This is just a thought experiment - I don’t have a need for this per se.
The 4x8 Altmill has roughly 3 extra inches of Z clearance compared to the 4x4 version. I’m wondering if it would be possible to CNC new Y-axis gantry plates that have an extra inch or two of clearance to improve the capabilities of my 4x4.
Now that I mention it, I wonder if the bolt pattern is the same between the 4x8 and the 4x4. If the 4x4 is sufficiently rigid, could we buy the Y-axis gantry plates for the 4x8 and install them?
Raising the height of the cross rail is one thing but wouldn’t you also need to increase the z rail travel range?
It would be nice to increase the Z clearance and 3" seems like a nice amount that shouldn’t affect rigidity by a lot.
@keglin One thing to consider in your experiment is that, if you simply raise the Y rails to get more Z clearance, you may well have issues with trying to cut through material. End mills are only so long. I raised the Y rails on my LM Mk1 to get more clearance above the Vortex. The downside is that I now need to add a second spoilboard under “normal” thickness material if I want to cut through it with a 1/8" end mill. I think that’s a reasonable tradeoff, but it can be a bit inconvenient.
That’s what I’m thinking I’ll do. I’m more often limited by the clearance of the gantry than I am limited by the length of my endmills. But if I’m in a situation where that matters, I’ll just chuck on another spoilboard or two
When and I think it is out the taller Y plates and the stiffing gusset are out in the CAD files for the 4X8 machine. I would like to do this so I can use my A-axis to its fullest. I was hoping to just buy these parts in the future. Maybe if enough of us bug the guys this will be offered as an upgrade kit in the future. I would prefer to get the nice black look that I currently have! As to needing to change the Z on my MK2 I have more than enough travel on it to handle the added height and my longer 2.2KW spindle helps as well. Note that the MK1s gantries do not have the T nut slot on the underside so the gussets bolts would require that a holes bored and would need to be tapped or so I have been told. If they don’t offer this we can pull the files and mill out our own plates and gussets on our current machines!