Demonstration-Dynamo-RVFM-EDU728-The-Demonstration-Dynamo-H&-Pulley-from-RVFM-is-mounted-on-a-base-plate-230-x-90mm-approx-which-also-carries-a-h&-drive-pulley-of-120mm-dia-It-is-coupled-to-the-smaller-dynamo-pulley-by-a-rubber-belt-to-give-a-step-up-ratio-RVFM-Demonstration-Dynamo-H&-Pulley-