Adjustable coiled tube straightening tool

[thehomeengineer]

Adjustable coiled tube straightening tool

Hi All

I am making a copper boiler for a 3" scale Foden steam engine and need to straighten approximately 44-foot of 3/8 coiled copper tube to make 63, 9" long fire tubes. I have purchased 2 x 25-foot coils of 20-gauge tube.
So, after a little research and viewing both commercially and homemade designs I came up with this which seems to work very well and is adjustable for other diameter tubes. I purchased the bobbins from eBay for a pound a piece which included the bearing and made the shafts and main body of the tool.

It works very simply, to set the bobbins you get a straight bar the same diameter as the tube to be un-coiled and straightened, adjust the bobbins to contact this bar so it can move smoothly between all six bobbins. Then roll the coiled tube between the bobbins. I went backwards and forwards a few times on the piece shown in the photo, as it was very bent before I started. Therefore, after this quick test it seems to work OK

Many thanks again for taking the time to view this post.