600 x 400 Aluminium Profile Gantry Router

Some time since I posted an intro but I have finally come up with a design for my first small gantry machine. I did try to design it a bit smaller but there seems to be a law of diminishing returns with the space taken at the edges which you can't use. I will have to try to make space in the workshop!

My criteria for building are a bit odd as I don't actully "need" a router per say, so in order what I want it for are:-

To find out about CNC and to build a reasonable machine (just to prove to myself that I can, my few remaining little grey cells willing)
To be able to cut aluminium to help with model engineering engine builds, at least 6mm thick profile cutting
Anything else that might be interesting, engraving, 3D carving in wood, etc.

I have opted to use aluminium profile for the main frame with aluminium plates for bracing and stiffness. Also I am hoping that being largely aluminium the weight will be a bit less to move about, my weight-lifting days are long gone. Also it is some 50 years since I last laid hands on an arc welding set and I was never much good at it (or welding). Benchtop design will fit adjustable feet at the corners.

So some pictures of the plan thus far:

Attachment 17773 Attachment 17776 Attachment 17774 Attachment 17772 Attachment 17775

All the profile is 90 x 45 heavy or 45 x 45 and I am hoping that if I order cut lengths they will be square and the same length where necessary, or will I have to trim them? As can be seen twin 1605 screws on what I call the Y-axis linked together with HTD belt. I thought 1605 as I am definitely more interested in metalwork than woodwork and hope that the smaller pitch will help with accuracy. I havn't shown it but I was thinking of diagonal bracing under the table. MDF spoil board at the moment but if I learn how not to plunge the bit into it I would replace it with a thick Aluminium plate with threaded holes.

Gantry sides are 20mm plate and the end brackets 10mm. X-axis (gantry) also 1605 screw and using standad BK/BF12 mountings. X-axis motor might need repositioning depending on it's size. I was guessing nema 23 3.1 Nm all round.

As drawn the Z-axis movement is only about 80mm but I was going to make the spindle mount moveable up and down on the backplate. I could get more Z movement by increasing the Y rail height but they don't seem to do a 135 x 90. There is sufficient space and length of screw to handle the extra travel.

Haven't given much thought to electrics yet, thoght I would get the mechanics done first. I have a couple of old but good laptops and was hoping to use one of those. Probably Mach 3 through CSMIO-IP but no rush to make that choice yet. I know laptops are a bit iffy for timing purposes but was hoping the IP board would solve that.

Looking forward to your comments, suggestions etc. Don't hold your breath on a full build thread though, I am a very slow worker, easily distracted and have lots of unfinished projects!

Cheers
John