If the throwbar extends beyond the edge of the splines (it shouldn't) you could mount a Tortoise to the side of the splines and engage the throwbar outside the support structure.
My concern would be with the need for drilling a sizeable hole right through the splines themselves to mount a Tortoise in the usual manner. The possibility of unplanned lateral failure makes me cringe! The best plan would probably add an extra thickness of spline extending a fair distance in both directions from the site of the actuator, then drilling the hole AFTER the adhesive is fully cured.
Another possibility is to use an Anderson link, which reduces the hole from 3/8" to 3/32" at the expense of some re-thinking of the under-layout mechanicals. The Anderson link is my point-thrower of choice, but I use either twin-coil machines or manual throws, and make under-layout connections with cable (monofilament fishing line.)
Chuck (modeling Central Japan in September, 1964)
I am finally going to build a permanent layout in the garage. I have been reading and planning for the last year. One of the things I have been very interested in is "spline roadbed." I like it due to the lack of waste and the natural easements it produces. I was all set to go with it when I was reading about the issue of switch machines. I never thought about it. Spline roadbed will be about 1 inch thick, and only a little wider than the track. Obviously I am going to have to mount them to something, but 1 inch thick is much thicker than what I have the Tourtise mounted to now. I have seen some pictures if people mounting the switch machine on a 1/8 thick board under the spline, but will the distance from the switch machine to the throw bar be a problem? Obviously the longer the wire is the less torque there is going to be.
1) Has anyone dealt with this yet?
2) Do you have any instructions or a website to go to?
Any input will be greatly appreciated.
James