[TheForge] Re: helical railing calculations

[Andy Vida]

Bruce Freeman wrote:
> 
> Ries,
> 
> I can see rolling a flat bar "the easy way" (i.e., deforming the short
> side) to a small diameter, but why would you ROLL a handrail "the hard
> way"?  Is that even possible?  I'm envisioning putting a, say, 2"x1/2"
> bar in a slip roll "standing on edge."  Sounds difficult to me.

	Slip rolls are not intended for use with anything 
	more than sheel metals, and most are sized for sheet
	of perhaps 16 ga. give or take.  As a shop teacher I
	have seen more than one set of rolls ruined where the
	student has attempted to roll 3/8" steel rod with it.

	The rolls I've seen for bending strap the hard way are
	perhaps 14" in diameter on an 8" diameter spindle, and
	hydraulically operated for both radius adjustment and
	rolling the stock through.  They are very slow, and
	very powerful machines, stoutly built to the task.
> 
> I would have presumed such a bend would be done hot around a mandrel
> (or around several posts in an acorn table, together acting as a
> mandrel).

	You can do it that way, but a roller will be a lot more
	precise.