The new cnc X axis will be around a meter in length. This presents some issues with material selection as steel that is 1100mm long by 350mm wide and 5mm thick will flex when only supported by the black columns at each end. I have some brackets to sure that up so the fixture plate will not be pushed away or vibrate under cutting load.
The linear rails are longer than the ballscrew to allow the gantry to travel the full length of the ballscrew. In this case a 1 meter ballscrew allows about 950mm of tip to tip travel and thus 850mm of cutter travel. The gantry is 100mm wide, shown as just the mounting plate in the picture above.
The black columns to hold the fixture plate are 38mm square and 60mm high solid steel. They come in at about 500grams a pop. The steel plate is about 15kg. I was originally going to use 38mm solid square steel stock as the shims under the linear rails but they came in at over 8kg each and the build was starting to get heavy.
The columns are m6 tapped both ends to hold the fixture plate up above the assembly. I will likely laminate some 1.2mm alloy to the base of the fixture plate to mitigate chips falling through the screw fixture holes into the rails and ballscrew.
I have to work out the final order of the 1/4 inch 6061 brackets that sure up the 5mm thick fixture plate yet. Without edge brackets you can flex the steel when it is only supported at the ends. Yes, I can see why vertical mills are made.
I made the plate that will have the gantry attached on the cnc but had to refixture things as the cnc can not cut something that long in any of the current axis.
It is interesting how much harder 6061 is compared to some of the more economic alloys when machining things. You can see the cnc machine facing more resistance especially on 6mm and larger holes. It will be interesting to see if the cnc can handle drilling steel at some stage.
