2x4 feet primo build in NJ (CNC noob alert 😉)

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#1

Hello all. I’ve messed with 3D printing for years but am brand new to CNC.

I just completed the build of a primo. The size is 3x5 feet (I know, large!), with a usable space of 2x4 feet. The Z height is 4”. I used some mid span supports but it seems to be of limited use. This will mostly be cutting wood.

Electronics are BTT SKR 1.4 Turbo with TMC2290 drivers, and I implemented dual end stops on this. I also added a z-max limit switch to home to. I did this, in conjunction with homing to x and y min position and soft end stops, in order to limit the number of ways in which the machine can tear itself apart. Firmware is most recent marlin (2.0.7.1 I think) with my own config (happy to share if that helps anybody)

Cable management is done using cable drag chains, still figuring out how I want to route the main power and vacuum hose.

What’s left to do is an enclosure to contain the dust, a dust boot, and it suffers from really jerky movement still on curves, which seems to be marlin related.

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#2

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#3

A few more pictures of my solution for the drag chain mounts and supports, mid span support, and my modified SKR box for the turbo. I am still deciding where to mount the controller lcd and emergency stops.

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#4

Fellow NJ peep here, in south jersey, where you at? We should try to link up.

#5

I’m in northern NJ, close to 78/parkway.

#6

Turning arcs on in your CAM package should solve the jerking. Or try basing your firmware off our nightly firmware builds. I just did some testing and sorted that out.
Cool build, welcome to the crew!

#7

Thanks Ryan, good to be here😊

My older/cheaper 3d printers that are running marlin don’t have this issue, so this smells like a Marlin problem (or jerk settings).

I’ll compare to the latest v1 repo again and see if I can get this resolved.

#8

Using arcs will solve it, but we also found that the classic jerk seems to have issues again and enabling Junction deviation was the solution.

#9

Excellent build Erik! Can you point me to the cable management parts you printed.

Thanks

#10

I’m about to build something similiar, why did u say the mid down supports seem of little use?

#11

Hi Brian, this is what I came up with: https://www.thingiverse.com/thing:4721840

#12

The mid-span supports will support the outer rails, but they don’t really do anything for the two tubes that carry the gantry. So perhaps a little less sag in the outer supports, but i think it’s of limited value. It’s just the reality/limitation/tradeoff of this design.

#13

I moved mine up to 2 foot by 4 today and did mid supports. I ran some tests and it doesnt seem too bad so far, but I only do wood so hopefully it’s not a major issue. I see how it can get out of square easier, so I install some hard stops so I can square the gantry before cutting.

We will see .

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#14

Yep, this is why I ended up with implementing dual end stops: repeatable squaring. I have soft end stops enabled so there’s the added bonus of having less chance of the machine moving beyond its physical limits.

#15

Awesome! Thanks! Again excellent setup. I am just waiting for electronics and printing cable chain and chain mounts now.