Steel Router 610 x 1220 x 200

[Stickio]

Hey Guys

I have been researching cnc machines for about 2 years now. Last year I took the plunge and built a MDF Router with Ali angles, skate bearings and threaded rod leadscrews.

The plan was to build the machine and learn about the process without spending too much money, over the past year I have spent most of my time upgrading and tweeking it.

I had always planned to make a better machine as my knowledge improves.

After making new parts for itself for the last few months I have reached the point where i want to start from scratch. I feel I now have the confidence to go out and spend some money and get some decent linears and ballscrews to make something more beefy and accurate.

So I have been mocking up some ideas etc and looking at alot of the other build logs and I really liked the design of Pavlo's Steel Framed machine, so much so that the design I have pretty much settled on is just a scaled up version of it.

There are a few reasons this design appealed to me:
It seems like it is strong.
Steel is pretty cheap
I have access to a mig welder
My current machine is not up to cuttilng Ali so fancy Ali Gantry sides and Z Axis are out. All the Ali pieces are all rectangular so Im hoping that I can order them in to size and only be left with the drilling.

Here are some pics of what I have come up with so far.


X Rails are 1500mm 20dia supported. Y is 800mm 16dia supported. Z is 300mm 16dia supported.


Outer section is 100x50 Steel Box. Bed supports are 40x40. 20mm x 5mm pitch ballscrew will be in the center of the frame.


Gantry is 50x50 Steel box. The strut at the bottom with the ballnut is some more of the 100x50. 16mm x 5mm pitch Y Ballscrew will run between the 2 horizontal 50x50 Y Rail supports.


Z Assembly is 300 x 150 x 20mm Ali plate with a 16mm x 5mm pitch Z Ballscrew. Approx 190mm Z travel.

I would really appreciate some feedback from you guys, nothing has been ordered yet so its not to late to change anything if it looks like I have missed anything out.

There are a few constraints that I would like to stick to:
I will be re using my existing electronics and spindle to keep the costs down. Kress 1050 spindle and 3NM NEMA23 Steppers.
I want the cutting area to be 2' x 4' so I can buy a 8' x 4' sheet and get them to get it cut into 4 at the store and drop it straight on the machine.
I may do some bits of Ail work on it, but the main use will be for acrylic and wood.

I do have a few things that I am unsure of:

I am not sure if my steppers will be up to the task of moving the heavy gantry around, I would really like to be able to take some pretty fast and aggresive cuts on wood and acrylic, I'm thinking quick direction changes in the X direction might be a problem?

Will I have problems with the X and Y leadscrews whiping?

Anyway I look forward to hearing some feedback.

Thanks for taking the time to read

Barry