This might be an interesting way to power a buffer and give it speed (and direction?) adjustment.
https://www.ebay.co.uk/itm/1HP-750W-ECO-Silent-Servomotor-Industrial-Sewing-Machine-Variable-Speed-Control/392966165354?_trkparms=aid%3D1110009%26algo%3DSPLICE.COMPLISTINGS%26ao%3D1%26asc%3D20200220094952%26meid%3D3b6a9dae495e4729b48cae33a71bce81%26pid%3D100008%26rk%3D1%26rkt%3D12%26sd%3D265009056757%26itm%3D392966165354%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3Ddefault&_trksid=p2047675.c100008.m2219