What do you think about my homemade frame?

here is a visual of the frame that I intend to make with my maslow cnc. It can be done with a 2440x1220 mm plate
What do you think ? Ideas for improvements?

See the flat pattern

That looks great. The top beam is under a lot of stress so I might reinforce the joint between the two sections of the top beam a little bit more. Overall I think it’s super elegant :slight_smile:

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I personally love having storage for full plywood sheets on my frame. That and its heavy duty caster wheels. I highly recommend both of those if space is limited in your shop.

Thanks for your comments, I’ll think about it!
Moreover, I just realized that I forgot the lower beam, the one that holds the plywood sheet :sweat_smile:

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I would also suggest some diagonal braces at the top to limit any lateral motion of the top beam.

Your design reminds me a lot of the GreenLean CNC. The website has lots of pics of how to assembly and how they cross brace all the vertical ribs of the frame.

Here my version 2

I noticed that the sled tended to tip over when it was near the edge. I am looking for a solution to be able to machine over the entire width of the plate (maybe by increasing the size of the central plate). Do you know if there are solutions elsewhere?

see if you can make the lower beam into something that is

  1. adjustable so that it can be flush to different thicknesses of material
  2. has a 6-9" vertical component to the lower beam to support the sled as you cut down at the bottom of the workpiece

if you make the lower brace flush with the bottom of your backing plate, it should be pretty easy to do that.

Thanks for your answer,
After doing some research, I couldn’t find a topic dealing with this “sled tip over problem”. Am I the only one with a problem? Or overall, people are not using 100% of the available area ?

have you seen the 8060 frame design with the skirt around the entire cut area?

take the sled off the machine and move it to a table.

use the chains (or string attached to where the chains attach to the sled) to
pull it to the edge of the table. see how close you can get the bit to the edge
of the table before the sled tilts.

you will find that:

at the top of the sled, it’s easy to get the bit to the edge of the table

on the sides of the sled, you can get pretty close (with the sled hanging out in
the air), exactly how close will depend on if you have the chain mount at the
right height. If you have it too high, it will tilt sooner

but at the bottom of the sled, you will find that the bricks will cause the sled
to tilt several inches before the bit gets to the edge.

the original machine used a 2x4 as the bottom support, and if you had a 3/4"
wasteboard and a 3/4" workpiece, this came very close to matching the thickness
of the 2x4 and so the bottom support gave you an extra 3.5" of room here.

but 3/4" plywood isn’t quite 3/4" thick, so this isn’t a great match, and
depending on your bricks 3.5" may not be quite enough (and you may not be
cutting 3/4" plyood to start with)

so an adjustable depth L shape that gives 6-9" of support will let you cut all
the wway to the bottom.

David Lang

At least cable tension diagonals crisscrossing between the uprights, if not a wood/compression member.