Compound angle calculation

[ifit]

I have to fit some pigs ear handrail around a set of kitewinder stairs  and need to join it in the corner so it is 45deg but both pieces rise 20deg, how do you work out the compound angle?

 

[joiner1970]

I might be wrong ( its been a long hard day) but I'm sure it can't be done. I'm sure when I've done pigs ear I've had to do  a level section either side of the corner then mitre into the pitch.

 

[Doug S]

Never had to do handrail but had same problem with dado rail and did what joiner1970 said.

 

[Holmz]

I have to fit some pigs ear handrail around a set of kitewinder stairs  and need to join it in the corner so it is 45deg but both pieces rise 20deg, how do you work out the compound angle?

The easy way is to align on angle in the horizontal and the other with the blade tilted.

With a pencil I have done it - I would need a sketch to envision what you are doing exactly, but it is something like Sin-1 (Sin(angle1) * Sin(Angle2))

However I think when I did it, I used vector math, so I had a 3x3 matrix with the Roll, one for pitch, one for yaw, and transformed the centre axis. I recall some chin-scratching at the time...

 

[ifit]

Yes I think it can not be done without a leveller but the job does not justify the time - Housing association job 12 houses to do

I might try getting it as close as I can and trimming the top and bottom and sand it in

 

[ifit]

I have done a quick sketch to work it out
the lines show where I will have to trim and sand

Would the cut to get them to meet be 45deg on the table and 20deg on the bevel?

 

[Doug S]

It might end up looking a pigs ear [wink]
Easiest way stop it 4" before corner and start again 4" after corner.

 

[andyman]

Never had to do handrail but had same problem with dado rail and did what joiner1970 said.

Yes agree can't go into corner ot looks awful