct.
Thanks

I dont know about any one else but these instructions really did my head in. Maybe its because im making a bag for a 70lt pot and also because I am pretty useless at maths. The bit that stumped me is trying to mark out an angle. Angles are pretty useless without the right tools. I tried using a triangle calculator on the net to give me the length of another side but I ended up needing about 8sq meters to mark it out on the floor.
LUCKILY for me I have a mother who can sew very well so I asked her to come around and help me. She asked what the base radius was {i made the radius smaller than the false bottom which is also smaller than the pot). She then made a circle with string and a pencil on pattern making fabric and cut it out. Then she drew a line about a meter long on a work bench and made almost a quarter circle with string and a pencil with the 1 meter radius. From the end of the quarter circle edge she measured back to the centre, the height of my pot (minus the false bottom). Then she took the circle she made first and folded it into quarters and then used the length of the outside round quarter edge to measure the inside curve of the large part circle she had marked out. Using this length to gives you a quarter of your bag wall. You then turn this into a half and then use the half to make full size on folded bag fabric.
I mmaaaayyy have got a few details wrong and obviously my mum was just wingin it from experience. She said she can alter it after to fit which you cant do unless you know how to sew. The end result hopefully will have double layers and nylon webbing for reinforcing ala BobBrews. It will also have double stiching called "french seems" oo la la .

If it works out then I reckon you guys are makin a mountain out of a mould hill.

If it doesnt work out then me and my mum are both stupid .

Ill post pics if and when its done.

Nosco,

That was the method the wife used on both my bigs, and they fit like a glove, perfect.

But then she is no stranger to dress making and sewing machines .

I guess the more complicated instructions are for us men, who don't have 20 years of dress making experience

I hope they work out for you

Ok its been a long time in the making but its finally finished

As it turns out I am dumb but luckily my mum isnt. Thanks mum. I would like to mention that she is turning 70 this month! and still going strong.

She used the method I explained before and in my first brew it worked like a charm. Nothing new except it has French seams which means there is no where for grains to get stuck. Not that it really makes any difference except tha I may be the only BIAB brewer in exsitance that has a bag with French seams I cant explain it so here are the pics.

Fantastic. Go Nosco's Mum .

Very nice, had to look up French seams

Very nice

I plugged your data in to the spreadsheet and got the same results onkeltuka.

I think your large angle is due to the shape of your kettle. Is it really sloped like that?
If you make the pot straight sided 54cm top & bottom, you will see your angle drop to 60ish degrees.

Probably too late now, but I would have just used the values you got.

Well at least you got what you needed in the end.

If you ever have to make another bag, or get another pot, just measure the diameter of the insides instead (Inner Diameter).