AndyUK's Build - 1.2x1.0m Gantry

[AndyUK]

Hi All,

First things first - Thankyou everyone. This forum is an amazing resource. I've spent the past year lurking and researching, and thought it was about time to get a build log started. Now, if you don't mind, lets begin the self-indulgence!

What do I want out of this?
The biggest draw for me is learning the skills in building and improving the thing. I want your opinions and suggestions. Secondly, I want an awesome tool that can help with my DIY projects going forwards - I would like to be able to work primarily in wood (I'm thinking small furniture building, engraving etc), but want to do small things in aluminium too (like parts for models, handy things for the house or whatever). One of the more exciting applications I have in mind for the future is helping my wife with her glass work - either by scoring / cutting / engraving glass, or creating moulds for the kiln.

Tools
So, I intend to expand my garage substantially... but, I have the basics like a chop-saw, bench drill, etc. My designs are conscious of the fact I have (occasional) access to a Bridgeport milling machine and a reasonable size lathe. The largest 'tool' in the garage is me (in every sense)... I'm a Physicist by trade so can handle electronics and equations - I have greater trouble with the structural design aspects and the physical creation, so those are what I want to learn the most about - I've never welded or tapped a hole before, so they're going to be fun to learn.

The Design So Far
I've thusfar chosen a gantry-based design, about 1.2m by 1.0m which gives me a working area of approximately 1.0m by 0.8m. I think this will be large enough for any project I can throw at it, but small enough to fit in the garage and still have a degree of stiffness! I've particularly liked the common design on this forum, and have used Joe Harris' thread and video logs in particular for ideas and inspiration (cheers!). I've also chosen a L-shape gantry, currently proposed to be created from a rectangular and box section steel extrusion, and a C style carriage to wrap around it, after looking at the gantry design study threads and following through the mathematics (largely helped by the cutting forces calculation spreadsheets on this forum). I was thinking of having a dual X-motor setup, which I know is the slightly less-favoured setup around here, but I don't like the idea of large timing belts - they just weird me out. I do plan to use small belts on all the drives though to give myself some gearing and alignment flexibility. I'd expect to go for one of the large Chinese water-cooled spindles with a VFD. I was anticipating welding the square sections for the gantry, and then using the milling machine to give me good parallel even faces - same goes for the large square tubes that the gantry moves along, but they won't be welded. Not sure if the gantry side plates and the z drive plates should be made from 20mm aluminium or steel yet, so would appreciate comments on that aspect - I think the weight is still feasible with steel, and as I can machine it...? I'm also not very good at knowing where it would be good to add adjustment features, and what form they should take.

Heres a few pictures of my plans so far.... Forgive my Solidworks skills... they're not the greatest!





I'd like your help with...
Everything!
Specifically at the moment, I'm at the stage of wanting to get the build started. I plan to construct the base frame and the adjustable height bed first, which means learning to weld. Before I dive in head first - I'd like your opinions on the overall design and in particular my base and bed design. Is there anything I've completely overlooked? The base is made from 80x80x4mm and the bed is made from 60x60x4mm square mild steel tubing, with the plates and angles you see made from 3mm mild steel. I planned to construct the base in four welded parts which will then bolt together - the two end squares, and the two central sections.

Here are a couple of detail shots:




Thanks All, and Happy Christmas!