Quote Originally Posted by silyavski View Post
I have another question about your design.
The holes on the steel are for moving the bed up and down? So, how will you keep the original parallelism of the rails that move the gantry, shimming every time? Or using the supports i see on one of the pictures and shimming and adjusting in vertical position connecting the table to the supports instead directly to the steel frame?
The main reason for including an adjustable height bed is so that the machine can maintain sufficient rigidity whilst cutting tall and short parts. This machine is plenty strong enough to cut aluminium at a respectable rate even with Z-axis fully extended, so I don't think Sasha will be moving the bed at all often. When it is moved, it will either have to be skimmed or shimmed. Putting shims on the 7 aluminium support blocks that the bed mounts to is probably the easiest way. Also bear in mind the holes for mounting the bed were drilled accurately using my milling machine, so the error introduced by moving the bed should not be very large.

Just to be clear, changing the height of the bed only affects the parallelism of the rails with respect to the bed. The measurements of rail straightness (and twist) we took effectively subtracted the error due to the non-parallelism of the bed, as once the bed is skimmed using the machine this error will be largely eliminated.

Quote Originally Posted by silyavski View Post
About the epoxy. You mentioned the brand. Where did you get it from? Abroad? How much epoxy was used? I have to do this very soon.
It was from the UK - I contacted lots of different companies who sold similar resin to see if they could get the hardener. You might want to ask Clive S where he got his as he got some much more recently than I did. The company 'Desperate Measures LTD' quoted £24.48 for 1kg of resin and £17.61 for the hardener to go with it. I think those prices do not include VAT, but I'm not sure.
I think we used about 600g of resin - I can't remember exactly. You can work out what mass of resin you need by just working out the volume (remember to include the bridge across the middle) and multiplying by the density they quote. About 4-5mm thick should be plenty.