5 Attachment(s)
Adjustable coiled tube straightening tool
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.
Attachment 21381Attachment 21382Attachment 21383Attachment 21384Attachment 21385
3 Attachment(s)
Up date on on coil straightening jig
Hi All
I have finally got around to using the coil straightening jig I made, it must be a few years back now.
The coil was initially uncoiled by hand for roughly 3' and then cut off at 27,1/4". Which would be enough material to make three 9" fire tubes per length. The 3/8" diameter copper was then fed back and forth through the jig and and rotated at the same time until straight. The tube came out really nice so really pleased with the homemade jig.
Attachment 470243/8" copper coil
Attachment 47025straightening jig
Attachment 47026Lengths nice and straight, ready to be cut in to three pieces to make boiler fire tubes.
Thank you for viewing
The Home Engineer