Peco turnout #6 with tortoise first attempt - Model Railroader Magazine

I have installed well over 200 tortoises over the years and come up with some tricks along the way.

When laying the turnout, I temporarily nail it where it is supposed to go and used a fine tip permanent marker to mark the roadbed where I need to drill the hole. I use a 5/16" bit but 3/8" will give you a bit more play. 

After drilling the hole I reinstall in the turnout. Underneath I use a homemade drilling template made using the drawing on the tortoise instruction sheet. The template is cut out from the instruction sheet and mounted on a 1/8" piece of hardboard (masonite). I drill out the 4 screw holes with a 3/32" bit and the actuation hole with the 5/16" bit. I glue a small 5/16" dia. dowel into the template. Its only about 1/2" tall

This allows me to insert the template into the hole I drilled in the plywood subroadbed. I then drill the 4 holes that hold the tortoise in place. This template makes drilling the mounting holes super easy and the dowel keeps everything align the actuator hole.  See image below for drilling template

Tortoise Template by Chuck Lee, on Flickr

After drilling the holes I remove the template and install two screws caddy corner from each other. I leave them sticking out a hair more than the mounting lip of the tortoise

I then put the tortoise switch up agains the plywood and give it a small twist to lock it into the screws I already installed. 

Once there the machine holds itself pretty well while I put the last two screws in. I then tighten the first two screw to secure it in place.

The last thing I do is install the 0.039" music wire rod (comes in 3 ft lengths).  I drop the Rod in from the top side through the throwbar in the turnout. To keep it from falling all the way through i put a small bend in the end of the wire. 

Underneath I add the little green pivot point onto the rod and slide it into the grooves on the tortoise. I then bend the end of the rod with my pliers to make the diamond shape shown below. This goes around the screw in the tortoise instead of into the minscule hole in the throw arm. So much easier to do.

TortoiseWire by Chuck Lee, on Flickr

The last thing I do is go back topside and trim off the excess wire from sticking up. i use a pair of diagonal cutters I have had for years to cut the wire. (they don't make tools like they used to)

in areas where access to the tortoise actuation screw is difficult I install the tortoises slightly different. I install the mounting screws the same way but i drop the rod down from the topside first, install the green pivot point on the wire, bend the wire into the diamond shape and install it around the actuator screw. I then install tortoise on the mounting screws. I finish up by putting in the last two screws to keep it in place.

This whole process takes about 5-10 minutes. 

There are also some instances where you can't have tortoise directly below the turnout. There ways around this too with some simple linkages.