Starting to design out my build, looking for critique

[Chrono]

Hi Chrono



When I first saw this design, I couldn't help but think that was far, far too flimsy

Now with your explanation of the gantry driven from one side only (above)......it's getting worse!

Don't forget that to reduce cutter breakage, wear, chipping, improve accuracy and surface finish, the whole machine must be as rigid as possible and subject to as little resonance and vibration as possible. This is why machines traditionally are made in cast iron or synthetic granite (Granitan etc) that are "dead" materials, they don't "ring".

In the latest design, you are driving the gantry from one end only (and I still can't understand what the benefit is of the lower ballscrew). This goes against evrything that you will read on this forum, "ballance your forces", " place the cutter forces in between the bearings" etc. It is akin to digging a hole in the garden whilst standing on a diving springboard!

And the 6mm thick gantry sideplate.......
Martin

First up, I am still driving the gantry on both sides. Just one side is resting on two HIWIN rails, while one is resting on a linear bearing on a smooth steel rod-type rail. Here is the model if you want a more detailed look.

Secondly, I appreaciate the feedback, but what exactly are the problem areas here, what needs to change? Most design decisions come from advice I got from the mechanical engineers at my place of work, some of which have been building similar highly-dynamic gantry machines for Zeiss, taking measurements. This is also where the rail division comes in. Looking back at my technical mechanics textbook, this should protect the linear rails from having to take on torque, while still handling static loads. So that is the reason why. I, obviously, cannot tell you if that will work or not, but that is why I am here, after all :D

Edit: Some pictures to illustrate the whole X-Axis setup, excuse the dreadful mouse-written writing.



Another constraint I am having, is that steel box section, for example, is pretty difficult for me to work with. I do have access to people who can weld for me, etc., but I pretty much have no way to assemble the machine where I need it to, in my workshop, or get it out of there, once assembled. It is on the first floor in my garage, with the only access being a small staircase barely wide enough for one person. Hence the aluminium profiles. If that is a no-go, the only other option i have, is a small hatch, not even high enough to kneel in, which will severely limit the machine's size, overall.

Then there is also my budget, which is pretty close to being used up, even with that design.

On a side note: do you have a link for the post from boyan? I would like to further read up on that build.

Thanks for the feedback,
Chrono