Orange amps and cabinets have two wooden rails underneath and most of people consider putting casters on Orange amps will prevent them to use those rails (some think it’s a sounding device, I have no opinion on that ^^ I rely on loudspeakers).
So, as I like those typical Orange wooden rails but not as much as keeping their full integrity (tegrity tegridy… whatever ^^), I’ve made up my mind to cut through them as to plant casters on the right place. Always usefull and healthy for many reasons.
First step is to measure the inside available of the cabinet/amp: for a Rocker 32 it’s 53,5 x 21 cm ( 20.86 x 8.26 inches) and make a piece of paper that size as a plan (check if it fits right inside the floor of the cabinet/amp, redo if not).
After taking apart the wooden rails, position the paper in the middle of the bottom plank (cabinet/amp upside down and secure it with few screws as well as drawing the rails’ position.
Now is the sensitive part: the paper size is the shadow of the plane inside bottom plank of the cabinet/amp. Position the mounting cups (Fenders are 55 mm max diameter) as to keep them inside this perimeter without touching the metallic corners and considering the axel cup is 15 mm wide in diameter ( 0.59 inch).
Put back the rails in place and use a crown saw (60 mm wide – 2.36 inches ) with a drill bit as a guide to make a centering hole by hand.
Then you can safely drill for real with the crown saw once the rails have been screwed in a dummy plank. You don’t wanna ruin the tolex 🙂
Check if all’s good by taking the rails back to their place on the cabinet/amp.
Now, using a wood drill bit of 15 mm (I only found a 14 mm but it did it ok by moving it gently inside the hole) drill the holes for the mounting cups.
Do a blank check of all of it and if there are no problem whatsoever, you can make pre-holes for the screws, screw the mounting cups and the rails put back the casters and voilà!
Pictures below!
More or less an answer to the thread on the Orange amps forum
https://forum.orangeamps.com/viewtopic.php?f=2&t=48905
Edit: the Orange forum is actually dead, they left their ground to so-called social media, a certain choice I don’t agree with because you cannot see what’s in social media if you’re not registered. It’s simply letting some billionaires privatise free information (at least the forum is still online and browsable). Too bad and too stupid from ya’ll guys, letting billionaires assholes being middle men in a good part of web society 🙁
https://orangeamps.com/articles/the-orange-amps-forum-is-coming-to-an-end/