Thread: Cast aluminium gantry router
No casting is good enough to use straight out the mould they all need machine prep work to be used and this is where the time and money comes into affect to make accurate surfaces etc.!!
Would make a good Kit for someone with access to milling machine but for a Kickstarter and to be useful straight out the box I don't think they'd be cheap enough to produce and be attractive.?
Last edited by JAZZCNC; 06-06-2014 at 06:47 PM.
I don't see why you would want to cast a gantry. The open back structure significantly limits stiffness.
If you compare it to a simple 80x160x4mm steel RHS section you would need to make the cast aluminum 'C' shape gantry have web and flanges of 60mm thick to match the bending and torsional stiffness.
Makes much more sense to cast the end connection down to the bearings blocks and ballscrew, with a neat interface to say a 160x80 RHS steel gantry.
Still haven't finished the gantry pattern as I'm flat out with work but I'm doing bits in between jobs.
I do know about shrinkage in casting, rule of thumb is 1/4" per foot,my alloy is 1-1.3%. It's accounted for in the pattern.
For anyone asking why? Here's why, I just want to cast it to see if it can be done and work.
The price of doing it in aluminium plate is crazy compared to casting it and once a pattern is made for casting you can repeat over and over. It'll all be one piece so no marking out, cutting and bolting plate together.
I can cut this to length, machine the ends then top and bottom for the rails and wherever parts are to be mounted. I might even bolt 2 castings back to back and make an "I" beam from them.
Watching with interest. G.
 instead of ][
 has similar vertical stiffness to ][, slightly better fore/aft stiffness, and massively better torsional stiffness. If you cast it then you can include baffle plates at intervals so long as you also bolt through these as well.
A simpler alternative is to do |] where ] is the cast part (with optional internal baffles or ribs) and | is a simple closer plate.
Still lots of effort all round but they are possible configurations and much better than just ].
By jonboycnc in forum DIY Router Build LogsReplies: 9Last Post: 12-01-2014, 10:26 PM
By EddyCurrent in forum Gantry/Router Machines & BuildingReplies: 34Last Post: 09-09-2013, 03:47 PM
By lateAtNight in forum Projects, Jobs & RequestsReplies: 1Last Post: 27-12-2012, 03:56 AM
BUILD LOG: Fixed Gantry RouterBy lateAtNight in forum DIY Router Build LogsReplies: 24Last Post: 28-05-2009, 10:30 PM
By Smiler in forum Milling Machines, Builds & ConversionsReplies: 0Last Post: 19-11-2008, 08:25 PM