hi,
i have some pictures for you as to recommended mounting of caster(s) in the footshell. this system has proven to work very well from styrene droids, wood droids and heavyweight alum droids.
1st i recommend either 1/4 inch alum plate or 1/8 steel plate for the two plates
top plate needs to be same size as the top of the footshell so it lays flat without gap at the ankle bolts to shell area.
lower plate needs to be cut to fit the shell area to give support to the sides of the shell
note the distance between the 2 plates will very as they depend on what caster you decide to use. you will want 1" to 1 1/2" distance between the bottom of shell and floor.
the distance between the plates are adjusted by the stand offs, you may have to add another or cut to get the distance you want.
angle of footshell to floor this is important all droids very somewhat but for a caster to work properly it needs to sit level with the floor. this adjustment is made with washers between the ankle and footshell on front or rear bolt.
note the bolts for the stand offs are countersunk so they lay flat with the top of the footshell
i used #8 bolts. the stand offs are for attaching 2 sections of threaded rod they usally come as 3 to a pack. these are available at lowes or home depot
i recommend not cheaping out on casters as these take a beating! use good quality and they will last a long time.
for mounting to the droid bottom plate keep in mind the top of the ankle cyls should be just level with the bottom of the skirt.
bolting to the droid can be done 2 ways that i know both work well.
1. 4 1/4x20 bolts down into the ankle. for this to work out well the ankle will need to be drilled and tapped. as you are tapping you will need to remove the tap every 2 or three turns of cutting to clear the resin chips or it will strip out your threads. and they should extend into the ankle 1 1/2 inches
or
2. the droid i currently have is 150 lb wood frame/legs and i have been testing another way to attach. this has survived 4 years so far and so many cons that i have lost count.
i used 6 wood screws extending into the ankle 2 inches. beware you will have to drill pilot holes into the ankle or it will crack the resin.
stay at least 3/4 inch from the edges of the ankle which ever way you decide to mount.
if you have any questions just ask.
