maximum size that we can cut with this CNC

I just ordered a Maslow today and wanted to no what is the maximum size that we can cut with this CNC.

1 Like

No one has built a frame larger than 8’x12’ and shared details, but an 8’x12’ frame gives you a 4’x8’ working area comfortably.

The belts can handle a larger frame, but I don’t know the upper limit, there.

1 Like

you can do a 12’ square frame giving you about a 8’ square work area

you can trade width for height (but not at a simple ratio) and there is work
pending to support adding extensions to the belts that would let you go to at
least a 10’ square workpiece (but not ETA on that work)

David Lang

The most honest answer is “we don’t know.” The Maslow 4 is new enough that we haven’t fully explored its limits. Certainly you can cut a 4’x8’ (1220x2440mm) sheet.
When you go larger there are a number of issues you may encounter, but I can’t say exactly at what size these issues kick in

  1. the accuracy of your cuts will get worse starting at the centers of your edges. This effect will get even worse when you reach a size where the arms start to collide with the supports for the router.
  2. the belt angles will be so shallow that the belts will be unable to pull the sled to the centers of the edges at all.
  3. the belts will unspool so far that the full force of the belt tension might pull the belt out of the spool. I ended up limiting the distance between my anchors to 4320x3770 mm for this reason. Might I have been too conservative? Certainly.

You can explore possible sizes using this tool: http://lang.hm/maslow/maslow4_frame.html

We at least should be able to math-out the current hard limit imposed by how much belt can fit onto the spool without causing issues. That’s independent of frame size, since there could be an arbitrary amount of excess belt outside the spool, though I feel like this would cause issue with retract all unless there was something on the belt to act as a stopper.

For a square work area, max should be close to the square root of (max_belt_on_spool^2)/2 across and tall if I am not too tired to be doing geometry.

if your anchors are 4320x3770 mm how big is your cut area?

I didn’t have a specific work area in mind, but wanted to maximize the size of my frame (which is my concrete driveway) so that I can possibly cut bigger pieces. I was also thinking that I would like to measure the accuracy of cuts to help find the limits you are looking for. I haven’t gotten to that, though.

Are there any designs posted for the Unistrut Frame @bar shows in calibration video?
I’m looking to build a 12ft x 7.5ft Unistrut /Frame and would love feedback. Particularly interested to know the parts list used for building the frame. I’m actually designing a frame with maximum length parts at 5ft, so that the frame can be easily disassembled and transported using a heavy duty ski bag. If I don’t need to go 12ft x 7.25ft I’m aok with that. I just can’t exceed 86" inches vertical height.

Thanks!

1 Like

If I’m remembering/interpreting correctly, Bar doesn’t give the design for the metal frame they have in the background because it has more flex than he feels is acceptable for him to recommend it.

2 Likes

also keep an eye on the thread

where thee is testing being done in the white and red areas of that graph.

the metal frame Bar built did not have any vertical supports between the ends of
the beams, that would reduce flex significantly

frame flex testing will hopefully show up in .77 this week (there was a .75.1 or
.74.1 that had it, but not a main release yet)

The difficulty you will have with a frame assembled from short parts is going to
be preventing flex.

I would suggest looking at
Possible super-simple frame as a posible
starting point, when preventing frame flex you need to look at where the forces
are and have a plan to counter them. Bar’s metal frame has two problems:

  1. the ends of the beams are unsupported so they can flex up and down (Y axis)
  2. as you apply tension, the frame can flex in the Z direction (probably less of
    an effect but still there)

for this super-simple frame concept, it is putting a beam directly between all 4
corners at a height that (nearly) eliminates the forces in the Z direction and
provides support in the X/Y direction so that the beams are all in compression,
none should have flexing loads on them (the loads on the corners will be uneven,
so there will be racking load on the frame, but if you can anchor it down enough
to prevent that, you should be in good shape)

David Lang

1 Like

looking at the math (and the calculator, I think you will be able to go up to a 10’ square area on a 15’ square frame when we get support for belt extensions (add a 3.5’ extension to each corner)

This will leave 4-6 inches wrapped around the spool at the far corner, and the full 14.5 ft of belt on the spool at the near corner. the corners will go a fair ways into the white area, so accuracy there will suffer a bit

There’s a few of us anchoring the Maslow directly to concrete… I haven’t actually assembled mine, but I’ve set the anchors :wink: