Making a Bucket, Mathematical Help Needed!

[Ray Von]

For reasons best known to my self, I wish to convert an ordinary plastic shot glass into something resembling a wooden bucket, IE: made from several sections of timber.

 

I will be using ordinary thin card (teabag box / cereal packet thickness.)

 

My plan falls down at this early stage, I need to identify some means of cutting the card into strips that match the shape of the bucket precisely (just cutting strips with parallel sides would produce slats that cross over and not marry up neatly.)

 

I'm sure there must be some kind of mathematical formula out there that will solve this little problem, probably involving pi squared? 

 

Here is a pic of the subject, plus some rudimentary dimensions / concept sketch of finished piece:

 

Many thanks in advance!

 

[rab]

Circumference = diameter x 22/7.

 

As this is the same for top and bottom,

the width of the strips at the base

will be 3/4 of the width at the top.

 

Hope this helps.

[bécasse]

The circumference of a circle is π x the diameter. Therefore the circumferences of both the top (notional) and bottom (actual) of a bucket will be proportional to their diameters, in this case 40 cm and 30 cm, so the top of each strip needs to be 1/3 wider (4/3 - 3/3) than its base, the extra width being split equally between left and right.

 

The circumference of the base of the bucket is approximately 94,5 cm (including a small allowance for the thickness of the card). It is up to you how wide you make each strip at the base but convenient widths would be 10,5 cm (requiring 9 strips) or 5,25 cm (requiring 18 strips). In the first case the extra width at the top would be 3,5 cm (split 1,75 cm either side) , in the second 1,75 cm (split 0,83 cm either side).

 

There are some approximations in this calculation which will be more apparent with the wider strips than the narrower ones, so the strips should be cut slightly over length and finally trimmed once they are all fitted, and it is probably wise to cut the final strip marginally wide, trimming it to fit as necessary.

[Ray Von]

Omitted to say that I'm working in millimetres, but I think that I can convert easily! Thank you.

[bécasse]

11 minutes ago, Ray Von said:

Omitted to say that I'm working in millimetres, but I think that I can convert easily! Thank you.

I have been through my post changing the dimensions to millimetres - and I would at least start with the wider (14 mm at the top, 10,5 mm at the bottom) strips. Incidentally, you will save yourself a lot of marking out and cutting if, in the flat prior to cutting them out, you lay the strips out alternate ways up.

[kevinlms]

In MRJ No. 98 there is an article by a Graham Rayner on making galvanised iron buckets & baths.

 

He uses sharpened pencils as a former.

[Ray Von]

22 hours ago, bécasse said:

I have been through my post changing the dimensions to millimetres - and I would at least start with the wider (14 mm at the top, 10,5 mm at the bottom) strips. Incidentally, you will save yourself a lot of marking out and cutting if, in the flat prior to cutting them out, you lay the strips out alternate ways up.

Cheers everyone! Here's a rather rough "trial run" :

 

This proves the theory is sound, not sure if I fully understand it though(!)