do you have access to an arc or mig welder? If so you can weld up a frame from 1inch tube steel.
Otherwise you can build one out of 75mmx35mm pine. Just make up 4 legs the height you want. Cut a section out near the top to put the 4ft lengths in. Bolt them in place and bolt some widths in, (they will be less than 12 inches).
Then do the same about 6-12 inches above the bottom.