Perfect copies each time and perfect 90 deg cuts along the curve.
Thanks for the advice Colin , but I'm ahead of you
unfortunately it's not 'simples' !
A cut 90 deg to the faces is precisely NOT what I need
Because of the way I want to lay the bendy-MDF flush onto the edges, and the fact these side-pieces diverge by about 13.4 degrees to the axis ( each ) ie. 26.8 degrees included angle, the template has been laid onto each side of the ply and shifted by 4.3mm on one side relative to the other . This is the tan of 13.42 degrees
Hence when finished, the curve , as well as having the correct expanding profile, also has an angle to the faces that goes from about 0 deg at the throat, to about 11 deg at the mouth end. It's a funny compound curve. Hence the only two ways I could think of doing it were :
(i) CNC router coming down vertically with the wood blocked-up at 13.4 degrees
(ii) mark curve on both sides , displaced, and spokeshave down to the line on both sides.
No. (ii) is cheaper !
Luckily - STOP PRESS - I have been getting on OK just now - I found the ply is somewhat directional in how it cuts, and have been able to get along well with the flat-based spokeshave pulling it the other way, and have finished another curve this afternoon . Looks like I have the 'knack' now.