I've asked another member to post a photo for me as I'm having difficulty managing pictures on this crapulous computer of mine. Once it is up I'll go into details about it.
At last! I managed to get a photo up!!

This set-up, which consist of a $40 angle grinder and a $30 stand and a bit of timber to make a base for it can make clean, square cuts which can be repeated by adding a stop.
It can handle tubing or flat material. Non slip matting helps hold the material being cut with minimal pressure being applied thus avoiding squashing thin wall tubing. Use thin "cutting" disks - not grinding disks.
The stand, as it came out of the box wasn't really stable but replacing nuts and bolts and using nylock nuts has made it quite robust and it has not needed adjustment since its first of many cuts. The base has a timber 'plate' to hold the material being cut on a level surface with the base of the stand to ensure that the cuts are perpendicular to the length. A bit of care in setting up gives good results.
